November 1, 1997AJP Heart and Circulatory Physiology
Myocardial, skeletal muscle, and renal blood flow during exercise in conscious dogs with heart failure
Key result
Pacing-induced heart failure in conscious dogs significantly attenuated the increase in cardiac output during moderate treadmill exercise (3.0 L/min vs 7.9 L/min in the control state; P<0.05).
Population
7 conscious dogs instrumented with left ventricular micromanometer, ultrasonic crystals, left atrial and…
Comparison
Moderate treadmill exercise after induction of… vs Moderate treadmill exercise in the control state.
Design
Preclinical
Follow-up
23 +/- 6 days (duration of pacing)
Authors
Discussion
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Implication
Attenuated exercise cardiac output in this canine HF model does not inform practice; leaves open translation of mechanisms to human heart failure.
Structured PICO
P
Population
7 conscious dogs evaluated for hemodynamic and neurohumoral responses to moderate treadmill exercise before and after pacing-induced heart failure.
I
Intervention
Moderate treadmill exercise (5 km/h) after induction of heart failure by rapid left ventricular pacing at 250 beats/min for 23 +/- 6 days.
C
Comparator
Moderate treadmill exercise (5 km/h) in the control state (prior to heart failure induction).
O
Outcome
Hemodynamic responses (cardiac output, myocardial, skeletal muscle, and renal blood flows) and neurohumoral responses (plasma catecholamines and lactate) during exercise.surrogate
Main Result
Absolute Event Rate: 3% vs 7.9%
p-value: p=< 0.05
In a canine model of pacing-induced heart failure, the normal increase in cardiac output and regional blood flows during exercise is severely attenuated, accompanied by exaggerated neurohumoral activation.
Cite This Study
Neumann et al. (1997) studied Pacing-induced heart failure (n=7). Pacing-induced heart failure vs. Control state (pre-heart failure) was evaluated on Cardiac output during exercise (p=< 0.05). Pacing-induced heart failure in conscious dogs significantly attenuated the increase in cardiac output during moderate treadmill exercise (3.0 L/min vs 7.9 L/min in the control state; P<0.05).