ATRIOVENTRICULAR (AV) BLOCKS

ATRIOVENTRICULAR (AV) BLOCKS:     Disorders of the atrioventricular (AV) node with conduction from the atria to the ventricles. Abnormalities range from slowing of the impulses through the AV node to complete failure of the AV node.   (See first degree AV block; second degree AV block; third degree AV block; and 2:1 AV block).
Read More

ATRIOVENTRICULAR (AV) DISSOCIATION

ATRIOVENTRICULAR (AV) DISSOCIATION:     A condition in which the atria and the ventricles beat independently from one another, and there is no communication between them through the atrioventricular (AV) node. Examples of AV Dissociation: Complete Heart Block (Third Degree Heart Block): -The AV node is not functioning which prevents the atrial beats to stimulate […]
Read More

ATRIOVENTRICULAR NODAL BYPASS TRACT

ATRIOVENTRICULAR NODAL BYPASS TRACT:     Conduction tissue connecting the atria directly to the bundle of His and bypassing the atrioventricular (AV) node. -Due to proposed James fiber. -Produces shortened AV conduction time (short PR interval).
Read More

ATRIOVENTRICULAR NODAL REENTRANT TACHYCARDIA (AVNRT)

ATRIOVENTRICULAR NODAL REENTRANT TACHYCARDIA (AVNRT):     A supraventricular tachycardia (SVT) due to a reentrant circuit within the atrioventricular (AV) node ECG findings: -Most common SVT. -Narrow QRS complexes. -May have retrograde P waves. -If P waves are present, the R to P interval is usually < 50% of the R to R interval.
Read More

ATRIOVENTRICULAR REENTRANT TACHYCARDIA (AVRT)

ATRIOVENTRICULAR REENTRANT TACHYCARDIA (AVRT):     A supraventricular tachycardia (SVT) due to reentrant circuit with one pathway within the AV node, and one pathway outside of the AV node (bypass tract). ECG Findings: Orthodromic: – Reentrant circuit goes down the AV node and up the bypass tract. – Narrow QRS complexes. – May have retrograde […]
Read More

AVNRT

AVNRT: See:  Atrioventricular nodal reentrant tachycardia; and supraventricular tachycardia.
Read More

AVRT

AVRT:     See:  Atrioventricular reentrant tachycardia; and supraventricular tachycardia.
Read More

AXIS

AXIS:     The axis of the heart is the major direction of overall electrical activity. It is measured in two different planes:  The coronal (vertical) plane and the transverse (horizontal) plane. The P wave axis and the QRS axis reflect electrical activity during depolarization. The T wave axis reflects electrical activity during ventricular repolarization. […]
Read More

BIATRIAL ABNORMALITY

BIATRIAL ABNORMALITY:     Conduction abnormality within the right and left atrium, which may be due to both right and left atrial enlargement (dilation), or right and left atrial hypertrophy (thickening). -Combination of criterial for right atrial abnormality and left atrial abnormality. -Right atrial abnormality: -P wave 2 (inferior leads):       >2.5 mm tall; […]
Read More

BIGEMINY

BIGEMINY:     Abnormal heart beats occurring every other beat (e.g. atrial bigeminy – premature atrial complexes (PACs) occurring every other beat; ventricular bigeminy – premature ventricular complexes (PVCs) occurring every other beat).
Read More