Control of the Cardiac Cycle

L/O To be able to identify key features of an ECGTo know the roles of the sinoatrial node, the atrioventricular node and the Purkyne tissue

13 April 2023

Myogenic Heart

• http://www.youtube.com/watch?v=MojGH5PXSTU

Synchronised pumping

Defibrillation

TV Lies

TV Lies

Control of the Cardiac Cycle

• Sinoatrial node (SAN) aka pacemaker – top of right atrium

• Atrioventricular node (AVN) – top of the inter-ventricular septum

• Purkyne Tissue – runs down the inter-ventricular septum

SAN, AVN and Purkyne Tissue

SAN, AVN and Purkyne Tissue

Electrocardiograms

Electrocardiograms

P = atrial excitation

QRS = excitation of ventricles

T = diastole

Heart Attacks

• Heart muscle respires fatty acids• Respiration of fat can only happen aerobically,

so the heart needs oxygen• A blood clot in the coronary artery starves

part of the heart muscle of oxygen and those cells die

Heart murmurs

• http://www.youtube.com/watch?v=XvtBpnV_lOE