Y. Shapira et al., EXERCISE-INDUCED SYNCOPE AND HOLTER-DOCUMENTED ASYSTOLE IN AN ENDURANCE RUNNER WITH MODERATE AORTIC-STENOSIS, Clinical cardiology, 19(1), 1996, pp. 71-73
The case of an endurance runner with moderate aortic stenosis, who had
recurrent syncope, is reported. A Holter recording during syncope rev
ealed asystole lasting 57 s. Head-up tilt table test with isoprotereno
l was abnormal. No important abnormality was found in sinus or atriove
ntricular nodal functions. It was postulated that the syncope was due
to exaggerated left ventricular baroreflex response, probably aggravat
ed by the increased vagal tone in an endurance runner. The patient was
given a beta-adrenergic blocker, and a pace maker was implanted becau
se of the profound cardio-inhibitory response. The arguments for this
approach are discussed.