sodium-pertechnetate-tc-99m and Heart-Valve-Diseases

Developments over the past decade have allowed one to visualize the right and left ventricles using radionuclide techniques and to study the influence of a wide range of physiologic, pharmacologic and surgical interventions on global and regional ventricular function thereby providing important diagnostic insight and improved therapeutic capabilities. These tests are relatively non-invasive, they can be performed serially, they may be performed in patients that are seriously ill, and they have no recognized risk other than low level radiation exposure. With continued improvement in noninvasive imaging and processing and in the sophistication of associated computer systems, one may expect significant and wide ranging additional contributions in the assessment of myocardial function using radionuclide ventriculographic techniques.

Topics: Cardiac Output; Coronary Disease; Diastole; Exercise Test; Heart; Heart Failure; Heart Valve Diseases; Heart Ventricles; Humans; Myocardial Infarction; Pain; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Systole; Technetium; Thorax; Ventricular Function

Topics: Cardiovascular Diseases; Coronary Circulation; Coronary Disease; Heart Valve Diseases; Humans; Isometric Contraction; Mitral Valve Prolapse; Myocardial Contraction; Physical Exertion; Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium; Thallium

To determine the effects of steady-state left ventricular systolic pressure alterations on radionuclide measures of left ventricular filling dynamics, we studied 15 normal patients and 17 patients with nonischemic heart disease. Micromanometer left ventricular pressures and computer assisted forward gated radionuclide angiograms were acquired simultaneously. Right atrial pacing maintained heart rates constant during the baseline condition and methoxamine and nitroprusside infusions. Diastolic filling dynamics, peak filling rate and time to peak filling rate were calculated using a three harmonic Fourier analysis of the left ventricular time-activity curves. Left ventricular systolic pressure increased to 165 +/- 25 mmHg with methoxamine (p < 0.001) and decreased to 106 +/- 18 mmHg with nitroprusside (p < 0.001) from a baseline value of 133 +/- 16 mmHg. Radionuclide left ventricular filling dynamics did not change significantly. Thus, we conclude that radionuclide measurements of left ventricular filling dynamics are not affected by modest, steady-state alterations in left ventricular systolic pressure and can therefore be useful for the assessment of left ventricular diastolic function during interventions which may also affect left ventricular systolic pressure.

Topics: Adult; Aged; Blood Pressure; Cardiac Catheterization; Heart Valve Diseases; Humans; Middle Aged; Radionuclide Imaging; Reference Values; Sodium Pertechnetate Tc 99m; Ventricular Function, Left

First-pass radionuclide angiography (FPRA) in the 30 degree right anterior oblique and equilibrium gated radionuclide angiography (EGNA) in the 45 degree left anterior oblique were used for quantitative measurements of left ventricular ejection fraction (LVEF). Equipment used was a 400T gamma-camera interfaced with a Simis III Informatek computer. The results were compared with contrast angiography (CA). The aim of this study was to determine the sensitivity of both radionuclide techniques. The present data are based on 65 patients in whom CA and EGNA were performed. In 47 patients both FPRA and EGNA were performed. Results suggested that in ischemic heart disease (IHD) and valvular heart disease (VHD) the EGNA technique is well correlated with CA (r = 0.9 and 0.73, respectively). FPRA correlated well only with CA in IHD (r = 0.86), but not in VHD (r = 0.18). This study indicates that both FPRA and EGNA are sensitive, noninvasive techniques for measuring ejection fraction in IHD, while in VHD, EGNA is more sensitive technique than FPRA.

Topics: Adolescent; Adult; Aged; Angiography; Coronary Disease; Erythrocytes; Heart; Heart Valve Diseases; Humans; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

Forty-one patients (25 male, 16 female) were studied by RNCA in our institution. There were 42 rest studies and 24 stress studies (66 studies total). Sixteen patients were normal, 15 had ASHD, seven had a cardiomyopathy, and three had left-sided valvular regurgitation. Each study was preprocessed using both the standard nine-point smoothing method and Fourier filtering. Amplitude and phase images were also generated. Both preprocessing methods were compared with respect to image quality, border definition, reliability and reproducibility of the LVEF, and cine wall motion interpretation. Image quality and border definition were judged superior by the consensus of two independent observers in 65 of 66 studies (98%) using Fourier filtered data. The LVEF differed between the two processes by greater than .05 in 17 of 66 studies (26%) including five studies in which the LVEF could not be determined using nine-point smoothed data. LV wall motion was normal by both techniques in all control patients by cine analysis. However, cine wall motion analysis using Fourier filtered data demonstrated additional abnormalities in 17 of 25 studies (68%) in the ASHD group, including three uninterpretable studies using nine-point smoothed data. In the cardiomyopathy/valvular heart disease group, ten of 18 studies (56%) had additional wall motion abnormalities using Fourier filtered data (including four uninterpretable studies using nine-point smoothed data). We conclude that Fourier filtering is superior to the nine-point smooth preprocessing method now in general use in terms of image quality, border definition, generation of an LVEF, and cine wall motion analysis. The advent of the array processor makes routine preprocessing by Fourier filtering a feasible technologic advance in the development of the RNCA study.

Topics: Adult; Aged; Angina Pectoris; Cardiomyopathy, Dilated; Coronary Disease; Female; Filtration; Fourier Analysis; Heart; Heart Diseases; Heart Valve Diseases; Humans; Male; Middle Aged; Myocardial Contraction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Tin Polyphosphates

A new scintigraphic count-based method for measuring absolute left ventricular volumes is presented. It is a fast and simple technique that allows geometrical assumptions to be avoided and is free of radiation attenuation corrections. This method requires the acquisition of an image of the left ventricle in the right anterior oblique projection and the collection of gated blood pool images in the left anterior oblique projection. To assess the accuracy of the method scintigraphic stroke volumes were compared with those derived from thermodilution measurements during cardiac catheterization in 20 subjects, and to assess its precision the technique was applied to phantom data of known radionuclide volumes. Excellent correlations were found between the scintigraphic and both the thermodilution (r = .98) and phantom data (r = .99). The reproducibility (r = .97) of results was investigated by repeating data acquisition and analysis for 15 subjects on two different days, and the interobserver variability (r = .97) of the method was studied by having two computer operators calculate volumes for the same patient data for 20 randomly selected studies.

Topics: Adult; Aged; Atrial Fibrillation; Cardiac Catheterization; Cardiac Output; Cardiac Volume; Coronary Disease; Female; Heart Valve Diseases; Heart Ventricles; Humans; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Thermodilution

Electrocardiographic gating provides an alternative method of acquiring first pass radionuclide ventriculograms from both ventricles. This report details the methods of acquisition and analysis, provides validation and reproducibility data, and describes applications of gated first pass radionuclide ventriculography using a count-based method. Left ventricular ejection fractions measured by gated first pass were correlated quite closely with gated blood pool ventriculography (n = 43; r = 0.95) but less well with contrast angiography (n = 23; r = 0.72). The right ventricular ejection fractions measured by gated first pass compared favorably with gated blood pool ventriculography (n = 32; r = 0.93). When one observer processed the images two times, the reproducibilities of RVEF (n = 10; r = 0.99) and LVEF (n = 10; r = 0.88) were excellent. Similarly, when two observers processed the images independently, the reproducibilities of RVEF (n = 11; r = 0.99) and LVEF (n = 11; r = 0.98) were excellent. The first pass studies were obtained in a right anterior obliquity, which provided the best atrioventricular chamber separation and provided a different view of global ventricular function and segmental wall motion from that provided by the standard blood pool views.

Topics: Adolescent; Adult; Aged; Cardiomyopathies; Female; Heart Diseases; Heart Valve Diseases; Humans; Male; Methods; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

Topics: Cardiology; Cardiomyopathies; Heart; Heart Function Tests; Heart Valve Diseases; Humans; Lung Diseases, Obstructive; Myocardial Infarction; Nuclear Medicine; Prognosis; Quality Control; Radiation Dosage; Radioisotopes; Reference Values; Sodium Pertechnetate Tc 99m; Terminology as Topic; Tomography, Emission-Computed

This study was designed to investigate the potential role of radionuclide angiographic phase imaging in defining ventricular pacing sites. Twenty patients were paced from multiple right ventricular and left ventricular sites. Ten patients had both normal wall motion and normal electrocardiograms (ECGs), while 10 patients had segmental wall motion abnormalities and/or bundle branch block. Both continuous pacing and premature ventricular stimuli were performed. Multiple (two to three) views of each pacing site were obtained by radionuclide angiography and the ventricular site was determined by subsequent phase imaging. Simultaneous 12-lead ECGs were also obtained. The phase-imaging technique accurately localized all 35 right ventricular and 21 of 25 (84%) left ventricular sites to a specific segment. Statistically, this localization ability was independent of baseline wall motion or conduction system disease. In addition, sites as close as 1.5 cm were identified. The 12-lead ECG distinguished left ventricular from right ventricular pacing sites in all patients. Segmental localization by ECG in the right ventricle was accurate in 24 of 35 (69%) and in the left ventricle in 17 of 25 (68%). Thus, radionuclide angiographic phase imaging provides excellent descriptive information regarding the focus of ventricular pacing ectopy and can define both sites of continuous pacing and intermittent premature ventricular stimulation. These findings provide a basis for further assessment of the role of phase imaging in the evaluation of patients with spontaneous ventricular ectopy.

Topics: Bundle-Branch Block; Cardiac Complexes, Premature; Cardiac Pacing, Artificial; Coronary Disease; Electrocardiography; Heart Valve Diseases; Heart Ventricles; Humans; Myocardial Infarction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Wolff-Parkinson-White Syndrome

Topics: Cardiac Output; Cardiomyopathies; Coronary Circulation; Coronary Disease; Coronary Vessels; Heart; Heart Diseases; Heart Valve Diseases; Heart Ventricles; Humans; International Cooperation; Lung Diseases, Obstructive; Myocardial Infarction; Perfusion; Quality Control; Radionuclide Imaging; Reference Values; Societies, Medical; Sodium Pertechnetate Tc 99m; Terminology as Topic; Tomography, Emission-Computed; World Health Organization

The stroke-volume ratio determined from the equilibrium gated blood-pool study has been utilized to assess valvular regurgitation, but it is difficult to get reproducible results using generally available equipment. We have developed a new approach utilizing the Fourier amplitude ratio of the left and right ventricles, which is easily implemented and reproducible. Initial clinical experience shows that 17 patients with valvular regurgitation were clearly distinguished from 30 patients without valve disease.

Topics: Aortic Valve Insufficiency; Heart Valve Diseases; Heart Ventricles; Humans; Mitral Valve Insufficiency; Pulmonary Valve Insufficiency; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium; Technology, Radiologic

Topics: Adult; Aged; Blood Volume; Cardiac Volume; Cardiomyopathies; Computers; Coronary Disease; Female; Heart Septal Defects, Atrial; Heart Valve Diseases; Heart Ventricles; Humans; Male; Middle Aged; Radiography; Radioisotope Dilution Technique; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium