Sex differences in arrhythmias

The aim of this review is to provide a summary of the principal sex-related differences in the presentation, clinical course, and treatment of cardiac arrhythmias as well as the current understanding of the mechanisms underlying these differences.

The mechanisms behind the sex differences in arrhythmias are not well understood yet. Recent studies in animals have provided some insight to explain the molecular basis by which sex hormones may be responsible for the female predisposition to long QT syndromes as well as the higher male predisposition to lethal arrhythmias after myocardial infarction. Recently discovered preferential transmission of long QT syndrome alleles to daughters as compared with sons, as well as sex differences in the activity of membrane transporters and in recently discovered myocardial cytochrome P450 enzymes, may explain the predisposition of women to acquired and drug-induced long QT syndrome and torsades de pointes. Important sex differences in the use of implantable cardioverter defibrillators and cardiac resynchronization therapy have also been reported. Women appear to be underrepresented among patients who receive implantable cardioverter defibrillators and cardiac resynchronization therapy devices. However, despite higher rates of adverse mechanical events, they seem to benefit at least as much as men from these therapies.

Sex-related differences should be taken into account to provide optimal diagnosis and treatment to patients with cardiac arrhythmias. Further studies are needed to explain the mechanisms behind these differences.