Stein P D, Sabbah H N, Khaja F, Anbe D T
Circulation. 1978 Mar;57(3):590-3. doi: 10.1161/01.cir.57.3.590.
This investigation was undertaken to explore the cause of the diminished second sound (S2) that may occur in normotensive patients with poorly performing ventricles. Intra-aortic sound and pressure were measured in 16 patients with angina; eight had normal ventricular performance (ejection fraction greater than or equal to 60%) and eight had poor performance (ejection fraction less than 50%). The amplitude of S2 was lower in patients with poor ventricular performance as was negative d/dt. Aortic pressure was conparable in both groups. The ampitude of S2 was linearly related to the rate of change of the pressure gradient that developed across the aortic valve during diastole (r = 0.82). The latter also correlated with negative dp/dt (r = 0.82). These observations indicate that in patients with poor ventricular performance, isovolumic relaxation may be compromised. This would cause a reduction of the rate of development of the diastolic pressure gradient, which would result in a diminished S2.
本研究旨在探究血压正常但心室功能不佳的患者中可能出现的第二心音（S2）减弱的原因。对16例心绞痛患者进行了主动脉内声音和压力测量；其中8例心室功能正常（射血分数大于或等于60%），8例心室功能不佳（射血分数小于50%）。心室功能不佳的患者S2幅度较低，负d/dt也较低。两组的主动脉压力相当。S2幅度与舒张期主动脉瓣上压力梯度的变化率呈线性相关（r = 0.82）。后者也与负dp/dt相关（r = 0.82）。这些观察结果表明，心室功能不佳的患者等容舒张可能受损。这将导致舒张压梯度的发展速率降低，从而导致S2减弱。
