Near R-on-T Phenomenon and Myocardial Capture Associated With a Novel Intravascular Lithotripsy System

BACKGROUND: Ventricular myocardial capture, or "shocktopics," is a known phenomenon during intravascular lithotripsy (IVL). While well documented with established systems, data on newer IVL platforms are limited. We report a case of near R-on-T phenomenon using a novel IVL system. CASE SUMMARY: A 74-year-old woman underwent percutaneous coronary intervention for a severely calcified left anterior descending artery lesion. During the application of a novel IVL system (Shunmei), frequent ventricular capture was observed. Several pulses occurred late in the T wave, representing a near R-on-T phenomenon. Despite these findings, the patient remained hemodynamically stable, and no sustained arrhythmias occurred. DISCUSSION: This case confirms that IVL-induced ventricular capture is a class effect rather than being device specific. The occurrence of near R-on-T capture highlights the potential for life-threatening arrhythmias, although the clinical course is typically benign. TAKE-HOME MESSAGES: Continuous electrocardiographic and hemodynamic monitoring are mandatory during IVL across all device platforms to detect myocardial capture. Operators should remain vigilant for R-on-T phenomena, which may pose a theoretical risk for malignant arrhythmias. The development of electrocardiogram-synchronized (gated) IVL delivery systems may represent a critical future step in eliminating the risk of R-on-T pulses and enhancing procedural safety.