These conditions, although quite different in nature, all have one thing in common – they result from serious blood flow interruptions in our bodies. While heart failure is a condition that can gradually intensify over time, the onset of a heart attack, cardiac arrest or a stroke is sudden.
Heart failure:
Starting with what is deemed the least serious of these conditions, heart failure fortunately does not mean instant death. This term is a bit of a misnomer as it does not mean the heart has come to a standstill, but it refers to a condition where the heart slowly over time is not pumping efficiently enough to meet the body’s need for blood.
The human body’s control system takes over when the body detects insufficient blood supply. It tries to compensate by raising stress hormones, causing the heart to beat faster and harder. Blood vessels narrow in an effort to stabilise blood pressure and blood is diverted from less important tissues to keep blood flowing to the heart and brain. Sodium and fluid are retained to supplement the volume of blood in circulation.
These are short term fixes, as over time the heart weakens further. Tissues and organs don’t get enough blood/oxygen, and fluid builds up in the lungs and tissues.
Heart attack:
A heart attack is basically a plumbing problem that occurs when the flow of blood in one or more of the coronary arteries to the heart is blocked. A blocked artery prevents oxygen-rich blood from reaching a section of the heart. Heart muscle cells in that section can suffer irreversible injury and die if the blockage is not removed in time. Blockages usually results from a rupture of the build-up from cholesterol-laden plaque that lines the arteries, or by a blood clot in a coronary artery.
The seriousness of a heart attack depends on the degree of blockage, where the blockage is and whether there are other coronary arteries that supply blood to that section of the heart. It also depends on whether the heart rhythm is disturbed, affecting the flow of blood to the rest of the body
Cardiac arrest:
While a heart attack is basically a plumbing problem, cardiac arrest is an electrical problem that occurs when the heart’s electrical system suddenly malfunctions. This can result in the stoppage of effective heart action, in which case the heart either beats rapidly and chaotically, or stops beating altogether. In technical terms this means the periodic impulses that trigger the normal coordinated heart muscle contractions (the pumping action of the heart) cease altogether, or cause a rapid irregular twitching (ventricular fibrillation or flutter). Immediate emergency cardiac care is the only chance of survival.
Some heart attacks (most of them don’t) can lead to cardiac arrest and other possible causes include heart failure or a clot in the lungs.
Stroke:
A stroke differs from heart attack, heart failure or cardiac arrest as it does not result from interrupted blood flow to the heart, but occurs when blood flow to a part of the brain is interrupted. This can be the result of:
- Blood clots that block an artery that supplies the brain, either in the neck area or in the brain itself.
- Hemorrhage that occurs when a blood vessel around or in the brain or ruptures.,
- Cerebral thrombosis that occurs when a blood clot (thrombus) forms within the brain itself.
When brain cells are deprived of the oxygen and glucose in blood that they need to survive, they wither and die.
Prevention is better than cure:
Healthy blood leads to healthy arteries and a healthy heart, which all follows on a healthy lifestyle. Lifestyle in this context refers to diet and exercise.
In terms of diet, avoid foods that take blood sugar levels on a continuous up and down roller coaster ride, and foods with unhealthy fats that can clog the arteries. Following the Mediterranean diet should be an integral part of a healthy lifestyle and will provide the blood (and body) with the necessary healthy nutrients.
While exercise boosts oxygen levels (crucial for the brain, which uses 20% of the oxygen in the blood), it also strengthens the heart, which is basically a muscle that needs exercise to become fit and to function effortlessly, just like any other muscle in the body.
Sources:
Heart attacks: Clarifying the causes and consequences. Published online in the April 2018 Harvard Heart Letter. Harvard Medical School. (www.health.harvard.edu)
Heart disease and stroke. Published online on WebMd. (www.webmd.com)
About cardiac arrest. Published online by the American Heart Foundation. (www.heart.org)
Symptoms of heart failure. Health Insight blog, February 2017.
Definitions of heart attack, cardiac arrest & stroke. Medical Dictionary. (www.medical-dictionary.thefreedictionary.com)
HEALTH INSIGHT
October 2018
