Cardiac Arrhythmias: Difference between revisions

The ventricle is activated through the dense network of Purkinje fibers originating from the bundle branches. They penetrate the myocardium, but predominantly the endocardium, and are the starting point of the ventricular activation. The left ventricular areas first excited are the anterior and posterior paraseptal wall and the central left surface of the interventricular septum. The last part of the left ventricle to be activated is the posterobasal area. Septal activation starts in the middle third of the left side of the interventricular septum, and at the lower third at the junction of the septum and posterior wall. Activation of the right ventricle starts near the anterior papillary muscle 5 to 10 msec after onset of the left ventricle. <ref>2</ref>