Introduction: Knowledge of factors causing pacing-induced cardiomyopathy
(PICM) is incomplete. We sought to estimate the incidence and
predisposing factors for PICM in South Asian population and evaluate if
the risk they portend adds up. Methods: Consecutive patients with
preserved LVEF undergoing pacemaker (PM) implantation between 2012 and
2018 were analysed. Results: A total of 749 patients (68.4% male; mean
age 59.2 ± 14.08 years) were included in the analysis. PICM developed in
74 (9.9 %) patients over a median follow up of 2.2 years (IQR 1.1-3.2).
Pre-implant LVEF, paced QRS duration and RV pacing burden were
independent predictors of PICM. Using 90% specificity cut-off values
for LVEF and paced QRS, and the value separating lowest tertile of RV
pacing from the higher tertiles, three risk factors were identified: (i)
baseline LVEF < 55%, (ii) paced QRS duration >
160 msec, and (iii) RV pacing burden > 33%. Patients with
two or more risk factors were at the highest risk (OR 11.62, 95% CI
4.62 - 29.21, p-value < 0.001) for developing PICM while those
with one risk factor had an intermediate risk (OR 3.89, 95% CI 1.62 -
9.34, p-value 0.002) when compared to those without any risk factors.
Conclusion: Low-normal baseline LVEF, wider paced QRS and higher RV
pacing burden independently predicted the development of PICM. The
presence of ≥2 factors increased the odds of PICM, twelve-fold. Striving
to get a narrower paced QRS, the only modifiable of the three risk
factors, will help mitigate the development of PICM.