کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5977360 | 1576220 | 2013 | 6 صفحه PDF | دانلود رایگان |
BackgroundVigorous left ventricular (LV) contraction with progressive ventricular emptying during orthostatic stress may induce hyper-responsiveness of cardiac mechanoreceptor and vasovagal syncope (VVS). We hypothesized that intracardiac volume reserve estimated by the left atrial (LA) volume index (LAVI) plays an important role in the mechanism of VVS.MethodsA total of 234 patients (115 male, 44 ± 18 years) who underwent head-up tilt test (HTT) and transthoracic echocardiography for unexplained syncope were consecutively enrolled. Patients with a positive HTT result (HTT+; n = 152) were compared with those with negative HTT response (HTTâ; n = 82).Results1. Compared to HTTâ patients, HTT+ patients were younger (41 ± 17 vs. 48 ± 17 years, p = 0.005), included a higher number of females (56% vs. 50%, p = 0.009) and showed higher basal heart rate (67 ± 12 vs. 63 ± 11 bpm, p = 0.047). 2. LAVI (20 ± 5 vs. 26 ± 13 ml/m2, p < 0.001), LV end-diastolic dimension (47.4 ± 3.7 vs. 49.0 ± 4.1 mm, p = 0.015), and the proportion of LV hypertrophy (13% vs. 24%, p = 0.027) were smaller and early diastolic mitral annulus velocity was higher (9.7 ± 3.0 vs. 8.5 ± 2.6 cm/s, p = 0.004) in HTT+ patients than those in HTTâ group. 3. LAVI (OR 0.917 (0.860-0.977), p = 0.007) was the only independent predictor of HTT induced VVS, and LAVI had a linear correlation with time to syncope during HTT (r = 0.39, p = 0.034). In addition, patients with LAVI â¥Â 36 ml/m2 did not faint during HTT.ConclusionSmall LA volume is an independent predictor of HTT-induced VVS. Limited intracardiac volume reserve might play an important role in the mechanism of VVS.
Journal: International Journal of Cardiology - Volume 166, Issue 1, 5 June 2013, Pages 44-49