Diastolic function in aortic valve disease: techniques of evaluation and pre-/postoperative changes

Area of Science:

• Cardiology
• Cardiovascular Physiology
• Biomedical Engineering

Background:

• Passive diastolic properties of the left ventricle are crucial for cardiac function.
• Myocardial hypertrophy, often due to pressure or volume overload, alters these properties.
• Diastolic function evaluation involves assessing ventricular and myocardial stiffness.

Purpose of the Study:

• To evaluate the impact of successful aortic valve replacement on passive diastolic properties of the left ventricle.
• To assess changes in myocardial stiffness and ventricular stiffness before and after valve replacement in patients with aortic valve disease.

Main Methods:

• Simultaneous high-fidelity pressure measurements and M-mode echocardiography were used.
• Left ventricular pressure-volume and stress-strain relationships were analyzed.
• Myocardial stiffness was calculated using a viscoelastic stress-strain relationship and nonlinear curve-fitting.

Main Results:

• Successful valve replacement significantly reduced pressure and volume overload.
• Left ventricular muscle mass index decreased significantly post-surgery in all patient groups.
• Myocardial stiffness showed a significant decrease after valve replacement, indicating improved diastolic function.

Conclusions:

• Successful aortic valve replacement improves passive diastolic properties of the left ventricle.
• Reduced myocardial stiffness is a key factor in improved diastolic function post-surgery.
• These findings highlight the importance of addressing valve disease for preserving diastolic mechanics.