Transesophageal Echocardiographic Assessment of Mitral Valve Position and Pulmonary Venous Flow During Cardiopulmonary Resuscitation in Humans

Abstract

Transesophageal echocardiography performed during manual CPR in humans disclosed three different patterns of mitral valve position and PVF during chest compression. The presence of an opened mitral valve with forward mitral flow and backward pulmonary venous flow during chest compression in a small number of subjects underscores this heterogeneity in blood flow and suggests the possible existence of a "left atrium pump" in addition to the currently known "left ventricle pump" and "chest pump" mechanisms.

What Is the Correct Depth of Chest Compression for Infants and Children? A Radiological Study

“…[5][6][7][8][9][10][11] We found that compressions at either the lower half of the sternum or the internipple line in the pediatric popu- (Table 2). This finding was different from previous research in adults in which compressions at either the lower half of the sternum or the internipple line led to compressions on the aorta rather than the heart.…”

“…The cardiac pump theory indicates that the reason for forward flow is direct squeezing of the heart. [5][6][7][8][9][10][11] According to the thoracic pump theory, circulation results from a change in intrathoracic pressure during rhythmic chest compressions. 12,13 A novel inference called the aortic pump theory was introduced recently.…”

Compression of the Left Ventricular Outflow Tract During Cardiopulmonary Resuscitation

“…16,17 Studies using TEE have focused on demonstrating valve positions to explain the mechanism of blood flow generated by external chest compression. 18,19 However, there has been no report regarding the morphologic change of the heart during external chest compression. This study was performed to investigate whether the recommended hand position for external chest compression is optimal for compressing the ventricles during standard CPR by observing the heart with TEE.…”

Stroke volumes and end-tidal carbon dioxide generated by precordial compression during ventricular fibrillation

“…In addition, Hwang and colleagues (31), studying human patients, described increases in the ascending aortic diameter during chest compression as additional evidence of a cardiac pump mechanism. Pulsed Doppler methods of study of transmitral and pulmonary venous flow during chest compression provided additional evidence that cardiac valves are competent during early phases of CPR (32).…”

“…Despite the controversy regarding the mechanism of blood flow during precordial compression, current evidence suggests that both cardiac and thoracic pump mechanisms operate. The cardiac pump predominates during early phases of CPR and with high force and frequency compression technique (19,(32)(33)(34). After prolonged cardiac arrest, the thoracic pump mechanism emerges (35,36).…”