Dynamic Changes in T‐Wave Amplitude during Tilt Table Testing: Correlation with Outcomes

Abstract

Changes in autonomic tone may play a role in syncope. Autonomic tone has been shown to affect cardiac repolarization in the ECG. Changes in the T wave can be seen during head-up tilt table (HUT) testing with unknown significance or relationship to outcomes. Twelve-lead ECGs during HUT testing from 150 patients were reviewed from a prospectively collected registry database. ECGs during supine-rest, 30-45-70 degrees tilt, and 5-minute supine recovery were reviewed. Changes in the T wave, that is, decreased amplitude with or without becoming negative or flipping from negative to positive, were recorded for each stage. Outcomes of the HUT test include nondiagnostic, postural orthostatic hypotension (POH), postural orthostatic tachycardia syndrome (POTS), and vasovagal response (VVR). Age (Younger: <50 year old; Older: > or = 50 year old) and gender were analyzed. Of 150 patients (108 women; 80 Younger), 135 had T-wave changes during HUT; changes resolved in 114 patients during supine recovery. Changes mostly occurred in inferior and anterolateral leads. POH occurred in 114 patients, POTS in 67, and VVR in 30. T-wave changes in V1 inversely correlated with POH (P = 0.005). T-wave changes in inferior leads II, III, aVF and in anterolateral leads V3-V6 positively correlated with POTS (P < 0.05). Female gender and younger age correlated with POTS independent of the leads (P < 0.05). Concomitant T-wave changes in V5 and V6 correlated with VVR; changes in aVF also correlated with VVR (P < 0.05). Dynamic T-wave changes during HUT testing in inferior and anterolateral leads are associated with POTS and VVR independent of age and gender. Changes in autonomic tone may play a role and need further study.