Cardiac monitoring is usually carried out using electrocardiography, which is a noninvasive process that records the heart's electrical activity and displays it in an electrocardiogram.

Information obtained from ECGs can then be used to direct the patient's treatment at a care facility, particularly in catheterization labs.

This is particularly good for EMS services, who need a compact, easy to use monitor and defibrillator, as well as for patient transport.

Most modern monitors also allow for transmission of an ECG sample to an emergency department for interpretation; this process may be used to speed up patient care in certain situations, such as bypassing the ED and proceeding to a cath lab.

Examples of monitor defibrillators are the Lifepak 12, 15 and 20 made by Physio Control, the Philips Heartstart MRx, and the E, R, and X Series by ZOLL Medical.

A third classification, the implantable loop recorder, provides both automatic and manual abilities.

For long term use, an Insertable Cardiac Monitor is placed under the skin and automatically detects and records abnormal heart rhythms for up to 5 years.

[7] Monitoring the fetal heart rate is becoming increasingly prevalent in the standard care of antepartum pregnant patients.

The accuracy of the wearable optical heart rate monitors varies with the type of exercise.