Linda Saju The Validity of "Empty Heart Syndrome" in the Pathogenesis of Neurocardiogenic Syncope
SchoolHudson High School
MentorFetnat Fouad-Tarazi, MD
The Validity of "Empty Heart Syndrome" in the Pathogenesis of Neurocardiogenic Syncope
The widely accepted hypothesis regarding the pathogenesis of neurocardiogenic syncope considers a decrease in ventricular volume known as the "empty heart syndrome," resulting in a neuro-autonomic imbalance. In order to validate this mechanism, we analyzed the PR dynamic decrease in patients during the Head-up Tilt (HUT) test.
Methods and Results
In a study of 97 patients with unexplained syncope, we calculated the PR dynamic decrease during the HUT test. The patient responses were divided into two groups: vasovagal response (VVR) and normal response (NR). The PR dynamic decrease during HUT was evaluated as the percent of shortening of PR from baseline to the average of the last two recordings during HUT. From the statistical analysis, it was noted that patients with VVR tended to be younger than ones with NR and were more likely to be female, have smaller PR intervals at baseline and have a greater PR interval decrease than NR patients.
Patients who exhibit a VVR tend to have greater percentage decrease in PR interval than NR patients. These patients also were more likely to be younger, female and have lower PR.