Cardiac Cycle and ECG Overview

These flashcards cover key vocabulary and concepts related to the cardiac conduction system and electrocardiogram interpretations.

Sinoatrial (SA) node

The heart's pacemaker located in the right atrium that initiates the heartbeat.

Atrioventricular (AV) node

Located at the junction of the atria and ventricles, it receives impulses from the SA node.

Purkinje fibers

Network of fibers that distribute impulses from the bundle branches to the ventricular muscle cells.

RR interval

The duration between two successive R waves in an ECG, used to calculate heart rate.

QT interval

Duration from the start of ventricular depolarization to the end of repolarization in the cardiac cycle.

ECG (Electrocardiogram)

Graphical representation of electrical activity of the heart.

Heart block

Condition where the AV node fails to conduct some impulses, slowing the heart rate.

Atrial fibrillation

Disorganized electrical activity in the atria, affecting blood filling and increasing clot risk.

Ventricular fibrillation

Disorganized electrical activity in the ventricles, leading to ineffective heart contractions.

Cardiac cycle

The sequence of events in one heartbeat, including periods of contraction and relaxation.