Effect of direct, reflex and exercise-provoked increases in sympathetic tone on idiopathic ventricular tachycardia.
Publication/Presentation Date
6-1-1992
Abstract
Exercise treadmill testing and direct enhancement of sympathetic influence with agents such as isoproterenol are often used to reproduce ventricular tachycardia (VT). The cardiac effects of, and arrhythmia responses to, graded exercise, isoproterenol infusion and lower body negative pressure (the latter 2 with and without atrial and ventricular stimulation) were studied in 11 patients with idiopathic VT. During maximal exercise, substantial increases in heart rate and blood pressure occurred, but only 2 of 9 exercised patients had VT (during recovery in both). During programmed stimulation alone, VT was initiated in 6 patients. During maximum levels of lower body negative pressure (-60 cm of water in most), mean systolic blood pressure decreased by 10 mm Hg, heart rate increased by 15 beats/min, and ventricular refractory period decreased by 10 ms. In 4 patients VT occurred spontaneously during lower body negative pressure; in 2, lower body negative pressure was the only intervention producing VT. During isoproterenol infusion VT occurred spontaneously in 2 patients; both had VT initiated during other interventions. Lower body negative pressure and isoproterenol increased VT rate, but did not prolong it. It is concluded that there is significant variability in arrhythmia responses to sympathetic augmentation, suggesting that additional covariables such as parasympathetic input and ventricular volume may also have a role in arrhythmia occurrence.
Volume
69
Issue
17
First Page
1433
Last Page
1438
ISSN
0002-9149
Published In/Presented At
Kienzle, M. G., Martins, J. B., Constantin, L., & Aschoff, A. (1992). Effect of direct, reflex and exercise-provoked increases in sympathetic tone on idiopathic ventricular tachycardia. The American journal of cardiology, 69(17), 1433–1438. https://doi.org/10.1016/0002-9149(92)90896-7
Disciplines
Medicine and Health Sciences
PubMedID
1590233
Department(s)
Department of Medicine
Document Type
Article