Atrial pacing at the maximum ventricular follow rate prolonged the duration that repetitive ventricular responses could be elicited to 70 minutes, compared to 22 minutes in sinus rhythm.
Does atrial pacing at maximum ventricular follow rate affect the duration of electrically induced repetitive ventricular responses in digitalized dogs?
Heart rate acceleration prolongs the period during which repetitive ventricular responses can be elicited in digitalis intoxication, likely due to intracellular potassium loss.
Absolute Event Rate: 70% vs 22%
After recovery from acetylstrophanthidin-induced ventricular tachycardia, a repetitive ventricular response (RVR) following a single diastolic stimulus could be elicited for 22 minutes. With atrial pacing at the maximum ventricular follow rate, RVR was obtainable for 70 minutes. A pause in pacing also evoked a ventricular ectopic beat; however, this persisted for only 27 minutes. The minimum heart rate required for RVR was always less than the minimum rate required for pause-induced ectopic beats. Extrasystoles following a pause during pacing, RVR in sinus rhythm, and RVR during rapid heart rates represent decreasing levels of ventricular automaticity corresponding to progressive dissipation of digitalis intoxication. The underlying mechanism for RVR probably is due to net loss of intracellular potassium, which can be induced both by digitalization and by rate acceleration.
Hagemeijer et al. (Tue,) conducted a other in Digitalis intoxication. Atrial pacing (heart rate acceleration) vs. Sinus rhythm was evaluated on Duration of elicitable repetitive ventricular response (RVR). Atrial pacing at the maximum ventricular follow rate prolonged the duration that repetitive ventricular responses could be elicited to 70 minutes, compared to 22 minutes in sinus rhythm.