Abstract
Background
Pacemaker (PM) has been an effective treatment in the management of patients with brady-arrhythmias. Chronic RV pacing may cause electrical and mechanical dyssynchrony which lead finally to reduced left ventricular ejection fraction (LVEF). This deterioration of LVEF has been defined as pacemaker induced cardiomyopathy (PICM). The incidence of PICM was described by many studies and ranged between 10% to 26%. The predictors for PICM have not been well studied. These studies were limited by variation in follow-up period and definition of PICM.
Objective
to study the incidence and predictors of PICM in patients who underwent pacemaker implantation in Ain shams University hospital.
Patients and Methods
This retrospective study included 160 patients who underwent single or dual chamber pacemaker implantation in Ain shams university hospital between 2010 and 2017 with the mean period 4.7±2.0 years. Implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT) patients were excluded. Individuals who had baseline transthoracic echocardiography (TTE) with normal LVEF ≥ 50% before implantation were included.
Results
This study included 160 patients who had single or dual chamber pacemaker implantation between 2010 and 2017. 45% were males and 55% were females, mean age was 55.5 years. It showed that the incidence of PICM is 7.5%. Wider native QRS durations, particularly >140 ms (p < 0.001), wider pQRS duration >150 ms (p < 0.001), Low normal ejection fraction <56 % preimplantation (p = 0.023) and increased LVEDD>53 mm and LVESD>38 mm (p < 0.001) are predictors for the development of PICM. Female gender was independent predictor for PICM (p = 0.058). There was no association between burden of right ventricular pacing (p = 0.782) or pacing site (p = 0.876) with the risk of development of left ventricular dysfunction.
Conclusion
The incidence of right ventricular pacing-induced left ventricular dysfunction is not uncommon, with an observed incidence of 7.5% in the current study. Wider native and paced QRS durations, Low normal ejection fraction (< 56 %) pre-implantation and increased LVEDD /LVESD post implantation are the most important predictors for the development of PICM.
List of abbreviations
PM= pacemaker, RV= Right ventricle, PICM = pacemaker induced cardiomyopathy, TTE= transthoracic echocardiography, DM= Diabetes Mellitus, HTN= Hypertension, BMI= Body Mass index, pQRSd= Paced QRS duration, SWMA= segmental wall motion abnormality, AF= Atrial fibrillation, SSS= Sick sinus syndrome, CHB= Complete heart block, AVB= Atrioventricular block, LVEF = left ventricular ejection fraction, LVEDD= Left ventricular end diastolic diameter, LVESD= Left ventricular end systolic diameter, ms= milli second.
Risk Stratification of Future Left Ventricular Dysfunction for Patients with Indications for Right Ventricular Pacing due to Bradycardia
