technetium-tc-99m-tetrofosmin and Cardiomyopathy--Hypertrophic

The aim of this study was to evaluate the washout rate of Tc-99m tetrofosmin in asymmetric septal hypertrophy (ASH). As Tc-99m tetrofosmin accumulation and retention depend on sarcolemmal and/or mitochondrial function, the presence or absence of abnormalities in the washout rate of Tc-99m tetrofosmin could provide information about sarcolemmal and/or mitochondrial damage noninvasively. The study group consisted of 18 patients with ASH and 10 healthy subjects. After intravenous injection of 1110 MBq (30 mCi) Tc-99m tetrofosmin, tomographic images were obtained 1 hour later (early image) and again 4 hours later (delayed image). Using tomographic images, the distribution and washout of tetrofosmin in the left ventricle was examined quantitatively. Short-axis SPECT images were divided into 5 segments (anterior, septal, lateral, inferior wall and apex) in early and delayed images, and the mean radioactivity counts were measured in each segment by drawing regions of interest. Washout rates of apex, anterior, septal, lateral and inferior walls were 0.34 +/- 0.06, 0.37 +/- 0.07, 0.36 +/- 0.07, 0.33 -/+ 0.08, 0.33 +/- 0.07 in ASH and 0.20 +/- 0.05, 0.23 +/- 0.05, 0.22 +/- 0.03, 0.21 +/- 0.03, 0.22 +/- 0.03 in the normal group, respectively. In ASH, the washout rates of all myocardial segments were significantly increased as compared to those of the normal controls (p < 0.05). The findings of the present study suggest that there could be dysfunction of sarcolemma and/or mitochondria in the entire left ventricle which would be important in the pathophysiology of this disease. Also our study revealed that Tc-99m tetrofosmin washout was higher in NYHA II-III patients compared to NYHA I patients and the degree of Tc-99m tetrofosmin washout corresponded well with the thickness of the interventricular septum and posterior walls.

Topics: Adult; Cardiomyopathy, Hypertrophic; Female; Humans; Male; Metabolic Clearance Rate; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity

The diagnostic value of technetium-99m tetrofosmin (TF) washout in hypertrophic cardiomyopathy (HCM) was examined by investigating its relation to the metabolic abnormality depicted by iodine-123 beta-methyl- p-iodophenylpentadecanoic acid (BMIPP) uptake and the left ventricular (LV) myocardial wall thickness as measured by magnetic resonance imaging (MRI). TF washout was evaluated in 31 patients with HCM and 23 normal control subjects using 30-min (early) and 3-h (delayed) TF single-photon emission tomography images. The LV myocardial wall was divided into 19 segments and the percentage TF washout, regional BMIPP uptake and LV wall thickness were measured in each segment. Mean TF washout in the patients with HCM was significantly faster than that in normal control subjects (23.7+/-5.7 vs 13.4+/-4.1, P<0.0001). In the patients with HCM, TF washout showed an excellent correlation with MRI wall thickness ( r=0.82, P<0.0001) and a good inverse correlation with regional BMIPP uptake ( r=-0.72, P<0.0001). In addition, a good linear correlation was observed between TF uptake and MRI wall thickness in the 19 regional segments. In conclusion, the degree of TF washout corresponds well with the severity of myocardial wall thickness and the degree of metabolic abnormality in patients with HCM. These results suggest that enhanced TF washout might provide additional clinical information regarding metabolic alterations in HCM.

Topics: Adult; Cardiomyopathy, Hypertrophic; Fatty Acids; Heart Ventricles; Humans; Iodobenzenes; Magnetic Resonance Imaging; Male; Metabolic Clearance Rate; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Statistics as Topic; Ventricular Dysfunction, Left

To investigate myocardial fatty acid metabolism and its relationship with left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM).. Thirty-nine patients with cardiomyopathies (58 +/- 14 y), comprising 15 DCM and 24 HCM, and 9 age-matched healthy controls were studied with 123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 99mTc-tetrofosmin (TF) electrocardiographically gated SPECT. As parameters of myocardial fatty acid metabolism, the heart-to-mediastinum ratio (H/M) and global washout of BMIPP were calculated from early and delayed planar images, while regional BMIPP uptake and washout were calculated from SPECT. In TF study, the H/M (H/M-TF) and LV ejection fraction (LVEF) were calculated as global parameters of perfusion and function, while regional TF uptake and wall thickening index were calculated as regional parameters of perfusion and function using the Quantitative Gated SPECT software. The differences in the parameters and the correlations between the parameters from the 2 studies were investigated by one-way ANOVA and multiple linear regression analysis.. BMIPP uptake was decreased (p < 0.05), and its washout was increased (p < 0.05) in DCM and HCM. In multiple linear regression analysis, global BMIPP parameters showed no significant correlation with LVEF (p > 0.05), but showed a significant correlation with H/M-TF (p < 0.05) in DCM and HCM. According to the partial correlation coefficient, early H/M was the only significant factor (p < 0.05) for predicting H/M-TF in DCM and HCM. Multiple linear regression analysis on regional parameters showed regional BMIPP parameters had no correlation with regional function (p > 0.05) but had a significant correlation with regional perfusion (p < 0.0001) in DCM. In HCM, regional BMIPP parameters showed significant multiple linear correlations with both regional function (p < 0.005) and perfusion (p < 0.0001). According to the partial correlation coefficients, delayed regional BMIPP uptake was the most significant factor for predicting regional function in HCM, while early regional BMIPP uptake was the only or the most significant factor for predicting regional perfusion in DCM and HCM, respectively.. In DCM, BMIPP uptake and washout could not reflect LV function. In HCM, regional delayed BMIPP uptake might be useful for evaluating regional function. In DCM and HCM, early BMIPP uptake might be largely determined by myocardial perfusion.

Topics: Adolescent; Adult; Aged; Cardiomyopathy, Dilated; Cardiomyopathy, Hypertrophic; Electrocardiography; Fatty Acids; Female; Gated Blood-Pool Imaging; Heart Ventricles; Humans; Iodobenzenes; Male; Middle Aged; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Statistics as Topic; Ventricular Dysfunction, Left

Myocardial fibrosis is considered to be an important factor in myocardial dysfunction and sudden cardiac death in hypertrophic cardiomyopathy (HCM). The purpose of this study was to compare myocardial fibrosis detected by late gadolinium enhancement (LGE) on cardiac MRI with myocardial perfusion and fatty acid metabolism assessed by single photon emission computed tomography in HCM.. We retrospectively evaluated 20 consecutive HCM patients (female, 7; mean age, 53.4 years) who underwent LGE, technetium-99m methoxyisobutylisonitrile/tetrofosmin (99mTc-MIBI/tetrofosmin), and iodine-123 beta-methyl-iodophenylpentadecanoic acid (123I-BMIPP) imaging. We calculated the myocardium-to-lumen signal ratio (M/L) for LGE in 17 segments based on the American Heart Association statement. Scoring of 99mTc-MIBI/tetrofosmin (PI) and 123I-BMIPP (BM) was performed for each segment using a 5-point scale (0, normal; 4, highly decreased).. Nineteen of 20 patients (95%) and 153 of 340 segments (45%) showed LGE. M/Ls were 0.42±0.16, 0.55±0.17, and 0.65±0.24 in PI0/BM0, PI0/BM1-4 and PI1-4/BM1-4, respectively. All M/Ls were significantly higher than that of a normal control (0.34±0.14) (p<0.001).. Myocardial fibrosis in HCM can occur despite normal perfusion and fatty acid metabolism, and is more strongly associated with disorders of fatty acid metabolism than with perfusion abnormalities. M/L may be a useful indicator of disease severity.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cardiomyopathy, Hypertrophic; Fatty Acids; Female; Fibrosis; Gadolinium DTPA; Humans; Iodine Radioisotopes; Iodobenzenes; Male; Middle Aged; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Retrospective Studies; Tomography, Emission-Computed, Single-Photon

Hypertrophic cardiomyopathy (HCM) patients often develop left--ventricular subendocardial ischaemia, a cause of chest symptoms, despite normal epicardial coronary arteries. The aim of this study was to examine whether ultrasonic tissue characterization or late gadolinium enhancement on cardiac magnetic resonance imaging can detect subendocardial ischaemia in patients with HCM.. Subendocardial ischaemia was quantified on exercise Tc-99m tetrofosmin myocardial scintigraphy in 29 non-obstructive HCM patients with asymmetric septal hypertrophy. Ultrasonic tissue characterization using cyclic variation of integrated backscatter (CV-IB) and late gadolinium enhancement on cardiac magnetic resonance imaging were analysed separately in the right halves and the left halves of the ventricular septum in relation to subendocardial ischaemia. Subendocardial ischaemia was identified in 17 (59%) patients. The ratio of CV-IB in the right-to-left halves of the ventricular septum was significantly higher in patients with subendocardial ischaemia (1.19 ± 0.10) than those without (0.84 ± 0.10, P = 0.04). The optimal cutoff for the detection of subendocardial ischaemia was the ratio of CV-IB >1.0, with a sensitivity of 80%, specificity of 71%, and accuracy of 76%. On the other hand, late gadolinium enhancement was not associated with subendocardial ischaemia in our cohort.. Ultrasonic tissue characterization using CV-IB separately in the right and left halves of the ventricular septum, but not late gadolinium enhancement on magnetic resonance imaging, provided useful information in detecting subendocardial ischaemia in patients with HCM. Ultrasonic tissue characterization may be useful in selecting patients who will benefit from medications to relieve chest symptoms.

Topics: Cardiomyopathy, Hypertrophic; Contrast Media; Echocardiography; Exercise Test; Female; Gadolinium DTPA; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

Myocardial perfusion abnormality in the left ventricle is known to be prognostic in patients with hypertrophic cardiomyopathy (HCM). Magnetic resonance imaging and necropsy studies on HCM hearts revealed myocardial lesions predominating in the area of ventricular septum-free wall junction. We assessed perfusion abnormality in this area and correlated it with the prognosis of HCM patients. We performed exercise Tc-99m tetrofosmin myocardial scintigraphy in 55 patients with nonobstructive HCM. Perfusion abnormalities were semiquantified using a 5-point scoring system in small areas of anterior junctions of basal, mid, and apical short axis views in addition to a conventional 17-segment model. All patients were prospectively followed for sudden death, cardiovascular death and hospitalization for heart failure or stroke associated with atrial fibrillation. Cardiovascular events occurred in 10 patients during an average follow-up period of 5.7 years. Stress and rest scores from anterior junction, and conventional summed stress score were significantly higher in patients with cardiovascular events than without (all P < 0.05). Anterior junction stress score of >2 produced a sensitivity of 50% and a specificity of 98% for cardiovascular events and was an independent predictor (hazard ratio 8.33; 95% confidence interval, 1.61-43.5; P = 0.01), with rest scores producing similar values, which were higher than summed stress score of >8 (5.68; 1.23-26.3; P = 0.03). The absence of myocardial perfusion abnormality in the narrow area of anterior junction differentiated HCM patients with low-risk.

Topics: Adult; Aged; Atrial Fibrillation; Cardiomyopathy, Hypertrophic; Chi-Square Distribution; Coronary Circulation; Death, Sudden, Cardiac; Disease Progression; Disease-Free Survival; Echocardiography; Exercise Test; Female; Heart Failure; Heart Ventricles; Humans; Kaplan-Meier Estimate; Magnetic Resonance Imaging; Male; Middle Aged; Multivariate Analysis; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Proportional Hazards Models; Prospective Studies; Radiopharmaceuticals; Risk Assessment; Risk Factors; Sensitivity and Specificity; Stroke; Time Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Septum

Patients with hypertrophic cardiomyopathy (HCM) sometimes develop myocardial ischemia during exercise in the absence of coronary lesions. The relationship between myocardial ischemia and ST-segment depression was investigated during exercise testing in patients with HCM.. Regional hypoperfusion and/or transient left ventricular cavity dilation, a parameter of subendocardial hypoperfusion, were assessed on exercise 99mTc-tetrofosmin myocardial scintigraphy in 42 patients with non-obstructive HCM. The scintigraphic results were further correlated with the ST-segment responses to exercise.. Regional hypoperfusion or transient left ventricular cavity dilation were observed in 19 (45%) or 16(38%)patients with HCM, respectively. The incidence of ST-segment depression > or = 0.1 mV during exercise testing was similar in HCM patients with regional hypoperfusion, with transient left ventricular cavity dilation, and without hypoperfusion (42%, 38%, 38%, p = 0.95). Furthermore, exercise-induced ST-segment depression > or = 0.1 mV occurred similarly irrespective of symptoms, exercise tolerance, the degree or the site of hypertrophy, or the presence or absence of resting ST-segment depression.. ST-segment depression during exercise testing was common in patients with HCM, but seems to be an unreliable marker of myocardial ischemia as assessed by exercise scintigraphy.

Topics: Aged; Cardiomyopathy, Hypertrophic; Electrocardiography; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

The purpose of this study was to determine whether myocardial imaging using technetium-99m tetrofosmin can noninvasively identify myocardial damage in hypertrophic cardiomyopathy (HC). The study consisted of 10 patients with apical HC, 10 with asymmetric septal HC (ASH) group, 5 with dilated cardiomyopathy (DC)-like group, and 20 healthy subjects. With use of a bull's-eye map of single-photon emission computed tomographic imaging, the total defect score of tetrofosmin and the washout rate were assessed in 5 segments (septum, and anterior, lateral, and inferior walls, and apex) of the left ventricle. A localized increase in defect score and washout rate was observed in the hypertrophied region in the group with apical HC. An increased washout rate was observed in the ASH group regardless of hypertrophy, suggesting that tetrofosmin retention by the mitochondria was impaired in the entire left ventricular wall. The washout rate was further increased at all segments in the DC-like group versus the ASH group. Tetrofosmin retention by mitochondria was impaired in the entire left ventricular wall in the ASH group and was increased further in the DC-like group. The dysfunction of myocardial cells was limited to the hypertrophied region in the apical HC group.

Topics: Cardiomyopathy, Dilated; Cardiomyopathy, Hypertrophic; Echocardiography; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

The objective of this study was to clarify the relationship between cardiac sympathetic nervous function (CSNF) and left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM).. Thirty-eight cases (32 males, 6 females; mean age, 56 +/- 15 y), consisting of 5 healthy control subjects, 15 patients with DCM, and 18 patients with HCM, were studied with (123)I-metaiodobenzylguanidine (MIBG) and (99m)Tc-tetrofosmin SPECT. CSNF was evaluated from cardiac uptake and washout of MIBG, whereas LV perfusion and function were evaluated from tetrofosmin uptake and wall thickening on electrocardiographically gated SPECT. As quantitative parameters of global cardiac MIBG uptake and washout, the heart-to-mediastinum ratio (H/M) and percentage washout were calculated from early and delayed planar images. As quantitative regional parameters, the regional uptake and percentage washout of MIBG were calculated from SPECT images dividing the left ventricle into 12 segments. In the tetrofosmin study, the H/M and LV ejection fraction were calculated as the parameters of global LV perfusion and function. As quantitative regional parameters, the regional uptake and wall thickening were also calculated for the 12 myocardial segments using the quantitative gated SPECT software. Multiple linear regression analysis was performed to investigate the correlations between the parameters from the 2 studies.. In DCM and HCM, multiple linear regression analysis of the regional parameters showed significant correlations between LV function and CSNF (P < 0.0001) and between LV perfusion and CSNF (P < 0.0001). According to the partial correlation coefficients, washout and early uptake of MIBG were the most significant factors for predicting LV function and LV perfusion, respectively.. In cardiomyopathies, CSNF was closely related to LV function. The quantitative parameters of MIBG washout could reflect cardiac functional impairment. Early MIBG uptake might be determined by myocardial perfusion in cardiomyopathies.

Topics: 3-Iodobenzylguanidine; Adolescent; Adult; Aged; Cardiomyopathy, Dilated; Cardiomyopathy, Hypertrophic; Coronary Circulation; Electrocardiography; Female; Heart; Humans; Iodine Radioisotopes; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sympathetic Nervous System; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

We encountered a patient with hypertrophic cardiomyopathy complicated with exercise-induced myocardial ischemia. Exercise-stress 99mTc-tetrofosmin imaging demonstrated reversible ischemia in the lateral wall, whereas resting fatty acid imaging with a new beta-methyl branched fatty acid analogue, I-123-15-(p-iodophenyl)-9-(R,S)-methylpentadecanoic acid (123I-9-MPA), showed impaired uptake and accelerated washout kinetics in the inferoapical and posteroseptal walls but not in the ischemia-related region. These findings suggest that the metabolic derangement is closely related to cardiomyopathy per se rather than exercise-induced myocardial ischemia in this patient with hypertrophic cardiomyopathy and a spastic coronary lesion so that myocardial perfusion and 123I-9-MPA imagings may contribute to clarifying the etiological background of impaired myocardial fatty acid metabolism.

Topics: Aged; Cardiomyopathy, Hypertrophic; Coronary Vasospasm; Exercise Test; Fatty Acids; Heart; Humans; Iodobenzenes; Male; Myocardial Ischemia; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

Unexpected breast uptake was observed in a 32-year-old woman referred for evaluation of hypertrophic cardiomyopathy. Diffuse and marked bilateral breast uptake of 123I-BMIPP and 99mTc-TF was shown by both planar and SPECT imaging during the first study, and the uptake of both radionuclides had decreased significantly eleven months later. At the time of the first radionuclide examination, she was occasionally breast feeding her 2-year-old child and had small amounts of milk production. At the follow up examination, the frequency of breast feeding was significantly reduced and she produced only small amounts of milk. Therefore, the uptake of 123I-BMIPP and 99mTc-TF may have been caused by lactation.

Topics: Adult; Breast; Cardiomyopathy, Hypertrophic; Child, Preschool; Fatty Acids; Female; Heart; Humans; Iodine Radioisotopes; Iodobenzenes; Lactation; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

We examined the usefulness of Tc-99m-tetrofosmin in detecting exercise induced perfusion abnormalities in patients with hypertrophic cardiomyopathy (HCM) and to clarify time-related changes in myocardial distribution of Tc-99m-tetrofosmin after a single injection. We studied 44 consecutive patients with HCM by means of exercise/rest Tc-99m-tetrofosmin single photon emission computed tomography (SPECT). After injecting 370 MBq of Tc-99m-tetrofosmin at the peak exercise, the early SPECT imaging was performed at 30 min (EX-30) and the delayed imaging at 180 min (EX- 180). Immediately after the delayed imaging, 740 MBq of Tc-99m-tetrofosmin was injected in the resting state, and the rest SPECT imaging was performed 30 min later. Exercise-induced regional perfusion defects and/or apparent reversible left ventricular cavity dilation were identified in 26 (68.2%) of the 44 patients. When EX-30 images and EX-180 images were compared, reverse redistribution was confirmed in 36 patients (81.8%). Reverse redistribution was detected most frequently in the septal portion of the anterior wall, followed by the septal portion of the posterior wall and the septum. Exercise/rest Tc-99m-tetrofosmin myocardial imaging was a useful method for assessing myocardial perfusion abnormalities in patients with HCM. Reverse redistribution was detected very frequently on early and delayed images of exercise. We assumed that reverse redistribution may reflect a retention disorder of Tc-99m-tetrofosmin caused by some metabolic dysfunction of myocytes.

Topics: Cardiomyopathy, Hypertrophic; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

Hypertrophic cardiomyopathy (HCM) is known to have the impairment of myocardial perfusion as well as irregularly hypertrophic myocardium. To evaluate myocardial perfusion and ventricular shape in HCM, 99mTc-Tetrofosmin scintigraphy was performed after exercise (Ex) and at resting state (Re) in 10 patients with HCM and was compared with early image (Ea) and delayed image (De) of 201Tl scintigraphy performed after exercise. SPECT images of both 99mTc-Tetrofosmin and 201Tl scintigraphy were analyzed with five scaled visual scores set in 18 segments. The complete concordance ratio between 99mTc-Tetrofosmin (Ex and Re) and 201Tl (Ea and De) images in segmental analysis was 75%. Image quality of 99mTc-Tetrofosmin was seemed to be superior to that of 201Tl scintigraphy. In 9 patients with HCM, 99mTc-Tetrofosmin scintigraphy was performed under the ECG gating and the thickness of septal and free wall was measured. Good correlation was observed with the data by ultrasound cardiography (r = 0.79, p < 0.002 in wall thickness, r = 0.84, p < 0.01 in the ratio of septal wall thickness to free wall thickness). Left ventricular shape (ventricular long axis) was closely resemble to that of left ventriculography by contrast medium. In conclusion, 99mTc-Tetrofosmin scintigraphy is useful for the evaluation of myocardial morphology as well as perfusion abnormality.

Topics: Adult; Cardiomyopathy, Hypertrophic; Female; Heart; Heart Ventricles; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon