[SCD-FORUM] 139E TWA and beta blockers. Dr. Roy

[SCD Symposium]

Prof. Thomas Bigger

       Thank you very much for your comments and bringing to my notice a
very good article. As a protocol we stop beta blockers prior to the
test to avoid patients from reaching TWA threshed heart rate and
hence an indeterminate test result. Beta blockers in fact reduce
the magnitude of MTWA. (Rashba EJ et al Circulation 2002; 105:
837-42, Murata M et al Circ J 2003; 67: 821-5, Komiya N et al
Clinic Electrophysiol 2005; 28: 680-4). Beta blocker induced
reduction in MTWA is one of the mechanism by which they may reduce
the risk of SCD. I do agree with you that there are only few
“contraindications” for TWA. If the patient can not exercise on a
treadmill like heart failure with very poor effort tolerance, we
use dobutamine infusion for heart rate acceleration. Atrial pacing
is also another option accelerate heart rate for TWA test.

Dr. Sunil Roy T.N
E mail: sunilroytn at calicutmedicalcollege.ac.in