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The Sympathetic Imbalance Hypothesis of QT Interval Prolongation
Author(s) -
ABILDSKOV J.A.
Publication year - 1991
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.1991.tb01332.x
Subject(s) - prolongation , stellate ganglion , qt interval , medicine , repolarization , long qt syndrome , cardiology , stimulation , electrocardiography , anesthesia , electrophysiology , alternative medicine , pathology
Sympathetic Imbalance. The demonstration of QT interval prolongation after left stellate ganglion stimulation led to the successful trial of left cervicothoracic sympathectomy for the control of arrhythmias in long QT syndromes. Based on those findings, sympathetic imbalance with excessive left‐sided effects became widely regarded as the mechanism of QT prolongation and arrhythmias in the syndromes. Prolongation of the interval was attributed to regional reduction of repolarization durations with exposure of previously cancelled electrocardiographic effects and arrhythmias to nonuniform recovery of excitability permitting reentrant excitation. Subsequent findings have not, however, supported this hypothesis. It has been shown that QT prolongation following left stellate ganglion stimulation is transient and unlikely to account for the sustained prolongation in the syndromes. It has also been shown that QT prolongation is not unique for left stellate stimulation and also occurs transiently after right stellate stimulation or bolus injections of catecholamines. It remains possible that sympathetic imbalance in the form of deficient right‐sided sympathetic effects on the heart that experimentally results in prolonged repolarization and sustained QT interval prolongation is a mechanism in long QT syndromes. ECG mapping suggests prolongation of repolarization in the region normally innervated by the right stellate ganglion and a plausible mechanism of torsade de pointes based on regionally disparate recovery has been proposed.