What brings on a heart attack?
There is no doubt that the biggest killer across the globe is cardiovascular disease. The major cause of cardiovascular disease is atherosclerosis, which is the progressive build-up of fat, inflammatory tissue, calcium and other cellular constituents in the walls of arteries, over many decades. Eventually, these fatty plaques rupture to cause blockages within the channel of arteries, leading to heart attack, stroke or other conditions, depending on the site of the blockage.
This has been established beyond doubt with strong associations with a variety of cholesterol abnormalities, high blood pressure, cigarette smoking and the different stages and manifestations of diabetes, with strong genetic factors thrown into the mix.
Although this is well-established, it needs to be separated from what actually makes these plaques rupture. Or, in other words, what is the precipitating event for an acute cardiac syndrome, such as a heart attack, with the background of an atherosclerotic process that builds up in the wall of the arteries over decades?
There are basically five categories of precipitants:
1) Psycho-social stress — Within a few hours of becoming acutely angry or anxious, you increase your risk for heart attack eight times, if you have previously stable plaques in your coronary arteries. Depression raises coronary risk in some studies up to 50%. There is a link between social isolation, loneliness and acute coronary syndromes. There is also the well described link between serious life events, such as the death of a loved one, relationship issues, even relocating your life, and heart attack. Dramatic societal events, such as terrorist attacks and earthquakes have been shown to increase heart attack risk & sudden cardiac death, by a factor of seven.
2) Exercise — Although regular, conditioned exercise is the second best drug on the planet (after happiness), unusual, unexpected bursts of exercise, such as the unfit, obese person running for the bus or train, or shovelling snow during bouts of extreme cold, are enough to put enormous strain on fatty plaques, potentially leading to heart attack.
3) Infection — Severe infections activate the immune system switching on inflammation and may acutely weaken and rupture a fatty plaque. A study from the University of New South Wales demonstrated that people who had a yearly flu vaccination had a 30% reduction in heart attack by reducing the risk of the severe infection related to influenza.
4) Radical diets — Although rapid fat burning diets such as Atkins, Paleo and the ketogenic diet are efficient for rapid weight loss, I have seen a handful of high risk patients suffering heart attacks during the rapid weight loss phase. My explanation for this is that abdominal obesity isn’t just an ugly lump of lard but also a toxic reservoir, storing, over years of exposure, a variety of synthetic chemicals and heavy metals. Once the fat is broken down rapidly, the toxins overwhelm the circulation, rupturing fatty plaques. Although this is uncommon, it still happens. Thus, it is my opinion that weight loss should be gradual.
5) Acute life indiscretions — A heavy binge of alcohol or the use of illegal drugs have been well described as significant precipitants for acute cardiac events, such as heart attack or sudden cardiac death.
Finally, recent work from the United States has suggested a mechanism whereby an acute fatty load may also do the same thing as other life indiscretions. Ten healthy males with normal blood pressure and normal cholesterol were divided into two groups. Five were given a very fatty milkshake, whilst the other five a low-fat meal with the same number of calories. This acute fatty load led to rather dramatic changes in their red cells, changing shape, becoming spiky & sticky, along with an increase in a chemical known as myeloperoxidase which reduces blood vessel elasticity and also generates oxidation of the so called good cholesterol, HDL. All these issues thicken the blood and acutely damage blood vessels.
It is my clinical experience that patients who are at high risk for heart disease exposed to one or a combination of any of these precipitants are at a much higher risk for an event. In fact, I hardly see a patient who experienced a heart attack without one of these precipitants.