An unconventional dose of epinephrine for a diagnostic test of catecholaminergic polymorphic ventricular tachycardia: A case report

Abstract

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare heritable arrhythmogenic disease, and the Mayo Clinic protocol-guided epinephrine test is commonly used for diagnostic purposes. Whether the Mayo Clinic protocol is enough for patients who are insensitive to catecholamine remains an unknown question. Our patient was a19-year-old female who presented with recurrent stress-induced syncope and was saved by cardiopulmonary resuscitation. The initial physical examination and complementary tests (ECG, blood laboratory, cardiac ultrasound, and cranial magnetic resonance angiography) showed no abnormalities on admission. Treadmill exercise testing shows non-sustained and polymorphic tachycardia. A subsequent epinephrine test was performed, and polymorphic ventricular tachycardia was not induced until using a high dose of epinephrine above Mayo Clinic protocol. Therefore, it is suggested that an unconventional dose of epinephrine may be needed fordiagnostic tests of CPVT for some insensitive individuals.