This still picture from a left ventricular angiogram shows a bulge in the anterolateral region of the left ventricle in systole suggestive of an aneurysm. A true aneurysm is composed of all three layers of the heart, namely endocardium, myocardium and pericardium. It has a wide neck and is very unlikely to rupture. In contrast, a pseudo aneurysm is a ventricular rupture sealed off by the pericardium. It has a narrow neck and has a high risk of secondary rupture. A true aneurysm can cause arrhythmias due to the viable tissue in the oorder zone with varying refractory periods which can cause re-entrant arrhythmias. It can also lead to refractory heart failure due to wasted systole – i.e., a portion of the ventricular blood moves in and out of the aneurysm without being pumped out into the aorta.
The region of the aneurysm is usually the territory of a poorly collateralised total or near total coronary occlusion. In this case it is near total occlusion of the left anterior descending coronary artery beyond a major diagonal with faint anterograde flow (blue arrows)


http://cardiophile.org/2008/12/features-of-left-ventricular-aneurysm.html