August 1, 1991Cardiovascular Research
Electrophysiological effect of varied rate and extent of acute in vivo left ventricular load increase
Key result
Rapid transient proximal aortic occlusion increased the frequency of ventricular ectopy compared to slow occlusion (87% vs 56%, p=0.01) in adult dogs.
Population
10 anaesthetised adult mongrel dogs (20-25 kg)
Comparison
Transient proximal aortic occlusion vs Preocclusion values; slow occlusions compared to…
Design
Preclinical
Authors
Discussion
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Implication
Hypothesis-generating for stretch-induced ectopy; human studies needed before clinical relevance.
Structured PICO
P
Population
10 adult mongrel dogs (20-25 kg) undergoing transient proximal aortic occlusion to evaluate the effects of acute left ventricular load increase.
I
Intervention
Transient proximal aortic occlusion (fast and slow occlusions, under innervated and denervated conditions)
C
Comparator
Preocclusion values; slow occlusions compared to fast occlusions
O
Outcome
Changes in monophasic action potential duration (MAPd), afterdepolarisations, and arrhythmogenicity (ventricular ectopy)surrogate
Main Result
Absolute Event Rate: 87% vs 56%
p-value: p=0.01
In a canine model, the speed rather than the magnitude of acute left ventricular load increase is the primary driver of ventricular ectopy, suggesting a mechanism of stretch-induced automaticity.
Cite This Study
Calkins et al. (1991) studied this question. Rapid transient proximal aortic occlusion vs. Slow transient proximal aortic occlusion was evaluated on Ventricular ectopy (p=0.01). Rapid transient proximal aortic occlusion increased the frequency of ventricular ectopy compared to slow occlusion (87% vs 56%, p=0.01) in adult dogs.