Wide 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 arriving early without preceding 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... are likely premature ventricular complexes (PVCA wide QRS complex that arrives early is called a premature ventricular complex (PVC). A PVC has a width of 0.12 seconds or longer. The elongated period of ventricular depolarization is caused by an abnormal, less efficient pathway of ventricular...). When the PVC comes in pairs, they are called ventricular couplets.
A series of PVC of three of more that terminates in the normal underlying rhythmWhile a rhythm as a whole may be irregular, segments may be regular. These regular periods are often referred to as the underlying rhythm. Apply the three step method to the underlying rhythm first. When naming a rhythm, the underlying... is called non-sustained ventricular tachycardiaIs a cardiac rhythm characterized by rapidly occurring wide QRS complexes with absent or infrequent P waves evident; the absence of atrial kick, the lack of filling time, and the tendency for ventricular tachycardia to change to ventricular fibrillation makes... (also referred to as a runA sudden group of 3 or more ectopic beats or complexes (also called a burst or a salvo). 1. Six Second ECG Guidebook (2012), T Barill, p. 204, salvoA sudden group of 3 or more ectopic beats or complexes (also called a burst or a run). 1. Six Second ECG Guidebook (2012), T Barill, p. 205, or burst of ventricular tachycardiaNon-sustained episodes of ventricular tachycardia (runs of VT) - consisting of 3 or more consecutive PVCs - can also be called bursts or salvos of ventricular tachycardia. A patient often senses a period of syncope during these episodes. Runs of...).
Premature ventricular complexes are often produced by enhanced sodium permeability of the ventricular myocytes, caused by increased catecholamine levels (increase in endogenous epinephrine can occur from a variety of conditions such as emotional stress, fatigue, anxiety, pain, infection). Other causes include myocardial 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 electrolyte imbalances.
