Arrhythmias are the most common cardiac complication encountered during pregnancy in women with and without structural heart disease [1-3]. Arrhythmias may manifest for the first time during pregnancy, and in other cases, pregnancy can trigger exacerbations in women with pre-existing arrhythmias [1,4-6]. Women with established arrhythmias or structural heart disease are at highest risk of developing arrhythmias during pregnancy. In addition, there has been an increase in the number of women of childbearing age with congenital heart disease (due to surgical advances), and these women are at particularly high risk for arrhythmias (figure 1) [1,2,7-11]. Because of these associations, any woman who presents with an arrhythmia should have a clinical evaluation with a complete history and cardiac examination, an electrocardiogram, and a transthoracic echocardiogram to evaluate for evidence of structural heart disease.
In general, the approach to the treatment of arrhythmias in pregnancy is similar to that in the nonpregnant patient. However, due to the theoretical or known adverse effects of antiarrhythmic drugs on the fetus, antiarrhythmic drugs are often reserved for the treatment of arrhythmias associated with clinically significant symptoms or hemodynamic compromise [12-14]. Treatment recommendations are hampered by the lack of randomized trials and very little or no data on efficacy or safety of antiarrhythmic drugs during pregnancy. Choice of therapy, for the most part, is based on limited data from animal studies, case reports, and observational studies, as well as clinical experience.
The prevalence, clinical presentation, and management of supraventricular arrhythmias during pregnancy will be reviewed. Electrocardiographic characteristics of supraventricular arrhythmias, as well as issues relating to conduction disorders, ventricular arrhythmias, and cardiac arrest during pregnancy, are discussed separately. (See "ECG tutorial: Atrial and atrioventricular nodal (supraventricular) arrhythmias" and "Maternal conduction disorders and bradycardia during pregnancy" and "Ventricular arrhythmias during pregnancy".)
MECHANISM OF ARRHYTHMOGENESIS IN PREGNANCY
The exact mechanism of increased arrhythmia burden during pregnancy is unclear, but has been attributed to hemodynamic, hormonal, and autonomic changes related to pregnancy.
The hemodynamic changes of pregnancy have been well studied, and a number of these changes likely contributes to the development of arrhythmias during pregnancy [15,16]. (See "Maternal cardiovascular and hemodynamic adaptations to pregnancy".)