Electrocardiographic methods including monitoring	Class	References
Twelve-lead electrocardiogram (ECG) should be obtained in all patients undergoing evaluation for known or suspected heart disease.		17
The 12-lead ECG provides diagnostic and prognostic information in patients with inherited high-risk syndromes including long QT syndrome (LQTS), short QT syndrome, Brugada Syndrome, and arrhythmogenic cardiomyopathy (ACM) and should be obtained.		17
Exercise ECG provides diagnostic and prognostic information for patients with LQTS ACM, hypertrophic cardiomyopathy (HCM), catecholaminergic polymorphic ventricular tachycardia, and documented or suspected arrhythmias related to exertion, and should be obtained.		17
Ambulatory ECG evidence of non-sustained ventricular tachycardia provides prognostic information in ischaemic cardiomyopathy, ACM, and HCM and should be obtained.		17
The signal-averaged ECG and QRS fragmentation may aid in the diagnosis of ACM.		18
The signal-averaged ECG and QRS fragmentation may be useful in risk stratification of Brugada syndrome.		18
Heart rate variability, heart rate turbulence, signal-averaged ECG, and T wave alternans analysis, when used in combination with additional clinical, electrocardiographic, and structural measures, may be useful for identifying high- and low-risk groups among patients with acquired structural heart disease.		19