BIOM1060 L2 ECG_2025

Electrocardiography (ECG)

A technique that records the overall spread of electrical activity of the heart during the cardiac cycle.

Pacemaker cells

Cells that generate impulses to initiate electrical activity in the heart.

Sinoatrial (SA) node

The heart's primary pacemaker, which generates impulses that spread through the atria.

Atrioventricular (AV) node

The node that receives impulses from the SA node and connects the atria to the ventricles.

QRS complex

The section of the ECG that represents ventricular depolarization.

T wave

The part of the ECG that indicates ventricular repolarization.

Diastole

The phase of the cardiac cycle when the heart relaxes and fills with blood.

Systole

The phase of the cardiac cycle when the heart contracts and pumps blood.

P wave

The part of the ECG that represents atrial depolarization.

Lead (in ECG)

A view of the electrical activity of the heart from a specific angle.

End Diastolic Volume (EDV)

The volume of blood in the ventricles at the end of diastole.

Stroke Volume (SV)

The volume of blood ejected from each ventricle during contraction.

End Systolic Volume (ESV)

The volume of blood in the ventricles at the end of systole.

Mean Electrical Axis

The average direction of spread of depolarization through the ventricles during the R wave.

Junctional rhythm

A heart rhythm where the SA node is non-functional, resulting in absent P waves.

Second-degree heart block

A condition where the AV node fails to conduct all SA node impulses, resulting in more P waves than QRS waves.

Ventricular fibrillation

A severe arrhythmia characterized by chaotic electrical activity and ineffective heart contractions.

PR interval

The time interval from the beginning of the P wave to the beginning of the QRS complex.

T-P interval

The period between the T wave and the succeeding P wave, indicating the resting state of the heart.