著者

Shirato Kunio KANAZAWA MASAHARU ISHIKAWA KEN NAKAJIMA TOSHIYUKI TAKISHIMA TAMOTSU

出版者

社団法人日本循環器学会

雑誌

Japanese circulation journal (ISSN:00471828)

巻号頁・発行日

vol.46, no.1, pp.113-123, 1982-01-20

被引用文献数

1

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We studied the effect of the pericardium on the end-diastolic pressure-segment length (P-L) relation in volume loading (Experiment I) and in acute ischemia (Experiment II). Experiment I: In 6 open chest dogs, segment length of left and right ventricles were measured using ultrasonic crystals during blood infusion. Drawing end-diastolic pressure (P, on ordinate) against segment length (L, on abscissa), the P-L curve with pericardium positioned upward compared to that without pericardium. The slopes (b) of the exponential curve (P = ae^<bL>) with pericardium were steeper than those without pericardium in both ventricles. The difference between the slopes with and without pericardium was significantly larger in the right ventricle (RV, 0.30 ± 0. 10, mean ± SEM) than in the left ventricle (LV, 0.05 ± 0.02, p < 0.05). These results show that the pericardium inhibits the distensibility of the free wall more in RV than in LV, and enhances a mechanical coupling of both ventricles during volume overload. Experiment II: In 8 open chest dogs, segment lengths of ischemic and non-ischemic regions in LV were measured after left circumflex coronary occlusion. When the segment lengths and LV pressure became stable, a pericardiectomy was performed. After the pericardiectomy, whereas heart rate and LV systolic pressure did not change, end-diastolic segment length in the ischemic region further lengthened (12.0 0.2 to 12.5 0.2 mm, p < 0.01) and that in the non-ischemic region did not change despite the concomitant fall in LV end-diastolic pressure (EDP, 11.9 0.6 to 9.8 0.6 mmHg, p < 0.01). These results suggest that the pericardium alters the LV end-diastolic pressure-volume relation and is one of the factors contributing to an increase in LVEDP during acute ischemia.