Electrical remodeling reflected by QRS and T vector changes following cardiac resynchronization therapy is related to survival in heart failure patients with left bundle branch block.
J Electrocardiol
; 48(4): 578-85, 2015.
Article
en En
| MEDLINE
| ID: mdl-25747167
INTRODUCTION: We investigated changes in electrocardiographic spatial QRS and T vectors as markers of electrical remodeling before and after cardiac resynchronization therapy (CRT) and their association with altered outcome. METHODS AND RESULTS: In 41 patients with LBBB, ECGpost was recorded during intrinsic rhythm after interrupting CRT pacing and compared to the pre-implant ECGpre and the ECG during CRT (ECGCRT). Mean spatial angles between QRS and T vectors were determined with the Kors matrix conversion. Left ventricular ejection fraction (LVEF) was determined with nuclear isotope ventriculography before CRT implantation (LVEFpre) and at inclusion (LVEFpost). Following CRT, LVEF improved significantly from 26 ± 10 to 36 ± 14% (p=0.01). Duration of QRSpre (168 ± 15 ms) was not different from QRSpost (166 ± 15 ms). A smaller angle between QRSCRT and Tpost was related to a greater angle between Tpre and Tpost (Pearson's R -0.61 - p<0.001). During follow-up (30 ± 2 months) 9 patients (22%) died. Univariate Cox regression revealed higher mortality in the patients with lower LVEFpost (HR 1.10, p=0.01), a larger angle QRSCRTTpost (HR 1.03, p=0.03), a smaller angle QRSpreQRSpost (HR 0.97, p=0.03) and smaller angle TpreTpost (HR 0.95, p<0.01). After adjusting for LVEFpost, only smaller angle TpreTpost was associated with mortality (HR 0.96, p=0.03). CONCLUSIONS: Electrical remodeling can be quantified by measuring the angles between spatial QRS and T vectors before, during and after CRT. In absence of QRS duration changes, more extensive electrical remodeling is associated with a significantly better survival. QRS and T vector changes deserve further investigation to better understand the individual response to CRT.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Bloqueo de Rama
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Electrocardiografía
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Terapia de Resincronización Cardíaca
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Insuficiencia Cardíaca
Tipo de estudio:
Diagnostic_studies
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Etiology_studies
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Incidence_studies
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Prognostic_studies
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Risk_factors_studies
Límite:
Aged
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Female
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Humans
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Male
País/Región como asunto:
Europa
Idioma:
En
Revista:
J Electrocardiol
Año:
2015
Tipo del documento:
Article
Pais de publicación:
Estados Unidos