Differences in cerebral and myocardial perfusion during closed-chest resuscitation

Substantial differences in cerebral and myocardial blood flow occur during cardiac arrest and artificial circulatory support using closed-chest techniques. This inequality can be explained by differences in generated driving pressures across the cerebral resistance vessels and the coronary vascular bed. The cerebral perfusion gradient appears more easily manipulated/improved by newer closed-chest CPR techniques, and regional cerebral blood flows of greater than or equal to 30% of normal can be produced. Myocardial perfusion pressure (aortic minus right atrial pressure difference) is more difficult to manipulate, and reported myocardial blood flow in canine CPR studies is usually less than 10 mL/min/100 g of tissue and thus does not even meet the estimated metabolic demands of the fibrillating heart. Contemporary cardiopulmonary resuscitation investigations are addressing this problem. Cardiac and cerebral resuscitation techniques must develop in parallel before clinically meaningful results can be obtained.