Abstract 2532: Observing Dying Human Heart
Objective Pulseless electrical activity (PEA) is a phase in the dying process which is considered poorly understood by resuscitation researchers. In fact, PEA was defined and well described prior to 1920. Animal studies before 1960 clearly elucidated that hypoxic/anoxic insults result in respiratory collapse, loss of consciousness, and cardiovascular collapse progressing to PEA and asystole. PEA is a brief phase in the dying process; efforts to assess PEA within human resuscitation have been limited by the crisis which rarely allows using devices such as TTE. PEA is increasing in in-hospital and pre-hospital venues; research to better understand PEA and its potential reversibility is needed.
Methods We selected a model of clinical death in which no resuscitation would be attempted. Following IRB approval, patients with brain death who were not transplant candidates were identified; informed consent was obtained from family for TTE to be performed by a researcher to follow heart contractions to cessation after life support withdrawal.
Results Discussion Two major findings in recent resuscitation studies have been the high rates of PEA and the realization that the process from collapse to PEA is a continuum. The EKG and TTE manifestations of these patients’ deaths are similar to the animal studies. None entered VF; each went from prolonged SB through various levels of AV block to asystole. EKG manifestations persisted many minutes after the pulse was lost. TTE demonstrated gradual weakening of pump function to pseudo PEA, true PEA and asystole. Diastole was affected quite early; ventricular volumes either did not increase or clearly decreased. Further studies should incorporate flow probes and cardiac dye to assess this finding which may provide new opportunities for research into the potential reversal of PEA.