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Effect of aortic valve stenosis (pressure overload) and regurgitation (volume overload) on left ventricular systolic
B Villari1, O M Hess, P Kaufmann
1Department of Internal Medicine, Cardiology, University Hospital, Zurich, Switzerland.
Insights
Diastolic dysfunction, including impaired relaxation and myocardial stiffness, often precedes systolic abnormalities in patients with aortic valve disease. Early peak filling rates do not reliably detect diastolic dysfunction in this population.
Area of Science:
- Cardiology
- Cardiac Physiology
- Heart Valve Disease
Background:
- Secondary left ventricular (LV) hypertrophy from chronic pressure or volume overload can cause systolic and diastolic dysfunction.
- The relationship between systolic and diastolic abnormalities in LV function is not well-defined.
Purpose of the Study:
- To investigate the relationship between systolic and diastolic abnormalities in left ventricular function in patients with aortic valve disease.
- To determine if diastolic dysfunction precedes alterations in myocardial contractility.
Main Methods:
- LV biplane cineangiography and high-fidelity pressure measurements were performed in 58 patients with aortic valve disease and 11 controls.
- Systolic function was assessed by ejection fraction, and diastolic function by time constant of LV pressure decay, peak filling rates, and myocardial stiffness constants.
Main Results:
- Ejection fraction was inversely related to LV relaxation time constant and myocardial stiffness.
- Diastolic dysfunction was present in most patients with pressure or volume overload, despite preserved systolic function.
- Reduced late peak filling rate was observed in some patients with aortic stenosis but not aortic regurgitation.
Conclusions:
- Abnormalities in LV relaxation and passive diastolic myocardial stiffness appear to precede alterations in myocardial contractility.
- Assessment of peak filling rates is not a reliable method for detecting diastolic dysfunction in patients with aortic valve disease.
Abstract:
In secondary hypertrophy from chronic pressure or volume overload, or both, systolic as well as diastolic abnormalities of left ventricular (LV) function have been described, but their relation has not been defined. In 58 patients with aortic valve disease (28 with aortic valve stenosis, and 30 with aortic regurgitation) and in 11 control subjects, LV biplane cineangiography was performed simultaneously with LV high-fidelity pressure measurements. LV ejection performance was assessed by ejection fraction, and diastolic function by the time constant of LV pressure decay, the early and late peak filling rates, and the constants of chamber (pressure-volume relation) and myocardial stiffness (stress-strain relation). In the entire cohort (n = 69), ejection fraction was inversely related to the time constant of LV relaxation (r = -0.58, p less than 0.001) and to the constant of myocardial stiffness (r = -0.62, p less than 0.001). Despite preserved systolic contractile function (as evaluated from the ejection fraction-mean systolic stress relation), abnormalities in LV diastolic function were present in 9 of 18 patients with pressure overload and 20 of 22 with volume overload. None of the 58 patients with aortic valve disease had a reduced early peak filling rate, whereas a reduction in late peak filling rate was observed in 3 with aortic stenosis, but in none with aortic regurgitation. This, it appears that abnormalities of relaxation and passive diastolic myocardial stiffness precede alterations in myocardial contractility. Assessment of peak filling rates is not helpful to detect diastolic dysfunction in patients with aortic valve disease.