Electrical Storm Triggered by Conus Branch Occlusion During Elective Percutaneous Coronary Intervention in Very Severe Aortic Stenosis: Rescue With Balloon Aortic Valvuloplasty Under Venoarterial Extracorporeal Membrane Oxygenation

We report a case of very severe aortic stenosis (AS) in which side-branch occlusion during elective percutaneous coronary intervention (PCI) precipitated life-threatening ventricular arrhythmias and hemodynamic collapse. The patient was a 72-year-old man with very severe AS who was scheduled to undergo a valve intervention. Preprocedural coronary angiography revealed a significant, newly developed stenosis in the right coronary artery, and an elective PCI was performed prior to valve treatment. Following intravascular lithotripsy and drug-eluting stent implantation, occlusion of the conus branch occurred, triggering recurrent ventricular tachycardia and ventricular fibrillation. Despite initiation of venoarterial extracorporeal membrane oxygenation and intra-aortic balloon pump support, the patient's hemodynamic status did not improve. Because excessive afterload due to very severe AS was considered the principal pathophysiological mechanism, emergency balloon aortic valvuloplasty was performed. This resulted in rapid hemodynamic stabilization and complete resolution of ventricular arrhythmias. This case illustrates that even a minor side-branch occlusion during PCI can lead to catastrophic outcomes in patients with very severe AS. Furthermore, it highlights that mechanical circulatory support alone may be insufficient, and that prompt relief of valvular obstruction is essential. Careful consideration of the indications and sequence of coronary intervention through discussions with a heart team is warranted for patients with very severe AS.