After 100 years, the 12-lead electrocardiogram (ECG) remains the most accessible and inexpensive noninvasive diagnostic and prognostic tool in cardiology. Almost every hospitalized patient will ...

In a “normal” electrocardiogram (ECG), the transition of the QRS axis in the precordial leads occurs between leads V 3 and V 4 (i.e., there is a dominant S in V 3 and a dominant R in V 4).

The QRS complex is positive in lead I and negative in lead II and also negative in lead aVF – indicating left axis deviation TIP When you see RBBB always look for 1 st degree heart block and/or left ...

From the Cardiology and Surgery Branches, National Heart Institute. Select the format you want to export the citation of this publication.

The ECG shows an irregularly irregular rapid ventricular rate, approximately 120 beats per minute, with no visible P waves. The frontal plane QRS axis is –30° and the R wave voltage in AVL is 15 mV.

The ECG shows sinus tachycardia at about 115 beats per minute with a PR interval of about 0.15 sec (normal). The P waves show normal duration, but they are peaked in II, II and AVF and their amplitude ...