Figure 33. Frontal view of the chest shows a combination biventricular pacemaker and an automatic implantable cardioverter defibrillator with a battery pack (B) and right atrial (RA), right ventricular (RV), and coronary venous (CV) leads. Note also the left ventricular calcification from a past myocardial infarction. The coronary venous lead is positioned in a vein draining the posterior inferior wall of the left ventricle so that it can stimulate functional myocardial tissue rather than the nonfunctioning tissue represented by the ventricular wall calcification and probable myocardial aneurysm.