miR Profile of Chronic Right Ventricular Pacing: a Pilot Study in Children with Congenital Complete Atrioventricular Block

Chronic ventricular pacing can lead to pacing-induced cardiomyopathy (PICM). Clinical data alone is insufficient to predict who will develop PICM. Our study aimed to evaluate the circulating miR profile associated with chronic right ventricular pacing in children with congenital complete AV block (CCAVB) and to identify candidate miRs for longitudinal monitoring. Clinical data and blood were collected from chronically paced children (N= 9) and compared with non-paced controls (N = 13). miR microarrays from the huffy coat revealed 488 differentially regulated miRs between groups. Pathway analysis predicted both adaptive and maladaptive miR signaling associated with chronic pacing despite preserved ventricular function. Greater profibrotic signaling (miRs-92a, 130, 27, 29) and sodium and calcium channel dysregulation (let-7) were seen in those paced > 10 years with the most dyregulation seen in a patient with sudden death vs. those paced < 10 years. These miRs may help to identify early adverse remodeling in this population.

Automated summary

Chronic ventricular pacing in children with congenital complete AV block (CCAVB) can lead to pacing-induced cardiomyopathy (PICM). This study evaluated the miR profile associated with chronic right ventricular pacing and identified potential miRs for longitudinal monitoring. The results showed differentially regulated miRs between paced children and controls, with both adaptive and maladaptive miR signaling predicted. Greater profibrotic signaling and sodium and calcium channel dysregulation were observed in patients paced for more than 10 years, particularly in a patient with sudden death. These miRs may be useful for early identification of adverse remodeling.