Gender differences in cardiac electrophysiology and arrhythmias. Part 1

Gender differences in cardiac pathophysiology and electrocardiographic parameters have been suggested since the early 20th century. More recently this has expanded to include cardiac electrophysiology. The mechanisms responsible for the disparities are being elucidated. Contributing factors may include: differing amounts of sex and gonadal steroids, differences in autonomic tone, and gender specific hemodynamic variables. Women have a longer corrected QT interval and men have a lower intrinsic heart rate. Atrial fibrillation is more common in men. Atrial fibrillation in men is often associated with coronary artery disease and in women with valvular heart disease. With advancing age, the gender difference in the prevalence of atrial fibrillation disappears, and women tend to develop elevated risk of stroke and poorer survival than their male counterparts, especially in those over 75 years of age. Accessory pathways causing re-entry tachycardia are more prevalent in men, while in women atrioventricular nodal re-entry tachycardia predominates. Women are more likely to develop drug induced arrhythmias, especially polymorphic ventricular tachycardia. Women have an increased propensity to develop torsade de pointes during complete heart block and symptomatic long QT syndrome. Men have a higher incidence of sudden cardiac death. Female survivors of cardiac arrest are less likely to have underlying coronary artery disease and have a lower frequency of inducible ventricular tachycardia at electrophysiologic study. Antiarrhythmic drug and device therapy for sudden cardiac death are equally efficacious in men and women. Incidence of arrhythmias, new onset, paroxysms and exacerbations are increased during pregnancy. Understanding the potential mechanisms responsible for the gender differences may dramatically alter patient care and influence future research.