Inappropriate ICD therapy due to proarrhythmic ICD shocks and hyperpolarization.
A 50-year-old man with an ischemic cardiomyopathy underwent ICD implantation for inducible ventricular fibrillation (VF). Sixteen months later he experienced inappropriate ICD therapy due to atrial fibrillation with a rapid ventricular response. The initial shock resulted in the initiation of VF (proarrhythmia) and the patient received an additional shock converting his rhythm to an idioventricular rhythm with a cycle length of 490 ms (122 beats/min). Due to lead hyperpolarization, the device oversensed ventricular events and the patient subsequently received additional shocks.
Department of Medicine, UMass Memorial Medical Center, Worcester, Massachusetts 05181, USA.
Edward
E
Healy
Sanjeev
S
Goyal
Clifford
C
Browning
Dionyssis
D
Robotis
Karthick
K
Ramaswamy
Karen
K
Rofino-Nadoworny
Lawrence
L
Rosenthal
D001281:Atrial Fibrillation / Q000628:therapy; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004562:Electrocardiography; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000209:etiology / Q000628:therapy