Frequently asked questions
Does cannabis use cause heart attacks?
– Angina = Feeling of discomfort in the chest or chest pain due to heart disease
– Beta-blockers = class of drugs used for the treatment of high blood pressure and heart diseases
– Coronary = with regard to the arteries of the heart
– Coronary disease (coronary heart disease) = narrowing of the arteries of the heart
– CRP (C-reactive protein) = indicator of inflammation
– Exercise time = Time in a stress test that tests heart function
– Longitudinal epidemiological studies = studies that follow a certain group of people (often several hundreds or thousands) for a long period of time to discover differences in subgroups, for example in dependency of life style and habits
– Myocardium = heart muscle
– Myocardial = with regard to the heart muscle
– Myocardial infarction = heart attack
Murray A. Mittleman and colleagues
We interviewed 3882 patients (1258 women) with acute myocardial infarction an average of 4 days after infarction onset. (. ) Of the 3882 patients, 124 (3.2%) reported smoking marijuana in the prior year, 37 within 24 hours and 9 within 1 hour of myocardial infarction symptoms. (. ) The risk of myocardial infarction onset was elevated 4.8 times over baseline (95% confidence interval, 2.4 to 9.5) in the 60 minutes after marijuana use. The elevated risk rapidly decreased thereafter. Conclusion: Smoking marijuana is a rare trigger of acute myocardial infarction.
Mittleman MA, Lewis RA, Maclure M, Sherwood JB, Muller JE. Triggering Myocardial Infarction by Marijuana. Circulation 2001;103(23):2805-2809.
Lindesmith Center (USA)
An analysis of the research methods used [in the study of Mittleman and colleagues] reveals glaring flaws. The sample size is statistically insignificant, no casual relationship has been established, and the study itself has never been replicated. (. ) Out of 3,882 patients who had heart attacks, 124 were current marijuana smokers and 9 had smoked within an hour of their heart attack. Based on this minuscule, self-selected sample, Dr. Mittleman concludes that the risk of a heart attack is 4.8 times higher after smoking marijuana. The sample size alone renders the results meaningless. Assuming that Dr. Mittleman’s conclusions are correct, the fact that heart attack risk for an otherwise healthy 50-year-old man is about 10 in 1 million highlights the sensationalism of the widespread publicity the study is receiving.
Lindesmith Newsletter. Junk Science Makes Headlines. Questionable Study Links Marijuana Smoking and Heart Attacks. June 15, 2001.
L.A. Gottschalk and colleagues
In view of associated findings that marijuana smoking decreased myocardial oxygen delivery, decreased exercise time until the onset of anginal pain, and increased myocardial oxygen demand in anginal patients, the use of marijuana by such patients is clearly inadvisable. Gottschalk LA, Aronow WS, Prakash R. Effect of marijuana and placebo-marijuana smoking on psychological state and on psychophysiological cardiovascular functioning in anginal patients.
Biol Psychiatry 1977;12(2):255-266.
The overall effect of cannabis use on the frequency of heart attacks is unknown. This can only be ascertained in longitidudinal epidemiological studies. There are some studies and case reports that support the assumption that cannabis use may be harmful in people with coronary disease and may trigger a heart attack. However, this seems to be a very rare event. Cannabis will not cause a heart attack in a healthy person.
There are some pharmacological effects of cannabis that may act preventive and some that may be damaging.
Factors that may be damaging:
– The decrease of oxygen delivery to the heart (only if cannabis is smoked), due to the production of carbon monoxide.
– The increase of heart rate of about 45% on average in the first hour after smoking. Thus a normal heart rate of 70 may increase to about 100. This increases labour and thus oxygen demand (or oxygen need) of the heart muscle.
– Changes of blood pressure. Cannabis may cause the blood pressure to increase when the person is lying down, and to decrease when the person stands up.
Factors that might be preventive:
– If the angina is based on a spastic contraction of the coronary arteries, cannabis may relax the spasm.
– Cannabinoids reduce platelet aggregation, thus they may reduce the tendency of the blood to form clots.
– Cannabinoids act anti-inflammatory. Inflammation measured as the level of CRP is associated with a higher risk of heart attack.
In coronary disease the heart attack risk of cannabis use may be as high as going for a walk or having sex. So if you feel chest pain while walking or if you know that you have a severe coronary disease you should better not take cannabis or only in low doses that do not significantly increase heart rate. These low doses are often high enough for the therapeutic effectiveness of cannabis. You can measure your heart rate yourself and find out how it changes in reaction to cannabis. In case of an accidential overdose you can prevent the increase of heart rate by taking a beta-blocker.
Frequently asked questions Heart attack: Does cannabis use cause heart attacks? Technical terms: – Angina = Feeling of discomfort in the chest or chest pain due to heart disease
Millions of cannabis smokers at risk of deadly heart attack and stroke, docs warn
- 20 Jan 2020, 19:00
- Updated : 20 Jan 2020, 17:00
MILLIONS of cannabis smokers are at risk of deadly heart attack and stroke, doctors have warned.
Experts say that for the first time ever there are more marijuana users in the US than cigarette smokers – and the number continues to grow.
In a review article published in the Journal of the American College of Cardiology, researchers estimated that more than two million US adults who reported marijuana use had cardiovascular disease.
This includes recreational use and approved medical uses, such as treatment of seizure disorders or chemotherapy-associated nausea and vomiting.
But observational studies have linked cannabis use to a range of cardiovascular risks, including stroke, arrhythmia and diseases that make it hard for the heart muscle to pump properly.
The investigators urged doctors to ask their patients about marijuana use, which can interfere with other medications that they might be prescribed.
Lead author Dr Muthiah Vaduganathan, of Brigham and Women’s Hospital’s Heart and Vascular Centre in Boston, Massachusetts, said: “Some observational studies have suggested an association between marijuana and a range of cardiovascular risks.
“We also know that marijuana is becoming increasingly potent.
There’s enough data for us to advise caution in using marijuana for our highest-risk patients
Dr Muthiah Vaduganathan Brigham and Women’s Hospital’s Heart and Vascular Centre in Boston
“Our review suggests that smoking marijuana carries many of the same cardiovascular health hazards as smoking tobacco.
“While the level of evidence is modest, there’s enough data for us to advise caution in using marijuana for our highest-risk patients, including those who present with a heart attack or new arrhythmia, or who have been hospitalised with heart failure.”
Certain cardiovascular medications, including statins and blood thinners, can be affected by cannabis use, the review found.
For example, statin levels can increase in the blood when used together with cannabis because both are metabolised through a network of liver enzymes.
What is the difference between a heart attack and a stroke?
HEART attacks and strokes are both life-threatening emergencies.
Yet, the quicker they are detected, the greater a person has of surviving their ordeal.
What are the signs of a heart attack?
Being able to quickly recognise the signs of an impending heart attack, could save a person’s life.
The symptoms will likely vary, person to person, but there are some common signs.
- chest pain – a tightness, heaviness, pain or burning sensation in the chest
- pain the arms, neck, jaw, back or stomach – the pain will be severe, rather than just uncomfortable
- feeling light-headed
- becoming short of breath
- feeling nauseous or vomiting
What is a stroke?
A stroke is a brain attack, and happens when the blood supply to the brain is interrupted.
Blood carries oxygen to the brain, and without it brain cells will begin to die off.
This is what causes the damage to other parts of the body, in stroke victims – for example speech problems or a weakness on one side.
There are two different types of stroke – ischaemic and haemorrhagic.
In a similar way to a heart attack, a stroke is caused by a narrowing of the blood vessels.
As we age our arteries become harder and narrow, increasing the chance of a blockage.
Certain medical conditions, as well as lifestyle factors such as smoking and being obese, increase the risk of a stroke.
All strokes are different, for some they can be relatively minor while for others they can prove catastrophic.
Around one in eight people die within 30 days of suffering a stroke, according to the Stroke Association.
What are the signs of a stroke?
This is why it is so important that people recognise the signs, as the quicker a person receives treatment the higher their chances of surviving.
If you suspect you or a loved one is suffering a stroke, it is vital to act FAST.
- Facial weakness – can the person smile? Has their face fallen on one side?
- Arm weakness – can the person raise both arms and keep them there?
- Speech problems – can the person speak properly, and understand what you’re saying. Is their speech slurred?
- Time to call 999
Dr Vaduganathan said: “The review provides detailed tables of many drugs administered for various cardiovascular conditions, with the anticipated effects of marijuana on each one.
“These will be helpful to cardiologists and pharmacists reviewing patients’ medications and will help them collaboratively decide whether they need to adjust dosing if the patient continues to use marijuana.”
The team also recommend that cardiologists screen their patients for cannabis use, asking them how often and how much they use.
Dr Vaduganathan said: “Vaping marijuana is becoming more and more common, and we know vaping marijuana increases the pharmacological effects of the drug.”
For patients who wish to continue to use cannabis, or who have other medically indicated reasons for use, the experts suggested limiting use as much as possible.
Vaping marijuana is becoming more and more common, and we know vaping marijuana increases the pharmacological effects of the drug
They also advised medics inform patients that vaping and certain synthetic forms of cannabinoids are particularly potent and may have greater adverse effects.
In some patients, cardiologists should test for marijuana use by urine toxicology screening, the reviewers recommend.
These include patients being considered for heart transplantation or those who present with early-onset heart attacks or heart failure at a young age.
Millions of cannabis smokers at risk of deadly heart attack and stroke, docs warn 20 Jan 2020, 19:00 Updated : 20 Jan 2020, 17:00 MILLIONS of cannabis smokers are at risk of