A relationship between T wave
alternans and left ventricular mechanical alternans in dilated cardiomyopathy.
Yuji Konno
Authors: Jiro Koyama; Sunao Toda; Jon Watanabe; Yuji Konno; Yoshito Koseki
8:00 - 6:00
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Objective: T wave
alternans (TWA) is establishing as a reliable predictor for fatal ventricular
arrhythmias. The underlying mechanism is presumably related to an alternative
release of Ca2+ from the sarcoplasmic reticulum. The purpose is to
test whether TWA accompanied by left ventricular mechanical alternans. Methods:
We investigated 7 patients with dilated cardiomyopathy during conventional
catheterization. TWA was measured with increasing heart rate (HR) from
resting HR to 90, 100 and 110 bpm by atrial pacing. A trend of peak left
ventricular pressure (LVP) was analyzed by fast Fourier transform to measure
magnitude of LVP alternans (LVPalt). Results: The figure shows a relationship
between Valt and LVPalt in a variety of HR (resting to 110 bpm). A
significant positive correlation was found (p<0.01), and TWA threshold of
positive test (Valt 1.92?V) corresponded to 1.82 mmHg of LVPalt. Conclusion:
TWA accompanied by mechanical alternans. Macroscopic mechanical alternans may
exist in patients with positive TWA test.
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