The impact of paced QRS duration on the expression of genes related to contractile function of the left ventricle in chronically paced patients from the right ventricular apex.

Background: Right ventricular (RV) apex has proven to induce abnormal left ventricular (LV) activation pattern leading to pacing-induced cardiomyopathy (PICM) in a substantial percentage of paced patients. This study assessed the impact of paced QRS duration on the expression in the peripheral blood of sarcoplasmic reticulum calcium ATPase (SERCA) and investigated whether its width is related to the extend of LV remodelling.

Methods: We enrolled 52 consecutive patients with preserved ejection fraction (EF) who underwent pacemaker implantation for bradycardic indications.