THE GENESIS OF THE 3RD AND 4TH HEART SOUNDS - A PRESSURE-FLOW STUDY IN DOGS
THE GENESIS OF THE 3RD AND 4TH HEART SOUNDS - A PRESSURE-FLOW STUDY IN DOGS
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DOI：
10.1172/jci111344
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发表时间：
1984-01-01
影响因子：
15.9
通讯作者：
KESTELOOT, H
中科院分区：
文献类型：
--
作者：
VANDEWERF, F;MINTEN, J;KESTELOOT, H
为了研究二尖瓣血流减速的机制及其对第三（S3）和第四（S4）心音发生的潜在影响，我们同时记录了25只开胸犬的左心房和左心室压力（微压计），二尖瓣血流速度（电磁导管尖端流速计），以及内部和外部心音图。在不同负荷条件下测量舒张时间间隔、二尖瓣压差（平面测量法）、最大二尖瓣流速以及血流的加速和减速。结果表明，二尖瓣血流在舒张早期和晚期的减速总是由负的跨瓣压差引起的。容量负荷后，舒张压、正（前向）和负（后向）跨瓣压差以及血流加速和减速增加，出现S3或S4（20：25只犬）。这些声音发生在血流减速阶段，可以从胸壁、左心室内和直接从自由暴露的左心室壁的心外膜表面记录。球囊闭塞下腔静脉后（17：25只），出现相反的变化，奔马音消失。结果表明，左心室压力上升，以响应充盈逆转跨膜压差和减速流动。左室壁在早期和晚期血流的减速可能是S3和S4发生的关键机制。
To examine the mechanism of mitral flow deceleration in diastole and its potential influence on the genesis of third (S3) and fourth (S4) heart sounds, we simultaneously recorded left atrial and left ventricular pressures (micromanometers), mitral flow velocity (electromagnetic catheter-tip flow velocity meter), and internal and external phonocardiograms in 25 open-chest dogs. Diastolic time intervals, transmitral pressure gradients (planimetry), maximum mitral flow velocity, and acceleration and deceleration of flow were measured under different loading conditions. It was found that deceleration of mitral flow in early and late diastole is always caused by a negative transmitral pressure gradient. After volume loading, diastolic pressures, positive (forward) and negative (backward) transmitral pressure gradients, and acceleration and deceleration of flow increased, and an S3 or S4 appeared (20:25 dogs). These sounds occurred during the phase of flow deceleration and could be recorded from the chest wall, inside the left ventricle, and directly from the epicardial surface of the freely exposed left ventricular wall. After balloon occlusion of the inferior vena cava (17:25 dogs), the opposite changes were observed and gallop sounds disappeared. The results indicate that the left ventricular pressure rise in response to filling reverses the transmitral pressure gradient and decelerates flow. Deceleration of inflow by the left ventricular wall in early and late diastole may represent a key mechanism in the genesis of S3 and S4.