technetium-tc-99m-pyrophosphate and Necrosis

Myocardial necrosis plays an important role in the pathogenesis of various cardiovascular disorders and can result from different myocardial insults. Its non-invasive identification and localisation therefore may help in the diagnosis of these disorders, as well as in prognosis and assessment of treatment response. Apoptosis, or programmed cell death, is important in the spectrum of myocardial damage since it is gradually becoming more apparent that cell death may begin as apoptosis and not as necrosis. First attempts to directly visualise the area of myocardial necrosis were based on recognition of myocardial infarction with "hot spot imaging agents" in patients with chest pain. Since then, the study of myocardial necrosis with gamma imaging agents has gone beyond the detection of myocardial infarction, and attempts have been made to diagnose other cardiovascular disorders associated with cardiac cell death such as heart transplant rejection, myocarditis, cardiotoxicity and cardiomyopathies. Traditionally, two hot spot imaging agents have been used for the detection of myocardial necrosis, (99m)Tc-pyrophosphate and (111)In-antimyosin. In addition, preliminary studies have demonstrated promising results with (99m)Tc-glucarate. Recently, (99m)Tc-annexin V has been successfully used for non-invasive gamma imaging of apoptosis after acute myocardial infarction, acute myocardial ischaemia, acute cardiac allograft rejection and malignant intracardiac tumours. This review article focusses on the characteristics of these different myocardial necrotic and apoptotic markers and compares their role in the assessment of myocardial damage.

Topics: Annexin A5; Apoptosis; Glucaric Acid; Heart; Humans; Immunoglobulin Fab Fragments; Myocardial Infarction; Myocardium; Necrosis; Organotechnetium Compounds; Pentetic Acid; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Pyrophosphate

Topics: Angina, Unstable; Coronary Artery Disease; Diagnosis, Differential; Heart; Humans; Myocardial Infarction; Myocardium; Necrosis; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Pyrophosphate

Topics: Heart; Humans; Image Processing, Computer-Assisted; Myocardial Infarction; Myocardium; Necrosis; Phantoms, Imaging; Radiopharmaceuticals; Technetium Tc 99m Pyrophosphate; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

For almost two decades, Tc-99m pyrophosphate has been the preferred infarct-avid imaging agent in nuclear cardiology. More recently, Indium-III- and Tc-99m-labeled antimyosin monoclonal antibody imaging have been extensively investigated. Although In-III antimyosin is not yet available in North America, this radioimmunoscintigraphic procedure is very promising for detection of both Q-wave and non-Q-wave myocardial infarction, especially when other standard diagnostic modalities fail to be contributive. When appropriately applied, radionuclide imaging with infarct-avid agents may provide very helpful clinical information.

Topics: Animals; Antibodies, Monoclonal; Humans; Indium Radioisotopes; Myocardial Infarction; Myocarditis; Myosins; Necrosis; Organometallic Compounds; Organotechnetium Compounds; Radionuclide Imaging; Technetium Tc 99m Pyrophosphate

Topics: Animals; Diphosphates; Heart; Humans; Myocardial Ischemia; Myocardium; Necrosis; Radionuclide Imaging; Reperfusion Injury; Technetium Tc 99m Pyrophosphate

The major value of hot-spot imaging of the myocardium is its ability to define areas of necrosis rather than areas of diminished blood flow or cellular function. Applications of hot-spot imaging include the diagnosis and quantitation of myocardial infarction, myocarditis, and cardiac transplant rejection. The two agents in clinical use, 99mTc-Pyrophosphate and radiolabeled antimyosin, are discussed.

Topics: Animals; Antibodies; Coronary Disease; Diphosphates; Graft Rejection; Heart Transplantation; Humans; Myocardial Infarction; Myocarditis; Myocardium; Myosins; Necrosis; Postoperative Complications; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

The necropsy findings of a large cell lymphoma involving only the pericardium and myocardium in a 62-year-old woman are reported. The initial presenting symptoms were heart failure followed by rapidly progressive heart block. The diagnosis of cardiac lymphoma was suggested by gallium and blood pool isotope studies, and was subsequently confirmed by operative myocardial biopsy. The clinical course was abrupt, and the patient died before therapy was instituted. While primary cardiac lymphoma is an extremely rare condition, experience in this case suggests that noninvasive isotope studies, particularly gallium and blood pool, are helpful in the diagnosis of atypical cardiomyopathy.

Topics: Diphosphates; Female; Gallium Radioisotopes; Heart Neoplasms; Humans; Lymphoma; Middle Aged; Myocardium; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Animals; Creatine Kinase; Dogs; Echocardiography; Electrocardiography; Humans; Myocardial Infarction; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates; Tomography, X-Ray Computed

Perioperative myocardial infarction (POMI) is a complication of coronary artery bypass grafting (CABG) with a potential prognostic impact. Technetium-99m pyrophosphate myocardial scintigraphy (MS) is used in the diagnosis of POMI; however it shows a limited sensitivity for subendocardial lesions. Cardiovascular magnetic resonance imaging (CMRI), in turn, has a high accuracy in the detection of myocardial necrosis.. To compare CMRI and MS for the detection of POMI after CABG.. A total of 24 patients with chronic coronary artery disease were studied using the delayed contrast enhanced CMRI and MS before and after CABG by analyzing the development of areas of perioperative myocardial necrosis (POMI). Biochemical markers of myocardial injury (CKMB and troponin I) were also determined before and after surgery.. Nineteen patients completed the study. Of these, 6 (32%) presented POMI on CMRI and 4 (21%) on MS (p = NS). Of the 323 left ventricular segments assessed, 17 (5.3%) showed perioperative necrosis on CMRI and 7 (2.2%) on MS (p = 0.013). Moderate agreement was observed between the methods (kappa = 0.46). There was disagreement regarding the diagnosis of POMI in 4 (21%) cases, most of them with small areas of perioperative necrosis on CMRI which were not visualized on MS. In all cases with POMI on CMRI, significant CKMB and troponin I elevations were observed.. Moderate diagnostic agreement was observed between the methods for the detection of POMI, but CMRI enabled visualization of small areas of perioperative myocardial necrosis which were not identified on MS and were associated with elevation of biochemical markers of myocardial injury.

Topics: Biomarkers; Chronic Disease; Coronary Disease; Creatine Kinase, MB Form; Female; Humans; Intraoperative Complications; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Necrosis; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Pyrophosphate; Troponin I

To develop a model that compares 2 different routes of antivenom administration (standard intravenous [IV] administration vs regional administration below a tourniquet) to assess their ability to limit muscle necrosis in a rabbit model of rattlesnake venom poisoning.. New Zealand white rabbits were randomly assigned to 4 groups. All animals underwent general anesthesia and were then injected intramuscularly (IM) with a sublethal dose of western diamond-back rattlesnake (Crotalus atrox) venom in the right thigh and a similar volume of normal saline (NS) control in the left thigh. Thirty minutes later, standard treatment group animals (n = 4) received 1 vial of reconstituted Antivenin (Crotalidae) Polyvalent (ACP) and 10 mL of NS through an ear vein. Experimental treatment group animals (n = 4) had their lower extremities exsanguinated and isolated by arterial tourniquets. One vial of ACP was then given through a distal IV in the envenomed extremity, and 10 mL of NS was given through an IV in the sham extremity. Tourniquets were removed 30 minutes later. Positive control group animals (n = 2) similarly had their lower extremities exsanguinated and isolated by tourniquets. They then received 10 mL of NS through distal IVs in each lower extremity. Tourniquets were again removed after 30 minutes. Negative control group animals (n = 2) received 2 doses of NS only (10 mL each) through an ear vein. Serum creatinine phosphokinase (CPK) levels were drawn at baseline and 48 hours following venom injection. At 48 hours, the animals were injected with technetium pyrophosphate. Two hours later, they were euthanized, and the lower extremities were scanned to determine levels of radionucleotide uptake in envenomed muscles compared to contralateral sham-injected muscles. The anterior thigh muscle groups were then removed, fixed, stained, sectioned, and analyzed in a blinded fashion by a veterinary pathologist for muscle necrosis grading.. There was no evidence of statistically significant differences in changes in serum CPK levels (from baseline to 48 hours), technetium pyrophosphate uptake ratios (right leg/left leg), or muscle necrosis indices in any 2-group analysis.. Results of this pilot study do not suggest any beneficial effect of ACP, in the dose and routes used, in limiting local muscle necrosis following IM rattlesnake venom poisoning in the rabbit model.

Topics: Animals; Antivenins; Creatinine; Crotalid Venoms; Crotalus; Disease Models, Animal; Hindlimb; Infusions, Intravenous; Injections, Intramuscular; Muscle, Skeletal; Necrosis; Rabbits; Radionuclide Imaging; Random Allocation; Technetium Tc 99m Pyrophosphate

We present the case of a young man who suffered severe anteroapical myocardial necrosis caused by electrocution. In addition to the enzymatic and electrocardiographic changes suggesting necrosis, a clear positive segmental image on 99mTc-pyrophosphate scintigraphy and a defect on a 201Tl SPECT scan at rest were also found. Although these tests were indicative of extensive anteroapical transmural myocardial necrosis, the echocardiographic study only revealed mild anteroapical hypokinesia.

Topics: Adult; Electric Injuries; Electrocardiography; Heart Arrest; Heart Injuries; Humans; Male; Myocardial Infarction; Myocardium; Necrosis; Technetium Tc 99m Pyrophosphate; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Diagnosis of acute myocardial necrosis by means of conventional electrocardiographic criteria or the release of cardiac enzymes is often difficult or even impossible in patients with out-of-hospital cardiac arrest due to ventricular fibrillation with subsequent cardiopulmonary resuscitation including several DC countershocks. Simultaneous thallium-201/technetium-99m pyrophosphate (PYP) tomography was prospectively applied to 57 patients without typical clinical or electrocardiographic signs of acute myocardial infarction within 48 h after successful resuscitation from out-of-hospital cardiac arrest. Scintigraphic evidence of acute necrosis was present in 23/57 patients (40%). Increased 99mTc-PYP uptake in the pericardial tissue was found in 24 patients (42%). Maximal creatine kinase (CK) concentration was increased in 50/57 patients (88%). CK-MB activity averaged 68+/-52 U/l in patients with positive and 17+/-13 U/l in patients with negative tomograms (P<0.0005), demonstrating the validity of 201Tl/99mTc-PYP tomography. It may be concluded that simultaneous 201Tl/99mTc-PYP tomography is a valuable tool for evaluation of myocardial necrosis after cardiopulmonary resuscitation including DC countershock. Acute myocardial necrosis, as indicated by scintigraphy, represents a potential trigger for the occurrence of ventricular fibrillation. Therefore, 201Tl/99mTc-PYP tomography can be recommended in order to guide further diagnostic and therapeutic interventions in patients after cardiopulmonary resuscitation in whom the underlying cause of the occurrence of ventricular fibrillation is obscure.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Cardiopulmonary Resuscitation; Creatine Kinase; Electric Countershock; Female; Heart; Humans; Isoenzymes; Male; Middle Aged; Myocardium; Necrosis; Prospective Studies; Radionuclide Imaging; Technetium Tc 99m Pyrophosphate; Thallium Radioisotopes; Ventricular Fibrillation

A scintigraphic technique employing technetium pyrophosphate uptake was used to identify the area of skeletal muscle damage in the lower leg of four runners 24 h after an ultramarathon footrace (160 km). Most of the race had been run downhill which incorporated an extensive amount of eccentric work. Soreness was diffuse throughout the posterior region of the lower leg. In order to interpret what increased technetium uptake reflects and to express extreme endurance related damages, a biopsy was taken from the 3-D position of abnormal uptake. In addition, intramuscular pressures were determined in the deep posterior compartment. Scintigraphs revealed increased technetium pyrophosphate uptake in the medial portion of the gastrocnemius muscle. For 3698 fibres analysed, 33 fibres (1%) were necrotic, while a few other fibres were either atrophic or irregular shaped. A cluster of necrotic fibres occurred at the fascicular periphery for one subject and fibre type grouping occurred for another. Ultrastructural analysis revealed Z-line streaming near many capillaries and variously altered subsarcolemmal mitochondria including some with paracrystalline inclusions. The majority of the capillaries included thickened and irregular shaped endothelial cells. Intramuscular pressures of the deep posterior compartment were slightly elevated (12-15 mmHg) for three of the four subjects. Increased technetium uptake following extreme endurance running does not just reflect muscle necrosis but also subtle fibre abnormalities. Collectively, these pathological findings are attributed to relative ischaemia occurring during the race and during pre-race training, whereas, intramuscular pressure elevations associated with muscle soreness are attributed to mechanical stress caused by extensive eccentric work during the race.

Topics: Adult; Humans; Male; Microscopy, Electron; Muscles; Necrosis; Pain; Physical Endurance; Physical Exertion; Pressure; Radionuclide Imaging; Running; Technetium Tc 99m Pyrophosphate

This study was performed to assess the influence of coronary reperfusion on the serial serum myosin light chain (LC)I levels and to evaluate the relationship between the peak LCI level and the infarct size calculated from single photon emission computed tomography (SPECT) with technetium-99m pyrophosphate (Tc-99m PYP) in 11 patients who underwent coronary reperfusion. Blood was drawn before reperfusion, immediately after reperfusion, and once a day for 14 days, to estimate the time course of serum LCI release. The infarct size estimated by Tc-99m PYP ranged from 7.3 to 62.4 ml. The LCI levels obtained before reperfusion were less than 2.5 ng/ml but those obtained immediately after reperfusion were much higher. The value ranged from 2.7 to 9.7 ng/ml and that expressed as a percentage of peak LCI (% peak LCI) ranged from 19 to 83%. Collateral circulation, reperfusion arrhythmia and the degree of residual stenosis had no influence upon the % peak LCI. The correlation between peak LCI levels and SPECT-determined infarct size was good, with a correlation of 0.76 (p less than 0.01, regression line by least squares method y = 3.31 + 1.53x). Early serum LCI might be influenced by coronary reperfusion but the peak LCI value reflected acute myocardial necrosis in patients who underwent coronary reperfusion.

Topics: Adult; Aged; Female; Heart; Humans; Male; Middle Aged; Myocardial Reperfusion; Myocardium; Myosin Light Chains; Myosins; Necrosis; Technetium Tc 99m Pyrophosphate; Tomography, Emission-Computed, Single-Photon

To date there have been no experimental studies specifically directed at effects of reperfusion intervals on skeletal muscle injury beneath the tourniquet. 99mTechnetium pyrophosphate (Tc 99) incorporation and correlative histology were used to assess injury 2 days after tourniquet application in muscles beneath (thigh) and distal (leg) to the cuff. Tourniquets were applied to rabbit hindlimbs for a total of either 2 or 4 hours. In the 4-hour series, tourniquet compression (either 125 mm Hg or 350 mm Hg cuff inflation pressure) was either continuous or interrupted by 10-minute reperfusion intervals after 2 hours or after every hour of cuff inflation. In the 2-hour series, tourniquet compression (350 mm Hg) was either continuous or interrupted by 10-minute reperfusion intervals after 2 hours or after every hour of cuff inflation. In the 2-hour series, tourniquet compression (350 mm Hg) was either continuous or interrupted by a 10-minute reperfusion interval after 1 hour. Pyrophosphate incorporation (Tc 99 uptake) was significantly greater in the thigh region than in the leg region in all of the 4-hour tourniquet groups. Tc 99 uptake was significantly reduced by reperfusion after each hour of cuff inflation. With 350 mm Hg tourniquet pressure, a reperfusion interval after 2 hours of cuff inflation tended to exacerbate tourniquet compression injury. Reperfusion intervals did not significantly affect Tc 99 uptake in the leg region of these groups. With a 2-hour tourniquet time, Tc 99 uptake in the thigh was significantly decreased by reperfusion after 1 hour of cuff inflation. Previous clinical recommendations, based on serum creatine phosphokinase abnormalities after experimental tourniquet ischemia, probably reflected tourniquet compression injury. Hourly reperfusion limits skeletal muscle injury during extended periods of tourniquet use.

Topics: Animals; Evans Blue; Female; Hindlimb; Male; Muscles; Necrosis; Rabbits; Reperfusion; Technetium Tc 99m Pyrophosphate; Time Factors; Tourniquets

PYP SPECT images were underwent in 15 patients with acute myocardial infarction 2-5 times in three weeks. PYP SPECT images were reconstructed as to include both vertebral images and myocardial images. Quantitative estimation of PYP images was performed by the ratio of maximal PYP myocardial uptake to maximal PYP vertebral uptake in the central sagittal images (%PYP). Disappearance of PYP images was defined as the day, when %PYP reached 50%. Normalization of serum myosin light chain I (LCI) level was defined as the day, when LCI level reached 2.5 ng/ml. %PYP decreased continuously and maximal PYP point remained at the same area. Shape of PYP images varied and diminished. In case of anterior wall infarction apical PYP uptake persisted longer than basal uptake. In case of inferior wall infarction basal PYP uptake persisted longer than apical uptake. The mean period from onset to the disappearance of PYP images was 9 +/- 3 days. Pattern of serial serum MB level was simple, however corresponding pattern of serial serum LCI level showed various types. The mean period from onset to the peak level was 4.1 +/- 1 day. Normalization of LCI level was 9.3 +/- 2.9 days. It showed that process of destruction of necrotic myocardium vary in each case. Weak relation was noted between disappearance of PYP images (DAY-PYP) and normalization of LCI level (DAY-LCI). DAY-PYP = 4.4 +/- 0.46 DAY-LCI (n = 13, r = 0.4). Quantitative PYP images were useful for detecting ongoing necrotic myocardium and serum LCI level was useful for estimating destruction of necrotic myocardium.2+ level were useful to study the process of destruction of necrotic myocardium.

Topics: Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Myocardium; Myosins; Necrosis; Technetium Tc 99m Pyrophosphate; Tomography, Emission-Computed, Single-Photon

No non-invasive quantitative method is currently available for measuring the amount of regional skeletal muscle necrosis in humans. A threshold method using 99Tcm pyrophosphate (PPi) with single photon emission computed tomography (SPECT) has been reported to quantify muscle necrosis successfully in a canine model. This method has been modified to measure muscle necrosis in the lower extremities of human patients. Modifications include adding background subtraction and using the contralateral unaffected lower extremity as background region. A region of interest was also manually drawn around the affected lower extremity muscle to exclude the tibia. In order to identify the group of patients with no significant necrosis and with diffuse hyperaemia, nine control subjects were studied. The variance of the counts within the pixels of the lower extremities was 132 (S.D. = 27). A variance of greater than 159 was considered as being significant for necrosis. Thirteen patients were studied. Six patients had significant muscle necrosis (462 ml, S.D. = 280 ml). All except one patient (who had a small amount of muscle necrosis) developed foot drop. Seven patients had no significant necrosis. All patients had normal ankle dorsiflexion. It is possible to quantify regional muscle necrosis using PPi with SPECT. Volume of necrosis determined by this method can also predict clinical outcome.

Topics: Aged; Female; Humans; Ischemia; Leg; Male; Middle Aged; Muscles; Necrosis; Technetium Tc 99m Pyrophosphate; Tomography, Emission-Computed, Single-Photon

Previous recommendations regarding the "safe" period of tourniquet hemostasis were based largely on studies of ischemia distal to the tourniquet. This study quantitatively analyzed skeletal muscle injury induced beneath and distal to a pneumatic tourniquet applied to the hindlimbs of rabbits for 1, 2, or 4 hours with a cuff inflation pressure of 125, 200, or 350 mm Hg. Technetium Tc 99m pyrophosphate incorporation after systemic injection (Tc 99 uptake) and correlative histology were used to evaluate tissue damage 2 days after tourniquet application. Compared with the contralateral control limbs, compression and ischemia induced statistically significant increases in Tc 99 uptake in the thigh and leg regions of all groups. Pyrophosphate incorporation was significantly greater in the thigh region than in the leg region after 2 hours of compression in the 200 and 350 mm Hg pressure groups and following 4 hours of compression in all pressure groups. Focal and regional fiber necrosis and degeneration were observed in thigh muscles after 2 hours of tourniquet compression. Two hours of continuous tourniquet application at clinically relevant cuff inflation pressures induced significant skeletal muscle necrosis beneath the tourniquet. Use of the lowest possible inflation pressure for a limited duration should minimize the degree of tissue injury caused by tourniquet application.

Topics: Animals; Diphosphates; Hemostasis, Surgical; Hindlimb; Muscles; Necrosis; Pressure; Rabbits; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Tourniquets

Patients with acute arterial occlusion may suffer from significant muscle necrosis. It is important to determine the amount of regional muscle necrosis for prognostic purposes and evaluation of therapy. We have used technetium-99m-pyrophosphate (PPi) with single photon emission computed tomography (SPECT) to quantitate muscle necrosis. A canine gracilis muscle ischaemia model was used. PPi was injected 1.5 h before the muscle preparation was removed from the dog. SPECT was performed on the muscle preparations. An automatic edge detection program using the threshold technique determined the number of pixels with significant PPi activity in each transaxial section. Volume was calculated by summing the number of pixels with significant PPi activity and multiplying by the voxel size. The results were compared with quantitation using computerized planimetry with nitroblue tetrazolium staining (correlation coefficient = 0.93). PPi with SPECT is an accurate method for quantiating muscle necrosis.

Topics: Animals; Diphosphates; Dogs; Muscles; Necrosis; Technetium; Technetium Tc 99m Pyrophosphate; Tomography, Emission-Computed, Single-Photon

The possibility of myocardial necrosis occurrence in coronary failure proceeding as atypical myocardial infarction was examined in 176 patients with chronic types of coronary heart disease and in experiments with 16 dogs with reversible coronary failure simulated in chronic tests. 99mTe-labeled pyrophosphate myocardial scintigraphy was used in the clinical studies. Myocardial pyrophosphate accumulation was recorded in 37% of patients with angina pectoris without a history of myocardial infarction and 73% myocardial infarction survivals. Histological evidence for small myocardial necroses at various stages of their development was found in 12 dogs. Recurrent transient myocardial ischemias were shown to be able to lead to myocardial necroses that are not always followed by a typical course of acute myocardial infarction.

Topics: Angina Pectoris; Animals; Chronic Disease; Coronary Disease; Diphosphates; Dogs; Heart; Myocardium; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

Ischemia-reperfusion damage to skeletal muscle may cause serious local as well as systemic complications, its impact predominantly related to the quantity of ischemic muscle in the lower extremity. To date, there has been no noninvasive method of estimating that quantity. The authors used single photon emission computed tomography (SPECT) to quantify the volume of muscle that takes up technetium-99 pyrophosphate above a baseline threshold. Compared with the standard technique of staining slices of the muscle with nitroblue tetrazolium they found a close correlation using SPECT (r = 0.88, p less than 0.01, n = 19) in the canine model. In humans, this clinically applicable noninvasive technique may allow the surgeon to document accurately the extent of muscle necrosis in the lower extremity, to anticipate the impact of an ischemia-reperfusion injury and evaluate methods of reducing the extent of post-ischemic skeletal muscle necrosis.

Topics: Animals; Diphosphates; Dogs; Leg; Muscles; Necrosis; Nitroblue Tetrazolium; Reperfusion Injury; Technetium; Technetium Tc 99m Pyrophosphate; Tomography, Emission-Computed

Skeletal muscle necrosis will result from prolonged periods of ischemia. The purpose of this study was to develop a method to estimate the extent of necrosis using nitroblue tetrazolium staining and technetium scanning. The bilateral canine gracilis muscle preparation with total vascular isolation was exposed to 4 hr of complete normothermic ischemia followed by reperfusion. After 45 hr of reperfusion 99mTc pyrophosphate (PYP) was injected and 3 hr later the muscles were harvested, cut into six slices, and stained with nitroblue tetrazolium. Biopsies were taken from tetrazolium-positive and -negative areas for electron microscopy to confirm the ability of the stain to distinguish viable from necrotic muscle. Computerized planimetry of the staining pattern was used to estimate the extent of necrosis as a percentage of the total muscle. Electron microscopy confirmed the validity of nitroblue tetrazolium to discriminate between viable and necrotic skeletal muscle in this experimental model. After 4 hr of ischemia the percentage necrosis was 30.2 +/- 6.1% (mean +/- SEM, n = 12), there was no difference in the extent of necrosis in left vs right paired muscles, using tetrazolium staining or technetium PYP uptake. There was a statistically significant correlation between the percentage necrosis and the density of 99mTc PYP uptake per muscle (r = 0.83, P less than 0.001) and per slice (r = 0.94, P less than 0.001). This study demonstrates the ability of tetrazolium staining to accurately differentiate between viable and necrotic skeletal muscle and provides a reproducible method for estimating the extent of necrosis in the gracilis muscle model.

Topics: Animals; Diphosphates; Dogs; In Vitro Techniques; Ischemia; Muscles; Necrosis; Nitroblue Tetrazolium; Radionuclide Imaging; Staining and Labeling; Technetium; Technetium Tc 99m Pyrophosphate

A retrospective review was done of 34 extremities studied between 1981 and 1985 with technetium-99m pyrophosphate scanning; 22 were subsequently amputated. Results of detailed pathologic examination or immediate postoperative examination of the resected extremity were available in 16 cases. In these cases, scanning had allowed correct prediction of the level of amputation and of the specific areas of muscle infarction in 13 cases. In the one case in which amputation was performed for infection rather than muscle necrosis, the lack of necrosis was correctly predicted with the scan. The limited results of this study indicate that the Tc-99m pyrophosphate scan allows the location of necrotic muscle to be predicted accurately and may therefore be a useful adjunct in determining the best level for ultimate amputation. Special caution is required in those cases in which muscle necrosis is due to acute causes (e.g., traumatic thrombosis) rather than chronic vascular disease.

Topics: Amputation, Surgical; Diphosphates; Extremities; Humans; Muscles; Muscular Diseases; Necrosis; Radionuclide Imaging; Regional Blood Flow; Retrospective Studies; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Animals; Antibodies, Monoclonal; Cyclosporins; Diphosphates; Graft Rejection; Heart; Heart Transplantation; Immunoglobulin Fab Fragments; Indium Radioisotopes; Male; Myocardium; Myosins; Necrosis; Radionuclide Imaging; Rats; Rats, Inbred Lew; Rats, Inbred SHR; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Adult; Antibodies, Monoclonal; Diphosphates; False Negative Reactions; False Positive Reactions; Female; Humans; Indium Radioisotopes; Male; Middle Aged; Myocardial Infarction; Myosins; Necrosis; Predictive Value of Tests; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Time Factors

The global myocardial extraction of lactate was measured in 13 halothane anesthetized dogs to assess the effect of electric countershock applied directly to the heart. Seven animals received two countershocks of 30 delivered joules each, while six animals were not shocked but were atrially paced to a rate of 190-200, both with and without occlusion of the vena cava to produce a mean arterial pressure of 40-50 mmHg. All animals had substantially positive lactate extraction in the baseline state (36 +/- 10% for countershock group vs. 41 +/- 3% for pacing group). Myocardial lactate extraction reached a markedly negative nadir 2.5 min after countershock (-19 +/- 15%), but returned toward normal by 6 min (10 +/- 6%). Lactate extraction was not significantly changed from baseline in the pacing group. The relationship between changes in regional myocardial blood flow (radiolabeled microspheres) and post-countershock myocardial damage (technetium pyrophosphate uptake) was assessed in six dogs shocked as above. Mean myocardial blood flow was increased minimally immediately after countershock (0.78 +/- 0.08 ml X min-1 X g-1 vs. 1.16 +/- 0.3), but there was no difference in blood flow between damaged and undamaged tissue at either time point. The epicardial-to-endocardial ratio of blood flow was unchanged after countershock (0.97 +/- 0.05 vs. 0.99 +/- 0.08). There was no relationship between myocardial damage and either the absolute amount of blood flow after countershock (r = -0.03) or the change in blood flow compared with the pre-shock period (r = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Coronary Circulation; Diphosphates; Dogs; Electric Countershock; Hemodynamics; Lactates; Lactic Acid; Microspheres; Myocardium; Necrosis; Regional Blood Flow; Technetium; Technetium Tc 99m Pyrophosphate

The management of an acutely ischemic extremity requires knowledge of the response of skeletal muscle (the largest component of the lower limb) to prolonged periods of complete normothermic ischemia. We have used the canine gracilis muscle model to evaluate the extent and distribution of ischemic necrosis after 3 and 5 hours of ischemia and 48 hours of reperfusion. Each muscle was cut into six slices, and the extent and distribution of postischemic necrosis identified by means of nitroblue tetrazolium staining and 99mTc pyrophosphate uptake. After 3, 4, and 5 hours of ischemia the extent of necrosis was 2.0% +/- 0.9%, 30.3% +/- 6.0%, and 90.1% +/- 3.5% (mean +/- SEM), respectively. A statistically significant correlation exists between the extent of necrosis and the uptake of 99mTc pyrophosphate uptake per gram of tissue (y = 1574.9x - 8.4, r = 0.84, p less than 0.001). Most necrosis was centrally located and found in the thickest portion of the muscle. We conclude that there is a graded response in the extent of skeletal muscle necrosis related to the length of ischemic stress rather than an "all-or-none" phenomenon. This central distribution of necrosis makes the usual external evaluation of ischemic damage clinically unreliable. In addition, since there was no enveloping fascia in this model, a compartment release alone may not prevent the development of skeletal muscle necrosis. This knowledge of the response of skeletal muscle to ischemia may lead to an improved clinical approach to an extremity suffering a prolonged ischemic insult.

Topics: Animals; Diphosphates; Dogs; Ischemia; Muscles; Necrosis; Nitroblue Tetrazolium; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Time Factors; Ultrasonography; Vascular Patency

We have previously demonstrated that enhanced glucose utilization in reperfused myocardium as assessed by F-18 2-deoxyglucose (FDG) and positron tomography predicts functional recovery. In this study, we compared segmental uptake of F-18 FDG with that of Tl-201 and Tc-99m (Sn) pyrophosphate (Tc-99m PPi) as conventional markers of tissue viability in seven dogs after a 3-hour intracoronary balloon occlusion and 20 hours of reperfusion. Myocardial blood flow was determined with microspheres. Regional retention fractions were calculated from tracer tissue concentrations, the arterial input function, and blood flow. Ischemic injury was assessed by triphenyltetrazolium chloride (TTC) staining and histologic analysis. At 24 hours, blood flow was 22% lower in reperfused than in control myocardium (p less than 0.05). Uptake of Tl-201 was related linearly to blood flow (r = 0.92), while glucose utilization and Tc-99m PPi were 2.9 (p less than 0.01) and 4.7 (p less than 0.05) times higher in reperfused than in control myocardium. Retention fractions of Tc-99m PPi increased with the degree of ischemic injury, while F-18 FDG uptake was highest in segments with mild cell injury. Thus, in ischemically injured myocardium, Tl-201 primarily reflects blood flow. F-18 FDG as a marker of glucose utilization identifies ischemically injured but viable tissue. The admixture of necrotic cells can be determined with Tc-99m PPi. Our results indicate that a dual tracer approach might best characterize the presence and extent of reversibly and of irreversibly injured tissue in a given myocardial region.

Topics: Animals; Coronary Circulation; Coronary Disease; Deoxy Sugars; Deoxyglucose; Dogs; Fluorine Radioisotopes; Heart; Hemodynamics; Myocardium; Necrosis; Polyphosphates; Technetium; Technetium Tc 99m Pyrophosphate; Thallium Radioisotopes; Tin Polyphosphates

Topics: Burns, Electric; Child, Preschool; Diphosphates; Humans; Male; Muscles; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Coronary Disease; Diphosphates; Electrocardiography; False Negative Reactions; Heart; Humans; Myocardium; Myoglobin; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

This study examined the effect of exposures to hyperbaric oxygen on the development of the edema and necrosis of muscle that are associated with compartment syndromes that are complicated by hemorrhagic hypotension. A compartment syndrome (twenty millimeters of mercury for six hours) was induced by infusion of autologous plasma in the anterolateral compartment of the left hind limb of seven anesthetized dogs while the mean arterial blood pressure was maintained at sixty-five millimeters of mercury after 30 per cent loss of blood volume. These dogs were treated with hyperbaric oxygen (two atmospheres of pure oxygen) and were compared with six dogs that had an identical compartment syndrome and hypotensive condition but were not exposed to hyperbaric oxygen. Forty-eight hours later, edema was quantified by measuring the weights of the muscles (the pressurized muscle compared with the contralateral muscle), and necrosis of muscle was evaluated by measuring the uptake of technetium-99m stannous pyrophosphate. The ratio for edema was significantly (p = 0.01) greater in dogs that had not been exposed to hyperbaric oxygen (1.15 +/- 0.01) than in the dogs that had been treated with hyperbaric oxygen (1.01 +/- 0.03), and the ratio for necrosis of muscle was also significantly (p = 0.04) greater in dogs that had not had hyperbaric oxygen (1.96 +/- 0.41) than in those that had been treated with hyperbaric oxygen (1.05 +/- 0.11). Comparisons were also made with the muscles of four normal control dogs and separately with the muscles of six normotensive dogs that had an identical compartment syndrome and normal blood pressure and were not treated with hyperbaric oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Compartment Syndromes; Diphosphates; Dogs; Edema; Hyperbaric Oxygenation; Necrosis; Radionuclide Imaging; Shock, Hemorrhagic; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Adolescent; Adult; Aged; Arm; Child; Diphosphates; Frostbite; Gangrene; Humans; Leg; Middle Aged; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Xeroradiography

Methods for evaluating cardiac myocyte necrosis utilizing antibodies specific for the heavy or light chains of cardiac myosin are reviewed. Cell death, associated with sarcolemmal disruption, results in the leakage of myosin light chains from the cytoplasm as well as the accessibility of myosin heavy chains to exogenous specific antibodies. Measurement of plasma light chain concentration has been useful in the diagnosis of myocardial infarction, though more recently, patients with congestive cardiomyopathy associated with an inflammatory infiltrate have been identified by an elevated plasma light chain concentration. The binding of myosin heavy chains to necrotic myocytes has been useful in the study of mechanisms of ischemic cell death in cell culture, in the diagnosis and quantification of myocardial infarction, both experimentally and clinically, and more recently in the study of experimental myocarditis and cardiac transplantation. It is hoped that these methods may evolve as useful clinical tools in the identification of those cardiomyopathy patients whose course is characterized by rapid myocyte loss.

Topics: Animals; Antibodies; Biopsy; Cardiomyopathies; Cell Survival; Creatine Kinase; Diphosphates; Heart; Heart Failure; Heart Transplantation; Humans; Immunoglobulin Fab Fragments; Indium; Isoenzymes; Mice; Myocardial Infarction; Myocardium; Myosins; Necrosis; Radioisotopes; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Thallium

Transthoracic electric countershock can cause necrotic myocardial lesions in humans as well as experimental animals. The authors investigated the effect on postcountershock myocardial damage of pretreatment with prazosin (0.1 mg/kg), an alpha-1 antagonist; L-metoprolol (0.5 mg/kg), a beta-1 antagonist, and verapamil (0.5 mg/kg), a calcium channel-blocking agent. Twenty dogs were anesthetized with halothane and given two transthoracic countershocks of 295 delivered joules each after drug or vehicle treatment. Myocardial injury was quantitated 24 h following countershock by measuring the uptake of technetium-99m pyrophosphate in the myocardium. Elevated technetium-99m pyrophosphate uptake occurred in visible lesions in most dogs regardless of drug treatment. For each of four parameters of myocardial damage there was no statistically significant difference between control animals and those treated with prazosin, metoprolol, or verapamil. These data suggest that adrenergic or calcium channel-mediated mechanisms are not involved in the pathogenesis of postcountershock myocardial damage.

Topics: Anesthesia, Inhalation; Animals; Calcium Channel Blockers; Dogs; Electric Countershock; Female; Halothane; Heart; Male; Metoprolol; Myocardium; Necrosis; Prazosin; Radionuclide Imaging; Sympatholytics; Technetium; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates; Verapamil

The use of up-to-date diagnostic methods and the estimation of the extent of myocardial lesion in patients with intermediate coronary conditions (serial assays of CPK and MV-CPK activity with subsequent computation of the weight of affected myocardium, ECTG and myocardial 99mTc-Sn-pyrophosphate scintigraphy using a gamma-counter) demonstrated: the presence of necrotic foci in patients with acute focal myocardial dystrophy; a considerable variation in the weight of affected myocardium; and high diagnostic value of ECTG for the assessment of the extent of myocardial lesion in patients with intermediate coronary conditions. Objective criteria have been worked out for the differential diagnosis of various intermediate coronary conditions.

Topics: Adult; Aged; Atrophy; Creatine Kinase; Diagnosis, Differential; Heart; Humans; Isoenzymes; Male; Middle Aged; Myocardial Infarction; Myocardium; Necrosis; Organ Size; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates

Tc-99m pyrophosphate (PYP) can localize in an acute myocardial infarct and other extraosseous lesions, including soft tissue necrosis and severe cellular injury A case of Tc-99m PYP uptake in calf muscle necrosis following transfemoral cardiac catheterization is presented. This was incidentally detected on Tc-99m PYP imaging performed for an acute myocardial infarction. Repeat Tc-99m PYP imaging one month later was normal, implying resolution of the ischemic muscle necrosis.

Topics: Diphosphates; Humans; Leg; Male; Middle Aged; Muscles; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

The authors present comparative characteristics of different methods of assessing the size of myocardial infarction. They included among others radioimmunoassay of myoglobin and the activity of MB-CPK in the blood serum, ECG charting with the calculation of the ST-coefficient and 99mTc-pyrophosphate scanning of the myocardium. The most informative methods were determination of the serum content of myoglobin and of its hourly increment, monitoring of the total rise of the ST segment and ST coefficient on the cartogram and the measurement of the area of accumulation of radiopharmacologic preparations during myocardial scanning.

Topics: Aged; Creatine Kinase; Diphosphates; Drug Therapy, Combination; Electrocardiography; Female; Heart; Humans; Isoenzymes; Isosorbide Dinitrate; Male; Middle Aged; Myocardial Infarction; Myocardium; Myoglobin; Necrosis; Nitroglycerin; Prognosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Time Factors

To depict the three-dimensional distribution of 99mTc-pyrophosphate in the heart, emission computed tomography (ECT) was performed, following the conventional planar imaging, in 32 cases with suspected acute myocardial infarction (AMI). There were 23 cases with evidence of AMI, 7 with unstable angina (UA), and 2 with dilated cardiomyopathy (DCM). While the planar images showed discrete cardiac activity in only 11 of the 23 cases (48%) with AMI, the ECT images delineated focal myocardial uptake clearly in 20 of them (87%). On the other hand, the ECT images revealed cardiac blood-pool activity without significant myocardial uptake in all cases with UA and DCM in which the planar images showed diffuse activity. Thus, the ECT imaging of 99mTc-pyrophosphate seems to be a valuable technique for assessing the presence and localization of myocardial necrosis, especially in cases showing diffuse cardiac activity in the planar imaging.

Topics: Adult; Aged; Angina Pectoris; Angina, Unstable; Cardiomyopathies; Diagnosis, Differential; Diphosphates; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Necrosis; Technetium; Technetium Tc 99m Pyrophosphate; Tomography, Emission-Computed; Tomography, X-Ray

Topics: Adult; Aged; Angina, Unstable; Diphosphates; Evaluation Studies as Topic; Female; Humans; Male; Middle Aged; Myocardial Infarction; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

Right ventricular infarction is not uncommon in patients with inferior myocardial infarcts. Phase and amplitude analysis of equilibrium gated cardiac blood pool studies is useful in documenting right ventricular damage complicating left ventricular infarction. In 15 of 37 patients with acute inferior infarction, right ventricular extension of the infarct was demonstrated by this approach, complementing the findings of infarct avid imaging with Tc-99m pyrophosphate (Tc-99m PYP).

Topics: Aged; Diphosphates; Female; Heart Ventricles; Humans; Male; Middle Aged; Myocardial Infarction; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Animals; Anterior Compartment Syndrome; Compartment Syndromes; Dogs; Edema; Female; Hyperbaric Oxygenation; Male; Muscles; Necrosis; Organ Size; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates

A quantitative scintigraphic method was introduced to examine the proximal, middle and distal third of the carpal scaphoid bone. 99mTc-Sn-pyrophosphate scintimetry was obtained by the use of a gamma camera equipped with a pinhole collimator. Of six patients in whom a unilateral fresh fracture of the scaphoid was clinically suspected, radiology showed a fracture of the scaphoid in four and no fractures in two. The method may be suitable in early diagnosis and further localization of clinically suspected fractures with initially non-diagnostic radiographs.

Topics: Adolescent; Adult; Carpal Bones; Female; Fractures, Bone; Humans; Male; Middle Aged; Necrosis; Polyphosphates; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates; Wound Healing; Wrist Injuries

Topics: Animals; Coronary Circulation; Diatrizoate Meglumine; Diphosphates; Dogs; Indium; Myocardial Infarction; Myocardium; Necrosis; Radioisotopes; Technetium; Technetium Tc 99m Pyrophosphate; Thallium; Tomography, Emission-Computed

Scintigraphy with 99mTc-pyrophosphate during bicycle ergometry has been undertaken in 32 patients with myocardial infarction in the early phase of its healing. There were 3 scintigraphic investigations: one during bicycle ergometry and two control ones - before and the day after the test. The determination of changes in the degree of 99mTc-pyrophosphate accumulation under the influence of the exercise in patients with myocardial infarction in the early phase of its healing permitted the authors to detect several variants in the time course of scintigraphic values. Drop or rise of concentration of the labelled pyrophosphate at the height of the bicycle ergometry test compared to the data obtained prior to it are apparently due to changed bloodflow in the focus of lesion during exercise. Changes in the character and intensity of accumulation of the radiodrug after bicycle ergometry can be explained in the majority of cases by increase of metabolic disorders in the myocardium, supervening during the exercise, and in some patients, possibly, to sustained decrease of bloodflow in the affected area of the cardiac muscle.

Topics: Adult; Aged; Diphosphates; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Time Factors; Wound Healing

Topics: Angina Pectoris; Arteriosclerosis; Coronary Disease; Diagnosis, Differential; Diphosphates; Humans; Male; Middle Aged; Myocardial Infarction; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

To test the hypothesis that the relationship between infarct area (IA) and area at risk (AR) varies in different layers of the left ventricle (LV), we occluded the circumflex coronary artery for 48 h in 20 conscious dogs. AR was determined by postmortem coronary stereoarteriography, and infarct area by pathological examination. Both AR and IA were divided into four layers: posterior papillary muscle (PPM), subendocardium (Endo), midwall, and subepicardium (Epi) and quantified with planimetry. Hemodynamics and regional myocardial flow with tracer microspheres (7-10 micrometers diam) were measured before and after coronary occlusion. IA was closely correlated with AR for PPM (r = 0.96), Endo (r = 0.97), and Epi (r = 0.92). However, the slope of IA/AR for Endo (1.30 +/- 0.08) was significantly steeper (P less than 0.05) than that for Epi (0.89 +/- 0.11); furthermore, the intercepts at zero infarction for PPM (0.5 +/- 0.1% of LV), Endo (4.2 +/- 0.4%), and Epi (0.1 +/- 0.7%) were significantly different from each other. Regional blood flow measurements indicate that the differences in IA/AR in various layers reflected earlier and greater total collateral flow to the noninfarcted AR in the epicardium. Thus IA/AR for the entire LV is a composite representing separate IA/AR specific to various transmural layers of the LV. In addition, this study demonstrates that the lateral border zone between the IA and the AR is minimal (less than 3-5 mm) in the subendocardium and midwall layers of the left ventricle.

Topics: Animals; Diphosphates; Dogs; Heart Ventricles; Myocardial Infarction; Necrosis; Perfusion; Risk; Technetium; Technetium Tc 99m Pyrophosphate

The effect of transthoracic direct current countershock on the myocardium of 21 newborn piglets was studied. Myocardial damage was quantified by measuring the myocardial uptake of technetium-99m pyrophosphate injected 24 hours after countershock. Substantial myocardial damage occurred in animals given greater than 150 joules/kg but not at lower energy doses. Damage occurred in both ventricular free walls, but more frequently in the right ventricle. The epicardial half of the myocardium was more severely affected than the endocardial half. The relationship between myocardial damage and total countershock energy dose was well modeled by an exponential function. Transthoracic direct current countershock appears unlikely to cause myocardial damage in newborn piglets unless greatly elevated energy doses are employed.

Topics: Animals; Animals, Newborn; Diphosphates; Electric Countershock; Electrocardiography; Myocardium; Necrosis; Swine; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Animals; Blood Flow Velocity; Body Burden; Bone and Bones; Bone Resorption; Calcium; Cardiomyopathies; Diphosphates; Dogs; Drug Interactions; Humans; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Tissue Distribution

The incorporation rate of 99mTc-pyrophosphate into the myocardium was studied in 123 patients with acute myocardial infarction at different stages of the disease. The capacity of the damaged myocardium to accumulate the labelled pyrophosphate decreased with its healing. The accumulation character of the radiopharmacologic preparation also changed. The revealed phenomena are explained by the features of the 99mTc-pyrophosphate concentration mechanisms of the damaged areas of the myocardium. during the necrosis phase pyrophosphate is accumulated in the irreversibly damaged myocardial cells. The incorporation of 99mTc-pyrophosphate into the myocardium at the late stages of the disease are explained by both the presence of the necrotized cells in the myocardium and possible binding of the radiopharmacologic preparation to collagen.

Topics: Diphosphates; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Time Factors

Topics: Coronary Disease; Diagnosis, Differential; Diphosphates; Heart Block; Humans; Myocardial Infarction; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

A survey is presented of research results of pyrophosphate myocardial scanning in 130 dogs and 150 patients with various myocardial lesions. The results of experiments in animals were immediately applied in clinical practice. The results showed that acute transmural myocardial lesions yielded practically in all instances positive scintigraphic findings. The findings in nontransmural infarctions were less convincing--they were positive in 60% of cases. Positive scintigraphic findings were also obtained in 80% of dogs with experimentally induced temporary ischaemia, and in 80% of dogs with experimentally induced dystrophy of the myocardium. In patients with angina pectoris positive findings were obtained in 1/3 of the cases, and in patients with cardiomyopathies, in 1/3 to 1/4 of the cases (in dependence on the etiology of the cardiomyopathy). It appears that 99mTc-PYP is a highly sensitive, but nonspecific, detector of myocardial lesions.

Topics: Angina Pectoris; Animals; Cardiomyopathies; Coronary Artery Bypass; Coronary Disease; Diphosphates; Dogs; Humans; Myocardial Infarction; Myocardium; Necrosis; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Adult; Aged; Clinical Enzyme Tests; Diphosphates; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Infarction; Myocardium; Myoglobin; Necrosis; Technetium; Technetium Tc 99m Pyrophosphate