There is a clear gender bias in the manifestation of heart disease in men and women. Women have heart attacks at a later age than men and when they do, often experience different symptoms — shortness of breath, unusual fatigue, cold sweat or dizziness instead of chest pain — than men. Now electrophysiologists — cardiologists specialising in heart rhythm disturbances — say their hearts also beat to a different tune.
The reason for the difference is the female hormone estrogen, which makes the electric systems of women’s hearts behave very differently from men’s. Women experience monthly fluctuations in heart rhythm — an abnormal heart rhythm is called arrhythmia; palpitations are more common, and most worryingly, the electrocardiogram (ECG), which is used to measure the heart’s electrical system, is a far less reliable predictor of heart disease in women than men. “The occurrence of a false positive ECG following physical exercise is as high as 25 per cent in women as compared to 10 per cent in men,” says senior cardiologist Dr K. K. Talwar, director, PGI, Chandigarh.
Even nuclear stress tests, done to separate false positive ECG tests from true positive, can be falsified in women because of changes in the position of the breast tissue that lie over the heart.
Since the symptoms of heart rhythm disorders are generalised, the fainting spells may be the first indications of the disorder. “The changes in heart rhythm are potentially life-threatening because if the heart beats too quickly or too slowly, it may interfere with it’s ability to pump adequate blood,” says Dr Balbir Singh, senior consultant, interventional cardiology, Apollo Hospital.
A rapid heart rate (tachycardia) causes the heart to beat too quickly, not giving it enough time to fill with blood in between each heart beat, which decreases the amount of blood the heart can deliver to the body. Tachycardias can occur at any age and may not be related to heart disease. Slow heart beat (bradycardia) is more common in a heart damaged by heart disease or age.
“In some cases, the cause of arrhythmia is a congenital defect, whose symptoms become visible at a later age. But its more common causes are damage to the heart because of coronary artery disease, pumping capacity (low ejection fraction) of the heart or other heart diseases,” says Dr T. S. Kler, executive director, cardiac sciences, Escorts Heart Institute and Research Centre.
Some of the palpitations are not related to abnormal heart rhythms but are caused by medication such as weight loss products or decongestants, caffeine, fear or stress, but when there is a sensation of the heart pounding while you have a normal blood pressure, you should go to a doctor
Apart from a healthier lifestyle, anti-arrhthymia medicines or implantable devices such as pacemakers and implantable defibrillators can help a person feel better. “A cardiac pacemaker is used when the heart beats too slowly or has other abnormal rhythm. They work by monitoring the electrical impulses in the heart and by delivering small electrical pulses when needed to get the heartbeat to normal,” explains Dr Kler. Priced between Rs 50,000 and Rs 2 lakh, the life of a pacemaker’s battery is about 10 years, with the new one priced between Rs 40,000 and Rs 1.5 lakh.
An implantable defibrillator monitors heart rhythms and delivers shocks when it senses them faltering or becoming rapid. It is priced between Rs 3.5 lakh and Rs 8.5 lakh. The life of the pulse generator is also 5 to 6 years, with a new one priced at Rs 3 lakh to Rs 7 lakh. “Though drugs and radio frequency ablation are not as effective as the implantable device, the high cost keeps people away from defibrillators,” says Dr Talwar. “With more people opting for them, however, the price is likely to come down substantially.”