Related Experiment Videos
Left ventricular dimensions and function during exercise in dogs with chronic right ventricular pressure overload
The American Journal of Cardiology
|April 1, 1984
Summary
Pulmonary artery constriction in dogs revealed normal left ventricular function at rest. However, exercise induced regional abnormalities in left ventricular contraction, particularly in the septal-lateral dimension, due to reduced septal contribution.
Area of Science:
- Cardiology
- Physiology
- Animal Models
Background:
- Chronic right ventricular pressure overload can affect left ventricular function.
- Understanding the impact of pulmonary artery constriction on cardiac mechanics is crucial.
Purpose of the Study:
- To investigate left ventricular (LV) dimensions and shortening at rest and during exercise after pulmonary artery (PA) constriction.
- To determine if chronic right ventricular (RV) pressure overload induces regional LV contractile abnormalities during exercise.
Main Methods:
- Conscious dogs underwent PA constriction via an inflatable cuff.
- LV dimensions and segment shortening were measured using ultrasonic crystals.
- RV pressures were monitored before and after PA constriction at rest and during treadmill exercise.
Main Results:
- PA constriction significantly increased RV pressures at rest and during exercise.
- LV function at rest remained normal, with decreased end-diastolic dimensions.
- During exercise, septal-lateral LV shortening decreased significantly, while other segments showed normal shortening.
Conclusions:
- Chronic RV pressure overload does not impair resting LV function.
- Exercise in the setting of RV pressure overload can induce regional LV contractile abnormalities.
- Reduced contribution of the ventricular septum to LV ejection may mediate exercise-induced abnormalities.