Junctional & Ventricular Rhythms

These flashcards cover key terms and definitions related to junctional rhythms and various cardiac rhythms.

AV Node

A group of specialized cells located in the lower portion of the right atrium, responsible for delaying electrical impulses.

Bundle of His

Located in the upper part of the interventricular septum, connecting the AV node with the two bundle branches.

Junctional Rhythm

A rhythm originating from the AV junction, especially if normal pacemaking fails.

Premature Junctional Complex (PJC)

Occurs when an irritable site within the AV junction fires before the next SA node impulse.

Junctional Escape Beat

A junctional beat that appears late after the expected sinus beat.

Accelerated Junctional Rhythm

A junctional rhythm with a rate of 60-100 bpm, indicating faster pacing from the AV junction.

Junctional Tachycardia

A rhythm originating in the bundle of His with a heart rate of 100-150 bpm.

Supraventricular Tachycardia (SVT)

A rapid heart rate originating above the ventricles, not specifically a junctional rhythm.

Retrograde Activation

The backward direction of electrical impulses that activates the atria in junctional rhythms.

Inverted P Wave

A P wave that appears inverted in specific leads due to retrograde activation from the AV junction.

PR Interval

The time interval between atrial depolarization and ventricular depolarization, usually shorter in junctional rhythms.

Ventricular Conduction Pathway

The normal pathway through which impulses are conducted from the AV node to the ventricles.

Compensatory Pause

A pause following a PVC during which the SA node resets its rhythm.

Irregular Rhythm

A rhythm characterized by variability, often seen in junctional escape beats.

QRS Complex

The graphical representation of ventricular depolarization on an ECG.

Sinoatrial (SA) Node

The primary pacemaker of the heart, located in the right atrium.

Atrial Depolarization

The process of electrical activation of the atria before ventricular contraction.

Junctional Bradycardia

A junctional rhythm with a rate slower than 40 bpm, indicating abnormal pacing.

BPM

Beats per minute, a measure of heart rate.

Ectopic Focus

An abnormal pacemaker site that can cause premature beats.

Multifocal PVCs

PVCs with multiple morphologies indicating more than one irritated area.

Bigeminy

A pattern where PVCs occur every second beat.

Trigeminy

A pattern where PVCs occur every third beat.

Quadrigeminy

A pattern where PVCs occur every fourth beat.

Idio-Ventricular Rhythm

A rhythm originating solely from the ventricles, typically with a rate of 20-40 bpm.

Ventricular Fibrillation

A life-threatening condition where ventricles quiver instead of contracting effectively.

Asystole

The absence of electrical activity in the heart, often referred to as cardiac standstill.

P Wave

The graphical representation of atrial depolarization on an ECG.

Atrioventricular Block (AV Block)

A blockage in the electrical conduction from the atria to the ventricles.

Delay of Impulse

A delay provided by the AV node allowing for efficient filling of the ventricles.

Electrical Impulse

The signal that triggers heart muscle contractions.

Ventricular Rate

The rate of electrical impulses in the ventricles, typically measured in bpm.

Pacemaker Cells

Cells in the heart that generate electrical impulses to control heart rate.

ECG leads

The electrodes placed on the body to create an electrocardiogram.

Clinical Electrocardiography

The study and interpretation of electrocardiograms to diagnose heart conditions.

Normal Sinus Rhythm

The typical rhythm of the heart, originating from the SA node.

Rhythm Regularity

A measure of how consistently the heart beats in a given duration.

Ventricular Tachycardia (VT)

A condition characterized by three or more consecutive PVCs with a rate exceeding 100 bpm.

Defibrillation

Delivery of an electrical current to terminate an abnormal heart rhythm.

T Wave

The graphical representation of ventricular repolarization on an ECG.

Cardiac Output

The volume of blood the heart pumps per minute.

Cervical Ribs

An additional set of ribs that can affect cardiac function.

Unifocal PVCs

PVCs that arise from a single irritable area in the ventricles.

Coupling (PVCs)

Two PVCs occurring back to back.

Premature Atrial Contractions (PACs)

Early heartbeats originating from the atrial tissue.

Impulse Generation

The creation of electrical signals that initiate heart contraction.

last Ordered Resemblance

The last recognizable heart rhythm before cardiac arrest.

Intrinsic Rate

The natural firing rate of the heart's pacemaker regions.

Myocardial Cells

The cells of the heart muscle responsible for contraction.