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A method for obtaining left ventricular (LV) volume curves, synchronized with average LV pressure (LVP) curves for calculation of LV contractility, is described. Multiple gated blood pool imaging was performed to calculate average LV volume curves. Simultaneously with this acquisition, LVPs and aortic pressures were measured by indwelling catheters and recorded on an FM tape recorder. These signals were fed to the computer as image information and averaged and processed by the software developed for this purpose. Pressure resolution of the calibrated images was 4 mmHg/pixel when provision was made for a maximum pressure of 200 mmHg. A good correlation (r=0.99) was obtained between the calculated peak LVPs and mean peak LVPs read from the chart recorder. The regression equation was: digitized peak LVP=1.04xchart recording-5.11 mmHg and the standard error of the estimate was 2.9 mmHg. Similar results were obtained with the aortic pressure (AP) measurements (digitized AP=0.94 x chart recording+6.37 mmHg, the standard error of the estimate was 3.8 mmHg). The digitized data also allowed the construction of pressure-volume loops for interpretation of ventricular contractility.

Nisoldipine (BAY k 5552) like nifedipine, is a dihidropyridine compound with strong calcium blocking activity. The purpose of this study was to measure and compare the absolute hemodynamic effects of these two drugs before and at 30 min, 60 min and 120 min after oral intake in 20 ischemic heart disease patients with radionuclide gated cardiac scintigraphy. No significant change was seen in end diastolic volume index with either of the drugs. With nifedipine the stroke volume index (SVI) increased significantly from the basal value at 30 min (P=0.004) and 60 min (P=0.034) yet not significantly at 120 min. The same trend was seen in left ventricular ejection fraction (LVEF) with significant increases at 30 min (P=0.02) and 60 min (P=0.025) yet not at 120 min. The cardiac index increased significantly at 30 min (P=0.001), 60 min (P=0.002) and 120 min (P=0.025) but the latter value was significantly lower than the 30 min value indicating the maximal effect had already passed. With nisoldipine the SVI increased significantly at 60 min (P=0.004) and 120 min (P=0.001) but not at 30 min. These changes were again reflected by a significant increase in LVEF at 60 min (P=0.021) and 120 min (P=0.002) without significant increase at 30 min. The increase in CI was highly significant at 60 min (P=0.003) and 120 min (P=0.001) without significant change at 30 min. Nisoldipine proved to be a potent calcium antagonist with slower onset and longer duration of action than nifedipine.

Nisoldipine is a newly developed calcium channel blocker with outstanding vasodilatory properties especially with regard to the coronary arteries. Thus it may find wide-spread application as a therapeutic agent in various ischemic heart disease syndromes. The purpose of this study was to evaluate the effect of nisoldipine on the diastolic function of the left ventricle (LV) in the clinical situation. A patient group on nisoldipine treatment was compared to a control group. In the nisoldipine group a maximum decrease of 17 mmHg in the mean systolic blood pressure with an increase in the mean peak ejection rate (0.78 EDV/s) and peak filling rate (0.52 EDV/s) were observed. Mean LV ejection fraction increased by 6.4% and the time to peak filling rate decreased by 36.5 ms. After eight weeks of treatment the acute effects of nisoldipine were similar to the previous study. Nisoldipine therefore tends to improve both the diastolic and systolic function of the left ventricle.

A radionuclide washout technique (WO), for calculation of the right ventricular ejection fraction (RVEF) which is independent of the exact position of the right ventricular region of interest was evaluated and results compared with first pass (FP) and equilibrium gated blood pool (GBP) values. Regression analysis between RVEF values of 24 patients obtained from FP and WO yielded a correlation coefficient (r) of 0.89, while a slightly poorer correlation coefficient was obtained when FP and GBP were compared (r=0.79) and between WO and GBP (r=0.71). No significant difference between RVEF values calculated from the three techniques was found (P<0.05) on inter- and intraobserver level. The radionuclide washout technique yields an accurate determination of RVEF without the necessity of outlining the RV accurately.