Author + information
- Received May 22, 1984
- Revision received October 9, 1984
- Accepted November 2, 1984
- Published online March 1, 1985.
- Shigetake Sasayama, MD, FACC*,1,
- Hiroshi Nonogi, MD1,
- Shunichi Miyazaki, MD1,
- Tsunetaro Sakurai, MD1,
- Chuichi Kawai, MD, FACC1,a,
- Shigeru Eiho, PhD1 and
- Michiyoshi Kuwahara, PhD1
- ↵aAddress for reprints:Chuichi Kawai, MD, The Third Division, Department of Internal Medicine, Kyoto University Hospital, Sakyo-ku. Kyoto 606, Japan.
Mechanisms related to alterations in the diastolic properties of the left ventricle during angina were studied in seven patients with coronary artery disease. Single plane left ventriculograms were obtained using a high fidelity micromanometer-tipped catheter in both the resting state and immediately after rapid cardiac pacing. In all patients, typical anginal pain developed with pacing stress. After atrial pacing, the left ventricular end-diastolic pressure increased from 10 ± 3 to 21 ± 7 mm Hg (± standard deviation) (p < 0.005) regardless of the changes in the end-diastolic volume. The ejection fraction was reduced from 59 α 10 to 48 ± 13% (p < 0.05). The diastolic pressure-volume curves shifted upward in post-pacing beats in four patients, while in three the curves shifted more to the right.
The regional myocardial function was expressed in quantitative terms by a radial coordinate system with the origin at the center of gravity of the end-diastolic silhouette. Two representative radial grids for normal and ischemic segments were selected. In the normal segment, the end-diastolic length was augmented by 15% (p < 0.005) and was associated with a 24% increase in stroke excursion with pacing stress (p < 0.05). The increase in diastolic pressure was accompanied by comparable increases in end-diastolic length, and the diastolic pressure-length relation moved up to the higher portion of the single curve. In the ischemic segment, the end-diastolic length remained unchanged in the post-pacing beat, but segment shortening was significantly reduced. The diastolic pressure was higher at any given length and the pressure-length curve clearly shifted upward, indicating regional alteration of the diastolic property of the ischemic myocardium.
Thus, the net global changes in the ventricular chamber compliance are determined by the complex interaction of changes in pressure-length relation of the regional myocardium.
- Received May 22, 1984.
- Revision received October 9, 1984.
- Accepted November 2, 1984.
- American College of Cardiology Foundation