RESUMEN
Many patients who survive an acute myocardial infarction (AMI) remain at risk of recurrent cardiac events and sudden cardiac death after discharge, despite optimal medical treatment. Assessment of the degree of left ventricular dysfunction and residual myocardial ischaemia is useful to identify the patients at greatest risk. In addition, there is increasing evidence that a number of other cardiovascular tests can be used to detect autonomic dysfunction and myocardial substrate abnormalities postAMI that increase the risk of life-threatening ventricular arrhythmias. These investigations include ECG-based tests (signal averaged ECG and T-wave alternans), Holter-based recordings (heart rate variability and heart rate turbulence) and imaging techniques (echocardiography and cardiac magnetic resonance), as well as invasive electrophysiological testing. This article reviews the current evidence for the use of these additional cardiac investigations among survivors of AMI to aid in their risk stratification for malignant ventricular arrhythmias and sudden cardiac death.
Asunto(s)
Muerte Súbita Cardíaca/etiología , Infarto del Miocardio/complicaciones , Taquicardia Ventricular/diagnóstico , Factores de Edad , Ecocardiografía , Electrocardiografía , Electrocardiografía Ambulatoria , Técnicas Electrofisiológicas Cardíacas , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Medición de Riesgo , Factores Sexuales , Taquicardia Ventricular/complicaciones , Disfunción Ventricular Izquierda/complicaciones , Disfunción Ventricular Izquierda/diagnósticoRESUMEN
Many patients who survive an acute myocardial infarction (AMI) remain at risk of recurrent cardiac events and sudden cardiac death after discharge, despite optimal medical treatment. Assessment of the degree of left ventricular dysfunction and residual myocardial ischaemia is useful to identify the patients at greatest risk. In addition, there is increasing evidence that a number of other cardiovascular tests can be used to detect autonomic dysfunction and myocardial substrate abnormalities postAMI that increase the risk of life-threatening ventricular arrhythmias. These investigations include ECG-based tests (signal averaged ECG and T-wave alternans), Holter-based recordings (heart rate variability and heart rate turbulence) and imaging techniques (echocardiography and cardiac magnetic resonance), as well as invasive electrophysiological testing. This article reviews the current evidence for the use of these additional cardiac investigations among survivors of AMI to aid in their risk stratification for malignant ventricular arrhythmias and sudden cardiac death.
Asunto(s)
Femenino , Humanos , Masculino , Factores de Edad , Muerte Súbita Cardíaca , Ecocardiografía , Electrocardiografía , Electrocardiografía Ambulatoria , Técnicas Electrofisiológicas Cardíacas , Imagen por Resonancia Magnética , Infarto del Miocardio , Medición de Riesgo , Factores Sexuales , Taquicardia Ventricular , Diagnóstico , Disfunción Ventricular Izquierda , DiagnósticoRESUMEN
Chronic L-thyroxine administration (6 micrograms/100g BW, ip, daily) for 2 or 3 months suppressed serum TSH concentrations and decreased both the incidence of spontaneous lymphocytic thyroiditis (LT) and the serum levels of anti-thyroglobulin (anti-Tg) antibodies in the diabetes prone BB/Wor rat. This suggests that TSH may play a role in the occurrence of LT in this rat model. In contrast to these observations, L-thyroxine administration did not affect the markedly increased incidence of LT or the elevated serum anti-Tg antibodies in iodine supplemented BB/Wor rats, suggesting that TSH stimulation is not necessary for the development of iodine induced LT in this rat model. Other factors, such as the increased antigenicity of highly iodinated Tg, may be more important.