Normal age-related changes in left ventricular function: Role of afterload and subendocardial dysfunction

Area of Science:

• Cardiology
• Cardiovascular Physiology
• Medical Imaging

Background:

• Normal aging involves changes in vascular and ventricular properties.
• The impact of these changes on left ventricular function remains unclear.

Purpose of the Study:

• To investigate age-related changes in left ventricular function.
• To determine the relationship between vascular properties and left ventricular function during aging.

Main Methods:

• Cardiac magnetic resonance (MR) imaging in 96 healthy subjects (20-79 years) measured global function, diastolic function (E/A ratio), and torsion to shortening ratio (TSR).
• Phase contrast MR imaging and Vicorder device assessed central aortic pulse wave velocity (PWV) and carotid-femoral PWV.
• MR tagging quantified epicardial torsion and endocardial circumferential shortening.

Main Results:

• Age-related declines were observed in E/A ratio (diastolic function) and cardiac output (global systolic function).
• End-diastolic volume index (structure) and TSR (systolic strain) also showed significant age-related changes.
• Increased TSR correlated with reduced cardiac output and end-diastolic volume index.
• Afterload (effective arterial elastance) was linked to reduced E/A ratio, while vascular stiffness was not significantly related to measured ventricular parameters.

Conclusions:

• In healthy aging, afterload, not vascular stiffness, is associated with diastolic dysfunction.
• Increased TSR, indicating relative subendocardial dysfunction, plays a role in age-related decreases in cardiac output and end-diastolic volume index.