J Korean Soc Emerg Med.  2003 Jun;14(2):178-184.

Mitral Regurgitation on Left Ventricular Contrast Echocardiography during Cardiopulmonary Resuscitation in Humans: Its Implications for the Mechanism of Forward Blood Flow

• Hwang SO
• Lee SY
• Kim H
• Lee KH
• Jang YS
• Choi HJ
• Yoo BS
• Lee SH
• Yoon J
• Choe KH
• Cho JH

Abstract

PURPOSE
In the mechanism of forward blood flow during cardiopulmonary resuscitation (CPR) in humans, the role of the left ventricle remains to be investigated. The aim of this study was to assess the role of the left ventricle in generating forward blood flow in humans during CPR by performing contrast echocardiography.
METHODS
Ten patients with non-traumatic cardiac arrest were enrolled. During CPR, a pigtail catheter was introduced to the left ventricle and a central venous catheter was introduced to the right atrium under transesophageal echocardiographic guidance. Ten (10) ml of agitated saline was injected into the left ventricle to perform contrast echocardiography during CPR. The direction of contrast flow and the presence of mitral regurgitation were assessed with a 135 degree longitudinal view. Pressures were traced in the left ventricle, the aorta, and the right atrium.
RESULTS
Forward flow toward the aorta and mitral regurgitation (MR) were visualized during compression systole on left ventricular contrast echocardiography in all patients: grade I in 1, grade II in 3, grade III in 4, and grade IV in 2 patients. There was no differences in the clearing times (29+/-24 vs 22+/-12 sec) or the numbers of chest compressions (53+/-32 vs 48+/-28) of the contrast from the left ventricle, the systolic left ventricular pressures (96+/-13 mmHg vs 126+/-48 mmHg), the systolic aortic pressures (90+/-11 mmHg vs 116+/-58 mmHg), the diastolic aortic pressures (33+/-13 mmHg vs 32+/-9 mmHg), the coronary perfusion pressures (23+/-12 mmHg vs 26+/-8 mmHg), and the end tidal carbon dioxide tensions (13+/-12 mmHg vs 9+/-3 mmHg) between the mild MR group (MR grades I and II) and the severe MR group (MR grades III and IV). The left ventricular ejection fraction was higher in the severe MR group than in the mild MR group.
CONCLUSION
Mitral regurgitation on left ventricular contrast echocardiography during compression systole suggests that cardiac pumping is the dominant mechanism in generating forward blood flow during standard CPR in humans.

Keyword

Cardiopulmonary resuscitation; Cardiac arrest

MeSH Terms

Aorta
Arterial Pressure
Carbon Dioxide
Cardiopulmonary Resuscitation*
Catheters
Central Venous Catheters
Dihydroergotamine
Echocardiography*
Heart Arrest
Heart Atria
Heart Ventricles
Humans*
Mitral Valve Insufficiency*
Perfusion
Stroke Volume
Systole
Thorax
Ventricular Pressure
Carbon Dioxide
Dihydroergotamine