Non Technical Summary
Animal Health Component
Research Effort Categories
Goals / Objectives
Ascertain the temporal evolution of the spontaneous ventricular arrhythmia in affected dogs aged 4 weeks to 2 years, using 24-hour ambulatory electrocardiographic monitoring (Holter recordings). Determine if the spontaneous arrhythmia is exacerbated during sleep, using Holter monitoring in conjunction with simultaneous time-lapsed video recordings.
Determine if selected electrophysiologic indices are consistent with a suspectedautonomic imbalance. In that regard, we will: Determine if the corrected QT interval (QTc) is prolonged during sleep in affected dogs but not in unaffected, control dogs of the same breed. Compare heart rate variability during wakefulness and sleep in affected dogs that die versus those that survive, using Holter recordings. Determine if selected electrophysiological properties (e.g., atrial and ventricular refractory periods, AV conduction times) of affected dogs are abnormal, if the arrhythmia can be induced with programmed-stimulation protocols, and if arrhythmias occur with or without autonomic blockade and programmed stimulation when compared to unaffected control dogs. Determine if selected anatomical indices are consistent with an autonomic imbalance. In that regard, we will: Determine (noninvasively) if the distribution of PGyDTl-labeled metaiodobenzyl-quanidine (MIBG) uptake into
sympathetic nerves is different in affected versus unaffected animals.