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Influence of verapamil therapy on left ventricular performance at rest and during exercise in hypertrophic
Insights
Verapamil improves heart function in hypertrophic cardiomyopathy patients by enhancing left ventricular (LV) performance and exercise capacity. This treatment offers significant hemodynamic benefits at rest and during physical activity.
Area of Science:
- Cardiology
- Pharmacology
- Exercise Physiology
Background:
- Hypertrophic cardiomyopathy (HCM) is a condition affecting heart muscle.
- Understanding the hemodynamic impact of medications in HCM is crucial for treatment.
Purpose of the Study:
- To assess the hemodynamic effects of verapamil in patients with HCM.
- To evaluate changes at rest and during exercise after chronic verapamil treatment.
Main Methods:
- 18 HCM patients received oral verapamil (up to 720 mg/day) for 7 weeks.
- Hemodynamic parameters including stroke volume index, heart rate, cardiac index, and vascular resistance were measured at rest and during exercise before and after treatment.
Main Results:
- Verapamil significantly increased left ventricular (LV) systolic performance (stroke volume index) at rest and during exercise.
- Heart rate decreased, while systolic vascular resistance and pulmonary artery pressures decreased significantly during exercise.
- Exercise capacity significantly improved following verapamil administration.
Conclusions:
- Chronic verapamil administration improves LV hemodynamics and exercise capacity in HCM patients.
- Verapamil demonstrates significant hemodynamic benefits in managing hypertrophic cardiomyopathy.
Abstract:
To determine the hemodynamic effect of verapamil at rest and during exercise, 18 patients with hypertrophic cardiomyopathy were studied before and after 7 weeks of treatment with oral verapamil (maximal dose, 720 mg/day). At rest and at peak exercise, verapamil produced a significant increase in left ventricular (LV) systolic performance in terms of stroke volume index (rest, from 43 +/- 11 to 53 +/- 11 ml/m2, p less than 0.001; exercise, from 46 +/- 11 to 51 +/- 10 ml/m2, p less than 0.01), whereas heart rate decreased (rest, from 81 +/- 14 to 70 +/- 11 min-1, p less than 0.001; exercise, from 150 +/- 21 to 141 +/- 18 min-1, p less than 0.01). Cardiac index at rest and during exercise remained unchanged. Systolic vascular resistance did not change at rest, but decreased significantly during exercise (974 +/- 243 to 874 +/- 174 dynes s cm-5; p less than 0.05). After verapamil administration, pulmonary artery pressures did not change at rest, but decreased significantly during exercise. This was probably due to a shift in the LV pressure-volume relation. The improvement in LV hemodynamics was associated with a significant increase in exercise capacity. The findings of this study indicate that in patients with hypertrophic cardiomyopathy, hemodynamic improvement at rest and during exercise can be achieved by chronic administration of verapamil.