Background: The heart has a central, ventro basal location in the thorax and is bordered bilaterally by the lungs, anteriorly by the sternum, and inferiorly by the diaphragm . It has an oblique position in the thoracic cavity, with the cardiac apex in the left hemi thorax. The long axis of the heart is rotated about 45º to both the sagittal and the coronal planes. In younger or slender individuals, the heart tends to be more vertical, whereas it tends to be more horizontal in obese patients. It is surrounded by the pericardial sac and has no physical connections with the surrounding structures except posteriorly and superiorly where the great arteries and the caval and pulmonary veins drain into the atria. The heart is a double, two-chambered pump “right-sided” and “left sided” chambers. The right chambers are more anteriorly positioned within the chest, the left chambers more posteriorly, and the ventricles are more inferiorly located than the atria.