Cardiovascular System Effects of Marijuana

Abstract

Marijuana and delta9-tetrahydrocannabinol (THC) increase heart rate, slightly increase supine blood pressure, and on occasion produce marked orthostatic hypotension. Cardiovascular effects in animals are different, with bradycardia and hypotension the most typical response. Cardiac output increases, and peripheral vascular resistance and maximum exercise performance decrease. Tolerance to most of the initial cardiovascular effects appears rapidly. With repeated exposure, supine blood pressure decreases slightly, orthostatic hypotension disappears, blood volume increases, heart rate slows, and circulatory responses to exercise and Valsalva maneuver are diminished, consistent with centrally mediated, reduced sympathetic, and enhanced parasympathetic activity. Receptor-mediated and probably nonneuronal sites of action account for cannabinoid effects. The endocannabinoid system appears important in the modulation of many vascular functions. Marijuana's cardiovascular effects are not associated with serious health problems for most young, healthy users, although occasional myocardial infarction, stroke, and other adverse cardiovascular events are reported. Marijuana smoking by people with cardiovascular disease poses health risks because of the consequences of the resulting increased cardiac work, increased catecholamine levels, carboxyhemoglobin, and postural hypotension.

Early endothelial dysfunction as a marker of vasculogenic erectile dysfunction in young habitual cannabis users

“…42 It is noteworthy that, marijuana smoking by people with either silent or overt cardiovascular disease poses health risks because of the consequences of the resulting increased cardiac work, increased catecholamine levels, carboxyhemoglobin and postural hypotension. 43 Hence, we can hypothesize that in our young healthy subjects with no cardiovascular risk factors, prolonged cannabis use might have acted as a secretagogue on the endocrine pancreas, thus inducing insulin resistance, endothelial dysfunction and different degrees of ED.…”

Letter to the Editor: “Reversible cardiomyopathy associated with acute inhaled marijuana use in a young adult”

“…It is rarely associated with cardiovascular events after acute administration (3,4). Cardiac failure may result from chronic use (5).…”

“…There is no clear evidence that marijuana is related to cardiovascular events in healthy adults or older patients with pre-existing heart disease (3,4). Physiologically, acute marijuana use leads to dose-dependent tachycardia, raised blood pressure and cardiac output, for which tolerance rapidly develops (3,4).…”

“…Physiologically, acute marijuana use leads to dose-dependent tachycardia, raised blood pressure and cardiac output, for which tolerance rapidly develops (3,4). Decreased peripheral vascular resistance and hypotension frequently occur (4).…”

“…Cardiovascular sequelae results from marijuana-induced increased myocardial oxygen consumption, reduced oxygen delivery from carboxyhemoglobinemia, hypotension, reduced angina perception, and impaired judgement in seeking medical assistance (3,4). Increased cellular oxidant stress worsens platelet activation and dyslipidemia (3).…”