The assessment of functional indices of left ventricular wall layers in cases with normal and high blood pressure by layer-specific strain methods

Introduction: The arterial hypertension leading to left ventricular remodeling induces accentuated ventricular wall thickness because of higher afterload. The several surveys about myocardial function in such cases were conducted by imaging studies for the evaluation of myocardial wall thickness without separating the different layers of each other. The aim of this investigation was the evaluation of the functional indices of each layer of the left ventricular myocardium by staining analysis of layers and demonstration of the relationship between ventricular structural remodeling and the functional changes of the ventricle myocardial layers in persons with normal and high blood pressure.

Methods: 88 cases (46.6% normotensive and 53.4% hypertensive) were studied by two-dimensional echocardiography and longitudinal and circumferential strain indices. These differentiated variables of heart layers (epicardium, mid myocardium, endocardium) were evaluated. All of them had been analyzed and compared in terms of diastolic dysfunction were compared. Normal diastolic function was defined as: E/A=1 to 2 and deceleration time=150 to 200 ms.

Results: Global longitudinal strain (GLS) and global circumferential strain (GCS) strains remarkably declined in epicardial and middle layers of myocardial in hypertensive cases with diastolic dysfunction, although this alternation did not reveal in cases without diastolic dysfunction.

Conclusion: The decreasing of GLS and GCS indices of mid-myocardial and epicardial layers have been predicted in cases with high pressure, and the evidences of this situation had been observed in cases with ventricular diastolic dysfunction.