P. Annila et al., EFFECT OF ATROPINE ON THE QT INTERVAL AND T-WAVE AMPLITUDE IN HEALTHY-VOLUNTEERS, British Journal of Anaesthesia, 71(5), 1993, pp. 736-737
Prolongation of the OT interval of the ECG represents an imbalance in
cardiac autonomic function and may predict cardiac arrhythmia. Vagal a
ctivity protects against prolongation of the OT interval which may be
associated with flattening of the T-wave of the ECG. The changes in QT
interval T-wave amplitude and respiratory sinus arrhythmia (RSA) were
studied after iv. administration of atropine 20 mug kg-1 or placebo t
o 10 healthy volunteers in a cross-over study. After atropine, a decre
ase in RSA occurred in all volunteers, but remained at baseline values
after placebo. Corrected OT interval (QTc) increased from 410 (20) ms
to 454 (11) ms (P < 0.001) 5 min after atropine and remained prolonge
d for the entire study period (60 min). The T-wave flattened significa
ntly (measured as R:T ratio) up to 30 min, without any changes in the
R-wave. No changes in the ECG occurred with placebo.