Left ventricular hypertrophy and diastolic dysfunction: their relation to coronary heart disease

Area of Science:

• Cardiology
• Cardiovascular Physiology
• Pathophysiology

Background:

• Diastolic dysfunction is an early indicator in coronary heart disease.
• It can precede systolic dysfunction, ECG changes, and chest pain.
• The ischemic cascade involves oxygen imbalance and metabolic changes impacting diastolic function.

Purpose of the Study:

• To elucidate the mechanisms underlying left ventricular (LV) diastolic dysfunction.
• To differentiate between intrinsic and extrinsic factors contributing to diastolic disorders.
• To highlight the importance of understanding LV relaxation and filling for treatment.

Main Methods:

• The study reviews intrinsic LV abnormalities: impaired relaxation, hypertrophy, and asynchrony.
• It examines extrinsic factors: increased central blood volume and ventricular interaction.
• Collagen structure and concentration are identified as key determinants of tissue distensibility.

Main Results:

• Intrinsic factors include impaired LV relaxation, hypertrophy-induced stiffness, and increased asynchrony.
• Extrinsic factors involve elevated LV pressure from increased blood volume and pericardial restraint.
• Myocardial hypertrophy increases collagen concentration via reactive fibrosis, enhancing tissue stiffness.

Conclusions:

• Diastolic dysfunction arises from intrinsic LV abnormalities (relaxation, hypertrophy, asynchrony) and extrinsic factors (blood volume, pericardial restraint).
• Myocardial hypertrophy and fibrosis significantly increase LV stiffness and diastolic dysfunction.
• Enhanced understanding of LV diastolic function mechanisms is crucial for effective treatment strategies.