THE NATURE OF THE DISORDER OF FUNCTION IN CHRONIC POSTINFARCTION ANEURYSM OF THE LEFT VENTRICLE.

Assessment of left ventricular function in five patients with chronic postinfarction left ventricular aneurysm was carried out at the time of left heart catheterization and compared with that in six normal subjects. One patient was investigated before and after surgical resection of the aneurysm. The presence of the aneurysm placed the left ventricle at a mechanical disadvantage in systole and increased the resistance to diastolic filling (impedance). This was true even in patients with normal cardiac indices who were not badly disabled. Resection of the aneurysm corrected both these abnormalities, and, as well, lowered the time-tension index at a time when calculated left ventricular work was much increased. These differences between normals and patients with aneurysms, and the changes occurring as a result of resection of an aneurysm, show that the presence of the aneurysm places the left ventricle at a mechanical disadvantage in systole as well as altering its diastolic filling characteristics.