Paroxysmal supraventricular tachycardia in patient with dilated cardiomyopathy and concomitant cardiac conduction defects: a case report and discussion

Abstract

Patients with dilated cardiomyopathy (DCM) often have intraventricular conduction disorders, which contribute to aggravation of heart failure, are progressive in most cases and can specify the prognosis of the disease. Paroxysmal supraventricular arrhythmias in such patients proceed with severe clinical manifestations, often accompanied by hemodynamic instability and syncope. A case report of patient (59 years old) with DCM, reduced left ventricular ejection fraction (35-37%), left bundle branch block, and paroxysmal orthodromic reciprocating tachycardia is presented. When an electrode was inserted on the right ventricular (RV) apex during the radiofrequency ablation, a third-degree atrioventricular (AV) block was recorded. This was maintained during the operation and was recurrent when trying to remove the electrode from the RV apex, and therefore there was a need for temporary and then permanent cardiac pacing therapy. Given DCM, reduced left ventricular ejection fraction, left bundle branch block, and the expected high percentage of RV pacing, a decision was made to implant a cardiac resynchronization therapy defibrillator. The literature review considers risk factors for formation of third-degree AV block during cardiac catheterization, methods of its prevention, as well as discusses the prognostic significance of catheter-induced conduction disorders, and indications for temporary and permanent cardiac pacing therapy.