Aortic valve replacement reduced left ventricular ALC1 content in patients with aortic stenosis from 11.2% to 4.2% (p<0.05), suggesting an adaptational response to pressure and volume overload.
Observational
Does aortic valve replacement reduce atrial-like myosin light chain-1 (ALC1) expression in patients with aortic valve disease?
Aortic valve replacement reduces the expression of atrial-like myosin light chain-1, which correlates with hemodynamic improvements in left ventricular pressure and wall stress.
Previously, we have reported on the selective accumulation of an atrial-like myosin light chain-1 (ALC1) in different forms of human ventricular hypertrophy. The present study involves the determination of ALC1 content in a control group and in patients with aortic stenosis or insufficiency before and 56 +/- 23 months after valve replacement and compares the hemodynamic and angiographic parameters. ALC1 was quantified densitometrically after two-dimensional electrophoretic resolution of biopsy specimens from the left ventricle and was expressed in percent of total ventricular light chain-1. The mean ALC1 content was 11.2 +/- 9.2% in preoperative aortic stenosis and 4.5 +/- 1.4% in aortic insufficiency, both being significantly (p less than 0.001) higher than the control value of 0.3 +/- 0.3%. After valve replacement, mean ALC1 content was lower than before, 4.2 +/- 3.3% (p less than 0.05) in stenosis and 3.4 +/- 3.1% (p = NS) in insufficiency. Left ventricular systolic pressure yields a significant (p less than 0.01) linear correlation (r = 0.45) with the ALC1 content in all preoperative and postoperative patients. Patient group averages of ALC1 content correlate directly with left ventricular systolic and end-diastolic pressure and wall thickness (r = 0.94-0.98) and, in an exponential fashion, with peak systolic circumferential wall stress (r = 0.98) but not with muscle mass or any other parameter. The ventricular ALC1 binds to myosin in proportion to its occurrence in the myocardium. The content of the endogenous ventricular light chain-1 did not change under pathological hemodynamics. The response in expression of the ALC1 to pressure and volume overload suggests an adaptational process.(ABSTRACT TRUNCATED AT 250 WORDS)
Sütsch et al. (Fri,) conducted a observational in Aortic stenosis or insufficiency. Aortic valve replacement vs. Preoperative state and control group was evaluated on Atrial-like myosin light chain-1 (ALC1) content in the left ventricle. Aortic valve replacement reduced left ventricular ALC1 content in patients with aortic stenosis from 11.2% to 4.2% (p<0.05), suggesting an adaptational response to pressure and volume overload.