Atropine in Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

Inclusion Criteria: * Age \>/= 6 years * Able to provide written informed consent * Clinical diagnosis of CPVT * Able to exercise on a treadmill * Successful completion of a minimum of 2 exercise stress tests without adverse events Exclusion Criteria: * Contraindication to treadmill stress testing according to Vanderbilt University Medical Center's clinical protocols (unstable angina, decompensated congestive heart failure, severe hypertension (≥ 170/90 mmHg), acute myocardial infarction (\<4 days), moderate to severe aortic stenosis, acute pulmonary embolism, severe pulmonary hypertension, outflow tract obstruction, hypertrophic cardiomyopathy, left main coronary stenosis, left bundle branch block) * Females who are pregnant * In the judgement of the investigator, any clinically significant ongoing medical or surgical condition that might jeopardize the subject's safety or interfere with the conduct of the study