abstract
presented
at the 1996 Congress of the ESC
Birmingham, UK
August 25 - 29, 1996
THE POTENTIAL PREDICTIVE
VALUE OF T WAVE ALTERNANS FOR ASSESSMENT OF RISK OF SUDDEN CARDIAC
DEATH IN HYPERTROPHIC CARDIOMYOPATHY
PACE 1995, Vol. 18, pg. 796
J. Kautzner, M. Murda'h, H. Nagayoshi, Y. Momiyama,
J.E.K. Hartikainen, P. Albrecht, A.J. Camm, W.J. McKenna, St.
George's Hospital Medical School, London, United Kingdom and Cambridge
Heart, Inc., Bedford, MA, USA
The prevention of sudden cardiac death in hypertrophic
cardiomyopathy (HCM) continues to be one of the major challenges
in clinical cardiology. As T wave alternans (ALT), i.e. alternating
morphology of the ST-T segment detectable on microvolt level,
has been shown to predict arrhythmia vulnerability to sustained
ventricular tachycardia or fibrillation (VT/VF), the potential
role of this method for evaluation of patients with HCM remains
to be defined. To determine the predictive role of ALT, ECG recordings
were made both at rest and during dynamic exercise using a bicycle
protocol to maintain heart rate at the level of 100-110 bpm in
33 patients with HCM (27 males, mean age.....years). The patient
population comprised 13 clinically high risk (Risk +) patients
(3 survivors of VT/VF, the rest presenting with two or more of
the following risk factors: family history of sudden cardiac death,
experience of syncope, the occurrence of non-sustained VT on Holter
recording and flat blood pressure response < 20mmHg during
exercise test). The remaining patients were classified as clinically
low risk group (Risk -). There were no significant differences
in age or gender between the two groups. ALT voltage > 1.0
µV at rest and 1.9 µV during exercise were required
for a positive test, and both the recording and analysis were
performed blind to clinical data.
| Risk + | |||||
| Risk - |
All 3 survivors of VT/VF were ALT +, whereas 1 Risk
+ patient labeled as ALT - showed changes in QRS complex morphology
during exercise.
In conclusion, ALT detected during low level dynamic
exercise has high potential to predict risk of sudden death in
patients with HCM.
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