Correspondence

Aortic-Valve Function during Cardiopulmonary Resuscitation

N Engl J Med 1993; 329:1965-1966December 23, 1993

Article

To the Editor:

Cardiac output during standard manual cardiopulmonary resuscitation (CPR) is 30 to 60 percent of the normal value1. A study in animals2 demonstrated improved systemic blood flow and increased coronary perfusion pressure during active compression-decompression CPR. In humans, a significantly higher systolic arterial pressure has been measured during active compression-decompression CPR than during standard CPR3. The newer technique produces negative intrathoracic pressure during the decompression phase, thereby improving venous return and transmitral left ventricular filling1-3 [see Cohen et al. elsewhere in this issue].

In an adult patient undergoing prolonged CPR after nearly drowning, we monitored aortic-valve function during both standard CPR and active compression-decompression CPR with the CardioPump device (Ambu International, Copenhagen, Denmark) by means of biplane transesophageal echocardiography (Sonos 1500, Hewlett-Packard, Andover, Mass.). We found that enhanced venous return and transmitral left ventricular filling were not the only differences between the techniques.

Echocardiographic findings during standard CPR were in accordance with recently published results4: the left ventricular cavity was reduced in size and the mitral valve closed during chest compression, whereas the mitral valve opened and the left ventricle filled during decompression. The aortic valve was closed during decompression and opened for only a short time at the end of the compression phase.

During active compression-decompression CPR, by contrast, the aortic valve was wide open during active decompression and closed only during the early compression phase. The aortic valve opened for a short time at the end of the compression phase (Figure 1Figure 1Long-Axis View of the Left Ventricle during Active Compression-Decompression CPR.). The mitral valve remained wide open during the entire decompression phase. As in standard CPR, the left ventricular cavity was reduced in size and the mitral valve was closed during chest compression.

The aortic valve is opened by a pressure gradient between the left ventricle and the aorta5. Our findings indicate that active compression-decompression CPR created a pressure gradient between the left ventricle and the aorta during active decompression. We assume that forward blood flow was also present along this pressure gradient during the decompression phase. Such forward blood flow might result in improved cardiac output during active compression-decompression, as compared with the standard technique.

Peter Mair, M.D.
Wilhelm Furtwaengler, M.D.
Michael Baubin, M.D.
University of Innsbruck School of Medicine, A-6020 Innsbruck, Austria

5 References

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   Halperin HR, Weisfeldt ML. New approaches to CPR: four hands, a plunger, or a vest. JAMA 1992;267:2940-2941
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   Cohen TJ, Tucker KJ, Redberg RF, et al. Active compression-decompression resuscitation: a novel method of cardiopulmonary resuscitation. Am Heart J 1992;124:1145-1150
   CrossRef | Web of Science | Medline

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   Cohen TJ, Tucker KJ, Lurie KG, et al. Active compression-decompression -- a new method of cardiopulmonary resuscitation. JAMA 1992;267:2916-2923
   CrossRef | Web of Science | Medline

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   Redberg RF, Tucker KJ, Cohen TJ, Dutton JP, Callaham ML, Schiller NB. Physiology of blood flow during cardiopulmonary resuscitation: a transesophageal echocardiographic study. Circulation 1993;88:534-542
   Web of Science | Medline

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   Heart muscle: the heart as a pump. In: Guyton AC. Textbook of medical physiology. 7th ed. Philadelphia: W.B. Saunders, 1986:150-64.
   

Citing Articles (3)

Citing Articles

1. 1

   Milo Engoren, Fred Severyn, Nancy Fenn-Buderer, Michael DeFrank. (2002) Cardiac output, coronary blood flow, and blood gases during open-chest standard and compression-active-decompression cardiopulmonary resuscitation. Resuscitation 55:3, 309-316
   CrossRef

2. 2

   Reinhard Malzer, Andrea Zeiner, Michael Binder, Hans Domanovits, Gabriele Knappitsch, Fritz Sterz, Anton N. Laggner. (1996) Hemodynamic effects of active compression-decompession after prolonged CPR. Resuscitation 31:3, 243-253
   CrossRef

3. 3

   (1995) Accidental Hypothermia. New England Journal of Medicine 332:15, 1033-1035
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