Time course of cardiac performance in hypertensive patients after verapamil assessed by nuclear ventriculography.

: The effects of oral verapamil monotherapy (320 mg/day) given to a group of essential hypertensive patients (n = 16) on blood pressure, electrocardiogram (ECG) and ventricular function measured by means of nuclear ventriculography (NV) were investigated. Verapamil significantly lowered systolic (SP) (p less than 0.001) and diastolic (DP) (p less than 0.001) blood pressure. Left ventricular ejection fraction (LVEF) and ejection rate (LVER) were reduced from 61.61 +/- 6.34 to 54.16 +/- 6.09% (p less than 0.001) and from 255.6 +/- 58.9 to 217.4 +/- 56.03% (p less than 0.02), respectively. On the other hand, in the right ventricle, the drug only reduced the right ventricular filling rate (RVFR) from 225.2 +/- 60.02 to 167.5 +/- 43.7% (p less than 0.05). Total blood volume (TBV) was also significantly diminished (p less than 0.05). Variations in LVEF (delta LVEF) and RVEF (delta RVEF) correlated with variations in blood pressures and TVB (delta TVB). The results indicate that the hypotensive action mechanism of verapamil could be explained at least in part by a reduction in LVEF and systemic vasodilatation.