SA Node

The SA node, usually the dominant pacemaker, is located in the right atrium at the opening of the superior vena cava. The SA (sinoatrial) node Read More

Salvo

A sudden group of 3 or more ectopic beats or complexes (also called a burst or a run). 1. Six Second ECG Guidebook (2012), T Read More

Segment

A line between waves. Segments measure time between waves (waves are not included in a segment). While waves are fairly self-explanatory, intervals measure time from Read More

Semilunar Valves

Valves located at the exit route of the ventricles; for the right ventricle, connects with the pulmonary artery; for the left ventricle, connects with the Read More

Sensitivity

A function of an artificial pacemaker to sense intrinsic electrical activity of the heart. 1. Six Second ECG Guidebook (2012), T Barill, p. 205 Read More

Septal Fascicle

Normal ventricular depolarization begins with the septal fascicle of the left bundle branch (causing a Q wave) followed by a simultaneous depolarization of the remaining Read More

Shock

Signs and symptoms of shock include shortness of breath, chest pain, hypotension, and an altered level of consciousness (due to hemodynamic compromise). As a general Read More