Comparison of tissue Doppler dynamics with Doppler flow in evaluating left atrial appendage function by transesophageal echocardiography in prehypertensive and hypertensive patients.

摘要

Increased blood pressure (BP) is associated with an increase in cardiovascular mortality and morbidity. We aimed to analyze the effect of increased BP onto the function of left atrial appendage (LAA) in early stages of hypertension. Transesophageal echocardiography (TEE) was prospectively performed to assess LAA functions in 120 patients with increased BP, and in 58 normotensive subjects without cardiovascular disease. Patients with increased BP were divided according to Joint National Committee VII (JNC VII) report: prehypertensive, stage-1 hypertensive and stage-2 hypertensive patients. During TEE, LAA late-emptying velocities (LAAEV) were significantly reduced only in stage-2 hypertensives as compared with control group (P < 0.001). In contrast, LAA late-contracting velocity (LAA TDI-D2) was significantly reduced in prehypertensive,stage-1 hypertensive and stage-2 hypertensive patients, when compared with control group (P < 0.05, P < 0.001, and P < 0.001, respectively). The LAA maximal areas were increased significantly only in stage-2 hypertensive patients when compared with control group (P < 0.05). During TEE, left atrial spontaneous echocardiographic contrast was found in 2 of 36 patients in prehypertension group, in 7 of 40 patients in stage-1 hypertension group, and in 10 of 44 patients in stage-2 hypertension group. Left atrial thrombi were observed in 3 (6.8%) patients of stage-2 hypertension group. In conclusion, in patients with untreated prehypertension and hypertension, elevation of afterload imposed on left atrium involved both left atrium and LAA, resulting in impairment of the LAA function. Tissue Doppler imaging (TDI) enables the detection of this functional impairment in early stages of hypertension, even in prehypertensive phase, when compared with conventional Doppler flow measurement of the LAA. Even in prehypertensive phase, BP should be decreased to normal levels to prevent the LAA dysfunction.