Changes Of Atrial Contraction Time And Electromechanical Time In Hypertensive Patients With Paroxysmal Atrial Fibrillation

Objective To study the changes of atrial contraction time and electromechanical time and their dispersion in hypertensive patients with paroxysmal atrial fibrillation by tissue Doppler imaging (TDI), the association of left ventricular diastolic function and geometric model with atrial contraction time and electromechanical time, the influential factors of atrial contraction time and electromechanical time in hypertensive patients and the predictive factors for the onset of paroxysmal atrial fibrillation in hypertensive patients. Methods One hundred three patients with essential hypertension were enrolled. Twenty three patients with history of paroxysmal atrial fibrillation (PAF group), eighty patients without history of paroxysmal atrial fibrillation (NAF group). According to Ganau categories of echocardiography, all patients were divided into four groups as following: normal left ventricle geometric model group(NG group, n=33), concentric remodeling group(CR group, n=24), concentric hypertrophy group(CH group, n=20) and eccentric hypertrophy group(EH group, n=26). According to stage of left ventricular diastolic dysfunction (on the basis of mitral and pulmonary venous flow velocity profile), all patients were also divided into three groups as following: normal filling pattern group(NF group, n=36), impaired relaxation group(IR group, n=34), pseudonormal/restrictive filling group(PN/R group, n=33). Twenty healthy subjects as control group were included. Atrial contraction time and electromechanical time were acquired by TDI on left and right atrioventricular annulus level (LA and RA, LP-A and RP-A). Their dispersion were calculated(T and TT). All patients were not take antihypertensive drugs more than two weeks before this study. We performed this study duringsinus rhythm. Patients with ischemic heart disease, cor pulmonale, diabetes mellitus, valvular heart disease, congenital heart disease, cardiomyopathy, pericarditis, secondary hypertension, hyperthyroidism, abnormal serum electrolyte values and arrhythmias were not included. Results l.In all objects, LP-A was longer than RP-A. RA was longer than LA. 2.LP-A, RP-A, LA, RA, T and TT of PAF group were longer than control group and NAF group (P<0.01 ~0.05). LP-A, RP-A, RA and TT of NAF group were longer than control group(P<0.05), but there was no significant difference in LA and T (P>0.05). 3.LP-A, RP-A, RA and TT of PN/R group were longer than NF group and IR group (P<0.01—0.05). There were also significant differences in LP-A and RP-A between NF group and IR group (P < 0.05). LA and T were not different in the three groups. 4. LP-A, RP-A, RA and TT of CH group and EH group were longer than NG group and CR group (P<0.01~0.05). LP-A, RP-A, RA and TT were not significant different between CH group and EH group (P>0.05). Compared with NG group, LP-A and RP-A of CR group were longer (P<0.05). LA and T had no difference in the four groups. 5.LP-A had correlation with LAd, LVMI, A, Ea, Aa and Ea/Aa. RP-A had correlation with systolic blood pressure, LVMI and Ea/Aa. LA had correlation with LAd and LVMI. RA had correlation with LVMI and Ea/Aa. TT had correlation with LVMI and Ea/Aa. 6.Multivariate logistic regression analysis showed that LAd, LVMI, Ea/Aa and LP-A were important predictors for the onset of paroxysmal atrial fibrillation in hypertensive patients. Conclusions 1 .Atrial electromechanical time is prolonged in all hypertensive patients, especial!;, in patients with paroxysmal atrial fibrillation, that also has larger dispersion, atrial contraction time and its dispersion. 2. The effect for atrial contraction time and electromechanical time is different in various left ventricular diastolic dysfunction and geometric model. 3.Atrial contraction time and electromechanical time and their dispersion have separately correlation with systolic blood pressure, LAd,...