Archives

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 More

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 More

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 More

One of two types of fibres that lie parallel to each other; with the influx of calcium into the cell the fibres bind together and Read More

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 More

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 More

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 More

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 More

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 More

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 More