Verapamil in stable effort angina: effects on left ventricular function evaluated with exercise radionuclide...

Area of Science:

• Cardiology
• Pharmacology

Background:

• Stable angina pectoris is a common condition characterized by chest pain due to myocardial ischemia.
• Left ventricular (LV) function is crucial for assessing cardiac performance, especially during exercise.
• Exercise-induced ischemia can lead to impaired LV function and reduced ejection fraction.

Purpose of the Study:

• To evaluate the effects of oral verapamil on left ventricular function in patients with stable angina pectoris.
• To determine if verapamil improves exercise capacity and anginal thresholds.
• To assess verapamil's impact on exercise-induced changes in left ventricular ejection fraction.

Main Methods:

• A double-blind, placebo-controlled study involving 12 patients with stable angina pectoris.
• Oral verapamil (320 mg/day) administration.
• Gated equilibrium radionuclide ventriculography used to measure LV function at rest and during exercise.
• Assessment of heart rate-blood pressure product, anginal threshold, and maximal exercise capacity.

Main Results:

• Verapamil reduced the heart rate-blood pressure product during exercise compared to placebo.
• Significant increases in anginal threshold (28 +/- 19 watts) and maximal exercise capacity (20 +/- 14 watts) were observed with verapamil.
• Left ventricular ejection fraction remained stable at rest with verapamil.
• Verapamil prevented the exercise-induced decrease in left ventricular ejection fraction, which was observed with placebo.
• Higher ejection fraction at identical workloads during verapamil therapy due to a smaller increase in end-systolic volume.

Conclusions:

• Oral verapamil is an effective treatment for effort angina.
• Verapamil improves exercise tolerance and anginal thresholds in patients with stable angina pectoris.
• Verapamil may prevent the decline in left ventricular ejection fraction caused by exercise-induced ischemia.