Case Report: Iatrogenic left main coronary artery dissection during premature ventricular contraction ablation managed with emergent coronary artery bypass grafting.

Premature ventricular contraction (PVC) ablation via retrograde aortic access is generally safe, but iatrogenic left main coronary artery (LMCA) dissection is a rare and potentially catastrophic complication. This case adds to the literature by describing LMCA dissection during PVC ablation managed with primary emergent coronary artery bypass grafting (CABG) rather than percutaneous coronary intervention (PCI), guided by intravascular ultrasound (IVUS) and Heart Team decision-making. A 60-year-old man with symptomatic, medication-refractory monomorphic PVCs (17.4% burden with nonsustained ventricular tachycardia) and preserved left ventricular function underwent elective PVC ablation via retrograde aortic access. Shortly after successful ablation at the aortomitral continuity, he developed sudden excruciating chest pain and anterior ST-segment elevation with hemodynamic instability. Emergent coronary angiography suggested LMCA dissection with occlusion of the proximal left anterior descending (LAD) artery and near-occlusive involvement of the proximal ramus intermedius. Balloon angioplasty restored limited flow, and intravascular ultrasound (IVUS) demonstrated an ostial LMCA dissection extending into both branches with true lumen compression and a heavily calcified proximal LAD segment, making complex LMCA bifurcation stenting high risk. After rapid Heart Team consultation, the patient underwent emergent CABG with left internal mammary artery (LIMA)-LAD and saphenous vein grafts to the ramus intermedius branch of the LMCA, along with intra-aortic balloon pump support. He was extubated and weaned off mechanical support on postoperative day 1 and discharged home on day 8; follow-up at 3 months revealed reduced ejection fraction (25%-30%) managed by advanced heart failure services. This case highlights mechanical LMCA ostial injury as a rare complication of retrograde PVC ablation and highlights the importance of immediate recognition of ST-segment elevation, emergent coronary angiography, and early involvement of a multidisciplinary Heart Team. IVUS is crucial to define dissection extent. When ostial or bifurcation LMCA dissection occurs in the setting of hemodynamic compromise and calcified, stent-unfavorable anatomy, guideline-directed emergent CABG can provide definitive and potentially life-saving revascularization.