Diastolic Dysfunction in Aortic Regurgitation

Background

Patients with severe aortic regurgitation show eccentric LV hypertrophy and structural changes of the myocardium. Reversibility of functional and structural changes after successful valve replacement may be limited. Persistent diastolic dysfunction has been observed in the present study late after aortic valve replacement. This finding has been explained by incomplete regression of the extra-cellular matrix 7 years after valve replacement. Interstitial fibrosis remains unchanged compared to the preoperative situation but was increased early after operation due to the reduction in LV muscle mass. Regression of LV hypertrophy was 40% after 2 and 55% after 7 years of valve replacement. Myocardial muscle fibers decreased slightly but remained hypertrophied even late after operation. Interstitital fibrosis was found to be positively correlated to myocardial stiffness and inversely to LV ejection fraction.

Thus, persistent diastolic dysfunction with maintained systolic ejection performance can be observed late after successful valve replacement in patients with severe aortic regurgitation. Altered diastolic function has been associated with increased filling pressures during strenuous exercise with signs of dyspnea.

Objective

Evaluation of myocardial structure and function in patients with chronic volume overload before and after valve replacement(LV-remodeling).

Methods

Pressure-volume measurements and myocardial biopsy samples for assessing myocardial function and structure.

Inclusion criteria

• Severe aortic regurgitation
• Successful valve replacement
• Informed consent
• Sinus rhythm
• No comorbidities
• No bundle branch block
• No pregnancy

Exclusion criteria

• Unwillingness to undergo postop. cath
• diabetes mellitus
• arterial hypertension
• bleeding disorder
• pulmonary hypertension