Clinical and laboratory testing

The history, physical examination, and ECG are of paramount importance in the evaluation of patients with a suspected arrhythmia.

· Resting Electrocardiogram: The judicious use of non-invasive diagnostic tests is an important element in the evaluation of patients with arrhythmias, and there is no test more important than the ECG. An algorithm for the diagnosis of specific tachyarrhythmias from the 12-lead ECG is as follows:

Some other outpatient monitoring systems available are:

· Traditional Holter: Continuous recording of ECG, usually for 24 or 48 hours.

· Event recorder: This is a patient activated recorder, although some newer models have automatic arrhythmia detection software to store asymptomatic episodes. Data is transmitted over the phone to a monitoring station.

· Mobile continuous outpatient cardiac telemetry: Continuous recording and analysis, with symptomatic or algorithm defined episodes transmitted automatically via cellular technology to monitoring station.

· Insertable cardiac monitor: Patient and algorithm defined episodes stored in the device, until interrogated either in office or remotely via home equipment and the internet.

· New patch monitors: These can record data for several weeks. Smartphone apps have been used to revolutionize external recording techniques and to detect atrial fibrillation.

· Other over-the-counter monitoring approaches (using certain types of watches) and other types of electrodes coupled to cell phones are also being used to detect atrial fibrillation and other rhythm disturbances.


Shen WK, Sheldon RS, Benditt DG, et al. 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society. J Am Coll Cardiol 2017.