Schwartz S L, Pandian N G, Cao Q L, Hsu T L, Aronovitz M, Diehl J
Department of Medicine, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02111.
J Am Coll Cardiol. 1993 Sep;22(3):907-13. doi: 10.1016/0735-1097(93)90210-r.
This study was designed to describe the hemodynamic abnormalities associated with the appearance of left ventricular diastolic collapse in the setting of regional left heart cardiac tamponade.
Cardiac tamponade after heart surgery is frequently associated with localized pericardial effusion. Although right ventricular diastolic collapse and right atrial collapse are reliable echocardiographic findings in patients with circumferential pericardial effusion and tamponade, they are often not present in postoperative patients with localized pericardial effusion and regional left heart tamponade. Left ventricular diastolic collapse has been described in such patients, but the degree of hemodynamic alteration that exists with this finding is not known.
Acute regional left heart tamponade was produced 14 times in seven spontaneously breathing anesthetized dogs by infusing fluid into an isolated compartment created in the pericardial space adjacent to the left ventricular free wall. Continuous echocardiographic imaging and hemodynamic monitoring of left ventricular, systemic arterial, right atrial, pulmonary capillary wedge and pericardial pressures were performed. Measurements at baseline were compared with those made at the onset of left ventricular diastolic collapse and at decompensated tamponade.
Left ventricular diastolic collapse was noted in all 14 episodes of regional tamponade. It occurred when pressure in the left pericardial compartment exceeded left ventricular diastolic pressure by 3.0 +/- 1.9 mm Hg. At the onset of left ventricular diastolic collapse, cardiac output and mean arterial pressure were significantly reduced from the control value (p < 0.05). Systolic hypotension was noted only twice at this stage, respiratory variation in systolic pressure > 10 mm Hg only once. The appearance of this sign was also associated with elevated left heart filling pressures.
Left ventricular diastolic collapse is a reliable sign of regional left ventricular tamponade and is associated with a reduction in cardiac output. This echocardiographic finding usually occurs before the development of arterial hypotension and pulsus paradoxus. Thus, left ventricular diastolic collapse is potentially more reliable than hypotension or pulsus paradoxus in the diagnosis of regional left ventricular tamponade.
本研究旨在描述在局限性左心心脏压塞情况下，与左心室舒张期塌陷出现相关的血流动力学异常。
心脏手术后的心包压塞常与局限性心包积液相关。虽然右心室舒张期塌陷和右心房塌陷是心包积液环绕和压塞患者可靠的超声心动图表现，但在局限性心包积液和局限性左心压塞的术后患者中通常不存在。此类患者中已有左心室舒张期塌陷的描述，但该表现存在时的血流动力学改变程度尚不清楚。
通过向与左心室游离壁相邻的心包腔内注入液体，在7只自主呼吸的麻醉犬身上诱发了14次急性局限性左心压塞。对左心室、体动脉、右心房、肺毛细血管楔压和心包压力进行连续超声心动图成像和血流动力学监测。将基线测量值与左心室舒张期塌陷开始时以及失代偿性压塞时的测量值进行比较。
在所有14次局限性压塞发作中均观察到左心室舒张期塌陷。当左心包腔压力超过左心室舒张压3.0±1.9 mmHg时发生。在左心室舒张期塌陷开始时，心输出量和平均动脉压较对照值显著降低（p<0.05）。在此阶段仅两次出现收缩期低血压，收缩压呼吸变异>10 mmHg仅一次。该征象的出现还与左心充盈压升高有关。
左心室舒张期塌陷是局限性左心室压塞的可靠征象，与心输出量降低相关。这一超声心动图表现通常在动脉低血压和奇脉出现之前发生。因此，在诊断局限性左心室压塞时，左心室舒张期塌陷可能比低血压或奇脉更可靠。
