Burst Exercise Testing Can Unmask Arrhythmias in Patients With Incompletely Penetrant Catecholaminergic Polymorphic Ventricular Tachycardia.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is characterized by cardiac arrest during sudden exertion. However, standard exercise stress testing (EST) lacks sensitivity, leading to misdiagnosis and undertreatment. After a nondiagnostic standard gradual EST, we report 6 patients who underwent a novel burst exercise test characterized by sudden high workload at the outset of testing. In 5 of 6 patients, the burst EST induced new and more complex arrhythmias versus standard EST, which compelled medication initiation in 3 patients. We postulate that this simple EST modification better mimics a typical CPVT triggering event and could improve diagnostic sensitivity and therapeutic decision making.
Competing Interests: Funding Support and Author Disclosures Dr. Roston is funded by the University of British Columbia Clinician Investigator Program and Friedman Scholars in Health Program and the George Mines Traveling Fellowship in Cardiac Electrophysiology. The study was supported by the Rare Disease Foundation “Innovative Therapies” Grant (to Drs. Roston, Santanani, and Krahn). Dr. Krahn has received support from the Sauder Family and Heart and Stroke Foundation Chair in Cardiology (Vancouver, British Columbia, Canada), the Paul Brunes Chair in Heart Rhythm Disorders (Vancouver, British Columbia, Canada), and the Paul Albrechtson Foundation (Winnipeg, Manitoba, Canada). The Hearts in Rhythm Organization (Dr. Krahn, Principal Investigator), which is funded by the Canadian Institute of Health Research (RN380020 – 406814), and the Heart and Stroke Foundation (G150008870 [Dr. Santanani, Principal Investigator]), supported the work. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
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