Denault André Y, Chaput Miguel, Couture Pierre, Hébert Yves, Haddad François, Tardif Jean-Claude
Department of Anesthesiology, Montreal Heart Institute and University of Montreal, Montreal, Quebec, Canada.
J Thorac Cardiovasc Surg. 2006 Jul;132(1):43-9. doi: 10.1016/j.jtcvs.2006.03.014.
Right ventricular outflow tract obstruction can be a cause of hemodynamic instability but it has not been described in non-congenital cardiac surgery.
The prevalence of right ventricular outflow tract obstruction was retrospectively studied in 670 consecutive patients undergoing cardiac surgery. Significant right ventricular outflow tract obstruction was diagnosed if the right ventricular systolic to pulmonary artery peak gradient was more than 25 mm Hg. The diagnosis was based on measurement of the right ventricular and pulmonary artery systolic pressure through the paceport and distal opening of the pulmonary artery catheter. To further validate the prevalence and the importance of right ventricular outflow tract obstruction, 130 patients were prospectively studied over a 12-month period.
In the retrospective cohort, 6 patients (1%) undergoing various types of cardiac surgical procedures were found to have significant dynamic right ventricular outflow tract obstruction with a mean gradient of 31 +/- 4 mm Hg (26 to 35 mm Hg). In the prospective study significant dynamic right ventricular outflow tract obstruction was identified in 5 patients (4%) (average peak: 37 +/- 15 mm Hg; range: 27 to 60 mm Hg). The typical transesophageal echocardiography finding was end-systolic obliteration of the right ventricular outflow tract. In patients with significant dynamic right ventricular outflow tract obstruction, hemodynamic instability was present in 10/11 patients (91%).
Right ventricular outflow tract obstruction is easily diagnosed using the paceport of the pulmonary artery catheter and should be considered as a potential cause of hemodynamic instability especially when transesophageal echocardiography reveals systolic right ventricular cavity obliteration.
右心室流出道梗阻可能是血流动力学不稳定的一个原因，但在非先天性心脏手术中尚未有相关描述。
对连续670例接受心脏手术的患者进行回顾性研究，以确定右心室流出道梗阻的发生率。如果右心室收缩压与肺动脉峰值压差超过25 mmHg，则诊断为显著的右心室流出道梗阻。该诊断基于通过肺动脉导管的起搏端口和远端开口测量右心室和肺动脉的收缩压。为了进一步验证右心室流出道梗阻的发生率及其重要性，在12个月的时间里对130例患者进行了前瞻性研究。
在回顾性队列中，6例（1%）接受各种心脏手术的患者被发现有显著的动态右心室流出道梗阻，平均压差为31±4 mmHg（26至35 mmHg）。在前瞻性研究中，5例（4%）患者被确定有显著的动态右心室流出道梗阻（平均峰值：37±15 mmHg；范围：27至60 mmHg）。经食管超声心动图的典型表现是右心室流出道在收缩末期闭塞。在有显著动态右心室流出道梗阻的患者中，10/11例（91%）存在血流动力学不稳定。
使用肺动脉导管的起搏端口很容易诊断右心室流出道梗阻，尤其当经食管超声心动图显示右心室腔在收缩期闭塞时，应将其视为血流动力学不稳定的一个潜在原因。
