Yamamura H, Nakazawa M, Park I, Nakanishi T, Momma K, Imai Y
Department of Pediatric Cardiology, Tokyo Women's Medical College, Japan.
Heart Vessels. 1994;9(6):307-14. doi: 10.1007/BF01745096.
Coordinated contraction of the ventricle is an important determinant of pump function, which seems to be particularly important in Fontan circulation with one pumping ventricle. We analyzed the synchronism of contraction of the two ventricles in 11 patients with a biventricular heart who had undergone Fontan operation. Curves representing ventricular volume changes in a cardiac cycle measured on angiograms were smoothed and divided into 20 segments. We calculated the number of segments of the same directional volume changes (synchronous changes) between the two ventricles (synchronous ratio). We also calculated the total volume of the two ventricles (the two as one whole ventricle) by adding their volumes in each segment and calculated the ratio (stroke volume ratio) of the aortic stroke volume from the whole ventricle to the sum of stroke volumes of the morphological right and left ventricles. If the two ventricles ejected the blood in a completely synchronous manner, these ratios should be 1.0. In seven patients with synchronous ratios of 0.75 or greater and a stroke volume ratio of greater than 0.95, the cardiac index was 3.2 +/- 0.3 l/min/m2, the maximum total volume (corresponding to end-diastolic volume) was 106 +/- 45% normal, and the ejection fraction was 0.44 +/- 0.10. In four patients with ratios of less than 0.70 and 0.95, respectively, the parameters were 2.4 +/- 0.5 (P < 0.05), 193 +/- 92%, and 0.33 +/- 0.08, respectively. The synchronous ratio was inversely correlated with cardiac output. In conclusion, synchronism of the cardiac cycle of the two ventricles affects Fontan circulation in patients with a biventricular heart.
心室的协调收缩是泵功能的一个重要决定因素，这在单心室的Fontan循环中似乎尤为重要。我们分析了11例接受Fontan手术的双心室心脏患者两个心室收缩的同步性。在血管造影片上测量的代表心动周期中心室容积变化的曲线被平滑处理并分成20段。我们计算了两个心室之间同向容积变化（同步变化）的段数（同步率）。我们还通过将每个段中两个心室的容积相加来计算两个心室的总体积（将两者视为一个整体心室），并计算了来自整个心室的主动脉搏出量与形态学上右心室和左心室搏出量之和的比值（每搏量比值）。如果两个心室以完全同步的方式射血，这些比值应为1.0。在7例同步率≥0.75且每搏量比值＞0.95的患者中，心脏指数为3.2±0.3 l/min/m²，最大总体积（对应于舒张末期容积）为正常的106±45%，射血分数为0.44±0.10。在4例同步率分别＜0.70和每搏量比值＜0.95的患者中，相应参数分别为2.4±0.5（P＜0.05）、193±92%和0.33±0.08。同步率与心输出量呈负相关。总之，双心室心脏患者两个心室心动周期的同步性影响Fontan循环。
