Abstract 2489: Physical Activity is Associated With Neurally Mediated Responses During Head Up Tilt Table Testing and Carotid Sinus Massage
AIMS: Endurance athletes are known to have poor tolerance to orthostatic stress and increased chances of neurocardiogenic syncope. The aim of this study was to identify association between regular physical activity and neurally mediated responses during Head up tilt table⇓ testing (HUTT) in patients with unexplained syncope.
Methods: This was a retrospective case control study including 1,336 patients who underwent HUTT and carotid sinus massage for unexplained syncope. Patients with carotid sinus hypersensitivity (CSH) and neurocardiogenic response (NCR) were identified and compared with patients who did not have these responses. Physical activity was defined as aerobic exercise for more than 30 minutes a day for at least 3 days a week for at least 6 months. Multivariable regression analysis was conducted to identify independent predictors of CSH and NCR.
Results: Seventy of 1336 patients had CSH and 564/1336 had NCR during HUTT. Physical activity was an independent positive predictor of both CSH (AOR 1.86, 95%CI (1.14–3.05); p=0.01) and NCR (AOR 1.31, 95%CI (1.04–1.65); p=0.02) upon multivariable regression analysis. CSH was more common in elderly patients (p=0.001) and male gender (p=0.001) while NCR was more common in young patients (p=0.003) and female gender (p=0.02). Patients with ischemic heart disease or hypertension were more likely to have CSH (p=0.04) and less likely to have NCR (p<0.001).
Conclusion: In conclusion, physical activity is associated with greater likelihood of neurally mediated responses during Head up tilt table⇓ testing and carotid sinus massage.