A narrow QRS complexThe electrical representation of ventricular depolarization; the atrial repolarization is also a part of the QRS. ECG interpretation relies heavily on the QRS complex. The QRS complex represents the depolarization of the ventricles. The repolarization of the atria is also... that arrives distinctly earlier than expected can be a premature atrial complexEarly QRS complexes (usually narrow) make the ECG rhythm pattern irregular. Atrial impulses are preceded by abnormal P waves, often biphasic, but always distinct from the P waves generated by a sinus node. Premature atrial complexes (PAC) are typically benign,... or a premature junctional complexA collection of waveforms (i.e. QRS complex and the ECG complex). 1. Six Second ECG Guidebook (2012), T Barill, p. 194 (PJC). A PJC can be preceded by an inverted P waveA wave generated from the depolarization of the atria; the P wave is upright when originating from the SA node. The P wave represents the depolarization of the right and left atria. The P wave begins with the first deviation..., no P wave (timing places the inverted P wave at the same time as the QRS – effectively burying the P wave), or even an inverted P wave after the QRS complex. The causes of a PJC are often unknown but can be related to catecholamine levels (higher epinephrine due to anxiety, fatigue, infection, pain, etc.), toxicity (digitalis for example) and ischemiaInsufficient supply of oxygen to meet the oxygen demands of tissue. Anaerobic metabolism becomes increasingly important during periods of ischemia. Ischemia results from an inadequate blood flow that fails to meet the oxygen demands (energy demands) of tissues. If tissues....
1. Six Second ECG GuidebookA Practice Guide to Basic and 12 Lead ECG Interpretation, written by Tracy Barill, 2012 Introduction The ability to correctly interpret an electrocardiogram (ECG), be it a simple six second strip or a 12 lead ECG, is a vital skill... (2012), T Barill, p. 203