Prolonged pauses in electrical activity – no P wavesA 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... or QRSThe 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... complexes – points to trouble at or near the sinus node.
The return of sinus rhythmAlso known as regular sinus rhythm or sinus rhythm, this cardiac rhythm is not a dysrhythmia; sinus rhythm originates in the sinoatrial (SA) node with a rate of 60-100/minute; P waves are upright in most leads and the QRS is... occurring off schedule – off the cadence expected from a consistently firing sinus node – suggests that the sinus node ceased impulse formation (sinus arrest or sinus pause).
Several mechanisms can cause the sinus node to falter including 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... and the untoward effects – toxicity – of nodalCommonly refers to the junction; for example, junctional rhythm is also known as nodal rhythm; may also refer to the sinoatrial node. 1. Six Second ECG Guidebook (2012), T Barill, p. 200 medications that slow nodal firing i.e. ABCD – amiodarone, beta blockers, calcium channel blockers, and digitalis. Perhaps the silver lining to this rhythmOften refers to a discernible pattern in time or distance between QRS complexes and/or P waves. is that the causes of a sinus arrest could be resolved i.e. alter medication dosing. A permanent implanted cardiac pacemakerAn electronic pulse generator that stimulates depolarization of the atria and/or the ventricles. 1. Six Second ECG Guidebook (2012), T Barill, p. 201 may not be required for those who experience pre-syncopal episodes.
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. 206