Crozatier B, Caillet D, Jouannot P, Hatt P Y
Basic Res Cardiol. 1979 Nov-Dec;74(6):639-48. doi: 10.1007/BF01907505.
Sustained mechanical alternation appeared after a spontaneous premature ventricular contraction in 6 open-chest dogs during the perfusion of the left circumflex coronary artery by Krebs-Henseleit solution equilibrated with 5% CO2 and 95% N2. The animals were instrumented with a catheter in the left ventricle and ultrasonic crystals in hypoxic and control segments. Left ventricular systolic pressure was significantly higher in the strong than in the weak beats with no significant difference of end-diastolic lengths in hypoxic and control segments. In hypoxic segments, systolic shortening was significantly larger in strong beats (11.9 +/- 1.9%) as compared with weak beats (5.1 +/- 1.6%) and with control beats preceding the premature ventricular contraction (9.7 +/- 1.6%) but the postextrasystolic beat was larger (17.9 +/- 1.3%). There was no significant change of systolic shortening in control segments during mechanical alternation which appears thus as a regional phenomenon which cannot be explained by the Starling mechanism: instead, alternation is attributed to a change of excitation-contraction coupling after a premature contraction with alternation of potentiation and attenuation of the inotropic state.
在6只开胸犬中，用含5%二氧化碳和95%氮气平衡的克雷布斯 - 亨泽莱特溶液灌注左旋冠状动脉时，自发室性早搏后出现了持续性机械交替。这些动物在左心室植入导管，并在缺氧段和对照段植入超声晶体。强搏动时左心室收缩压显著高于弱搏动，缺氧段和对照段的舒张末期长度无显著差异。在缺氧段，强搏动时的收缩期缩短（11.9±1.9%）显著大于弱搏动（5.1±1.6%）以及早搏前的对照搏动（9.7±1.6%），但早搏后的搏动更大（17.9±1.3%）。在机械交替期间，对照段的收缩期缩短无显著变化，因此机械交替表现为一种局部现象，不能用斯塔林机制来解释：相反，交替归因于早搏后兴奋 - 收缩偶联的变化，伴有变力状态的增强和减弱交替。
