Reversible acute Fontan circulation failure secondary to retrogradely conducted junctional rhythm: clinical echocardiographic correlation

Abstract

BackgroundSequential atrioventricular activation plays a critical role in the physiology of Fontan circulation. Although bradycardia is usually well tolerated, retrogradely conducted junctional rhythm may acutely increase atrial pressure impairing cardiac output. Echocardiographic evaluation can reveal clues of this hemodynamic condition. The clinical impact of arrhythmic disturbance on the follow up of patients who had undergone total cavo-pulmonary connection is well recognized but the role of, transient periods of retrogradely conducted junctional rhythm on the immediate post-operative course is less defined.Case presentationWe describe two cases of acute Fontan circulatory failure due to postoperative retrogradely conducted junctional escape rhythm despite an adequate heart rate and circadian variation. The patients rapidly improved after atrial pacing, allowing discharge with a minimal dose of diuretic.ConclusionIn the absence of any hemodynamic target, hearth rhythm should be systematically checked after TCPC irrespective of adequacy of heart rate. Likewise, efficiency of temporary atrial pacing should be granted and surgeons should have a low threshold for epicardial lead implantation.