sodium-pertechnetate-tc-99m and Cardiomyopathy--Hypertrophic

The aim of this study was to assess the optimal method to evaluate asynchrony in equilibrium radionuclide angiography (RNA).. We studied 20 patients (14 males and 6 females, age range 25-60 yr) with RNA during atrial and sequential atrioventricular (AV) pacing, which increased left ventricular (LV) asynchrony. Both studies were performed at the same heart rate. Asynchrony was assessed either on phase images, by computing the standard deviation of the phase distribution (SD-P) and by sector analysis. Systolic and diastolic asynchrony were evaluated as the coefficient of variation of time to end systole (CV-TES) and time to peak filling rate (CV-TPFR) in four sectors. In addition, phase values were computed on time-activity curves from the same sectors, and their standard deviation (SD-Psec) was computed.. During atrial pacing SD-P was 32.3 degrees +/- 6.7 degrees and did not change during AV pacing (32.1 degrees +/- 5.6 degrees, p = n.s.). Both CV-TES and CV-TPFR had a significant increase during AV pacing (from 7.7% +/- 3.9% to 11.5% +/- 6.4%, p < 0.01, and from 8.4 degrees +/- 5.8 degrees to 12.9 degrees +/- 6.7 degrees, p < 0.001). AV pacing led to a significant increase in SD-Psec (from 6.3 degrees +/- 4.0 degrees to 12.6 degrees +/- 9.7 degrees, p < 0.05). Moreover, reproducibility was assessed in 15 additional age-matched patients. The results of the reproducibility study indicate a better repeatability for CV-TES and CV-TPFR.. The findings of this study suggest that sector analysis with calculation of indices of LV systolic and diastolic asynchrony is better suited for quantitation of LV temporal nonuniformity.

Topics: Cardiac Catheterization; Cardiac Pacing, Artificial; Cardiomyopathy, Hypertrophic; Coronary Disease; Erythrocytes; Female; Fourier Analysis; Gated Blood-Pool Imaging; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Contraction; Reproducibility of Results; Sodium Pertechnetate Tc 99m; Ventricular Function, Left

We previously showed that exercise capacity in patients with hypertrophic cardiomyopathy (HCM) is related to peak exercise cardiac output. Cardiac output augmentation during exercise is normally dependent on heart rate (HR) response and stroke volume (SV) augmentation by increased left ventricular end-diastolic volume and/or increased contractility. We hypothesized that in contrast to normal subjects, peak exercise capacity in patients with HCM is determined by the diastolic filling characteristics of the left ventricle during exercise, which would in turn determine the degree to which SV is augmented, and that HR is a relatively unimportant determinant of peak exercise capacity.. Twenty-three patients with HCM underwent invasive hemodynamic evaluation and measurement of maximal oxygen consumption (VO2max) during erect treadmill exercise to assess the relative importance of changes in HR and SV in determining exercise capacity. Hemodynamic responses to erect and supine exercise were compared in 10 of these patients. In a separate group of 46 patients with HCM, the relation between VO2max and exercise diastolic filling indexes was assessed. Peak HR during erect exercise was 92 +/- 8% of predicted maximum. VO2max was 29.0 +/- 6.4 mL.kg-1.min-1 and was related significantly to peak exercise cardiac index and SV index (r = .71, P < .001 and r = .66, P = .001, respectively) but not to peak HR, HR deficit, or resting or peak pulmonary capillary wedge pressure. Peak cardiac output during erect exercise was not related to peak HR (r = .13, P = NS). When erect and supine exercise were compared, peak HR was lower in the supine position (153.3 +/- 19.9 beats per minute supine versus 172.0 +/- 17.6 beats per minute erect, P = .003), but peak exercise cardiac index was similar (7.9 +/- 2.6 L.min-1.m-2 supine versus 7.5 +/- 2.8 L.min-1.m-2 erect). Pulmonary capillary wedge pressure was higher at rest in the supine versus erect position (15.3 +/- 5.2 versus 8.1 +/- 6.1 mm Hg) but was not significantly higher at peak exercise in the supine versus erect position (28.5 +/- 8 versus 22.4 +/- 11.6 mm Hg erect, P = NS). In the separate group of 46 patients with HCM, VO2max was significantly inversely related to time to peak filling at peak exercise (r = -.60, P < .0001) but did not correlate with time to peak filling at rest, resting ejection fraction, peak filling rate, or peak exercise peak filling rate.. SV is the major determinant of peak exercise capacity in the erect position in patients with hypertrophic cardiomyopathy. This in turn is determined by the exercise left ventricular diastolic filling characteristics. HR augmentation does not appear to be a major determinant of peak cardiac output in the erect position.

Topics: Adult; Cardiomyopathy, Hypertrophic; Case-Control Studies; Exercise Test; Exercise Tolerance; Female; Gated Blood-Pool Imaging; Heart; Hemodynamics; Humans; Male; Oxygen Consumption; Sodium Pertechnetate Tc 99m; Stroke Volume; Ventricular Function, Left

Topics: Adolescent; Adult; Cardiomyopathy, Hypertrophic; Diastole; Echocardiography; Electrocardiography; Gated Blood-Pool Imaging; Heart Ventricles; Humans; Middle Aged; Sodium Pertechnetate Tc 99m; Ventricular Function, Left

Total and regional (by 7 zones) contractility of left ventricular functions in 25 patients with hypertrophic cardiomyopathy (HCMP) were characterized by a different combination of normal and elevated values of total and regional ejection fractions, rate indices of systolic expulsion. Normal or slightly changed values of the end-diastolic volume were combined with normal or elevated values of the stroke volume. Comparative analysis of the values characterizing cardiodynamics, led to working out criteria of differential diagnosis in HCMP patients with heart pain and in CHD patients with myocardial hypertrophy (predominance of the signs of left ventricular hyperfunction in the former and contractility hypofunction and asynergy in the latter). Changes in the diastolic filling of the left ventricle indicated its disturbed diastolic function in both groups of patients.

Topics: Adolescent; Adult; Cardiomyopathy, Hypertrophic; Coronary Disease; Diagnosis, Differential; Humans; Middle Aged; Myocardial Contraction; Sodium Pertechnetate Tc 99m; Ventricular Function, Left; Ventriculography, First-Pass

To determine right (RV) and left ventricular (LV) volumes, a new technique was developed using ECG-gated single-photon emission computed tomography (SPECT). RV volumes of nine patients and LV volumes of 22 patients measured by SPECT and biplane contrast cineangiography were compared. In addition, volume and ejection fraction (EF) of the RV and LV were obtained by SPECT for 10 normal controls, 21 patients with old myocardial infarction (OMI), eight patients with hypertrophic cardiomyopathy (HCM) and 12 patients with dilated cardiomyopathy (DCM), and these results were compared. The intracardiac blood pool was labeled with Tc-99m sodium pertechnetate and 32 images were recorded through 180 degrees by a rotating gamma-camera. End-diastolic and end-systolic counts during 50 msec were recorded during 50 or 60 cardiac cycles. These counting data were reconstructed as tomographic images of vertical long-axial slices with thickness of a pixel without any attenuation correction. The numbers of voxels within the % cut-off level were summed, and the sum was multiplied by the one voxel volume. The cut-off level for ventricular delineation was determined as 45% by phantom studies. 1. The values obtained from SPECT and contrast angiography correlated well. 2. In normal controls, LV end-diastolic and end-systolic volumes were significantly less than those of the RV (p less than 0.05, p less than 0.001) and LVEF was significantly greater than the RVEF (p less than 0.001). 3. In OMI (single vessel disease), both end-diastolic and end-systolic volumes of the LV were significantly greater than those of normals (p less than 0.01, p less than 0.001) and LVEF was significantly less. In HCM end-systolic volumes of the RV were significantly less (p less than 0.05) than those of the normals. 4. LV volume was greater and LVEF was extremely low both in DCM and in OMI (multivessel disease) compared to that of the normals. In DCM, RV end-systolic volumes was greater and RVEF was lower than that of OMI (multi-vessel disease), indicating the deterioration of RV contractility , primarily in DCM. From these findings, it was concluded that this noninvasive technique may be useful for estimating left and right ventricular volumes.

Topics: Adult; Aged; Cardiomyopathy, Dilated; Cardiomyopathy, Hypertrophic; Female; Heart; Heart Ventricles; Humans; Male; Middle Aged; Myocardial Infarction; Radiography; Sodium Pertechnetate Tc 99m; Stroke Volume; Tomography, Emission-Computed

12 patients with cardiomyopathy were examined by MRT and first pass angiocardiography. MRT provides detailed images of cardiac anatomy and abnormalities without using any contrast medium. The first pass method is an excellent complement to MRT. The functional imaging describes regional wall motion of myocardium exactly. Both non-invasive methods are useful for the diagnosis of cardiomyopathy.

Topics: Cardiac Output; Cardiomyopathies; Cardiomyopathy, Dilated; Cardiomyopathy, Hypertrophic; Electrocardiography; Gold Radioisotopes; Heart Ventricles; Humans; Magnetic Resonance Spectroscopy; Myocardial Contraction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Topics: Cardiomyopathy, Hypertrophic; Coronary Disease; Fourier Analysis; Heart; Humans; Myocardial Contraction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium

Topics: Adolescent; Adult; Angiography; Blood Pressure; Cardiac Output; Cardiomyopathy, Dilated; Cardiomyopathy, Hypertrophic; Contrast Media; Coronary Disease; Erythrocytes; Female; Heart; Humans; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

This study was designed to more clearly define the relation between various invasive hemodynamic measurements and left ventricular (LV) timing intervals, ejection rate and filling rate derived from the radionuclide angiographic volume curve. Twenty-eight patients were studied with simultaneous intracardiac micromanometer pressure and dP/dt recordings, gated radionuclide angiography and M-mode echocardiography. These techniques permitted multiple variables of systolic and diastolic function to be measured at a constant atrial paced rate of 100 beats/min. There was a strong correlation between peak ejection rate and ejection fraction (r = -0.97) and between peak ejection rate and maximum positive dP/dt (r = -0.85). There also was a strong correlation between peak filling rate and maximum negative dP/dt (r = -0.85). A weaker correlation existed between the time constant of LV relaxation and the peak filling rate (r = -0.49) and between the LV end-diastolic pressure and the peak filling rate (r = -0.62). There was no correlation between the modulus of chamber stiffness and filling rates, and no association was observed between the time to peak filling rate and the hemodynamic variables. Thus, under the conditions studied, the measured peak ejection and filling rate, determined from the radionuclide angiographic volume curve, correlated well with accepted invasive hemodynamic measurements.

Topics: Adult; Aged; Cardiac Catheterization; Cardiomyopathy, Hypertrophic; Coronary Disease; Echocardiography; Erythrocytes; Female; Heart; Hemodynamics; Humans; Male; Manometry; Middle Aged; Myocardial Contraction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium; Time Factors