Assessment of Left Ventricular Functions in Hypertensive Diabetic Patients by Speckle Tracking Imaging: Correlation with Brain Natriuretic Peptide Levels

Abstract

Background: Hypertension and diabetes are major contributors to structural changes including myocardial fibrosis and progressive alteration of LV systolic and diastolic functions. Two-dimensional speckle tracking echocardiography is a reliable imaging modality that overcomes the limitations of Tissue Doppler imaging and allows a more accurate assessment of myocardial deformation at the global and regional levels. Objectives: The investigation aims to assess Left Ventricular functions in patients with hypertension and/or diabetes who have apparently preserved LV systolic function; using speckle tracking echocardiography, and correlate the findings with plasma Brain Natriuretic Peptide levels. Methods: Twenty healthy subjects were enrolled as a control group. Sixty patients with hypertension and/or diabetes were recruited and assembled as three equal groups, hypertensives, diabetics, and hypertensive-diabetics. 2D-STE was performed to assess LV longitudinal strain and strain rate. Plasma BNP levels were measured for all subjects. Results: Global systolic longitudinal strain was significantly reduced in patients compared to controls (P=0.001). It was more reduced in group 4. Global systolic SR was reduced in patients compared to controls, being more significantly reduced in groups 2 and 4 (P=0.001). Global early diastolic SR was reduced in patients compared to controls (P=0.001). Meanwhile, Global late diastolic SR values were higher among patients, especially groups 2 and 4 (P=0.001). BNP levels were significantly higher in group 4 compared to group 1 (P=0.000), group 2 (P=0.000), and group 3 (P=0.000). BNP levels and global systolic strain in group 4 were significantly correlated. Conclusion: LV systolic dysfunction was found among all patients groups, confirmed by the significant reduction in LV global longitudinal systolic SR. Hypertensive-diabetics exhibited lower global strain than patients with hypertension only and patients with diabetes only, even though their EF showed no apparent difference. Elevated BNP levels, being the highest among group 4, indicate the presence of ventricular dysfunction, even before chamber failure occurs.