RESUMEN
Microvolt T-wave alternans (MTWA) is an electrocardiographic marker for predicting sudden cardiac death. In this study, we aimed to study the relation between MTWA and scar assessed with cardiac magnetic resonance imaging (CMR) in patients with ischemic cardiomyopathy (ICM) or dilated cardiomyopathy (DCM). Sixty-eight patients with positive or negative MTWA and analysable CMR examination were included. Using CMR and the delayed enhancement technique, left ventricular ejection fraction (LVEF), volumes, wall motion and scar characteristics were assessed. Overall, positive MTWA (n = 40) was related to male gender (p = 0.04), lower LVEF (p = 0.04) and increased left ventricular end-diastolic volume (LVEDV) (p < 0.01). After multivariate analysis, male gender (p = 0.01) and lower LVEF remained significant (p = 0.02). Scar characteristics (presence, transmurality, and scar score) were not related to MTWA (all p > 0.5). In the patients with ICM (n = 40) scar was detected in 38. Positive MTWA (n = 18) was related to higher LVEDV (p = 0.05). In patients with DCM (n = 28), scar was detected in 11. Trends were found between positive MTWA (n = 15) and male gender (p = 0.10), lower LVEF (p = 0.10), and higher LVEDV (p = 0.09). In both subgroups, the presence, transmurality or extent of scar was not related to MTWA (all p > 0.45). In this small study, neither in patients with ICM or DCM a relation was found between the occurrence of MTWA and the presence, transmurality or extent of myocardial scar. Overall there was a significant relation between heart failure remodeling parameters and positive MTWA.
Asunto(s)
Arritmias Cardíacas/etiología , Cardiomiopatías/complicaciones , Cardiomiopatía Dilatada/complicaciones , Cicatriz/complicaciones , Muerte Súbita Cardíaca/etiología , Insuficiencia Cardíaca/etiología , Miocardio/patología , Anciano , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/prevención & control , Cardiomiopatías/diagnóstico , Cardiomiopatías/fisiopatología , Cardiomiopatías/terapia , Cardiomiopatía Dilatada/diagnóstico , Cardiomiopatía Dilatada/fisiopatología , Cardiomiopatía Dilatada/terapia , Cicatriz/diagnóstico , Cicatriz/fisiopatología , Muerte Súbita Cardíaca/patología , Muerte Súbita Cardíaca/prevención & control , Femenino , Fibrosis , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Volumen Sistólico , Función Ventricular Izquierda , Remodelación VentricularRESUMEN
Knowledge about potential differences in infarct tissue characteristics between patients with prior life-threatening ventricular arrhythmia versus patients receiving prophylactic implantable cardioverter-defibrillator (ICD) might help to improve the current risk stratification in myocardial infarction (MI) patients who are considered for ICD implantation. In a consecutive series of (ICD) recipients for primary and secondary prevention following MI, we used contrast-enhanced (CE) cardiovascular magnetic resonance (CMR) imaging to evaluate differences in infarct tissue characteristics. Cine-CMR measurements included left ventricular end-diastolic and end-systolic volumes (EDV, ESV), left ventricular ejection fraction (LVEF), wall motion score index (WMSI), and mass. CE-CMR images were analyzed for core, peri, and total infarct size, infarct localization (according to coronary artery territory), and transmural extent. In this study, 95 ICD recipients were included. In the primary prevention group (n = 66), LVEF was lower (23 ± 9% vs. 31 ± 14%; P < 0.01), ESV and WMSI were higher (223 ± 75 ml vs. 184 ± 97 ml, P = 0.04, and 1.89 ± 0.52 vs. 1.47 ± 0.68; P < 0.01), and anterior infarct localization was more frequent (P = 0.02) than in the secondary prevention group (n = 29). There were no differences in infarct tissue characteristics between patients treated for primary versus secondary prevention (P > 0.6 for all). During 21 ± 9 months of follow-up, 3 (5%) patients in the primary prevention group and 9 (31%) in the secondary prevention group experienced appropriate ICD therapy for treatment of ventricular arrhythmia (P < 0.01). There was no difference in infarct tissue characteristics between recipients of ICD for primary versus secondary prevention, while the secondary prevention group showed a higher frequency of applied ICD therapy for ventricular arrhythmia.
Asunto(s)
Arritmias Cardíacas/prevención & control , Medios de Contraste , Desfibriladores Implantables , Cardioversión Eléctrica/instrumentación , Imagen por Resonancia Cinemagnética , Infarto del Miocardio/terapia , Miocardio/patología , Prevención Primaria/métodos , Prevención Secundaria/métodos , Anciano , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/etiología , Arritmias Cardíacas/mortalidad , Arritmias Cardíacas/fisiopatología , Distribución de Chi-Cuadrado , Estudios Transversales , Cardioversión Eléctrica/efectos adversos , Cardioversión Eléctrica/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/mortalidad , Infarto del Miocardio/fisiopatología , Valor Predictivo de las Pruebas , Estudios Prospectivos , Volumen Sistólico , Análisis de Supervivencia , Resultado del Tratamiento , Función Ventricular IzquierdaRESUMEN
Left ventricular (LV) remodeling following myocardial infarction (MI) is the result of complex interactions between various factors, including presence or absence of early revascularization. The impact of early revascularization on the relationship between infarct tissue characteristics and LV remodeling is incompletely known. Therefore, we investigated in patients with versus without successful early revascularization for acute MI potential relations between infarct tissue characteristics and LV remodeling with contrast-enhanced (CE) cardiovascular magnetic resonance (CMR). Patients with versus without successful early revascularization underwent CE-CMR for tissue characterization and assessment of LV remodeling including end-diastolic and end-systolic volumes, LV ejection fraction, and wall motion score index (WMSI). CE-CMR images were analyzed for infarct tissue characteristics including core-, peri- and total-infarct size, transmural extent, and regional scar scores. In early revascularized patients (n = 46), a larger area of infarct tissue correlated significantly with larger LV dimensions and a more reduced LV function (r = 0.39-0.68; all P ≤ 0.01). Multivariate analyses identified peri-infarct size as the best predictor of LV remodeling parameters (R(2 )= 0.44-0.62). In patients without successful early revascularization (n = 47), there was no correlation between infarct area and remodeling parameters; only peri-infarct size versus WMSI (r = 0.33; P = 0.03) and transmural extent versus LVEF (r = -0.27; P = 0.07) tended to be related. A correlation between infarct tissue characteristics and LV remodeling was found only in patients with early successful revascularization. Peri-infarct size was found to be the best determinant of LV remodeling. Our findings stress the importance of taking into account infarct tissue characteristics and success of revascularization when LV remodeling is studied.
Asunto(s)
Imagen por Resonancia Cinemagnética , Infarto del Miocardio/fisiopatología , Revascularización Miocárdica , Remodelación Ventricular/fisiología , Anciano , Medios de Contraste , Intervención Médica Temprana , Femenino , Humanos , Aumento de la Imagen , Masculino , Persona de Mediana Edad , Infarto del Miocardio/terapiaRESUMEN
We present the case of a 44-year-old woman with acute coronary syndrome and multiple coronary artery-left ventricular microfistulae at angiography. To evaluate the clinical significance of this observation and to obtain further insights into this rare disease, the patient was further examined with echocardiography and both magnetic resonance imaging and single-photon emission computed tomography, which showed considerable abnormalities.