Marijuana And Heart Disease: Marijuana use is common, and although once widely illegal, its use for medicinal purposes is growing and it’s recreational use decriminalized in some US states. This article is not designed to support any particular view on the drug, but simply to present evidence available in the medical literature regarding marijuana and heart disease. Although it’s neuropsychiatric complications are well documented, little is known about marijuana and heart disease. Due to its widespread use, its side effects are often trivialized, however there are a growing number of reports of concerning cardiovascular side effects. While its important to note that these side effects are uncommon, it’s important to be aware of potentially harmful effects. In this article we discuss some of the reported adverse effects of marijuana on the heart.

Marijuana, Heart Attacks And Heart Related Deaths

Multiple reports have described an association between marijuana and heart disease, specifically heart attacks, heart failure, and even sudden death. One of the weaknesses of these studies is that cigarette smokers or other drug users often use marijuana and and therefore its difficult to pin down what underlies the outcomes. However that doesn’t mean that the marijuana isn’t having a bad effect also.

In addition to causing heart attacks some studies have linked the use of marijuana to worse outcomes after heart attacks. In one study of almost 4000 patients, the risk of heart attack was around 5 times higher than average in the hour after use of the drug. This has been backed up by other reports. After a heart attack, marijuana smokers are more likely to die than non-users. One study demonstrated the risk was around 4 times higher in those using the drug at least once a week.

Several reports have reported an association between marijuana use and sudden death. The issues with this however is that case reports typically represent rare events, and in many of these reports other drugs were also abused. There are series however that link several sudden deaths to marijuana use where no other drugs were picked up on toxicology testing. A recent report from France demonstrated that although still relatively uncommon, the incidence of reported cardiovascular complications attributed to marijuana use is increasing. More concerning however, the death rate of patients with reported complications was 25%.

Marijuana And Heart Rhythm Problems

In one study a patient who passed out and developed a very dangerous heart rhythm after marijuana use was found to have a reduction in coronary artery blood flow. After the marijuana was stopped the coronary artery flow reverted to normal and the dangerous rhythm wouldn’t reappear even when special techniques were used to try and induce it.

More commonly reported is the association between marijuana smoking and the development of an irregular heartbeat called atrial fibrillation. In the majority of these reports atrial fibrillation occurred shortly after marijuana inhalation. There was usually no recurrence of atrial fibrillation after marijuana was stopped, with the rhythm only documented to recur in those who continued to smoke it. Interestingly, the true scale of the problem may be underreported given that atrial fibrillation may often occur silently.

Marijuana And Heart Disease – A Case Of Stopping The Heart

One study implicated cannabis in ‘cardiac asystole’ that basically means the heart stops beating. A patient was noted to have heart pauses of almost 6 seconds long on cardiac monitoring with the pauses related to periods of cannabis inhalation. Upon stopping use of cannabis, repeat monitoring showed that there were no further pauses. In this particular case, there is a clear association between the drug use and the development of a lethal cardiac rhythm.

Marijuana And Heart Disease – Possible Explanations

Scientific publications have recognized the potential side effects of marijuana for several decades and although there has been much speculation, there has been no clear explanation for these. There are some theories that may explain the association of marijuana and heart disease. A proposed reason for harmful effects is the slowing down of blood flow in the coronary arteries. In the study reported above, a patient who passed out and developed dangerous heart rhythms after marijuana use was found to have a reduction in coronary blood flow. After the marijuana was stopped the coronary flow reverted to normal and the dangerous rhythm disappeared. In a separate report, the phenomenon of slow coronary flow in association with marijuana use actually led to a major heart attack.

Although most associate marijuana with relaxing effects, within minutes of smoking it there is an increase in heart rate, blood pressure and thus increased heart workload. Those using marijuana are also proven to be more likely smoke, to use other illicit drugs, and also to have a poorer diet. All of course risk factors for heart disease.

Marijuana And Heart Disease – What To Make Of It

Marijuana smoking is relatively common and therefore the associated side effects are often trivialized. As seen above however, there are a growing number of studies and reports in the medical literature regarding the potentially harmful side effects of marijuana. On one hand, given the number of marijuana users and the relatively small numbers of patients affected, it can be argued that although these side effects have been documented they are still rare. On the other hand however, it could be that these side effects although occurring more commonly are simply not reported and so a lot more common than we think. This is backed up by the fact that the number of reports, particularly of marijuana use and cardiovascular disorders is growing significantly. Ultimately to definitively settle the issue, well-designed studies involving a large number of patients are required. Until that time however it would be wise to at least acknowledge a potentially harmful association.

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