Authors: Colin Michie Paediatrician, Denise Harford, Anticoagulation Nurse
In the quiet of the night, you can often hear your heart – a soft, calming rhythm. You can feel pulses at your wrists – the shockwaves from every contraction of your heart. Each beat starts from the pacemaker at the back of the heart. This elegant, architectural marvel of specialised cells several centimetres long, half a centimetre wide and several millimetres deep is the sinoatrial node. These cells send out their signal across the cardiac muscle 100-200,000 times a year. A wonderful, hi fidelity system to be treasured, pacemakers are jewels that drive all hearts, whether they are in our fellows, in a fish or a lobster.
Give back your heart to itself, to the stranger who has loved you all your life, whom you ignored for another, who knows you by heart. Take down the love letters from the bookshelf, the photographs, the desperate notes, peel your own image from the mirror. Sit. Feast on your life.
‘Love after Love’, Derek Walcott, 1976 (Sea Grapes)
Our heart pacemaker system can malfunction, particularly as we get older. The most common abnormality of heart rhythms in the Caribbean is atrial fibrillation. Not a story spread in all those romantic lyrics! Atrial fibrillation usually starts with periods of irregular, rapid beats. Over time, these become longer. Atrial fibrillation is seen sometimes in younger endurance athletes. It can be found in about 1% of those in their 60s, increasing to over 10% in those in their 80s. It is more common in men. Perhaps a third of cases run in the family (particularly those with European ancestry) as there are genetic contributions. Many illnesses can damage the careful electrical design of the pacemaker, such as high blood pressure, heart valve malfunctions, chest disease, obesity, smoking or moderate to high alcohol consumption. Diabetes, kidney disease and thyroid problems can harm your pacemaker too. Contrary to urban legend, drinking caffeine does not produce atrial fibrillation!
You may think you have a problem with your heart rhythm if your pulse races or you experience palpitations. Atrial fibrillation can cause lethargy, shortness of breath, chest pain or faintness. There are two large problems with atrial fibrillation (AF). First, about a third of folk do not know when they have it. Second, when the heart beats irregularly, the blood can thicken, forming clots or emboli. These can travel to the brain and block blood vessels, killing nerve cells by cutting off their oxygen – this is ischaemia, or stroke. Atrial fibrillation is the most common cause of stroke. AF is associated with other forms of brain damage including dementia and heart failure too. These illnesses put great strains on families, communities and medical supports. We all need to look carefully at atrial fibrillation and follow a dictum of “Detect, Protect, Correct, Perfect.’
Recently, small cardiac monitors, about half the size of a carpenter’s pencil, have been implanted under the skin of volunteers to track their heartbeats. Routine electrocardiographs (ECG checks) and even most wearable devices miss intermittent rhythm abnormalities. These implants showed that AF can be undetected and silent – subjects were unaware of irregular beats. This links with another finding too, that in stroke patients, a substantial number has atrial fibrillation they did not previously suspect.
Help is at hand! If atrial fibrillation develops, the blood can to be thinned to prevent emboli and strokes. This anticoagulation process may employ warfarin, which antagonises vitamin K in the blood clotting process. The name Warfarin is derived from “Wisconsin Alumni Research Foundation” and “coumarin”; it was originally isolated from mouldy clover in cattle feed. Warfarin needs regular monitoring. Newer medicines or NOACs (non-vitamin K antagonising oral anticoagulants) do not need these regular checks. Trials over the last 8-10 years show these treatments, taken daily, prevent stroke.
Different methods can be used to control a misbehaving pacemaker. In an emergency, an electrical shock, cardioversion, can convert atrial fibrillation into a normal rhythm. In some situations, the pacemaker “wiring” can be tackled surgically using a fine catheter (the procedure of ablation). Sometimes, medications may assist. A number of patients might benefit from an implanted pacemaker to support their pacemaker. These technological miracles are becoming smaller, with progressively longer battery life. Newer models will not interfere with imaging tests such as a magnetic resonance image (MRI) scan. However, we all differ, so careful evaluation by a cardiologist will guide you to a tailored approach. Finding and treating atrial fibrillation will prolong healthy life.
Heart health helps your amazing node stay in its best possible shape. Nudges towards regular physical activity, eating less meat and more plants, stopping smoking, having enough sleep and reducing avoidable stresses are all important. Syncopated rhythms, sly jazz or even ponum, zouk or bacchata has a part in this – just not when delivered from your pacemaker.
https://www.cdc.gov/heartdisease/atrial_fibrillation.htm
www.heartrhythmalliance.org
healthawareness.co.uk
