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Background: The American College of Cardiology Interventional Council published consensus-based recommendations to help identify resuscitated cardiac arrest patients with unfavorable clinical features in whom invasive procedures are unlikely to improve survival., Objectives: This study sought to identify how many unfavorable features are required before prognosis is significantly worsened and which features are most impactful in predicting prognosis., Methods: Using the INTCAR (International Cardiac Arrest Registry), the impact of each proposed "unfavorable feature" on survival to hospital discharge was individually analyzed. Logistic regression was performed to assess the association of such unfavorable features with poor outcomes., Results: Seven unfavorable features (of 10 total) were captured in 2,508 patients successfully resuscitated after cardiac arrest (ongoing cardiopulmonary resuscitation and noncardiac etiology were exclusion criteria in our registry). Chronic kidney disease was used in lieu of end-stage renal disease. In total, 39% survived to hospital discharge. The odds ratio (OR) of survival to hospital discharge for each unfavorable feature was as follows: age >85 years OR: 0.30 (95% CI: 0.15 to 0.61), time-to-ROSC >30 min OR: 0.30 (95% CI: 0.23 to 0.39), nonshockable rhythm OR: 0.39 (95% CI: 0.29 to 0.54), no bystander cardiopulmonary resuscitation OR: 0.49 (95% CI: 0.38 to 0.64), lactate >7 mmol/l OR: 0.50 (95% CI: 0.40 to 0.63), unwitnessed arrest OR: 0.58 (95% CI: 0.44 to 0.78), pH <7.2 OR: 0.78 (95% CI: 0.63 to 0.98), and chronic kidney disease OR: 0.96 (95% CI: 0.70 to 1.33). The presence of any 3 or more unfavorable features predicted <40% survival. Presence of the 3 strongest risk factors (age >85 years, time-to-ROSC >30 min, and non-ventricular tachycardia/ventricular fibrillation) together or ≥6 unfavorable features predicted a ≤10% chance of survival to discharge., Conclusions: Patients successfully resuscitated from cardiac arrest with 6 or more unfavorable features have a poor long-term prognosis. Delaying or even forgoing invasive procedures in such patients is reasonable., Competing Interests: Author Disclosures Dr. Kern has served as a Science Advisory Board Member for Zoll Medical and Physio-Control, Inc., now part of Stryker, Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Despite advances over the past decade, the incidence of cardiogenic shock secondary to acute myocardial infarction has increased, with an unchanged mortality near 50%. Recent trials have not clarified the best strategies in treatment. While dedicated cardiac shock centers are being established, there are no standardized agreements on the utilization of mechanical circulatory support and the timeliness of percutaneous coronary intervention strategies. In some centers and prospective registries, outcomes after placement of advanced mechanical circulatory support prior to reperfusion therapy with percutaneous coronary intervention have been encouraging with improved survival. Here, we suggest systems of care with a treatment pathway for patients with acute myocardial infarction complicated by cardiogenic shock., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Patients who are comatose after cardiac arrest continue to be a challenge, with high mortality. Although there is an American College of Cardiology Foundation/American Heart Association Class I recommendation for performing immediate angiography and percutaneous coronary intervention (when indicated) in patients with ST-segment elevation myocardial infarction, no guidelines exist for patients without ST-segment elevation. Early introduction of mild therapeutic hypothermia is an established treatment goal. However, there are no established guidelines for risk stratification of patients for cardiac catheterization and possible percutaneous coronary intervention, particularly in patients who have unfavorable clinical features in whom procedures may be futile and affect public reporting of mortality. An algorithm is presented to improve the risk stratification of these severely ill patients with an emphasis on consultation and evaluation of patients prior to activation of the cardiac catheterization laboratory., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Previous investigations of out-of-hospital cardiac arrest (OHCA) have shown that the waveform characteristic amplitude spectral area (AMSA) can predict successful defibrillation and return of spontaneous circulation (ROSC) but has not been studied previously for survival., Objectives: To determine whether AMSA computed from the ventricular fibrillation (VF) waveform is associated with pre-hospital ROSC, hospital admission, and hospital discharge., Methods: Adults with witnessed OHCA and an initial rhythm of VF from an Utstein style database were studied. AMSA was measured prior to each shock and averaged for each subject (AMSA-avg). Factors such as age, sex, number of shocks, time from dispatch to monitor/defibrillator application, first shock AMSA, and AMSA-avg that could predict pre-hospital ROSC, hospital admission, and hospital discharge were analyzed by logistic regression., Results: Eighty-nine subjects (mean age 62 ± 15 years) with a total of 286 shocks were analyzed. AMSA-avg was associated with pre-hospital ROSC (p = 0.003); a threshold of 20.9 mV-Hz had a 95% sensitivity and a 43.4% specificity. Additionally, AMSA-avg was associated with hospital admission (p < 0.001); a threshold of 21 mV-Hz had a 95% sensitivity and a 54% specificity and with hospital discharge (p < 0.001); a threshold of 25.6 mV-Hz had a 95% sensitivity and a 53% specificity. First-shock AMSA was also predictive of pre-hospital ROSC, hospital admission, and discharge. Time from dispatch to monitor/defibrillator application was associated with hospital admission (p = 0.034) but not pre-hospital ROSC or hospital discharge., Conclusions: AMSA is highly associated with pre-hospital ROSC, survival to hospital admission, and hospital discharge in witnessed VF OHCA. Future studies are needed to determine whether AMSA computed during resuscitation can identify patients for whom continuing current resuscitation efforts would likely be futile., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to describe usage of the wearable cardioverter-defibrillator (WCD) during mandated waiting periods following myocardial infarction (MI) for patients perceived to be at high risk for sudden cardiac arrest (SCA)., Background: Current device guidelines and insurance coverage require waiting periods of either 40 days or 3 months before implanting a cardioverter-defibrillator post-myocardial infarction (MI), depending on whether or not acute revascularization was undertaken., Methods: We assessed characteristics of and outcomes for patients who had a WCD prescribed in the first 3 months post-MI. The WCD medical order registry was searched for patients who were coded as having had a "recent MI with ejection fraction ≤35%" or given an International Classification of Diseases, Ninth Revision 410.xx diagnostic code (acute MI), and then matched to device-recorded data., Results: Between September 2005 and July 2011, 8,453 unique patients (age 62.7 ± 12.7 years, 73% male) matched study criteria. A total of 133 patients (1.6%) received 309 appropriate shocks. Of these patients, 91% were resuscitated from a ventricular arrhythmia. For shocked patients, the left ventricular ejection fraction (LVEF) was ≤30% in 106, 30% to 35% in 17, >36% in 8, and not reported in 2 patients. Of the 38% of patients not revascularized, 84% had a LVEF ≤30%; of the 62% of patients revascularized, 77% had a LVEF ≤30%. The median time from the index MI to WCD therapy was 16 days. Of the treated patients, 75% received treatment in the first month, and 96% within the first 3 months of use. Shock success resulting in survival was 84% in nonrevascularized and 95% in revascularized patients., Conclusions: During the 40-day and 3-month waiting periods in patients post-MI, the WCD successfully treated SCA in 1.4%, and the risk was highest in the first month of WCD use. The WCD may benefit individual patients selected for high risk of SCA early post-MI., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Cardiocerebral resuscitation (CCR) is a new approach for resuscitation of patients with cardiac arrest. It is composed of 3 components: 1) continuous chest compressions for bystander resuscitation; 2) a new emergency medical services (EMS) algorithm; and 3) aggressive post-resuscitation care. The first 2 components of CCR were first instituted in 2003 in Tucson, Arizona; in 2004 in the Rock and Walworth counties of Wisconsin; and in 2005 in the Phoenix, Arizona, metropolitan area. The CCR method has been shown to dramatically improve survival in the subset of patients most likely to survive: those with witnessed arrest and shockable rhythm on arrival of EMS. The CCR method advocates continuous chest compressions without mouth-to-mouth ventilations for witnessed cardiac arrest. It advocates either prompt or delayed defibrillation, based on the 3-phase time-sensitive model of ventricular fibrillation (VF) articulated by Weisfeldt and Becker. For bystanders with access to automated external defibrillators and EMS personnel who arrive during the electrical phase (i.e., the first 4 or 5 min of VF arrest), the delivery of prompt defibrillator shock is recommended. However, EMS personnel most often arrive after the electrical phase -- in the circulatory phase of VF arrest. During the circulatory phase of VF arrest, the fibrillating myocardium has used up much of its energy stores, and chest compressions that perfuse the heart are mandatory prior to and immediately after a defibrillator shock. Endotracheal intubation is delayed, excessive ventilations are avoided, and early-administration epinephrine is advocated.

Despite substantial progress in the diagnosis and treatment of acute ST-segment elevation myocardial infarction (STEMI), implementation of this knowledge into routine clinical practice has been variable. It has become increasing clear that primary percutaneous coronary intervention (PCI) is the preferred method of reperfusion if it can be performed in a timely manner. Recent European data suggest that transfer for direct PCI may also be preferable to fibrinolytic therapy. We believe it is time to establish a national policy for treatment of patients with STEMI to develop a coordinated system of care similar to that of the level 1 trauma system.

Objectives: This study was designed to compare outcome after adult defibrillation dosing versus pediatric dosing in a piglet model of prolonged prehospital ventricular fibrillation (VF)., Background: Weight-based 2 to 4 J/kg monophasic defibrillation dosing is recommended for children in VF, but impractical for automated external defibrillator (AED) use. Present AEDs can only provide adult shock doses or newly developed attenuated adult doses intended for children. A single escalating energy sequence (50/75/86 J) of attenuated adult-dose biphasic shocks (pediatric dosing) is at least as effective as escalating monophasic weight-based dosing for prolonged VF in piglets, but this approach has not been compared to standard adult biphasic dosing., Methods: Following 7 min of untreated VF, piglets weighing 13 to 26 kg (19 +/- 1 kg) received either biphasic 50/75/86 J (pediatric dose) or biphasic 200/300/360 J (adult dose) therapies during simulated prehospital life support., Results: Return of spontaneous circulation was attained in 15 of 16 pediatric-dose piglets and 14 of 16 adult-dose piglets. Four hours postresuscitation, pediatric dosing resulted in fewer elevations of cardiac troponin T (0 of 12 piglets vs. 6 of 11 piglets, p = 0.005) and less depression of left ventricular ejection fraction (p < 0.05). Most importantly, more piglets survived to 24 h with good neurologic scores after pediatric shocks than adult shocks (13 of 16 piglets vs. 4 of 16 piglets, p = 0.004)., Conclusions: In this model, pediatric shocks resulted in superior outcome compared with adult shocks. These data suggest that adult defibrillation dosing may be harmful to pediatric patients with VF and support the use of attenuating electrodes with adult biphasic AEDs to defibrillate children.

Objectives: The goal of this study was to determine the magnitude and mechanisms of hemodynamic improvement of an automated, load-distributing band device (AutoPulse, Revivant Corp., Sunnyvale, California) compared with conventional cardiopulmonary resuscitation (C-CPR)., Background: Improved blood flow during cardiopulmonary resuscitation (CPR) enhances survival from cardiac arrest., Methods: AutoPulse CPR (A-CPR) and C-CPR were performed on 30 pigs (16 +/- 4 kg) 1 min after induction of ventricular fibrillation. Aortic and right atrial pressures were measured with micromanometers. Regional flows were measured with microspheres; A-CPR and C-CPR were performed with 20% anterior-posterior chest compression, with (n = 10) and without (n = 10) epinephrine. A pressure transducer was advanced down the airways during chest compressions (n = 10), and magnetic resonance imaging (MRI) was performed., Results: AutoPulse CPR improved coronary perfusion pressure (CPP) (aortic - right atrial pressure) without epinephrine (A-CPR 21 +/- 8 mm Hg vs. C-CPR 14 +/- 6 mm Hg, mean +/- SD, p < 0.0001) and with epinephrine (A-CPR 45 +/- 11 mm Hg vs. C-CPR 17 +/- 6 mm Hg, p < 0.0001). AutoPulse CPR improved myocardial flow without epinephrine and cerebral and myocardial flow with epinephrine (p < 0.05). AutoPulse CPR also produced greater myocardial flow at every CPP (p < 0.01). With A-CPR, high airway pressure was noted distal to the carina, which corresponded to an area of airway collapse on MRI, and which was not present with C-CPR., Conclusions: AutoPulse CPR improved hemodynamics over C-CPR in this pig model. AutoPulse CPR with epinephrine can produce pre-arrest levels of myocardial and cerebral flow. The improved hemodynamics with A-CPR appear to be mediated through airway collapse, which likely impedes airflow and helps maintain higher levels of intrathoracic pressure.

Objectives: This study investigated the effect of prolonged cardiac arrest and subsequent cardiopulmonary resuscitation on left ventricular systolic and diastolic function., Background: Cardiac arrest from ventricular fibrillation results in cessation of forward blood flow, including myocardial blood flow. During cardiopulmonary resuscitation, myocardial blood flow remains suboptimal. Once the heart is defibrillated and successful resuscitation achieved, reversible myocardial dysfunction, or "stunning," may occur. The magnitude and time course of myocardial stunning from cardiac arrest is unknown., Methods: Twenty-eight domestic swine (26 +/- 1 kg) were studied with both invasive and noninvasive measurements of ventricular function before and after 10 or 15 min of untreated cardiac arrest. Contrast left ventriculograms, ventricular pressures, cardiac output, isovolumetric relaxation time (tau) and transthoracic Doppler-echocardiographic studies were obtained., Results: Twenty-three of 28 animals were successfully resuscitated and postresuscitation data obtained. Left ventricular ejection fraction showed a significant reduction 30 min after resuscitation (p < 0.05). Regional wall motion analysis revealed diffuse, global left ventricular systolic dysfunction. Left ventricular end-diastolic pressure increased significantly in the postresuscitation period (p < 0.05). Isovolumetric relaxation time (tau) was significantly increased over baseline by 2 h after resuscitation (p < 0.05). Similar findings were noted with the Doppler-echocardiographic analysis, including a reduction in fractional shortening (p < 0.05), a reduction in mitral valve deceleration time (p < 0.05) and an increase in left ventricular isovolumetric relaxation time at 5 h after resuscitation (p < 0.05> By 24 h, these invasive and noninvasive variables of systolic and diastolic left ventricular function had begun to improve. At 48 h, all measures of left ventricular function had returned to baseline levels., Conclusions: Myocardial systolic and diastolic dysfunction is severe after 10 to 15 min of untreated cardiac arrest and successful resuscitation. Full recovery of this postresuscitation myocardial stunning is seen by 48 h in this experimental model of ventricular fibrillation cardiac arrest.

Objectives: The aim of this study was to determine the sensitivity, specificity and utility of the cardiovascular examination in predicting cardiac hemodynamics in patients with advanced chronic congestive heart failure., Background: Although the physical signs of acute left heart failure have been shown to correlate relatively well with cardiac hemodynamics, their reliability in estimating hemodynamics in patients with chronic heart failure has recently been questioned., Methods: We prospectively recorded the history, cardiovascular physical signs present at bedside examination and the hemodynamic measurements obtained at right heart catheterization in 52 patients with chronic congestive heart failure undergoing in-hospital evaluation for possible heart transplantation. In addition, we obtained chest radiographs and multigated nuclear scans for the evaluation of left ventricular function., Results: Pulmonary rales, a left ventricular third heart sound, jugular venous distension and the abdominojugular test, when positive, indicated higher right heart pressures and lower measures of cardiac performance. The presence of jugular venous distension, at rest or inducible, had the best combination of sensitivity (81%), specificity (80%) and predictive accuracy (81%) for elevation of the pulmonary capillary wedge pressure (> or = 18 mm Hg). Furthermore, in this population sample, the probability of an elevated wedge pressure was 0.86 when either variable was present., Conclusions: The bedside cardiovascular examination in the patient with chronic heart failure is extremely useful in identifying patients with elevation of right and left heart pressures. Examination for jugular venous distension at rest or by the abdominojugular test is simple and highly sensitive and specific in assessing left heart pressures in these patients.

Two new modifications of manual cardiopulmonary resuscitation, high impulse compression at a rate of 120/min and interposed abdominal compression at a rate of 60/min, have been reported to produce better hemodynamic responses than standard cardiopulmonary resuscitation at 60/min. However, the effect of these two new methods on initial resuscitation success and 24 hour survival is unknown. In this study, 30 mongrel dogs were divided into three equal groups, each treated with one of three types of manual cardiopulmonary resuscitation. Ventricular fibrillation was induced electrically in morphinized, endotracheally intubated dogs emerging from halothane anesthesia. After 3 minutes of circulatory arrest without intervention, one of the three techniques of manual cardiopulmonary resuscitation was begun, and continued for 17 minutes. Defibrillation was performed at 20 minutes. Successful resuscitation was defined as a mean arterial blood pressure of at least 60 mm Hg, without chest compressions, 10 minutes after the initial defibrillation attempt. Intensive care was provided for 2 hours, including hemodynamic and respiratory monitoring, and drug intervention when required. Twenty-four hour survival and neurologic deficit were used as critical measures of outcome. Ten of 30 animals survived 24 hours with a mean neurologic deficit score of 5% (normal = 0, brain dead = 100). There was no difference in initial resuscitation success, 24 hour survival or neurologic deficit of the survivors among the three manual cardiopulmonary resuscitation methods. Aortic diastolic and calculated coronary perfusion pressures were similar for all three methods. Well performed standard manual cardiopulmonary resuscitation is as effective as these modified versions (high impulse compression and interposed abdominal compression) when compared in the same animal model.

Expired end-tidal carbon dioxide (PCO2) measurements made during cardiopulmonary resuscitation have correlated with cardiac output and coronary perfusion pressure when wide ranges of blood flow are included. The utility of such measurements for predicting resuscitation outcome during the low flow state associated with closed chest cardiopulmonary resuscitation remains uncertain. Expired end-tidal PCO2 and coronary perfusion pressures were measured in 15 mongrel dogs undergoing 15 min of closed chest cardiopulmonary resuscitation after a 3 min period of untreated ventricular fibrillation. In six successfully resuscitated dogs, the mean expired end-tidal PCO2 was significantly higher than that in nine nonresuscitated dogs only after 14 min of cardiopulmonary resuscitation (6.2 +/- 1.2 versus 3.4 +/- 0.8 mm Hg; p less than 0.05). No differences in expired end-tidal PCO2 values were found at 2, 7 or 12 min of cardiopulmonary resuscitation. A significant decline in end-tidal PCO2 levels during the resuscitation effort was seen in the nonresuscitated group (from 6.3 +/- 0.8 to 3.4 +/- 0.8 mm Hg; p less than 0.05); the successfully resuscitated group had constant PCO2 levels throughout the 15 min of cardiac arrest (from 6.8 +/- 1.1 to 6.2 +/- 1.2 mm Hg). Changes in expired PCO2 levels during cardiopulmonary resuscitation may be a useful noninvasive predictor of successful resuscitation and survival from cardiac arrest.

The effect of the duration of inadequate coronary perfusion pressure on resuscitation from cardiac arrest was examined in 32 mongrel dogs with a mean weight of 22 +/- 5 kg. In all dogs, the heart was electrically fibrillated and closed chest compression with assisted ventilation was performed for 15 minutes. At this time, all dogs had an inadequate coronary perfusion pressure (mean 7 +/- 9 mm Hg) and were randomized to a control group (group 1) with continued closed chest compression or to one of the three groups with open chest cardiac massage. These three groups differed only in the duration of continued closed chest compression before initiation of open chest massage (15, 20 and 25 minutes, respectively, in groups 2, 3 and 4). The control group (group 1) had no significant increase in coronary perfusion pressure, and only one of the eight dogs could be resuscitated. The three groups with open chest cardiac massage had a significant increase in coronary perfusion pressure (from 5 +/- 9 to 51 +/- 26 mm Hg, p less than 0.05), but the rate of successful resuscitation depended on the duration of inadequate coronary perfusion pressure before cardiac open chest massage. In group 2, six of eight dogs were resuscitated (p less than 0.05 compared with the control group); in group 3, three of eight dogs were resuscitated and in group 4 none of the eight dogs was resuscitated. The resuscitation rate was significantly (p less than 0.05) greater in group 2 than in group 4. These findings indicate that techniques that improve coronary perfusion pressure during cardiopulmonary resuscitation must be applied before extensive myocardial cellular dysfunction occurs if the probability of successful resuscitation is to be improved.