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[Left ventricular adaptive response after surgery of aortic valve replacement for severe valvular stenosis].

BACKGROUND
Myocardial hypertrophy is a compensatory mechanism in patients with severe aortic stenosis. The left ventricle fits the systolic pressure through a hypertrophic process with increased wall thickness. The effects of elevated ventricular afterload reduce ventricular myocardial elasticity and decrease coronary flow with increased myocardial work, oxygen consumption, and mortality. Aortic valve replacement surgery can cause regression of left ventricular hypertrophy and improve patient survival. The aim of this study was to evaluate left ventricular adaptive response after surgery of aortic valve replacement for severe valvular stenosis.


MATERIAL AND METHODS
An observational, analytical, longitudinal study that included patients with diagnosis of aortic stenosis with evidence of left ventricular hypertrophy undergoing valve replacement during the period January 2013 to September 2014. Echocardiographic studies were performed before surgery and six months thereafter. Pre- and postoperative means were compared with Student t test for related samples. Statistical significance was considered at p ≤ 0.05.


RESULTS
24 patients were included, with an average age of 57.5 years, with no gender predominance, of which 87.5% had history of smoking and 50% with hypertension. There was no statistically significant difference in diastolic and systolic diameter before and after surgery. The interventricular septum was 14.9 ± 2.3 mm preoperative and 12.8 ± 2.2 mm postoperative (p = 0.001). The back wall was 14.2 ± 1.8 mm preoperative and 12.5 ± 2.2 mm postoperative (p = 0.002). The ventricular mass before surgery was 154.8 ± 54.3 g/m(2) and then 123.2 ± 41.4 g/m(2) (p = 0.000). The maximum preoperative transvalvular gradient was 93 ± 35 mmHg and postoperative was 32.2 ± 14.4 mmHg (p = 0.00). The average preoperative transvalvular gradient was 56.3 ± 19 mmHg and postoperative was 7.5 ± 16.49 mmHg (p = 0.00).


CONCLUSIONS
The interventricular septum, posterior wall, and left ventricular mass decreased significantly after aortic valve replacement. The maximum and mean transvalvular gradient decreased significantly after surgery for aortic valve replacement.