Kardiologia polska 2016 Oct 07() doi 10.5603/KP.a2016.0131
The management of patients with asymptomatic severe aortic stenosis (ASAS) is still under discussion. Therefore, it is advisable to search for the parameters of early damage to left ventricular function.
The aim of the study was to assess exercise-induced changes in left ventricular global longitudinal strain (GLS) in ASAS.
The ASAS group consisted of 50 patients (26W/24M, aged 38.4±18.1) meeting the echocardiographic criteria of severe aortic stenosis (AVA<1cm², AVAI<0.6cm²/m², Vmax. >4m/s, mean aortic gradient>40mmHg), with normal left ventricular ejection fraction (LVEF≥55%), sinus rhythm on the ECG, without significant concomitant valvular heart diseases. The control group consisted of 21 people matched for age and sex. Echocardiographic examinations and echocardiographic stress tests with the assessment of GLS using the speckle tracking imaging were performed.
The ASAS group was characterised by statistically significantly higher left ventricular mass index (LVMI) and higher LVEF. GLS values at rest in both groups were within normal limits but were significantly higher in the control group (-18.9±2.4% vs -20.7±1.7%, p=0.006). An increase in GLS at peak exercise in both groups was observed, lower in the ASAS group (not statistically significant difference -0.8±3.0% vs -2.2±3.1%, p=0.086). Changes in GLS during exercise (∆GLS) did not correlate with the parameters of the severity of aortic stenosis. In the multivariate model, LVMI proved to be a factor associated with GLS at rest and during exercise.
In patients with ASAS GLS is a non-invasive marker of an early stage of left ventricular myocardial damage associated with myocardial hypertrophy. An increase in GLS during exercise in the ASAS group, smaller than in the control group, indicates a preserved functional reserve of the left ventricular myocardium but smaller than in healthy individuals. The assessment of the clinical usefulness of exercise-induced changes in GLS requires further research.