Improved coronary artery blood flow following the correction of systolic dyssynchrony with cardiac resynchronization therapy.
Int J Cardiol
; 167(5): 2167-71, 2013 Sep 01.
Article
en En
| MEDLINE
| ID: mdl-22704862
BACKGROUND: Coronary blood flow (CBF) is improved by cardiac resynchronization therapy (CRT) and impaired by right ventricular apical (RVA) pacing in patients with heart failure. However, the underlying mechanism remains unclear. METHODS: Twenty-nine non-ischemic heart failure patients who responded to CRT underwent transthoracic echocardiography examination including both left anterior descending (LAD) CBF and tissue Doppler imaging in 3 pacing modes: intrinsic conduction, RVA pacing and biventricular (BiV) pacing. LAD velocity-temporal integral (LAD-VTI) and duration were measured. Systolic dyssynchrony was assessed with the standard deviation of a 12-left ventricular segmental model (Ts-SD). RESULTS: BiV pacing improved while RVA pacing reduced CBF compared to intrinsic conduction (all p<0.05). Both Ts-SD and ventricular septal velocity deteriorated during RVA pacing but improved during BiV pacing (all p<0.05). When systolic dyssynchrony was induced, lower LAD-VTI (9.5 ± 3.4 versus 12.7 ± 5.1cm, p=0.001) and shorter LAD diastolic duration (483 ± 92 versus 542 ± 106 ms, p=0.010) were detected than synchronous status. Systolic dyssynchrony was inversely related to septal velocity (r=-0.41), p<0.001 and LAD-VTI (r=-0.30, p=0.007), with the latter found to be moderately correlated to septal velocity (r=0.30, p=0.007). CONCLUSION: Regional LAD flow was improved in patients subjected to BiV but worsened in those treated with RVA pacing in non-ischemic heart failure CRT responders. Systolic dyssynchrony was more commonly observed in patients subjected to RVA pacing. Reduction of septal velocity with dyssynchrony may directly lead to reduced LAD flow. Improvement of septal velocity by CRT and hence LAD flow may be an important mechanism in determining the response to CRT.
Palabras clave
BiV; CBF; CRT; Cardiac resynchronization therapy; Coronary blood flow; HF; LAD; Myocardial velocity; RVA; Systolic dyssynchrony; TDI; VTI; biventricular; cardiac resynchronization therapy; coronary blood flow; heart failure; left anterior descending coronary artery; right ventricular apical; tissue Doppler imaging; velocitytime integral
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Velocidad del Flujo Sanguíneo
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Circulación Coronaria
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Vasos Coronarios
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Terapia de Resincronización Cardíaca
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Cardiomiopatías
Tipo de estudio:
Diagnostic_studies
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Observational_studies
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Prevalence_studies
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Risk_factors_studies
Límite:
Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Int J Cardiol
Año:
2013
Tipo del documento:
Article
País de afiliación:
Hong Kong
Pais de publicación:
Países Bajos