So what is an electrocardiogram (SECA ECG or EKG, shortened from the German Elektrokardiogramm)? It is a visual graphic produced by an electrocardiogram machine, which prints onto a piece of scaled tape the electrical signals of the heart recorded from the time the equipment is attached. Electro, which is the first part of the word is related to the electrical impulses or activity that are given out by the heart, Cardio is Greek for heart and Gram, has a Greek root meaning "to write". In the US, the abbreviation "EKG" which as mentioned earlier is the german abbreviation is often preferred over "SECA ECG". "SECA ECG" is used a lot in the United Kingdom and many other countries.

The Sinoatrial node is the place that the heart's electrical pulses come from, the electrical pulse, pulses through the heart's conductive tissue and makes it contract. The electrical pulse that is given out by the Sinoatrial node is then measured by placing electrical pads on each side of the heart. The pulse of electricity moves through the heart it is printed down by the SECA ECG machine. The figures displayed on the electrocardiograph SECA ECG are then interpreted to let the health professional understand what is happening through the heart. Giving indications of the beat of the heart and any drop of the electrical impulse through the heart.

If a health professional is attempting to ascertain the working function of the heart a health professional will look to the newer processes of ultrasound or nuclear medicine testing. SECA ECG's are the most practical way of seeing if there is an unbalanced heart beat particularly in the case of conductive tissue damage in the heart or high and low amounts of dissolved salts.