The Postural Orthostatic Tachycardia Syndrome: A Neurocardiogenic Variant Identified During Head‐Up Tilt Table Testing

Abstract

Head upright tilt table testing has emerged as an accepted modality for identifying an individual's predisposition to episodes of autonomically mediated hypotension and bradycardia that are sufficiently profound so that transient loss of consciousness ensues (neurocardiogenic syncope). However it has also become apparent that less dramatic falls in blood pressure, while not sufficient to cause full syncope, may produce symptoms such as near syncope, vertigo, dizziness, and TIA-like episodes. We have identified a subgroup of individuals with a mild form of autonomic dysfunction with symptoms of postural tachycardia and lightheadedness, disabling fatigue, exercise intolerance, dizziness, and near syncope. During baseline tilt table testing these patients demonstrated a heart rate increase of > or = 30 beats/min (or a maximum heart rate of 120 beats/min) within the first 10 minutes upright (unassociated with profound hypotension), which reproduced their symptom complex. In addition these patients exhibit an exaggerated response to isoproterenol infusions. Similar observations have been made by others who have dubbed this entity the Postural Orthostatic Tachycardia Syndrome (POTS). We conclude that POTS represents a mild (and potentially treatable) from of autonomic dysfunction that can be readily diagnosed during head upright tilt table testing.

Temporal lobe epilepsy and postural orthostatic tachycardia syndrome (POTS)

“…The diagnostic criteria are: heart rate increase ¼ 30 bpm within 5 min of standing or upright tilt, heart rate of 120 min within 5 min of standing or upright tilt, development of orthostatic symptoms without orthostatic hypotension, and absence of a known cause of autonomic neuropathy [6,7]. The present patient met these criteria; i.e., her rate increase was dramatic and even greater than the reported increase (from 79 AE 13 to 112 AE 28; mean AE SD bpm) observed by Sandroni et al [5] The same group also noted the likely benefit of beta-blockers which were introduced successfully in our patient.…”

Síndromes de disfunción autonómica asociados con intolerancia ortostática.

“…El denominado síndrome de taquicardia ortostática postural (STOP, POTS en inglés) se caracteriza primordialmente por la presencia de taquicardia persistente al asumir la posición erecta que, en ocasiones, alcanza frecuencias de 160 por minuto o más (19). Se asocia, además, a síntomas inespecíficos como fatiga severa, intolerancia al ejercicio y mareos y, con frecuencia, se manifiesta con presíncope o síncope recurrente.…”

Neurally Mediated Syncope

“…The blood pressure tends to decrease only slightly. 10 The specificity and sensitivity of the HUTT test are hard to determine because of methodologic differences in the test's performance. The absence of a "gold standard" also makes it difficult to determine normal versus abnormal results.…”

“…In these cases, the hypotension is part of a general autonomic disorder that affects many other organs and functions. 8,9 One form of autonomic dysfunction is postural orthostatic tachycardia syndrome (POTS), 10 which results from a failure of peripheral vasoconstriction. Patients present with hypotension, fatigue, and dizziness.…”