Pacing and clinical electrophysiology : PACE
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Pacing Clin Electrophysiol · Mar 1997
Methods other than tilt testing for diagnosing neurocardiogenic (neurally mediated) syncope.
The recording of spontaneous episodes of bradycardiac neurocardiogenic syncope (NCS) has shown that: a prolonged ventricular asystole seems necessary to cause syncope; asystole is preceded by other bradyarrhythmias in the vast majority of cases; some warning symptoms precede the loss of consciousness in most cases; conventional dual-chamber pacing is efficacious both in patients with a positive response to carotid sinus massage (CSM) and eyeball compression test (EBC) and in those with a positive response to tilt-testing (TT). CSM, EBC, and TT are established tools for diagnosing NCS, when the recording of spontaneous syncope is lacking. When combined together, they are probably able to correctly identify most patients affected by NCS. ⋯ Our knowledge suggests that the correlation may be unsatisfactory, owing to the following: the variability of the mechanism of spontaneous syncope from patient to patient and also, in the same patient, from one episode to another; the discordance of the type of response when 2 or 3 tests are positive in the same patient, the response being more frequently asystolic with CSM and EBC and more frequently vasodepressor with TT: the different timing between hypotension induced by CSM (in which it follows the bradycardia) and that induced by TT (in which it usually precedes the bradycardia) and the uncertainty about the timing of hypotension during the spontaneous syncope; the good reproducibility of the spontaneous event by CSM and EBC, but not by TT, when cardiac asystole is the manifestation of NCS; and the fairly high rate of false-positive results of cardiovascular reflexivity maneuvers. Hypotension is the main reason for the failure of pacemaker therapy in all the forms of neurocardiogenic syncope (NCS), whether diagnosed by CSM, EBC, or TT. Thus, the need arises to correctly identify the magnitude of the hypotensive reflexes of spontaneous events.
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Pacing Clin Electrophysiol · Mar 1997
Cardiovascular syncope is the most common cause of drop attacks in the elderly.
Drop attacks are defined as a sudden loss of postural tone without loss of consciousness. The mechanism is often unknown. This report examines findings in consecutive elderly patients with drop attacks referred to a dedicated "syncope and falls" center. ⋯ A diagnosis was established in 25 (71%); cardioinhibitory cartoid sinus syndrome (CSS) or mixed CSS in 15, vasodepressor CSS in 3, orthostatic hypotension in 5, vasovagal syncope in 1, and gait imbalance in 1. In 21%, more than one pathological diagnosis was present. In conclusion, absence of a history of syncope is unreliable in elderly patients, and these individuals should be routinely investigated for hemodynamic changes during carotid massage and standing.