TY - JOUR
T1 - Effect of bundle branch block on microvolt T-wave alternans and electrophysiologic testing in patients with ischemic cardiomyopathy
AU - Morin, Daniel P.
AU - Zacks, Eran S.
AU - Mauer, Andreas C.
AU - Ageno, Shaun
AU - Janik, Matthew
AU - Markowitz, Steven M.
AU - Mittal, Suneet
AU - Iwai, Sei
AU - Shah, Bindi K.
AU - Lerman, Bruce B.
AU - Stein, Kenneth M.
N1 - Funding Information:
This work was supported in part by grants from the National Institutes of Health (R01 HL-56139), the Rosenfeld Heart Foundation, the Michael Wolk Foundation, the Raymond and Beverly Sackler Foundation, and New York Cardiology Associates.
PY - 2007/7
Y1 - 2007/7
N2 - Background: T-wave alternans (TWA) and electrophysiology study (EPS) are used for risk stratification for sudden death. Objective: The purpose of the study was to determine the effect of bundle branch block or intraventricular conduction delay on TWA and EPS. Methods: 386 patients with coronary artery disease, nonsustained ventricular tachycardia, and left ventricular ejection fraction ≤40% underwent TWA and EPS, and were followed for 40 ± 19 months. Results: Patients with wide QRS were more likely than narrow QRS patients to have nonnegative TWA (77% vs 63%, P <.01) or positive EPS (60% vs 48%, P = .03). Nonnegative TWA predicted the combined endpoint of ventricular tachyarrhythmia or death in narrow QRS (HR = 1.64, P = .04) but not wide QRS patients (HR = 1.04, P = .91). Similarly, positive EPS predicted the combined endpoint in narrow QRS (HR = 2.28, P <.001) but not wide QRS patients (HR = 0.94, P = .84). In multivariate analysis, QRS width and TWA, as well as QRS width and EPS, were independent predictors of events. There was no TWA- or EPS-based difference in arrhythmia-free survival within any specific wide QRS morphology. Conclusion: TWA and EPS are more often abnormal in patients with a wide QRS than in those with a narrow QRS. In patients with narrow QRS, both TWA and EPS stratify patients according to their risk of ventricular tachyarrhythmia or death. However, among patients with a wide QRS, regardless of specific QRS morphology, the risk is high and comparable regardless of TWA or EPS results. Therefore, the only truly low-risk group consists of those patients with negative test results and a narrow QRS.
AB - Background: T-wave alternans (TWA) and electrophysiology study (EPS) are used for risk stratification for sudden death. Objective: The purpose of the study was to determine the effect of bundle branch block or intraventricular conduction delay on TWA and EPS. Methods: 386 patients with coronary artery disease, nonsustained ventricular tachycardia, and left ventricular ejection fraction ≤40% underwent TWA and EPS, and were followed for 40 ± 19 months. Results: Patients with wide QRS were more likely than narrow QRS patients to have nonnegative TWA (77% vs 63%, P <.01) or positive EPS (60% vs 48%, P = .03). Nonnegative TWA predicted the combined endpoint of ventricular tachyarrhythmia or death in narrow QRS (HR = 1.64, P = .04) but not wide QRS patients (HR = 1.04, P = .91). Similarly, positive EPS predicted the combined endpoint in narrow QRS (HR = 2.28, P <.001) but not wide QRS patients (HR = 0.94, P = .84). In multivariate analysis, QRS width and TWA, as well as QRS width and EPS, were independent predictors of events. There was no TWA- or EPS-based difference in arrhythmia-free survival within any specific wide QRS morphology. Conclusion: TWA and EPS are more often abnormal in patients with a wide QRS than in those with a narrow QRS. In patients with narrow QRS, both TWA and EPS stratify patients according to their risk of ventricular tachyarrhythmia or death. However, among patients with a wide QRS, regardless of specific QRS morphology, the risk is high and comparable regardless of TWA or EPS results. Therefore, the only truly low-risk group consists of those patients with negative test results and a narrow QRS.
KW - Bundle branch block
KW - Electrophysiologic study
KW - QRS
KW - T-wave alternans
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U2 - 10.1016/j.hrthm.2007.02.027
DO - 10.1016/j.hrthm.2007.02.027
M3 - Article
C2 - 17599676
AN - SCOPUS:34250719341
SN - 1547-5271
VL - 4
SP - 904
EP - 912
JO - Heart Rhythm
JF - Heart Rhythm
IS - 7
ER -