Higashidate M, Tamiya K, Kurosawa H, Takanashi Y, Imai Y
Department of Pediatric Cardiovascular Surgery, Heart Institute of Japan, Tokyo Women's Medical College.
J Thorac Cardiovasc Surg. 1988 Jul;96(1):88-91.
We used real-time measurement of the tricuspid valve annular area in anesthetized dogs to study the optimal size of the annular area for annuloplasty. During control conditions, the maximum tricuspid annular area appeared at the onset of ventricular systole. The minimum tricuspid annular area appeared between the ventricular isovolumic relaxation phase and the early ventricular filling phase. The maximum annular area varied in seven dogs between 2.18 and 3.10 cm2, and the minimum annular area ranged between 1.68 and 2.45 cm2. In regular sinus rhythm (heart rates 97 to 120 beats/min), the maximal decreases in tricuspid annular area during one cardiac cycle ranged from 14.3% to 23.6% of the maximum size. When the tricuspid annular area after the annuloplasty was kept larger than the minimum area that was observed during the cardiac cycle in the control study, cardiac output and right atrial pressure remained unchanged, as a result of unobstructed ventricular filling. On the other hand, when the annular area was reduced to smaller than the minimum area seen in the control study, a decrease in cardiac output and an elevation of right atrial pressure ensued. These findings suggest that the tricuspid annular area can be safely decreased by annuloplasty to the minimum area seen in the control study without causing a reduction of cardiac output or an elevation of right atrial pressure.
我们通过对麻醉犬三尖瓣环面积进行实时测量，来研究用于瓣环成形术的最佳环面积大小。在对照状态下，三尖瓣环最大面积出现在心室收缩期开始时。三尖瓣环最小面积出现在心室等容舒张期与心室早期充盈期之间。7只犬的最大环面积在2.18至3.10平方厘米之间变化，最小环面积在1.68至2.45平方厘米之间。在规则窦性心律（心率97至120次/分钟）时，一个心动周期中三尖瓣环面积的最大减小幅度为最大面积的14.3%至23.6%。当瓣环成形术后的三尖瓣环面积保持大于对照研究中心动周期内观察到的最小面积时，由于心室充盈未受阻，心输出量和右心房压力保持不变。另一方面，当环面积减小到小于对照研究中所见的最小面积时，心输出量降低，右心房压力升高。这些发现表明，通过瓣环成形术可将三尖瓣环面积安全地减小至对照研究中所见的最小面积，而不会导致心输出量降低或右心房压力升高。
