Radionuclear measurement of peripheral hemodynamics in selection of vasodilators for treatment of heart failure.

In order to select the optimal vasodilator for the treatment of patients with congestive heart failure (CHF), the acute effects of three vasodilators (isosorbide dinitrate (ISDN) 5 mg, nifedipine 10 mg, and prazosin 1 mg) on peripheral capacitance and resistance vessels (CV and RV) were evaluated by a newly devised radionuclear technique (Study 1). Thirty-six patients with chronic CHF were divided into Group A (ejection fraction (EF) greater than or equal to 35%, n = 20, mean EF: 47.2 +/- 6.

[Comparison of two-dimensional echocardiography with 201T1-single photon emission computed tomography for evaluating the myocardial infarct zone].

The reliability of measuring the myocardial infarct zone by two-dimensional echocardiography (2 DE) was compared with that by regional myocardial blood flow as evaluated by single photon emission computed tomography (SPECT) in 47 patients with old myocardial infarction, with ventricular aneurysm (An group; n = 15), and without ventricular aneurysm (Non-An group; n = 32). Short-axis images of the left ventricle at the level of the mitral valve, the papillary muscles, and the apex were obtained both by 2DE and SPECT. The left ventricular wall was divided into 36 segments in 2DE and 40 segments in SPECT with reference points at the posterior end of the right side of the interventricular septum.

[Right ventricular ejection and regional wall motion evaluated by cardiac blood pool emission computed tomography].

Calculating right ventricular (RV) ejection fraction (EF) is difficult because of geometrical problems such as irregular trabeculations, a separate infundibulum, and variations in the right ventricular shape. We performed 99mTc ECG-(dual)gated cardiac blood pool emission computed tomography (ECT) in 10 patients with ischemic heart disease, three patients with dilated cardiomyopathy (DCM), and eight normal subjects as controls, and RVEF and % shortening of the RV were calculated to evaluate right ventricular function. Methods were as follows: 1) RVEF: The region of interest (ROI) of the RV was determined on reconstructed short-axial images, and then the RV counts in the ROI were summed from the apical slice to the RA-RV boundary slice.

[Infarct size determined by emission computed tomography using 99mTc-PYP: effect of coronary thrombolysis].

Emission computed tomography with 99mTc-PYP was used to estimate infarct size in 38 patients with documented acute myocardial infarction. In the present study, the effect of thrombolysis with Urokinase on infarct size and on left ventricular function was assessed. Fourteen patients with acute myocardial infarction who underwent intracoronary thrombolysis within six hours after the onset of symptoms, and 24 patients who underwent conventional therapy were the subjects of this study.

[Left ventricular asynergy detected by cardiac blood pool emission computed tomography using the subtraction method].

To evaluate left ventricular regional wall motion, ECG dual-gated cardiac blood pool ECT was performed for 25 patients with ischemic heart disease, including 19 cases of myocardial infarction, five cases of angina pectoris, and one case of post A-C bypass surgery. There were six normal controls. Following SPECT obtained using 32 views (180 degrees), the vertical and horizontal long axes were reconstructed from transaxial images.