DRUG SENSITIVITY AND ANTIARRHYTHMIC TREATMENTIN CHILDREN WITH IDIOPATHIC POLYMORPHICVENTRICULAR TACHYCARDIA

摘要

Background. Idiopathic polymorphic ventricular tachycardia (IPVT) in children is sometimes refractory for beta blocking agents and causes sudden death. Purpose. To investigate drug sensitivity and to evaluate the depletion of IPVT by antiarrhythmic agents. Patients and Methods. Three patients with IPVT were evaluated. The diagnosis was made at 7 years of age in average. Case land 2 had syncope on exercise, Case 3 complained of fatigue. Treadmill exercise test (TMT) was performed for the patients. The IPVT was induced in Case 1 and 2, but in Case 3, IPVT was also recognized at rest. Adenosine triphosphate, verapamil, propranolol and nicorandil (Case 3) were administered at onset of IPVT. The depletion of IPVT was evaluated with Holter ECG and the TMT. Result. IPVT is sensitive for propranolol in Case 1, and is sensitive for ATP and propranolol in Case 2. Case 3 shows no response for the three drugs, but is completely depressed by nicorandil. Nadolol is administered for Case 1 and its IPVT is controlled. IPVT is depleted by atenolol, verapamil and sotalol in Case 2. Case 3 is treated with empiric amiodarone but is refractory. Conclusion. Drug sensitivity test for IPVT does not always indicate the clinical results.