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Hemodynamic effects of verapamil in left ventricular valvular volume overload
Insights
Intravenous verapamil improved cardiac function in patients with aortic and mitral insufficiency by reducing vascular resistance. Its vasodilatory effects outweighed negative inotropic effects, suggesting potential therapeutic benefits.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Aortic and mitral insufficiency can be complicated by high systemic vascular resistance.
- Calcium channel blockers are known to reduce systemic vascular resistance.
Purpose of the Study:
- To evaluate the effects of intravenous verapamil on hemodynamics in patients with aortic and mitral insufficiency.
- To determine if verapamil's vasodilatory effects outweigh its negative inotropic effects in these conditions.
Main Methods:
- Intravenous verapamil was administered to 23 patients (11 with aortic insufficiency, 12 with mitral insufficiency).
- Hemodynamic parameters including cardiac index, forward stroke volume index, and regurgitant fraction were measured.
- Left ventricular stress and contractile performance measures were assessed.
Main Results:
- Verapamil increased cardiac index and forward stroke volume index in both groups.
- Regurgitant fraction significantly decreased in patients with both aortic and mitral insufficiency.
- Left ventricular end-systolic stress decreased in both groups; end-diastolic stress decreased in the mitral insufficiency group.
- No significant change in contractile performance was observed, but end-systolic stress-to-volume index ratio fell in the mitral insufficiency group.
Conclusions:
- The vasodilatory effects of intravenous verapamil appear to predominate over negative inotropic effects in patients with aortic and mitral insufficiency.
- Verapamil may be a valuable option for patients intolerant to other vasodilators, those with concurrent ischemic heart disease, or supraventricular arrhythmias.
Abstract:
The hemodynamic consequences of aortic and mitral insufficiency may be influenced by the high systemic vascular resistance often seen in these patients. Since the calcium antagonists have been shown to reduce systemic vascular resistance, we evaluated the effects of intravenous verapamil in 23 patients. In 11 patients with aortic insufficiency, verapamil resulted in a 20% increase in cardiac index (p less than 0.001), 18% increase in forward stroke volume index (p less than 0.001), and a 24% decrease in regurgitant fraction (p less than 0.005). In the 12 patients with mitral insufficiency, verapamil resulted in a 19% increase in both cardiac index (p = 0.004), and forward stroke volume index (p less than 0.001), while there was a 19% decrease in regurgitant fraction (p less than 0.02). Left ventricular end-systolic stress decreased significantly in both groups as did end-diastolic stress in the mitral insufficiency group. There was no significant change in several measures of contractile performance, though the end-systolic stress-to-volume index ratio fell significantly (p less than 0.04) in the mitral insufficiency group. Our findings suggest that the vasodilatory effects of intravenous verapamil predominate over the negative inotropic effects in patients with aortic and mitral insufficiency. Verapamil may be of use in patients intolerant to other vasodilators, patients with concomitant ischemic heart disease, or those with supraventricular arrhythmias.