More reasons why men and women are not the same (gender differences in electrophysiology and arrhythmias).

It has become increasingly apparent in recent years that there are important differences in the presentation and clinical course of many cardiovascular disorders in men and women. These gender differences extend to clinical cardiac electrophysiology, with respect to basic electrophysiology as well as the presentation and clinical courses of many arrhythmias. Women have been noted to have higher heart rates at rest and longer corrected QT intervals compared with men. Differences in gender hormones may explain some of these findings, but precisely how is still not well understood. Differences have also been documented in the incidence and prevalence of specific arrhythmias, including atrial fibrillation, other supraventricular tachycardias, and sudden cardiac death. Variations in arrhythmia frequency with respect to the menstrual cycle have been observed. In addition, an increase in arrhythmia frequency or the new onset of arrhythmias has been noted during pregnancy. With the increasing use of implantable cardioverter defibrillators and cardiac resynchronization therapy, it has been shown that men and women derive equal survival and symptom reduction benefit. However, it has been found that the use of these devices in women is much lower than would be expected from the prevalence of disease in the population. The reasons for this lower utilization rate are not well understood and remain to be explored. In conclusion, the goal of this review is to summarize the currently available published reports regarding gender differences in cardiac electrophysiology and arrhythmias and to provide an update from recent studies.