The Secret of the Beating Heart
(Extracts from an educational session for Toastmasters on 7th Feb 2025)
The heart beats approximately 70 times a minute. 60 min in an hour. 24 hours in a day. If you do the math, you will find it beats about one hundred thousand times per day. More than 36 million heart beats per year. Multiply that by 70 and you will get the number of times the heart beats in a lifespan of 70 years! If each heartbeat was a stride, in 70 years, a human being would have walked more than 2 million kilometres, which is more than 50 times the circumference of the earth.
Understanding terminology related to the heart
HEART ATTACK is what doctors call myocardial infarction. It means the heart muscle has been wounded or damaged because of lack of oxygen. A heart attack almost always causes severe chest pain. But in some diabetic patients, a heart attack can occur without chest pain. Healing from a heart attack will leave scars in the heart. The ECG is a tool to show evidence of both injury and scarring.
HEART FAILURE is when the heart has become too weak to pump blood efficiently. Heart failure can occur after a heart attack if the damage is extensive. If the heart attack is small, there will be no heart failure. Heart failure can also occur from diseases other than heart attacks.
CARDIAC ARREST is the term used when the heart has stopped beating. It is not the same as a heart attack. Some heart attacks can lead to cardiac arrest which is why all heart attacks must be treated promptly.
First aid measures for a heart attack
A heart attack is mostly from a block in the coronary arteries which supply oxygen to the heart muscle. The following first aid measures can help improve blood flow while the patient is being taken to a hospital.
1. Give a tablet of aspirin to chew and swallow. This will help to prevent the block in the coronary artery from increasing in size.
2. Give a tablet called nitrate (glyceryl trinitrate or GTN is the best) to be kept under the tongue where it will dissolve and be absorbed into the blood. This will dilate the blocked blood vessel and allow blood to squeeze past the block and nourish the heart muscle.
It is good to keep an aspirin and a nitrate handy in your first aid tool kit. Sometimes the difficulty is in deciding if chest pain is from the heart or not. The pain that comes from the heart and the pain that comes from the food pipe can look similar. The pain from the heart, called angina, is because there is not enough oxygen supply to the heart muscle. The pain from the food pipe, called reflux pain, is because acid from the stomach regurgitates into the food pipe. Typically, the pain from the heart will have a constricting feeling, will be associated with fear and sweating, and can be experienced in the left arm too. The pain from reflux is more of a burning pain with burping but can have many of the features of angina. When in doubt, give aspirin and nitrate as a first aid measure.
The Secret of the Beating Heart
The heart beats, on the average, 70 times a minute. That means each heartbeat takes 0.8 seconds. The actual work of pumping out blood involves a squeezing of the heart muscle. This takes 0.3 seconds and is called systole. During the remaining 0.5 seconds, the heart relaxes and fills its chambers with an inflow of fresh blood. This relaxation phase is called diastole. During these 0.5 seconds of diastole the heart muscle receives nutrition and oxygen through the coronary arteries. In other words, the heart is designed to work for 0.3 seconds, and to rejuvenate for 0.5 seconds during every heartbeat. The message is that, to function effectively for a long period of time, we must have the equivalent of diastole in our lives daily. Diastole implies allotting time for rest and rejuvenation. Sleep is Nature’s prescription for rest and rejuvenation. When we deliberately shorten our duration of sleep, we do so at our own peril. Activities that produce flow also rejuvenates us. Those who do the work they love are lucky, for they experience flow at work. A general principle is that focused attention in any form can be a source of rejuvenation. Hence, the health benefits of yoga, tai chi, slow-paced breathing, mindfulness and meditation. The secret of the heart’s effectiveness is there in every heartbeat.