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Myopotential Inhibition of Unipolar QRS‐inhibited (VVI) Pacemakers, Assessed by Ambulatory Holter Monitoring of the Electrocardiogram
Author(s) -
BREIVIK KJELL,
OHM OLEJØGEN
Publication year - 1980
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.1540-8159.1980.tb05257.x
Subject(s) - medicine , asystole , cardiology , qrs complex , holter monitor , ambulatory , atrioventricular block , artificial cardiac pacemaker , bradycardia , sick sinus syndrome , anesthesia , electrocardiography , heart rate , blood pressure
Seventy‐four patients with unipolar QRS‐inhibited pacemakers (VVI) were Holter monitored to assess the occurrence of pacemaker inhibition caused by skeletal muscle potentials during daily activities. Fifty patients had high‐grade atrioventricular block and 24 had sinoatrial disease. Chest wall stimulation prior to monitoring revealed asystole of > 4 seconds duration in 22 patients, and ventricular rates between 25 and 56 beats per minute in 52 patients. Fifty‐one patients (69%) had one or more episodes of pacemaker inhibilion from myopotentials. Inhibition occurred in all types of pacemakers studied, but was most frequent and of longest duration in patients with Siemens‐Elema 207/70 (13/14 patients), Cordis OmniStanicor (6/7 patients), CPI Microlith (5/6 patients), and Medtronic 5945 (8/30 patients). This was not unexpected considering the filter characteristics of the pacemakers. Nine patients (12%) presented symptoms which might be ascribed to pacemaker inhibition. The longest asystole observed was 3.2 s. Seven patients had pacemaker spikes falling on or near T‐waves of spontaneous heart beats because their pacemakers had been rendered refractory by myopotentials. No serious arrhythmias were seen during episodes of pacemaker inhibition or interference. More emphasis should be put on the improvement of filter characteristics of unipolar VVI‐pacemakers. Pacemaker patients with symptoms of myopotential inhibition should be equipped with either a bipolar or ventricular triggered (VVT) pacemaker or with a sensitivity and/or pacing mode programmable pacemaker.