Association of site of right coronary artery occlusion and recovery of complete heart block in acute inferior wall myocardial infarction undergoing primary angioplasty: The RECOVER-CHB study.

AIM: Complete heart block (CHB) complicates a significant fraction of acute inferior wall ST-elevation myocardial infarctions (IW-STEMI) and is associated with high morbidity. Relationship between right coronary artery (RCA) occlusion site and CHB recovery remains incompletely characterised in the primary percutaneous coronary intervention (PCI) era. The objective of this study was to evaluate whether the site of RCA occlusion (ostio-proximal/mid versus distal) independently predicts the rate and duration of CHB recovery following primary PCI in acute IW-STEMI.

METHODS

This prospective observational study enrolled 100 patients with acute IW-STEMI with CHB who underwent primary PCI at a tertiary care centre in India. Patients were divided into Group 1 (ostio-proximal/mid RCA occlusion, n = 62) and Group 2 (distal RCA occlusion, n = 38). In-hospital serial electrocardiogram monitoring was performed till recovery/permanent pacing.

RESULTS

The overall CHB recovery rate was 91%, with no significant difference between Group 1 (88.71%) and Group 2 (94.74%, p = 0.48). Median recovery time was 12 h in both groups (p = 0.21). Independent predictors of reduced recovery included wide complex escape rhythm and associated right ventricular myocardial infarction. Multivariate analysis identified wide QRS pattern, higher baseline creatinine, development of acute kidney injury and heart failure as independent factors delaying CHB recovery in this critical patient subset.

CONCLUSION

Angiographic site of RCA occlusion does not independently predict CHB recovery after primary PCI. Prompt revascularization, metabolic status, and haemodynamic stability are key determinants of conduction recovery, supporting an expectant management strategy with serial electrocardiogram monitoring rather than early permanent pacing based solely on lesion location.