Outcomes of CPR in the presence of partial occlusion of left anterior descending coronary artery

Utility of the Ventricular Fibrillation Waveform to Predict a Return of Spontaneous Circulation and Distinguish Acute From Post Myocardial Infarction or Normal Swine in Ventricular Fibrillation Cardiac Arrest

“…[22][23][24] Dominant frequency and number of singularity points have been studied by optical mapping in isolated hearts and shown to be slower in ischemia and heart failure. 25 Characteristics of the VF waveform have been studied for their ability to predict ROSC after a shock in both human [13][14][15][16] and animal [17][18][19][20][21] studies, but with variable reported predictive power. As a result, it has remained unclear if waveform parameters are sufficiently useful as a threshold to decide whether to deliver a shock or continue chest compressions.…”

“…29 After the initiation of chest compressions in swine in which VF was induced by balloon occlusion of the LAD, animals with the deflated catheter remaining in place in the LAD had a lower value of AMSA compared with animals in which the balloon catheter was withdrawn. 16 Figure 3. AMSA (A) and slope (B) for first compared with second or later shocks.…”

“…12 When untreated VF is prolonged beyond 4 minutes and up to about 10 minutes, the myocardium is described as being in the circulatory phase, 11 and in this phase the characteristics of the VF waveform, including parameters based on frequency and amplitude such as amplitude spectral area (AMSA) and slope, have shown good promise as predictors for achieving a return of spontaneous circulation (ROSC) in human and animal studies. [13][14][15][16][17][18][19][20][21] However, it is unclear whether the predictive ability of AMSA and slope to achieve ROSC is affected by the underlying myocardial substrate, such as the presence of an acute MI, a prior MI without acute ischemia, or normal myocardium. Furthermore, survival of cardiac arrest hinges on not only care during resuscitation but also care in the postresuscitation period, including emergent cardiac catheterization for acute MI.…”

Percutaneous left ventricular assist in ischemic cardiac arrest

“…The current model for persistent VF is supported by an experimental study that indicates chronic ischemic heart failure does not reduce the chance of successful defibrillation but primarily affects outcomes with regard to postresuscitation cardiac function (53). Other studies have suggested that ischemically induced cardiac arrest with LAD occlusion (54) or stenosis (55) are clinically relevant and that persistent ischemia due to impaired LAD flow markedly reduces the success rate of defibrillation compared with other mechanisms for VF and thus increases the risk of persistent VF. A model with persistent severe LAD ischemia thus seems valid for the setting of persistent VF.…”

Resumption of Chest Compressions After Successful Defibrillation and Risk for Recurrence of Ventricular Fibrillation in Out-of-Hospital Cardiac Arrest

“…Higher VF recurrence rates have been observed in the setting of myocardial ischemia and during reperfusion in a rabbit model 17,18 and in swine models. 19,20 In addition, it has been proposed that CCs can trigger VF recurrence by a commotio-cordis-type mechanism 21 or by electric depolarization from the CC itself resulting in a long-short electric activation sequence, as observed in a swine model. 22 To explore the influence of the timing of CC resumption on VF recurrence, we focused on the first 30 seconds postshock, a time frame where the postshock pause to CC resumption would be most variable.…”