Conduction disorders in the postoperative period of cardiac surgery impede prompt clinical recovery and prolong hospitalization. The severity of this complication and the need of specific management justify a better identification of the predictive factors of its occurrence after cardiac surgery.

The aim of this study is to identify the predictive factors of pace maker dependency in these patients.

It is a 25 patients’ descriptive retrospective study carried out in the cardiology department of Charles Nicolle's Hospital in Tunis (Tunisia) between 1997 and 2014. We included all patients with a high-grade atrioventricular conduction disorder requiring definitive pacemaker implantation following cardiac surgery. We studied the preoperative clinical and electrocardiographic characteristics of patients, surgical indications, the type of postoperative conduction disorder and the moment of its occurrence. We also investigated the pacemaker dependency of each patient during his last follow-up.

The mean age was 44 years and 9 months. Our population was made of 14 men (56%) and 11 women. Correction of acquired heart disease was the dominant indication of operation (68%).

Preoperatively, 14 patients (56%) were in sinus rhythm.

A pacemaker implantation was indicted for a complete AV block in 23 patients (92%). Postoperatively, 10 patients (40%) had an immediate complete AV block. After pacemaker implantation and at the last follow-up, 9 patients were dependent of their pacemaker. The immediate occurrence of AV block is the only factor significantly correlated to the pacemaker dependency (P=0.041).

This study highlights the importance of a regular and pronged follow-up of patients undergoing cardiac surgery since conduction disorders may occur many years later.