“An echocardiogram showed that the tip of the pacemaker catheter extended through the right ventricular apical wall of the epicardium.”
“It has been known that muscle fibers in a heart are arranged in such a way that their orientation changes continuously from endocardium to epicardium of the free wall.”
“Coronary vessels supplying arterial blood to the heart penetrate the epicardium before entering the myocardium.”