A Rare Case of Supraventricular Tachycardia During Pregnancy and Successful Management in Crisis Situation with Electrical Cardioversion and Radiofrequency Ablation

The occurrence of symptomatic maternal arrhythmias during pregnancy is a cause of concern for the well-being of both the mother and the fetus. In women of reproductive age, the commonest arrhythmia is paroxysmal supraventricular tachycardia (SVT). SVT in pregnancy is defined as any tachyarrhythmia with a heart rate greater than 120 beats/min [1]. There are no reliable data on the incidence of paroxysmal SVT in pregnant women. The incidence in the general population is 35 per 1,00,000 person-years [2]. Over half of these patients are asymptomatic. The main mechanism for the development of SVT is via reentry (atrioventricular nodal reentrant tachycardia in 60 % of cases and atrioventricular reentrant tachycardia in 30 % cases) [3]. Episodes of SVT occur with increased frequency during pregnancy particulary in third trimester. Proposed mechanisms include the hyperdynamic circulation, the altered hormonal milieu, increased circulating levels of catecholamines, increased adrenergic receptor sensitivity and increased maternal effective circulating volume causing atrial stretch [4, 5]. Potential risk factor for SVT in pregnancy is underlying congenital or structural heart disease [6]. In most cases, there is no history of heart disease. Physical treatment like sinus carotid massage or Valsalva maneuvers followed by drug therapy is tried in hemodynamically stable patients. In cases of failure of above measure or when there is hemodynamic compromise, electrical cardioversion or invasive method like radiofrequency ablation is justified, which may jeopardize the mother and her fetus. No large-scale studies or randomized control trials regarding safety of ECV in pregnancy and agents for successful cardioversion are available [7]. The recommendations published by American College of Cardiology/American Heart Association Task Force on Practice Guidelines/European Society of Cardiology Committee for Practice Guidelines are solely based on expert consensus [8]. We present a case of maternal SVT with hemodynamic instability which failed to respond to physical and drug therapy.