Holter monitoring in conscious dogs. Assessment of arrhythmias occurring in the late reperfusion phase after coronary occlusion.
Arrhythmias occurring in the late reperfusion phase, i.e., up to 3 days after episodes of 5 min, 15 min, and 4 hr of coronary occlusion (CAO), were investigated in six conscious, chronically instrumented dogs using the Holter monitoring technique. The arrhythmic ratio (AR% = number of premature ventricular complexes x 100/total number of beats) of a 24-hr preocclusion control record was 0.004% and did not differ from the values assessed for day 1 (0.004%) and 2 (0.001%) of the late reperfusion phase after 5 min CAO. After 15 min, CAO increased, but insignificantly elevated AR values were registered on days 1 (2.5%), 2 (0.26%), and 3 (0.1%) of the late reperfusion phase. On day 1 of the late reperfusion phase after 4 hr CAO, the AR increased markedly to 75%. On day 2 of this phase, the AR was lower (20%) but still significantly elevated. On day 3, the AR was 3.5%, a value still markedly, although not significantly, above the preocclusion control level. We conclude that in conscious dogs, arrhythmias in the late reperfusion phase do not occur after 5 min CAO. However, after 15 min CAO and, especially, after 4 hr CAO, an increase in arrhythmic activity occurs in the late reperfusion phase and gradually declines towards the preocclusion control level over a period of 3 days. Thus, it could be demonstrated that the long-term assessment of reperfusion arrhythmias by ECG monitoring using the Holter technique is feasible in conscious dogs. This method represents a promising approach to clinically relevant experimental investigations on the therapeutic efficacy of a new antiarrhythmic drugs.
Krumpl
G
G
Pharmakologisches Institut, Universität Wien, Vienna, Austria.
Todt
H
H
Schunder-Tatzber
S
S
Raberger
G
G
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D003327:Coronary Disease / Q000503:physiopathology*; D003331:Coronary Vessels / Q000502:physiology; D004285:Dogs; D015716:Electrocardiography, Ambulatory; D005260:Female; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology*; D013997:Time Factors