Perioperative Predictors of Conducting System Disorder after Open Heart Surgery that may Indicate for Permanent Pacemaker Implantation

Abstract Background: Cardiac conduction abnormalities have been observed following heart surgery. Although transient bradyar-rhythmias resolve within a few days of surgery, persistent conduction disturbances necessitating permanent pacemaker implantation (PPI) occur in a significant number of patients undergoing traditional heart surgery. Aim of Study: To investigate perioperative predictors of conducting system disorder after open heart surgery, indications and prevalence for permanent pacemaker implantation after open heart surgery. Patients and Methods: The present retrospective study was conducted on 134 adult patients who underwent various surgeries (open-heart surgery; all CABG operations, CABG and valve operations, valve only operations and other opera-tions including modified Bentall's procedure, excision of atrial myxomas, personalized external aortic root. All redo and emergency operations at Ain Shams University Hospital, Cardiothoracic Surgery Department (cardiothoracic Academy) during 6 months While patients with congenital heart disease (or post congenital heart surgery), patients who already had a PPM or implantable cardioverter defibrillator (ICD) and patients with an indication for PPM were excluded from the study. Results: We found that 30 patients (22%) had arrhythmia (off bypass rhythm), these arrhythmias were LBBB in one patient (1%), RBBB in 4 patients (5%), AF in 14 patients (10%) and complete heart block with external transient pace-maker inserted in 11 patients (8%). While with extended ICU follow up (Morbidity) we found that PPM in our study were all post valve replacement, 4 patients with a PPM implanted postoperatively underwent aortic valve replacement either as a stand-alone procedure or in conjunction with other cardiac surgical procedures for pathology like HOCM, Aortic root abscess, Aortic ANNURYSIM and sever calcific aortic sten-oses. That may be related to the extra surgery itself or the time consumed to do so in the AVR surgeries, two of them were mitral valve replacement both with Sorin metallic valve and one patient after discharge from hospital through regular follow-up with no mortality.
Conclusion: With close monitoring during an extended ICU stay, patients with complete heart block were paced with an external transient pacemaker in 8% of cases. The incidence of severe postoperative bradyarrhythmia requiring permanent pacemaker insertion was found to be 5% and varies by type of surgery, with valve replacement being the most common due to conduction system trauma.