Atrial electromechanical conduction delay in patients with neurocardiogenic syncope

Aim: In the present study, we aimed to investigate the presence of atrial electromechanical conduction delay in patients with neurocardiogenic syncope (NCS) which was diagnosed with Head-up tilt table test (HUTT) and the accurateness of the test in order to use as a method in patients with NCS.Introduction: Syncope is defined as sudden and reversible loss in tonus and consciousness due to reversible decrease in blood flow to the brain. In the absence of any structural heart disease, syncope resulting from neural reflexes in various conditions is called as NCS. HUTT is the most important test in the diagnosis of NCS. Assuming the interatrial delay as a potential cause of syncope, we assesed interatrial and intraatrial electromechanical conduction delays with non-invasive tissue Doppler method.Methods: 29 patients (24 female/5 male, mean age:30,6±15,9) who experienced vasovagal syncope in HUTT (HUTT+) and 23 healthy control (6 female/17 male, mean age:34.7±16.3 ) (HUTT -) were included into the study. All subjects were investigated with conventional and tissue Doppler echocardiography. Atrial electromechanical conduction delay (PA) was defined as the interval from the beginning of P vawe in the ECG to the beginning of A vawe measured in tissue Doppler.Results: When comparing the groups in terms of atrial electromechanical conduction delay, there was no sig nificant difference in interatrial electromechanical conduction delay (PA-RA)-(PA-LA) (p>0.05) however, there was significant difference in intraatrial electromechanical conduction delay (p<0.01 and left atrial electromechanical conduction delay (Septum-PA)-(PA-LA) (p<0.0001). There was negative correlation between left atrial electromechanical conduction delay(Septum-PA)-(PA-LA) and intraatrial electromechanical conduction delay (Septum-PA)-(PA-RA) (r=-0,468, p=0.001) but there was positive correlation between interatrial electromechanical conduction delay (PA-RA)-(PA-LA) (r=0.507, p=0.001).Conclution: In the present study, we demonstrated that there is a delay in atrial electromechanical conduction delay in patients with NCS. Results of our study show that intraatrial electromechanical conduction delay and intraleft atrial electromechanical conduction delay can me detected with tissue Doppler method which is a non-invasive examination with an acceptable rate of error. These data imply that tissue Doppler examination is an appropriate method to evaluate NCS.Key Words: Atrial electromechanical conduction delay; Tissue Doppler; Neurocardiogenic syncope.