Burst stimulation improves hemodynamics during resuscitation after prolonged ventricular fibrillation.
BACKGROUND
Although return of spontaneous circulation (ROSC) is frequently achieved during resuscitation for sudden cardiac arrest, systolic blood pressure can then decrease, requiring additional myocardial support. Previous studies have shown that a series of 1-ms electrical pulses delivered through the defibrillation patches during ventricular fibrillation (VF) can stimulate the autonomic nervous system to increase myocardial function following defibrillation. We hypothesized that a similar series of electrical pulses could increase myocardial function and blood pressure during the early post-resuscitation period.


RESULTS
Six swine were studied that underwent 6-7 min. Each animal received 5, 10, 15, or 20 pulse packets consisting of 6 10 A, 1-ms pulses every 3-4 s in random order whenever systolic blood pressure became less than 50 mmHg. All four sets of pulse packets were delivered to each animal. Systolic blood pressure and cardiac function (left ventricular +dP/dt) were increased to pre-stimulation levels or above by all four sets of pulse packets. The increases were significantly greater for the longer than the shorter number of pulse packets. The mean+/-SD duration of the time that the systolic pressure remained above 50 mmHg following pulse delivery was 4.2+/-2.5 min.


CONCLUSIONS
Electrical stimulation during regular rhythm following prolonged VF and resuscitation can increase blood pressure and cardiac function to above prestimulation levels.
Walcott
Gregory
G
University of Alabama at Birmingham, Birmingham, AL, USA. gpw@crml.uab.edu
Melnick
Sharon
S
Killingsworth
Cheryl
C
Ideker
Raymond
R
D000818:Animals; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure; D016887:Cardiopulmonary Resuscitation; D004195:Disease Models, Animal; D004554:Electric Countershock / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000294:innervation*; D006439:Hemodynamics; D008297:Male; D013552:Swine; D013997:Time Factors; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000503:physiopathology / Q000628:therapy*; D016277:Ventricular Function, Left; D017725:Ventricular Pressure