2017 Volume 33 Issue 2 Pages 111-119
The goals for the identification of arrhythmias using a 12-lead electrocardiogram (ECG) are as follows. The detection of a P-wave at 2 : 1 A–V conduction with an atrial flutter or atrial tachycardia is important. When confronted with a wide QRS tachycardia, it is necessary to determine if the arrhythmia is ventricular tachycardia or supraventricular tachycardia with ventricular conduction delay. The QRS morphology of a ventricular arrhythmia may allow for the site of origin to be determined, which is important information for catheter ablation. Even if there is no arrhythmia in a 12-lead ECG, the proarrhythmic factor can occasionally be identified. Inherited arrhythmias (e.g., LQTS, short QTS, and Brugada syndrome) can be diagnosed with a resting 12-lead ECG; however, in cases of catecholaminergic polymorphic ventricular tachycardia (CPVT), the resting 12-lead ECG is normal. Therefore, an exercise stress ECG and history of syncope are important for diagnosis. Cardiac diseases (e.g., cardiomyopathy) are also important bases of arrhythmia and we can observe abnormalities with a 12-lead ECG, even without an arrhythmia.
