Erbel R, Schweizer P, Krebs W, Meyer J, Effert S
Z Kardiol. 1978 Oct;67(10):688-94.
Ecg, left ventricular pressure measured by micromanometer-tipped catheter, and dimension measured by echocardiography were simultaneously recorded in 24 patients with coronary artery disease and 9 normal subjects. In analogy to pressure-volume diagrams, pressure-dimension diagrams were constructed, the area in systole and diastole and the cycle efficiency calculated. In patients with coronary artery disease the normal rectangular shape of the pressure-dimension diagram shows two typical deviations: 1. a dimension decrease during isovolumetric contraction and dimension increase during isovolumic relaxation in 42% of the patients, in 31% in patients with stenosis of the right coronary artery, in 56% in patients with stenosis of the left anterior descending coronary artery, in 85% in patients with a reduced ejection fraction. 2. An exact reflected image was found only in patients with stenosis of the right coronary artery and reduced ventricular function in 23%. The abnormal dimension changes are the result of an asynchronized contraction and relaxation with inward movement of one part and outward movement of another part of the left ventricle. These changes are caused by ischemic or fibrous areas of the ventricle. Independent of left ventricular pressure and dimension changes we found that the cycle efficiency was useful to study regional myocardial work. It ranged from 81.7 +/- 2.5% in the normal subjects to 74.8 +/- 1.8% in patients with reduced ventricular function. From the diastolic part of the pressure-dimension diagram the regional compliance was calculated. Dependent on coronary artery disease the regional compliance was decreased even at rest.