Evaluation of ventricular-vascular coupling in patients with type 2 diabetes mellitus using 2-dimensional speckle tracking imaging

The elastic and functional coupling of heart and vessels makes the stroke work (SW) of the heart optimal. Speckle tracking imaging (STI) can evaluate the myocardial strain and function. We studied ventricular-vascular coupling in 80 diabetic patients with different systolic function using STI. The patients were divided into two groups according to ejection fraction (EF): the diabetes mellitus with normal EF (DMN) group and the diabetes mellitus with abnormal EF (DMA) group. Forty-two volunteers served as control group. The relative wall thickness (RWT), left ventricular mass index (LVMI), stroke volume (SV), SW, rate-pressure product (RPP), systemic vascular resistance index (SVRI), left ventricular end-systolic elastance (Ees), effective arterial elasticity (Ea) and ventricular-vascular coupling index (VVI) were measured and calculated by conventional echocardiography. The longitudinal strain (LS) at basement (LSBA), papillary muscle (LSPM) and cardiac apex (LSAP) was assessed with STI. It was found: (A) compared with control group, in DMN and DMA groups, LSBA, LSPM and LSAP decreased, and they were lower in DMA group. (B) VVI, RPP and SVRI increased, and they were higher in DMN group; Ees decreased, and it was lower in DMA group. (C) LSBA, LSPM, and LSAP had negative correlation with VVI. LSAP, RWT, LVMI and SW were independent predictors for VVI. The area under the receiver operating characteristic (ROC) curves was used for identification of DMA and DMN with LSBA, LSPM, and LSAP, and the area under the ROC of LSAP was the largest. This study supports that myocardial LS could reflect the ventricular-vascular coupling. Different segments had an order to "respond to" the state of the coupling, and the cardiac apex might be the earliest.