Effects of marihuana and placebo marihuana smoking on hemodynamics in coronary disease.

Abstract

The effects of smoking 1 marihuana and 1 placebo marihuana cigarette on cardiovascular hemodynamics were evaluated by echocardiography in a double‐blind crossover study in 10 patients with angina pectoris. Smoking marihuana increased the heart rate and systolic and diastolic blood pressures, did not significantly change the end‐systolic volume and cardiac index, and decreased the end‐diastolic volume, stroke index, and ejection fraction. Smoking placebo marihuana did not significantly change the heart rate, blood pressure, and end‐systolic volume, and decreased the end‐diastolic volume, stroke index, cardiac index, and ejection fraction. The decrease in stroke index and ejection fraction after marihuana was greater and lasted longer than after placebo marihuana. The decrease in stroke index, cardiac index, and ejection fraction after placebo marihuana may be attributed to increased carboxyhemoglobin level. The increase in heart rate and blood pressure after marihuana is attributed to delta‐9‐tetrahydrocannabinol (THC). The decrease in stroke index and ejection fraction after marihuana may be attributed to delta‐9‐THC in addition to increased carboxyhemoglobin level.