Coronary flow and left ventricular diastolic function in aortic regurgitation

Area of Science:

• Cardiovascular Medicine
• Echocardiography
• Cardiac Physiology

Background:

• Aortic regurgitation (AR) can impair myocardial perfusion, potentially due to abnormal coronary perfusion pressure, ventricular hypertrophy, or diastolic dysfunction.
• This study investigated the roles of ventricular hypertrophy and diastolic function in altered myocardial perfusion in AR.

Purpose of the Study:

• To determine the relationship between left ventricular diastolic function and coronary flow distribution in patients with aortic regurgitation.
• To assess the impact of aortic valve replacement on diastolic function and coronary flow.

Main Methods:

• Multiplane transesophageal echocardiography (TEE) was used to assess coronary Doppler flow velocity in the left anterior descending artery in 15 AR patients before and after valve replacement.
• Coronary flow velocity integrals and mitral inflow patterns were correlated with hemodynamic and echocardiographic indices of diastolic function.
• Patients were compared to 10 healthy controls.

Main Results:

• Aortic regurgitation was associated with reduced diastolic:systolic coronary flow velocity integral ratio and increased early:late diastolic velocity integral ratio.
• These altered coronary flow patterns correlated with impaired left ventricular diastolic function and elevated pulmonary wedge pressure.
• Valve replacement normalized diastolic function parameters and coronary flow distribution, with decreased pulmonary wedge pressure and increased coronary perfusion pressure.

Conclusions:

• Diastolic ventricular dysfunction, rather than left ventricular mass, is linked to disordered myocardial perfusion in aortic regurgitation.
• Aortic valve replacement improves diastolic function and normalizes coronary flow phasic distribution.
• Echo-Doppler parameters of diastolic dysfunction can identify patients with compromised coronary perfusion and aid preoperative assessment.