Sino-atrial nodal artery occlusion causing acute sinus node dysfunction after percutaneous coronary intervention: Case report and systematic review.

Background: New antithrombotic medications and improved stent designs have reduced branch occlusion, although the sino-atrial nodal artery (SANA) may still be occluded after a percutaneous coronary intervention (PCI), causing sinus node dysfunction (SND). Ischemic sinus nodes are usually asymptomatic but can cause sinus arrest sometimes requiring pacemaker placement. In rare cases, junctional escape rhythms, a manifestation of sinus exit blocks after PCI, can predict cardiogenic shock.

Methods: We present a case study of a patient who underwent bifurcation PCI to the LMCA to the LCX but subsequently developed cardiogenic shock as a result of SND, a junctional escape rhythm required substantial inotropic support. This case offers an exemplification of a sparsely documented, yet infrequent manifestation of iatrogenic ischemic SND at an unorthodox site, the confluence of the LMCA-LCX. In addition, we conducted a comprehensive analysis of 22 scholarly works pertaining to the subject of sinus node dysfunction (SND) subsequent to PCI resulting from ischemia caused by stenosis or occlusion of the SANA.

Results: RCA was responsible for 96.1% of SND cases, whereas LCX was responsible for 3.9%. SND was asymptomatic in 49.3% of cases and junctional escape rhythm in 37.6% of symptomatic cases. 28% needed a temporary transvenous pacemaker, while 7.8% needed a permanent one. Interventional management recanalized the SANA in 5.2% of patients, restoring flow.

Conclusion: Transient sino-atrial node ischemia after PCI can cause acute SND. Before stent implantation, doctors should consider SND. Complete plaque evaluation around the SANA is needed before choosing the best PCI procedure.