The phase of relaxation during the cardiac cycleA complete cardiac cycle occurs with each audible ‘lub-dub’ that is heard with a stethoscope. During this heartbeat, both atria simultaneously contract followed soon after by the contraction of the ventricles. Systole is the contractile phase of each chamber while...; occurs for the atriaRight and left atria (1/3 volume and muscle mass of the ventricles) pump blood to the ventricles. Chambers and Layers of the Heart 1. Six Second ECG Guidebook (2012), T Barill, p. 190 and the ventriclesThe larger chambers of the heart (3 times the volume and muscle thickness than the atria), responsible for the pumping of blood to the lungs and the rest of the body.; blood enters the heart’s chambers and the coronary arteriesThe coronary arteries provide blood to the heart tissues, carrying blood first across the epicardium, then the myocardium and finally terminating in the endocardium. The epicardium forms the outer layer of the heart. The myocardium forms the middle layer and... during diastole; note that diastole is as important as systoleA contraction phase of the cardiac cycle; systole takes about 1/3 of the time of the cardiac cycle (2/3 of the time is taken by diastole). A complete cardiac cycle occurs with each audible ‘lub-dub’ that is heard with a... – the negative pressure created by chamber relaxation and opening draws blood into the chamber; diastole lasts approximately twice the period of systole (for heart rates up to 150-170/minute).
1. Six Second ECG GuidebookA Practice Guide to Basic and 12 Lead ECG Interpretation, written by Tracy Barill, 2012 Introduction The ability to correctly interpret an electrocardiogram (ECG), be it a simple six second strip or a 12 lead ECG, is a vital skill... (2012), T Barill, p. 22, 195