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Valsalva‐Induced Variations in the Intracardiac Signal
Author(s) -
ROSENQVIST M.,
LAGERGREN H.,
STRANDBERG H.,
EDHAG O.
Publication year - 1985
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1985.tb05905.x
Subject(s) - intracardiac injection , medicine , valsalva maneuver , cardiology , blood pressure
Variations in the intracardiac signal may substantially effect the sensing function of cardiac pacemakers. As the Valsalva maneuver causes a change in heart volume, its effect on the intracardiac signal was studied in seven patients with an adequate escape rhythm who had permanent ventricular pacemakers. During generator replacement, they were asked to perform a standardized Valsalva maneuver. An increase from the baseline amplitude ranging from 5% to 70% was noted during forced expiration against the closed glottis. There was a decrease from the baseline ranging from 15% to 50% after terminafion of this maneuver. Similar changes were noted for the rate of voltage change (slew rate). The magnitude of these alterations was most pronounced in patients with comparatively low intracardiac amplitudes. Because marked changes in the intracardiac signal can result from the Valsalva maneuver, it might be an important source of undersensing among patients with permanent pacemakers.