No-reflow after cardiac arrest

Abstract

Successful resuscitation of the brain requires unimpaired blood recirculation. The study addresses the question of the severity and reversibility of no-reflow after cardiac arrest. Adult normothermic cats were submitted to 5, 15 and 30 min cardiac arrest by ventricular fibrillation. The extent of no-reflow was assessed in each cardiac arrest group after 5 min closed chest cardiac massage in combination with 0.2 mg/kg epinephrine or after successful resuscitation followed by 30 min recirculation. Reperfusion of the brain was visualized by labelling the circulating blood with FITC-Albumin. Areas of no-reflow, defined as absence of microvascular filling, were identified by fluorescence microscopy at 8 standard coronal levels of forebrain, and expressed as percent of total sectional area. During cardiac massage, no-reflow affected 21 +/- 5%, 42 +/- 38% and 70 +/- 27% of forebrain after 5, 15 and 30 min cardiac arrest, respectively. After 30 min spontaneous recirculation following successful resuscitation of the heart, no-reflow significantly declined to 7 +/- 11% after 5 min cardiac arrest (p < 0.05) but persisted in 30 +/- 11% and 65 +/- 21% of forebrain after 15 and 30 min cardiac arrest, respectively (n.s.). Our observations demonstrate that resuscitation of the heart by closed chest massage causes severe (and after prolonged cardiac arrest irreversible) no-reflow of the brain. This suggests that no-reflow is an important cause of post-resuscitation brain pathology.