Following the depolarization of the interventricular septum, ventricular depolarization then progresses from the endocardium through to the epicardium across both ventricles producing an R wave

The phenomenon of R wave progression utilizes the following six leads: V1, V2, V3, V4, V5, V6. The chest leads provide information on the sagittal

Heart Rate; calculated by counting the number of QRS complexes in six seconds and multiplying by 10; rate is also determined by measuring the number

One of several causes of dysrhythmias, the re-entry loop often results in tachycardias; the re-entry loop requires an area with slowed speed of conduction, an

Occasionally, a lead view provides a mirror-like representation for the opposite surface of the heart. For example, ST elevation in anterior leads (V1-V4) may present

Also known as normal sinus rhythm or sinus rhythm, this cardiac rhythm is not a dysrhythmia; sinus rhythm originates in the sinoatrial (SA) node with

In phase 3 of the action potential, once the cell repolarizes to threshold potential to –90 mV, the cell’s ion channels are once again receptive

Follows depolarization, involving the return to a pre-depolarization state; the myocardial cell’s electrical potential returns from +30 mV to its polarized state of –90 mV;

Conduction along the electrical pathway opposite in direction from what occurs in sinus rhythm. 1. Six Second ECG Guidebook (2012), T Barill, p. 204

Often refers to a discernible pattern in time or distance between QRS complexes and/or P waves.

An ECG rhythm that is initiated by one of several intrinsic pacemaker sites of a heart will often generate a regular, even rhythm pattern. This

A bundle branch block must satisfy two criteria – a wide QRS complex and a notch in the QRS complex. To distinguish between a RBBB