‘’Atrial fibrillation increases the risk of stroke four fold’’

What percentage of those with a heart ailment go on to develop arrhythmias? What triggers such a condition? Is this genetic?

Dr Paul Dorian

There are hundreds of different types of heart diseases and dozens of different types of arrhythmia. To put it roughly, heart diseases contribute one third of all the possible diseases in the world and a quarter of these heart diseases are due to heart rhythm disorders. The likelihood of developing a heart rhythm disorder also depends on the type of atrial fibrillation and the severity of atrial fibrillation. In a condition called, ‘primary arrhythmia syndrome’ the heart is structurally normal but electrically abnormal. Atrial fibrillation is the most common type of heart rhythm disorder and can occur in presence or even in absence of a structural heart disease. In India, one of the common causes of developing atrial fibrillation is a rheumatic valvular heart disease that occurs in patients who suffer a condition called ‘rheumatic fever’ due to bacterial infection. Many a times high or uncontrolled blood pressure can lead to thickening of the heart muscle or hypertrophy of heart, thereby later developing atrial fibrillation in many cases. There are cases where atrial fibrillation can occur in absence of any abnormality of heart. This condition is called as ‘idiopathic atrial fibrillation’ which could be inherited and genetic but such cases are not very common. Heart rhythm disorders are most commonly linked to an underlying heart disease. Increased income levels lead to better nutrition status, obesity, high blood pressure and diabetes which are risk factors for developing a coronary artery disease, that in turn leads to arrhythmia.

What are the symptoms of atrial fibrillation? Is it age specific, are obese and hypertensive people more susceptible to it? What complications could arise if left untreated?

Atrial fibrillation in many but not all patients causes the heart to beat rapidly and irregularly, that is felt by the patient as ‘palpitations’, an unpleasant sensation of rapid and irregular heart beat in the chest leading to dizziness, light headedness, shortness of breath and effort intolerance (difficulty in carrying out routine activities like carrying a load or climbing stairs) However, diagnosis is difficult since other diseases can also cause similar symptoms. The only certain way to diagnose atrial fibrillation is by recording electrical signals of the heart with the help of electrocardiogram. It is a very commonly used test which is relatively simple, quick and non invasive and provides 100 per cent accuracy in diagnosis of atrial fibrillation if it exists at the time of the test. Sometimes, atrial fibrillation is intermittent. It means, patients may have it few hours every day, few hours every week or even few hours every month, where most of the times patients are perfectly fine but from time to time they would suddenly develop a rapid and irregular heart rhythm and to diagnose this, we need to capture this abnormality the moment it occurs because once the episode is over patients once again start feeling fine and start feeling completely normal.

We take this condition seriously because: Patients with atrial fibrillation frequently feel unwell, tired and are unable to function properly. It also increases the risk of stroke. In such a person,the collecting chambers of heart called , ‘atria’ are not beating properly. This may lead to formation of blood clots in the heart chamber that can get dislodged, traverse through circulation and get impacted in the blood vessels supplying the brain, blocking the blood flow to that part of the brain causing an irreversible damage to brain, leading to stroke. Very importantly, this complication can be prevented by giving blood thinners or ‘anti-coagulants’, that prevent the formation of blood clots, in turn preventing stroke.

What are some of the drugs to prevent arrhythmias? How do they act? Is the mechanism different? How expensive are these drugs? Are they accessible to heart patients in countries such as India?

Two types of drugs are used to treat atrial fibrillation. First type is ‘anti-arrhythmic’ drugs. This is a category of drugs with a chemical effect on the electrical function of heart. And their purpose is to prevent atrial fibrillation or to restore the heart rhythm and revert it to normalcy. There are approximately seven or eight different types of such drugs available worldwide. None of them are particularly new. They are modestly effective in restoring the heart beat. They don’t work perfectly in at least half of the patients. They can have serious side effects and they are not so easy for patients to take due to their side effects. They are not very expensive. Most commonly used drug worldwide is Amiodarone (also most commonly used in India), but it needs monitoring due to potential side effects. The second type is even less expensive and probably simpler but doesn’t completely fix the underlying problem, they are called ‘rate control drugs’, which are a relatively simpler option. They don’t restore the heart rhythm to normalcy but can control excessively fast heart rate. Patients usually feel better and don’t suffer from excessive symptoms of atrial fibrillation. The third category of drugs doesn’t treat the underlying heart rhythm problem but are designed to prevent the complication of atrial fibrillation, which is clot formation, leading to stroke. These drugs are called anti-coagulants. The cost of drugs in this class varies. The more traditional drug in this category is Warfarin which has been in the market for the last 50 years and its cost is not high. But patients on Warfarin therapy need to be monitored very frequently and carefully to check whether the blood thinner is not over-acting or under acting. The monitoring is relatively complicated and it can be costly. Some of the novel oral anti-coagulants that are present in the market since last few years are expensive but easier to regulate as they don’t require frequent monitoring due to their predictable effect.

What is the incidence of atrial fibrillation (Asian vs Western) ? Have there been any studies to establish this correlation?

Atrial fibrillation increases the risk of stroke approximately four-fold. For instance, if a patient is around 65 years of age and does not have atrial fibrillation, the risk of developing stroke is about 0.5 to 1 per cent per year. In persons with atrial fibrillation, the risk increases to around three to four per cent per year and is as high as 10 per cent per year in a patient above 75 or 80 years of age. As far as the risk of stroke related to atrial fibrillation is concerned, there is not much difference between India and the Western world. Strokes are relatively common in India or Asia compared to North America or Western Europe, and that is possibly because there are more patients with valvular heart disease in Asia due to higher incidence of rheumatic valvular heart diseases and also because of the rising incidence of uncontrolled blood pressure.

You recently visited India. What is the awareness level of antiarrhythmia amongst patients, doctors etc?

I did not get an opportunity to meet patients in India but I did interact extensively with cardiologists and physicians in India. The awareness levels in doctors about arrhythmias is extremely high. They are extremely well informed are using the latest treatment options to treat patients. The only limitations that I see from the treatment perspective are essentially related to the availability of medical care in smaller communities of the country side and some of the complexities involving very large population with standard of living not as high as the Western world.

You have been a pioneer in revolutionising standard practices in resuscitative medicine. Tell us something about your findings and how they could be applied in clinical settings.

This is my life story in a way and something close to my heart. Currently much of my research rests on the belief that when you have a complicated condition like atrial fibrillation to manage with relatively complicated treatments, the best way to manage the problem is to simplify the management as much as possible. We are working on a system of care around this belief by involving patients as partners in their own healthcare. Our programme involves:

1. Identifying or increasing the diagnosis of the heart rhythm disorder by routine ECG screening.
2. Providing an educational material to patient for their easy understanding of the disease and to understand their treatment better.
3. Keeping a checklist of items for doctors ensuring a standardised approach in treatment for all patients with atrial fibrillation.

shalini.g@expressindia.com