Chemla D, Hébert J L, Coirault C, Salmeron S, Zamani K, Lecarpentier Y
Institut National de la Santé et de la Recherche Médicale U. 451, Loa-Ensta-Ecole Polytechnique, Palaiseau, France.
Am J Physiol. 1996 Oct;271(4 Pt 2):H1287-95. doi: 10.1152/ajpheart.1996.271.4.H1287.
It has been suggested that pulmonary artery pressure at the end of ejection is close to mean pulmonary artery pressure, thus contributing to the optimization of external power from the right ventricle. We tested the hypothesis that dicrotic notch and mean pulmonary artery pressures could be of similar magnitude in 15 men (50 +/- 12 yr) referred to our laboratory for diagnostic right and left heart catheterization. Beat-to-beat relationships between dicrotic notch and mean pulmonary artery pressures were studied 1) at rest over 10 consecutive beats and 2) in 5 patients during the Valsalva maneuver (178 beats studied). At rest, there was no difference between dicrotic notch and mean pulmonary artery pressures (21.8 +/- 12.0 vs. 21.9 +/- 11.1 mmHg). There was a strong linear relationship between dicrotic notch and mean pressures 1) over the 10 consecutive beats studied in each patient (mean r = 0.93), 2) over the 150 resting beats (r = 0.99), and 3) during the Valsalva maneuver in each patient (r = 0.98-0.99) and in the overall beats (r = 0.99). The difference between dicrotic notch and mean pressures was -0.1 +/- 1.7 mmHg at rest and -1.5 +/- 2.3 mmHg during the Valsalva maneuver. Substitution of the mean pulmonary artery pressure by the dicrotic notch pressure in the standard formula of the pulmonary vascular resistance (PVR) resulted in an equation relating linearly end-systolic pressure and stroke volume. The slope of this relation had the dimension of a volume elastance (in mmHg/ml), a simple estimate of volume elastance being obtained as 1.06(PVR/T), where T is duration of the cardiac cycle. In conclusion, dicrotic notch pressure was of similar magnitude as mean pulmonary artery pressure. These results confirmed our primary hypothesis and indicated that human pulmonary artery can be treated as if it is an elastic chamber with a volume elastance of 1.06(PVR/T).
有人提出，射血末期的肺动脉压接近平均肺动脉压，从而有助于优化右心室的外部功率。我们对15名男性（50±12岁）进行了测试，这些男性因诊断性右心和左心导管插入术被转诊至我们实验室，以验证重搏波切迹压和平均肺动脉压可能具有相似大小的假设。研究了重搏波切迹压和平均肺动脉压之间的逐搏关系：1）在静息状态下连续记录10个心动周期；2）在5名患者进行瓦尔萨尔瓦动作期间（共研究178个心动周期）。静息状态下，重搏波切迹压和平均肺动脉压无差异（21.8±12.0 vs. 21.9±11.1 mmHg）。在以下情况下，重搏波切迹压和平均压之间存在强线性关系：1）在每名患者研究的连续10个心动周期中（平均r = 0.93）；2）在150次静息心动周期中（r = 0.99）；3）在每名患者进行瓦尔萨尔瓦动作期间（r = 0.98 - 0.99）以及所有心动周期中（r = 0.99）。静息状态下，重搏波切迹压与平均压的差值为 -0.1±1.7 mmHg，瓦尔萨尔瓦动作期间为 -1.5±2.3 mmHg。在肺血管阻力（PVR）的标准公式中，用重搏波切迹压替代平均肺动脉压，得到一个将收缩末期压力和每搏量线性关联的方程。该关系的斜率具有容积弹性（mmHg/ml）的量纲，容积弹性的一个简单估计值为1.06（PVR/T），其中T为心动周期时长。总之，重搏波切迹压与平均肺动脉压大小相似。这些结果证实了我们的主要假设，并表明人类肺动脉可被视为一个容积弹性为1.06（PVR/T）的弹性腔室。
