Atrial Fibrillation (AF) - An Important Controllable Condition That Most Have Not Heard Of
Atrial fibrillation or Afib or AF for short is a condition where the atria of the heart (the upper two smaller heart chambers) beat irregularly. This leads to a “quivering” of the heart and a disordered rhythm (also called arrhythmia). Apart from symptoms of palpitations and light-headedness, which are not that common (most patients with AF have no symptoms), the major challenge is that of the potential complications of AF, mainly stroke.
Unfortunately, this is a condition not many have heard of, but presents as a significant problem the older you are, especially above the age of 65. Because of the disordered beating of the heart, there is an increase in the risk of clot formation inside the atrial chambers and if the clot dislodges and goes into the brain, it can cause a stroke. There is a 5 times increased risk of stroke in patients with AF and AF is the cause of 10% to 1/3rd of all strokes [1]. Since AF is asymptomatic or minimally symptomatic most of the times, stroke is often the first clinical symptom of AF in a quarter of cases [1].
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AF is usually diagnosed on an ECG. A recent paper from China [2] has shown that yearly ECG picks up AF better than a once in 2 years screening schedule, while quarterly screening is better than yearly, with no further benefit from weekly testing.
AF for long has been considered a disease of the West probably because the condition was not widely known and longevity in South Asia has gone up only in the last few decades. Now that the demographics are changing, AF has been found to be almost as prevalent. The SMART study of villagers in Western India using a handheld ECG device found a 3.1% prevalence [1] in those above the age of 65 and 1.6% in all patient groups put together. There are 90.7 million (9.07 crore) people above the age of 65 in India. A 3% prevalence would mean 2.7 million or 27 lakh people, which is not only not a small number, but difficult to manage as well, given our poor public health infrastructure and lack of doctors. The annual incidence of stroke in patients with AF is also around 3% [3], which means every year, around 81,000 people with AF are likely to get strokes, which is again a burden our health systems can’t handle. If AF can be identified in advance and if anti-coagulation can be started as a preventive measure, the risk of strokes can reduce drastically.
A wearable device like an Apple Watch can also pick up the disordered rhythm and alert us to the possibility of AF [4].
In short, as part of an annual health check, an ECG is a must, especially if you are above 65 years of age, or if you have parents or grand-parents in that age group. A wearable device like an Apple Watch or Fitbit may also help pick up this condition. Please remember to ask your physician about AF and if found, make sure that blood thinners are started appropriately.
Footnotes
1. Soni A, Karna S, Fahey N, et al. Age-and-sex stratified prevalence of atrial fibrillation in rural Western India: Results of SMART-India, a population-based screening study. Int J Cardiol. 2019 Apr 1;280:84-88. doi: 10.1016/j.ijcard.2018.12.016. Epub 2018 Dec 6. PMID: 30551905; PMCID: PMC6378127.
2. Zhang W, Chen Y, Miao CY. Lancet Healthy Longev 2021, July 23, 2021
3. Bai Y, Wang YL, Shantsila A, Lip GYH. The Global Burden of Atrial Fibrillation and Stroke: A Systematic Review of the Clinical Epidemiology of Atrial Fibrillation in Asia. Chest. 2017 Oct;152(4):810-820. doi: 10.1016/j.chest.2017.03.048. Epub 2017 Apr 17. PMID: 28427968.
4. Perez MV, Mahaffey KW, Hedlin H et al; Apple Heart Study Investigators. Large-Scale Assessment of a Smartwatch to Identify Atrial Fibrillation. N Engl J Med. 2019 Nov 14;381(20):1909-1917. doi: 10.1056/NEJMoa1901183. PMID: 31722151; PMCID: PMC8112605.