The Evaluation Of Atrial Fibrosis In Patients With Essential Hypertension By Integrated Backscatter

Objective To evaluate left atrial fibrosis in essential hypertensive patients by integrated backscatter (IBS). Methods A total of 71 consecutive patients with essential hypertension (39 males, median age 54) and 27 healthy subjects(12 males, median age 47) from Nov. 2005 to March 2006 were studied. Patients with essential hypertension were divided into no myocardiac hypertrophy group (n=37, 19 males, median age 53) and myocardiac hypertrophy group (n=34, 20 males, median age 57.5) by Ganau categories of echocardiography. They were divided into the normal diastolic function group(n=35, 16 males, median age 52) and the impaired diastolic function group(n=36, 23 males, median age 57) according to left ventricular diastolic function with mitral and pulmonary venous flow velocity profile. Average IBS and cyclic variation of integrated backscatter(CVIB) were measured by IBS on left atrial posterior wall and IBS% were calculated. All patients were sinus arrhythmia when IBS were performed, excluding cor pulmonale, ischemic heart disease, congenital heart disease, myocardia disease, pericardial disease, hyperthyroidism, diabetes, secondary hypertension, arrhythmia, valvular heart diseases, electrolyte disorders. Results 1. There were no difference in average IBS among the no myocardiac hypertrophy group, myocardiac hypertrophy and control group. IBS% was lower in the control group than in the no myocardiac hypertrophy group and hypertrophy group(p<0.05, p<0.01), IBS% was lower in no myocardiac hypertrophy than hypertrophy group(p<0.05). CVIB was the highest in the control group and the lowest in myocardiac hypertrophy group (p<0.05). 2. Average IBS was lower in control group than the impaired diastolic function group (p<0.05), IBS % was lower in the control group and normal diastolic function group than impaired diastolicfunction group (p<0.01), but there were not difference between control group and normal diastolic function group. CVIB was higher in control group than normal diastolic group and impaired diastolic function group (p<0.05), but there were not difference between the later two groups . Conclusions 1. In essential hypertensive patients increased IBS% and decreased CVIB should suggest fibrosis on the left atrial posterior wall. 2. The IBS% and CVIB of the left atrial posterior wall are different in hypertensive patients with different left ventricular geometric pattern, and in patients with different left ventricular diastolic function, these results may show difference of atrial fibrosis level. The IBS% and CVIB are useful new markers in evaluating atrial fibrosis in hypertensive patients.