Sex Differences in Arrhythmias

There are differences in the basic electrophysiology of ion channel function and action potential morphology between men and women that contribute to differences in the incidence and prevalence of cardiac arrhythmias. Electrocardiographic intervals are different based on sex, as are conduction intervals and refractory periods at electrophysiology study. Baseline heart rates are higher in women. The corrected QT interval is longer in women, accounting for a greater susceptibility to torsades de pointes. The most common supraventricular tachyarrhythmia in women is atrioventricular nodal reentry tachycardia, while the incidence of atrioventricular nodal reentry and atrioventricular reentry tachycardia is similar in men. Outcomes with catheter ablation are comparable between the sexes, although complication rates are higher in women. Men have a greater risk of developing atrial fibrillation than women, although women with atrial fibrillation dominate the older patient population. Sudden cardiac death is more common in men. There are sex differences in cardiac events related to the long QT syndrome as well as with other inherited cardiac arrhythmias such as Brugada syndrome and arrhythmogenic right ventricular cardiomyopathy. Women are more prone to proarrhythmia from antiarrhythmic drugs. Complications from implantable device therapy such as pacemakers and defibrillators are more common in women, although outcomes are comparable between the sexes. Women have a greater benefit from cardiac resynchronization therapy. Pregnancy may be associated with new onset or increased frequency of supraventricular tachycardia. The use of pharmacotherapy during pregnancy must consider potential adverse effects on the fetus.