Six Second ECG Glossary
Helping you understand the technical terms of ECG interpretation
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12-Lead ECG
The 12-lead ECG provides 12 views of the heart. The 12 views are generated through only 10 electrodes. Four limb electrodes attach to the inner...
Read More12-Lead ECG – lead views
The ten electrodes combine to provide 12 views of the heart. The limb leads combine to provide the three bipolar leads (leads I, II, and...
Read More12-Lead ECG – systematic analysis
Equipped with a carefully formed clinical impression of the patient, a systematic approach to 12-lead ECG interpretation makes the 12-lead ECG a reliable assessment tool....
Read More12-Lead Views
The ten electrodes combine to provide 12 views of the heart. The limb leads combine to provide the three bipolar leads (leads I, II, and...
Read More15 and 18 Lead ECG
A 12 Lead ECG provides a fairly good electrical picture of the left side of the heart. The right side of the heart is somewhat...
Read MoreAberrant Conduction
For about 15% of rhythms with wide QRS complexes, impaired bundle branch conductivity prolongs ventricular depolarization. Ischemia, infarction, and antiarrythmics can slow or block transmission...
Read MoreAbnormal P Wave
A normal wave is typically upright in leads I, II and aVF, and biphasic in lead V1. An abnormal P wave can possess several alternate...
Read MoreAbnormal T Wave
A wave that includes both an upright (positive) and downward (negative) deflection. Expect a T wave to follow every QRS complex. The T wave is...
Read MoreAbsolute Refractory Period
Period when the cardiac cells cannot depolarize irrespective of the strength of the electrical impulse. 1. Six Second ECG Guidebook (2012), T Barill, p. 189
Read MoreAccelerated Idioventricular Rhythm
Cardiac rhythm that originates from the ventricular with a rate of 40-100/minute; QRS is wide with P waves absent. Pacemaker sites can deliver impulses faster...
Read MoreAccelerated Junctional Rhythm
A cardiac rhythm that originates from the AV junction with a rate of 60-100/minute; QRS complex is most often narrow with P waves that are...
Read MoreAccelerated Rhythms
Rhythms that are not quite tachycardias but are faster than what is expected from a pacemaker site. These rhythms are called accelerated rhythms. For example,...
Read MoreAccessory Pathway
Alternative connecting pathway between the atria and the ventricles (beside the bundle of His); resulting syndrome is called Woolf-Parkinson-White syndrome. 1. Six Second ECG Guidebook...
Read MoreAction Potential
The electrical activities of a cell from depolarization to repolarization; 5 phases (0-4) take place largely involving the sodium, potassium and calcium ions. 1. Six...
Read MoreAction Potential – Phase 0
Phase of depolarization: for myocardial cells the slow sodium channels open, and then, if threshold potential is reached, fast sodium channels open; note that cells...
Read MoreAction Potential – Phase 1
Depolarization has now completed; repolarization begins with the efflux of potassium from the cell. 1. Six Second ECG Guidebook (2012), T Barill, p. 202
Read MoreAction Potential – Phase 2
Potassium leaves the cell while calcium enters the cell resulting in an electrical plateau; the calcium entering the cell is significant because it initiates the...
Read MoreAction Potential – Phase 3
Potassium leaves the cell resulting in the cell becoming increasingly negative; at 60-70 mV, the cell’s fast sodium channels begin to be receptive to causing...
Read MoreAction Potential – Phase 4
The polarized state of the cell with resting negative potential of approximately –90 mV; early in this phase, the sodium-potassium ATP pump restores the cell...
Read MoreAerobic Metabolism
Metabolism that utilizes oxygen is called aerobic metabolism. Energy production through oxygenation (with oxygen) yielding 32 ATP molecules from the interaction of one glucose and...
Read MoreAgonal Rhythm
A fatal dysrhythmia with rates usually less than 20/minute and common widening of the QRS; also referred to as the dying heart. Asystole is characterized...
Read MoreAlpha Stimulation
The peripheral vasoconstriction that results from circulating catecholamines (epinephrine & norepinephrine). 1. Six Second ECG Guidebook (2012), T Barill, p. 190
Read MoreAnaerobic Metabolism
Energy production without oxygen with only 2 ATP produced as well as lactic and pyruvic acid. When energy demands surpass the supply of vital energy...
Read MoreAnterior Fascicle
The left bundle branch splits into the septal, anterior and posterior fascicles. Normal ventricular depolarization begins with the septal fascicle of the left bundle branch...
Read MoreAnterior Infarction and R wave progression
Poor R wave progression (i.e. not until leads V5 or V6) may signal an anterior infarction. In line with QRS axis deviation, abnormal R wave...
Read MoreANCC Accredited Courses
Earn contact hours through our Six Second ECG Essentials, Six Second ECG Master Class, and SEPSA courses.
Six Second ECG® Essentials
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