The means consist of noting something a little technical, ST segment elevation of the electrogram — translated into English, that means that if there's an electrical signal in the heart, and one part of the ECG — which we call the ST segment — elevates, that is a sure sign of a heart attack.
En lenguaje simple, eso significa que si hay una señal eléctrica en el corazón, y una parte del ECG — a la que llamamos el segmento ST — se eleva, éso es un signo seguro de un ataque al corazón.