Electrocardiographic and echocardiographic evaluation of left atrial mechanical functions in vasovagal syncope patients

Aim: In this study, we aimed to investigate the presence of atrial volume and decreasing of contraction force by measuring left atria lvolume and contraction with the Head-up tilt table test (HUTT) in patients who were diagnosed with neurocardiogenic syncope (NCS). Introduction:Syncope is defined as temporary and spontaneous recoverable loss of consciousness due to a temporary decrease in blood flow to the brain and therefore sudden tonus loss. In the absence of any structural heart disease, syncope resulting from neural reflexes in various conditions is called NCS. HUTT is the most important test in the diagnosis of NCS. Assuming that the reduction of atrial volume and contraction as a potential cause of syncope, we assessed it by measuring with echocardiography and tissue Doppler. Methods: 45 patients (26 female/19 male , mean age:26,4±9,2) who experienced vasovagal syncope in HUTT (HUTT+) and 40 healthy control (17 female/23 male , mean age:28,8±10,5 )(HUTT-) were included in to the study. All subjects were investigated with conventional and tissue Doppler echocardiography. Left atrial volume is calculated by using Simpson's method and left atrial ejection force (LAEF) is calculated by using the formula 0,5x1,06 gr/cm3 x mitral annulus area x (peak A velocity)2 in tissue Doppler echocardiography. Results: When comparing the groups in terms of left atrial ejection force, there was a significant difference between the groups' positive vasovagal syncope and the negative group in HUTT (p=0,05). In both groups, there was a positive correlation between atrial ejection force and left atrial volume (r=0,287, P=0,016) and left atrial volume index r=0,261, P=0,029). Conclusion: At the end of this study, we showed that the left atrial ejection force and the left atrial volume index were significantly lower in positive vasovagal syncope patients than those in the negative vasovagal syncope patients. Also, we showed that the decreased left atrial ejection force and volume index may play a role in the pathophysiology of neurocardiogenic syncope. Key Words: Left atrial ejection force, Left atrial volume index, Neuro cardiogenic syncope.