Author/Editor     Žižek, David; Cvijić, Marta; Tasič, Jan; Jan, Matevž; Frljak, Sabina; Zupan, Igor
Title     Effect of cardiac resynchronization therapy on beat-to-beat T-wave amplitude variability
Type     članek
Source     Europace
Vol. and No.     Letnik 14, št. 11
Publication year     2012
Volume     str. 1646-52
Language     eng
Abstract     AimsT-wave amplitude variability (TAV) is a promising non-invasive predictor of arrhythmic events in patients with dilated cardiomyopathy. We aimed to evaluate the effect of cardiac resynchronization therapy (CRT) on native TAV, its relation with left ventricular (LV) reverse remodelling and the occurrence of ventricular tachyarrhythmias (VTs).Methods and resultsIn this prospective study, we included 40 heart failure patients with left bundle branch block in sinus rhythm (25 male; 16 with ischaemic aetiology; aged 62.7 +/- 9.5 years; New York Heart Association class II-IV). Echocardiographic parameters and TAV were evaluated at baseline and 6 months after implantation of CRT device combined with an implantable cardioverter-defibrillator. T-wave amplitude variability was determined by a 20-min high-resolution electrocardiogram Holter recording during native conduction. After TAV assessment, patients were monitored for 15.7 +/- 5.2 months for the occurrence of VTs. Decrease in median TAV [from 40.45 muV (24.75-56.00) to 28.15 muV (20.93-37.95), P = 0.004] was observed after 6 months of CRT. However, decrease of median TAV was only noticed in patients with LV reverse remodelling [46.9 muV (27.5-70.0) to 25.8 muV (20.2-32.4), P < 0.001] and in patients without VTs [40.5 muV (27.5-55.9) to 24.4 muV (17.1-31.5), P < 0.001]. Native median TAV > 35.4 microV after 6 months of CRT had an 83% sensitivity and 93% specificity for predicting the occurrence of VTs.ConclusionsDecrease of TAV after CRT is associated with LV reverse remodelling and indicates a reduction of the intrinsic arrhythmogenic substrate. Median TAV after CRT had a good predicting value for VT occurrence in long-term follow-up.
Descriptors     CARDIOMYOPATHY, CONGESTIVE
TACHYCARDIA, VENTRICULAR
DEFIBRILLATORS, IMPLANTABLE
ELECTRIC COUNTERSHOCK
ECHOCARDIOGRAPHY
ELECTROCARDIOGRAPHY
TREATMENT OUTCOME
PROSPECTIVE STUDIES