Acute myocardial infarction (MI), particularly inferior MI, may be complicated by the occurrence of third-degree atrioventricular (AV) block. This block is usually temporary, but in some cases it will require a permanent pacemaker (PPM). We report a case of inferior MI and primary percutaneous coronary intervention (PCI) of the right coronary artery (RCA). The third-degree AV block persisted as a result of the no-reflow phenomenon after PCI on the RCA, only to resolve after a second PCI on the left anterior descending (LAD). Improvement in the perfusion of the AV node via the RCA after PCI on the LAD may be able to explain this finding. This case suggests that complete revascularization should be achieved before deciding on the implantation of a PPM.
Keywords: AV-node physiology; Case report; No-reflow phenomenon; Pacemaker; Primary PCI; ST-elevation MI; Third-degree atrioventricular block.