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The influence of hypertrophy on myocardial function
European Journal of Cardiology
|May 1, 1976
Summary
Chronic left ventricular overload, whether pressure or volume, decreases contractility. Aortic valve replacement in stenosis patients reduces hypertrophy and improves heart function, indicating overload extent is key.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Left ventricular hypertrophy (LVH) can result from chronic pressure (PL) or volume overload (VL).
- Assessing left ventricular contractility is crucial for understanding heart function under stress.
Purpose of the Study:
- To compare left ventricular contractility in patients with pressure overload (PL) and volume overload (VL) hypertrophy.
- To evaluate the effects of aortic valve replacement on left ventricular hypertrophy and contractility.
Main Methods:
- Assessed basal left ventricular contractility using peak isovolumic velocity of shortening (Vpm), mean velocity of circumferential fiber shortening (mean VCF), and mean normalized systolic ejection rate (MNSER).
- Measured left ventricular muscle mass and contractile indexes pre- and post-aortic valve replacement in 15 patients with aortic stenosis.
Main Results:
- Both PL and VL groups showed decreased contractile indexes compared to controls, with extent of hypertrophy being more critical than overload type.
- Aortic valve replacement significantly reduced left ventricular muscle mass and improved Vpm, mean VCF, MNSER, and Vmax.
- Postoperative improvement in contractile function was observed, with abnormal responses to handgrip becoming normal in most patients.
Conclusions:
- The extent of left ventricular hypertrophy, rather than the type of chronic mechanical overload, significantly impacts contractility.
- Aortic valve replacement effectively reverses left ventricular hypertrophy and enhances both resting and exercise contractile function in patients with aortic stenosis.