Active compression-decompression resuscitation: analysis of transmitral flow and left ventricular volume by transesophageal echocardiography in humans. Cardiopulmonary Resuscitation Working Group

Abstract

Objectives: This study was designed to test the hypothesis that active compression-decompression cardiopulmonary resuscitation increases transmitral flow and end-decompression left ventricular volume over levels achieved with standard manual cardiopulmonary resuscitation.

Background: Recently, cardiopulmonary resuscitation incorporating active compression and decompression of the chest has been demonstrated to improve hemodynamic status in a canine model and in humans after cardiac arrest.

Methods: The active compression-decompression device was applied midsternum in five consecutive patients and results compared sequentially (in random order) with those of standard manual cardiopulmonary resuscitation. Both techniques were performed at 80 compressions/min with a 1.5- to 2-in. (3.8 to 5.1 cm) compression depth and a 50% duty cycle. Transesophageal echocardiographic data obtained in each patient included the velocity-time integral of transmitral pulsed Doppler recordings and two-dimensional images of the left ventricle in the long-axis view. Planimetric volume measurements of the left ventricle were obtained at both end-compression and end-decompression.

Results: No difference was observed in end-compression volume between the two techniques (p = 0.81). Increased end-decompression volume (active compression-decompression technique 81.3 +/- 12.5 vs. standard technique 69.4 +/- 10.8, p < 0.05), stroke volume (active compression-decompression technique 32.6 +/- 6.8 vs. standard technique 17.6 +/- 5.2, p < 0.05) and velocity-time integral of transmitral flow (active compression-decompression technique 15.8 +/- 4.3 vs. standard technique 7.8 +/- 2.3, p < 0.05) were found in the active compression-decompression group. The transmitral velocity-time integral was highly correlated with left ventricular stroke volume (r = 0.90).

Conclusions: Improved transmitral flow, end-decompression left ventricular volume and stroke volume are seen with active compression-decompression resuscitation, suggesting a biphasic cardiothoracic cycle of flow. Active decompression of the chest appears to be a beneficial adjunct to standard cardiopulmonary resuscitation.