Quinones M A, Gaasch W H, Alexander J K
Circulation. 1976 Feb;53(2):293-302. doi: 10.1161/01.cir.53.2.293.
To determine the sensitivity of several isovolumic and ejection phase indices of myocardial contractility to loading, inotropic stimulation and heart rate in man, 14 patients (pts) were studied during cardiac catheterization with simultaneous recordings of left ventricular (LV) pressures and ultrasound dimensions. Measurements were made of instantaneous and mean circumferential fiber shortening velocity (VCF), maximal (max) rate of LV pressure rise (dP/dt), dPHdt divided by end-diastolic circumference [(dP/dt)/C], (DP/dt)/C divided by aortic valve opening pressure [(dP/dt/CP], PEAK CONTRACTILe element velocity (VCE) using total LV pressure, VCE extrapolated to zero total pressure (Vmax), VCE at a developed pressure of 10 mm Hg (VCEDP10) and dP/dt at a common isovolumic developed pressure of 40 mm Hg [(dP/dt)/DP40]. Resulta are expressed in per cent change of the mean for the group. Acute preload increase (8.6% increase in end-diastolic circumference) with volume expansion at constant heart rate in 7 pts produced insignificant changes in VSF, an 8.3% increase in max dP/dt, no change in (dP/dt)/C, a variable response in (dP/dt)/CP, 18% reduction in peak VCE, 16% reduction in Vmax, 14% increase in VCEDP10, and a 10% increase in (dP/dt)/DP40. An acute increase in afterload produced by angiotensin in 8 pts (44% increase in peak stress) led to a 38% decrease in VCF, a 2.5% increase in max dP/dt, no significant change in (dP/dt)/C, a 26% reduction in (dP/dt)/CP, variable responses in peak VCE and Vmax, an 11% increase in VCEDP10 and minor changes in (dP/dt)/DP40. All of the contractility indices were augmented significantly by isoproterenol and atrial pacing. In a given patient, max, dP/dt appears to be useful in the assessment of acute changes in inotropic state since the magnitude of its response to abrupt changes in preload is small and to afterload insignificant. Normalizing max dP/dt for end-diastolic circumference assures better stability during loading with good sensitivity to inotropic stimulation. VCF may be used whenever changes in afterload are minimal. The isovolumic measurements of VCE (regardless of whether total or developed pressure is used) lack sufficient stability during acute changes in loading conditions to warrant their use in the quantitative assessment of acute changes in inotropic state.
为了确定人体中心肌收缩力的几个等容相和射血相指标对负荷、变力性刺激和心率的敏感性，在心脏导管插入术期间对14例患者进行了研究，同时记录左心室（LV）压力和超声尺寸。测量了瞬时和平均圆周纤维缩短速度（VCF）、左心室压力上升最大（max）速率（dP/dt）、dPHdt除以舒张末期周长[（dP/dt）/C]、（DP/dt）/C除以主动脉瓣开放压力[（dP/dt/CP]、使用左心室总压力的峰值收缩元件速度（VCE）、外推到总压力为零时的VCE（Vmax）、在10 mmHg的发育压力下的VCE（VCEDP10）以及在40 mmHg的等容发育压力下的dP/dt[（dP/dt）/DP40]。结果以该组平均值的百分比变化表示。7例患者在恒定心率下通过容量扩张使急性前负荷增加（舒张末期周长增加8.6%），导致VCF变化不显著，max dP/dt增加8.3%，（dP/dt）/C无变化，（dP/dt）/CP有可变反应，峰值VCE降低18%，Vmax降低16%，VCEDP10增加14%，（dP/dt）/DP40增加10%。8例患者中由血管紧张素引起的急性后负荷增加（峰值应力增加44%）导致VCF降低38%，max dP/dt增加2.5%，（dP/dt）/C无显著变化，（dP/dt）/CP降低26%，峰值VCE和Vmax有可变反应，VCEDP10增加11%，（dP/dt）/DP40有微小变化。所有收缩力指标均被异丙肾上腺素和心房起搏显著增强。在给定患者中，max dP/dt似乎可用于评估变力性状态的急性变化，因为其对前负荷突然变化的反应幅度较小，对后负荷的反应不显著。将max dP/dt按舒张末期周长进行归一化处理可确保在负荷期间具有更好的稳定性，同时对变力性刺激具有良好的敏感性。只要后负荷变化最小，就可使用VCF。在负荷条件急性变化期间，VCE的等容测量值（无论使用总压力还是发育压力）缺乏足够的稳定性，因此不适合用于变力性状态急性变化的定量评估。
