Sudden death can be the first manifestation of Coronary artery disease in women. Because Coronary artery disease is often the cause of sudden death, women develop this usually 10-20 years later than men in a pattern following the development of Coronary artery disease. However, female survivors of cardiac arrest are less likely to have underlying Coronary artery disease and more likely to have dilated cardiomyopathy (enlargement of the heart chambers), or a normal heart. Also, they are more likely to have valvular heart disease or abnormalities in heart rhythm as causal. They likely benefit as much as men from implantable defibrillators, a device that corrects heart rhythm abnormalities, but overall fewer women have been studied in the clinical trials involving these devices.
Women are more likely to have toxic effects from some antiarrhythmic drugs. Some of these drugs which result in ECG abnormalities predispose them to multiform ventricular tachycardia, a special form of ventricular tachycardia which is potentially life threatening. Because of this, women are more likely to be hospitalized for initiation of this drug therapy.
Less dangerous but more frequent are the supraventricular tachycardias (rapid heart rate initiated in the upper heart chambers). Women have more frequent supraventricular tachycardia than men (2:1 ratio) and their symptoms may be triggered by pregnancy or the particular phase (luteal phase) of the menstrual cycle. One frequent form of supraventricular tachycardia is atrial fibrillation (rapid, irregular activity/”fluttering” of the atria). The prevalence of atrial fibrillation is higher in men and increases with age, but because women survive longer, overall there are more women than men with atrial fibrillation. Atrial fibrillation in women is more frequently associated with valvular heart disease or cardiomyopathy (dilatation, meaning enlargement), while in men it is more often associated with Coronary artery disease. Women who develop atrial fibrillation are more likely to die than men with the same condition. They tend to have faster heart rates than men when they develop atrial fibrillation and their risk of recurrence after cardioversion (regularization of rhythm) is somewhat higher. Their risk for stroke after age 55 is as high as in men and therefore they should receive longterm anticoagulation. This is, however, complicated by their higher risk of bleeding from the anticoagulation therapy; therefore, they need more careful follow-up and fine adjustment of their dosing.