RESUMEN
BACKGROUND: Thrombolytic treatment substantially reduces mortality and morbidity in acute myocardial infarction. This survival benefit rapidly declines when thrombolysis is delayed. In our department this delay has previously been measured to be 40 (10-360) minutes. It is important to reduce this time loss. MATERIAL AND METHODS: From two ambulances, 168 patients ECGs were recorded and transmitted to the coronary care unit (CCU) where they were interpreted by a cardiologist or an internist. Patients with an ECG diagnostic of acute myocardial infarction were taken directly to the CCU by-passing the emergency room. In the CCU the nurses were ready to start thrombolytic treatment once consent was given. RESULTS: All 168 ECGs were of excellent quality. 16 of the ECGs transmitted were diagnostic of an acute myocardial infarction. In 15 patients the diagnosis of acute myocardial infarction could be verified on arrival. These were thrombolized at median 15 (8-32) minutes after their arrival at the hospital entrance. INTERPRETATION: Pre-hospital recording and interpreting of ECGs can markedly reduce the time delay between the arrival at the hospital and the starting of thrombolysis in patients with ECGs diagnostic of acute myocardial infarction.
Asunto(s)
Ambulancias , Electrocardiografía/métodos , Servicios Médicos de Urgencia , Infarto del Miocardio/tratamiento farmacológico , Terapia Trombolítica , Adulto , Anciano , Ambulancias/normas , Electrocardiografía/normas , Servicios Médicos de Urgencia/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/mortalidad , Noruega , Telemedicina/métodos , Telemedicina/normas , Factores de TiempoRESUMEN
OBJECTIVES: The aim of the present study was to establish the accuracy and reproducibility of left atrial volume measurements by three-dimensional (3D) echocardiography compared to 2D biplane and monoplane measurements. BACKGROUND: No echocardiographic technique is generally accepted as optimal for estimation of left atrial size. METHODS: Left atrial volumes of 18 unselected cardiac patients were obtained with magnetic resonance imaging (MRI) (volumes 145 +/- 58 ml). These volumes were compared with those obtained with different echocardiographic methods: a multiplane 3D method based on 90 images acquired by apical probe rotation, a simplified 3D method using only the three standard apical views, and 2D biplane and monoplane methods based on area-length, disc summation and spherical formulas. RESULTS: The echocardiographic methods significantly underestimated maximum left atrial volumes as obtained by MRI by 14-37% (p < 0.001). Accuracy, expressed as 1 SD of individual estimates around this systematic underestimation, was 25 to 27% for all methods, except for the 2D 2-chamber monoplane method (37%). Interobserver coefficient of variation was between 14 and 20% for all methods (n.s.). CONCLUSION: All echocardiographic methods significantly underestimated left atrial volumes as obtained by MRI. A minor non-significant improvement in individual echocardiographic estimates by the 3D methods was obtained at the cost of more time consumption. In unselected patients ultrasound image quality precludes significant improvement of left atrial volume measurements by the applied 3D methods.