The region of the thorax behind the sternum and in front of the spine – includes the heart, esophagus, trachea and the major vesselsSeveral major vessels enter and exit the heart. The arteries carry blood away from the heart while the veins bring blood to the heart. While memorizing the major vessels is unnecessary, having a basic picture of the major vessels is... attached to the heart.
The heart is a wondrous organ about the size of your fist, weighing in at less than a pound (about 400 grams). Each day, the adult heart beats over 100,000 times, delivering 7500 litres of blood to the tissues of the body. The heart is dynamic, ever sensitive and responsive to mechanical, chemical and electrical stimuli. It continuously fluctuates in rateHeart Rate; calculated by counting the number of QRS complexes in six seconds and multiplying by 10; rate is also determined by measuring the number of large squares between two R waves; i.e. –1 large square = heart rate of 300/minute. and force in response to our physiologic and environmental needs.
Situated in the mediastinum directly behind the sternum, approximately 2/3 of the heart is left of the sternal border, resting on the diaphragm. The heart’s apex is at the bottom of the heart pointing left near the 5th intercostal space (ICS). The base of the heart is located near the 2nd intercostal space to the right of the sternum.
The heart is not positioned straight up. Rather, it sits on its right border (the base of the septum is pulled to the left) with the right chamber rotated anteriorly. Visualize the patient’s right lateral border of the heart being pulled forward. In turn, this would bring the left border of the heart more posterior. Nevertheless, the larger left ventricleThe left ventricle ejects blood into the aortic arch to the body. Within the arch, the coronary arteries branch off first followed by three main arteries that branch to the brain (carotids) and the upper thorax (subclavian artery). The chambers... occupies the majority of the anterior, lateral and inferior surfaces of the heart.
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. 8, 199