abstract
presented
at the 1995 ACC
New Orleans, Louisiana
March 20-22, 1995
Electrical Alternans During Rest and Exercise
as Predictors of Vulnerability to Ventricular Arrhythmias
J Am Coll Cardio Feb. 1995; Special Issue:1027-39N.
A. Mark Estes, Douglas P. Zipes, Nabil El-Sherif, Ferdinand J.
Venditti, *David S. Rosenbaum, *Paul Albrecht, *Paul J. Wang,
Philip C. Krause, *Richard J. Cohen. Tufts University, New England
Medical Center, Boston, MA, Massachusetts Institute of Technology,
Cambridge MA.
Electrical alternans representing visually inapparent
beat-to-beat alternating amplitude on the electrocardiogram, has
been reported to predict vulnerability to ventricular arrhythmias
during atrial pacing. We hypothesized that electrical alternans
recorded during sinus rhythm and with the heart rate elevated
by exercise would be similarly predictive. In the pilot phase
of a multicenter study, electrical alternans recordings were made
at rest, during a bicycle protocol to maintain the heart rate
100-110 bpm, and analyzed using a spectral method incorporating
noise reduction software. Ventricular vulnerability was defined
by prior episodes of clinical ventricular tachycardia(VT) or ventricular
fibrillation(VF) or by VT or VF induction at electrophysiology
study. The results are:
p | ||||||
Rest | 0.14 | |||||
Exercise | 0.005 | |||||
Rest/Exer | <0.005 |
+PV: positive predictive value -PV: negative predictive value
RR: relative risk
p: significance level
Conclusions: Electrical
alternans can be measured during exercise and is an accurate predictor
of vulnerability to ventricular arrhythmias. Electrical alternans
measured during sinus rhythm at rest is not as accurate a predictor.
Combining rest and exercise electrical alternans results is more
predictive of arrhythmia vulnerability than rest or exercise alone.
1 Oak Park Drive
Bedford, MA 01730
617-271-1200