β-Blockers for the treatment of cardiac arrest from ventricular fibrillation?

Oral amiodarone and propranolol in maintenance therapy of postimplantation tachycardia: An observational study

Left ventricular assist devices (LVADs) are widely used as end-stage therapy in patients with advanced heart failure, whereas implantation increases the risks of development of sustained ventricular tachycardia at the later postimplantation stage. Therefore, this study aimed to evaluate the clinical efficacy of orally administered amiodarone and propranolol in 3 patients with ventricular tachycardia (VT) after LVAD implantation who were resistant to initial anti-antiarrhythmic drugs. This retrospective cohort study consisted of the initial evaluation of the clinical data of 14 adult patients who underwent implantation of LVAD between January 2019 and March 2021. A total of 3 patients with resistant VT were finally included. In all cases, the patients were initially administered amiodarone in the different doses intravenously to stabilize the critical condition, whereas its oral form along with that of propranolol was used as maintenance therapy in the first 2 cases. In the third case, amiodarone was withdrawn because of the risk of development of hyperthyroidism, while oral propranolol was used in the treatment. The assessment in the 16-month follow-up period after discharge did not show presence of non-sustained and sustained VT in all 3 cases. In the ventricular arrhythmia-free group, the total mortality rate within the follow-up period was 11.1 ± 7.78 months in the 3 patients. We suggest that maintenance oral therapy of propranolol and amiodarone can significantly decrease the risks of complications in patients with VT after implantation of ventricular assist device in the long term.

Esmolol, vector change, and dose-capped epinephrine for prehospital ventricular fibrillation or pulseless ventricular tachycardia

BACKGROUND

Refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) cardiac arrest describes a subset of patients who do not respond to standard Advanced Cardiac Life Support (ACLS) interventions and are associated with poor outcomes. Esmolol administration and vector change defibrillation have shown promise in improving outcomes in these patients, however evidence is limited.

OBJECTIVES

This study compares clinical outcomes between patients with prehospital refractory VF/pVT who received an Emergency Medical Service (EMS) bundle, comprised of esmolol administration, vector change defibrillation, and dose-capped epinephrine at 3 mg, to patients who received standard ACLS interventions.

METHODS

This multicenter, retrospective, cohort study evaluated medical records between October 18, 2017 and March 15, 2022. Patients were enrolled if they experienced a prehospital cardiac arrest with the rhythm VF or pVT, had received at least three standard defibrillations, at least 3 mg of epinephrine, and 300 mg of amiodarone. Patients who received the EMS bundle after its implementation were compared to patients who received standard ACLS interventions prior to its implementation. The primary outcome was sustained return of spontaneous circulation (ROSC), defined as ROSC lasting 20 min without recurrence of cardiac arrest. Secondary outcomes included the incidence of any ROSC, survival to hospital arrival, survival at hospital discharge, and neurologically intact survival at hospital discharge.

RESULTS

Eighty-three patients were included in the study. Thirty-six were included in the pre-EMS bundle group and 47 patients were included in the post-EMS bundle group. Patients in the pre-EMS bundle group achieved significantly higher rates of sustained ROSC (58.3% vs 17%, p < 0.001), any ROSC (66.7% vs 19.1%, p < 0.001), and survival to hospital arrival (55.6% vs 17%, p < 0.001). The rates of survival to hospital discharge (16.7% vs 6.4%, p = 0.17) and neurologically intact survival at hospital discharge (5.9% vs 4.3%, p = 1.00) were not significantly different between groups.

CONCLUSIONS

Patients who received the EMS bundle achieved sustained ROSC significantly less often and were less likely to have pulses at hospital arrival. The incidence of neurologically intact survival was low and similar between groups.

The first case series analysis on efficacy of esmolol injection for in-hospital cardiac arrest patients with refractory shockable rhythms in China

Background: This study assessed the effects of esmolol injection in patients with in-hospital cardiac arrest (IHCA) with refractory ventricular fibrillation (VF)/pulseless ventricular tachycardia (pVT).

Methods: From January 2018 to December 2021, 29 patients with IHCA with refractory shockable rhythm were retrospectively reviewed. Esmolol was administered after advanced cardiovascular life support (ACLS)-directed procedures, and outcomes were assessed.

Results: Among the 29 cases, the rates of sustained return of spontaneous circulation (ROSC), 24-h ROSC, and 72-h ROSC were 79%, 62%, and 59%, respectively. Of those patients, 59% ultimately survived to discharge. Four patients with cardiac insufficiency died. The duration from CA to esmolol infusion was significantly shorter for patients in the survival group (SG) than for patients in the dead group (DG) (12 min, IQR: 8.5–19.5 vs. 23.5 min, IQR: 14.4–27 min; p = 0.013). Of those patients, 76% (22 of 29) started esmolol administration after the second dose of amiodarone. No significant difference was observed in the survival rate between this group and groups administered an esmolol bolus simultaneously or before the second dose of amiodarone (43% vs. 64%, p = 0.403). Of those patients, 31% (9 of 29) were administered an esmolol bolus for defibrillation attempts ≤ 5, while the remaining 69% of patients received an esmolol injection after the fifth defibrillation attempt. No significant differences were observed in the rates of ≥ 24-h ROSC (67% vs. 60%, p = 0.73), ≥ 72-h ROSC (67% vs. 55%, p = 0.56), and survival to hospital discharge (67% vs. 55%, p = 0.56) between the groups administered an esmolol bolus for defibrillation attempts ≤ 5 and defibrillation attempts > 5.

Conclusion: IHCA patients with refractory shockable rhythms receiving esmolol bolus exhibited a high chance of sustained ROSC and survival to hospital discharge. Patients with end-stage heart failure tended to have attenuated benefits from beta-blockers. Further large-scale, prospective studies are necessary to determine the effects of esmolol in patients with IHCA with refractory shockable rhythms.

Effects of Cardiac Massage and β-Blocker Pretreatment on the Success Rate of Cardiopulmonary Resuscitation Assessed by the Canine Ischemia/Reperfusion-Induced Ventricular Fibrillation Model

BACKGROUND

Effects of rapid electrical defibrillation and β-blockade on coronary ischemia/reperfusion-induced ventricular fibrillation (VF) during cardiopulmonary resuscitation (CPR) remain unknown.Methods and Results:After induction of VF by 30 min of ischemia followed by reperfusion, animals were treated with defibrillation alone (Group A, n=13), 2 min of open-chest cardiac massage followed by defibrillation (Group B, n=11), or the same therapy to Group B with propranolol (1 mg/kg, i.v.) treatment before ischemia/reperfusion (Group C, n=11). If return of spontaneous circulation (ROSC) was not attained, each therapy was repeated ≤3 times (Set-1). When ROSC was not obtained within Set-1, cardiac massage was applied to all animals followed by defibrillation, which was repeated ≤3 times (Set-2). ROSC after Set-1 was 8% in Group A, 82% in Group B and 82% in Group C, whereas that after Set-2 was 62% in Group A, 100% in Group B and 82% in Group C. Each animal with ROSC in Groups A (n=8) and B (n=11) showed sinus rhythm, whereas those in Group C (n=9) had sinus rhythm (n=5), atrial fibrillation (n=1), accelerated idioventricular rhythm (n=2) and atrioventricular block (n=1). Post ROSC heart rate and mean arterial pressure were significantly lower in Group C.

CONCLUSIONS

Cardiac massage increased the likelihood of ROSC vs. rapid defibrillation, but β-blocker pretreatment may worsen hemodynamics and electrical stability after ROSC.

Refractory Ventricular Fibrillation Treated with Double Simultaneous Defibrillation: Pilot Study

Introduction

Refractory shockable rhythm has a high mortality rate and poor neurological outcome. Treatments for refractory shockable rhythm presenting after defibrillation and medical treatment are not definite. We conducted research on the application of double simultaneous defibrillation (DSiD) for refractory shockable rhythms.

Methods

This is a retrospective pilot study performed using medical records from 1 January 2016 to 31 December 2017. The prephase was from January to December 2016. The post-phase was from January to December 2017. During the prephase, we conducted conventional defibrillation with one defibrillator, and during the post-phase, we conducted DSiD using two defibrillators. Primary outcome was survival to hospital discharge. Secondary outcomes included survival to hospital admission and good neurological outcome at 12 months. Statistical analysis was conducted using Fisher's exact test. Data were regarded statistically significant when p < 0.05.

Result

A total of 38 patients were included. Twenty-one patients underwent conventional defibrillation, and 17 underwent DSiD. The DSiD group had a higher survival to admission rate (14/17 (82.4%) vs. 6/21 (28.6%), p=0.001) and showed a trend for higher survival to discharge (7/17 (41.2%) vs. 3/21 (14.3%), p=0.078). Good neurological outcome at 12 months of the DSiD group was higher than that of the conventional defibrillation group, but the difference was not statistically significant (5/17 (29.4%) vs 2/21 (9.5%), p=0.207).

Conclusion

In patients with refractory shockable rhythms, DSiD has increased survival to hospital admission and a trend of increased survival to hospital discharge. However, DSiD did not improve neurological outcome at 12 months.

Handling of Ventricular Fibrillation in the Emergency Setting

Ventricular fibrillation (VF) and sudden cardiac death (SCD) are predominantly caused by channelopathies and cardiomyopathies in youngsters and coronary heart disease in the elderly. Temporary factors, e.g., electrolyte imbalance, drug interactions, and substance abuses may play an additive role in arrhythmogenesis. Ectopic automaticity, triggered activity, and reentry mechanisms are known as important electrophysiological substrates for VF determining the antiarrhythmic therapies at the same time. Emergency need for electrical cardioversion is supported by the fact that every minute without defibrillation decreases survival rates by approximately 7%–10%. Thus, early defibrillation is an essential part of antiarrhythmic emergency management. Drug therapy has its relevance rather in the prevention of sudden cardiac death, where early recognition and treatment of the underlying disease has significant importance. Cardioprotective and antiarrhythmic effects of beta blockers in patients predisposed to sudden cardiac death were highlighted in numerous studies, hence nowadays these drugs are considered to be the cornerstones of the prevention and treatment of life-threatening ventricular arrhythmias. Nevertheless, other medical therapies have not been proven to be useful in the prevention of VF. Although amiodarone has shown positive results occasionally, this was not demonstrated to be consistent. Furthermore, the potential proarrhythmic effects of drugs may also limit their applicability. Based on these unfavorable observations we highlight the importance of arrhythmia prevention, where echocardiography, electrocardiography and laboratory testing play a significant role even in the emergency setting. In the following we provide a summary on the latest developments on cardiopulmonary resuscitation, and the evaluation and preventive treatment possibilities of patients with increased susceptibility to VF and SCD.

A Recalcitrant Electrical Storm and Implantable Defibrillator Exhaustion: Treatment Implications According to and Beyond Guidelines

A 60-year-old patient presented with recalcitrant electrical storm (ES). Mild sedation and initial antiarrhythmic combination of esmolol and amiodarone did not affect the intensity of ES, which resulted in battery exhaustion. Oral propranolol in addition to intravenous amiodarone might be preferred in hemodynamically stable patients before interventional therapies. (Level of Difficulty: Intermediate.)

Triple-sequential defibrillation for refractory ventricular fibrillation in a 24-year-old male out of hospital cardiac arrest

Refractory ventricular fibrillation encountered during cardiac arrest has a mortality rate of 97%.1 As per the advanced cardiac life support (ACLS) guidelines, the management algorithm of ventricular fibrillation consists of chest compressions, epinephrine, defibrillation, and anti-arrhythmics.2 There have been reports describing the use of the fast-acting selective β-blocker, esmolol, and dual-sequential defibrillation in the management of ventricular fibrillation that is refractory to standard ACLS. We present a case of a 24-year-old male who had an out-of-hospital cardiac arrest, with refractory ventricular fibrillation despite high-quality cardiopulmonary resuscitation (CPR) and ACLS management. Along with standard ACLS, triple-sequential defibrillation was used to achieve return of spontaneous circulation (ROSC) after 82 minutes of downtime. An electrocardiogram (ECG) after ROSC showed an ST-elevation myocardial infarction (MI), and the patient underwent angiography showing a 100% occlusion of his left anterior descending artery. Following management of his coronary artery disease, he was discharged from the hospital 16 days later and was neurologically intact.

Extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest: a registry study

Aims

Out-of-hospital cardiac arrest (OHCA) without return of spontaneous circulation (ROSC) despite conventional resuscitation is common and has poor outcomes. Adding extracorporeal membrane oxygenation (ECMO) to cardiopulmonary resuscitation (extracorporeal-CPR) is increasingly used in an attempt to improve outcomes.

Methods and results

We analysed a prospective registry of 13 191 OHCAs in the Paris region from May 2011 to January 2018. We compared survival at hospital discharge with and without extracorporeal-CPR and identified factors associated with survival in patients given extracorporeal-CPR. Survival was 8% in 525 patients given extracorporeal-CPR and 9% in 12 666 patients given conventional-CPR (P = 0.91). By adjusted multivariate analysis, extracorporeal-CPR was not associated with hospital survival [odds ratio (OR), 1.3; 95% confidence interval (95% CI), 0.8–2.1; P = 0.24]. By conditional logistic regression with matching on a propensity score (including age, sex, occurrence at home, bystander CPR, initial rhythm, collapse-to-CPR time, duration of resuscitation, and ROSC), similar results were found (OR, 0.8; 95% CI, 0.5–1.3; P = 0.41). In the extracorporeal-CPR group, factors associated with hospital survival were initial shockable rhythm (OR, 3.9; 95% CI, 1.5–10.3; P = 0.005), transient ROSC before ECMO (OR, 2.3; 95% CI, 1.1–4.7; P = 0.03), and prehospital ECMO implantation (OR, 2.9; 95% CI, 1.5–5.9; P = 0.002).

Conclusions

In a population-based registry, 4% of OHCAs were treated with extracorporeal-CPR, which was not associated with increased hospital survival. Early ECMO implantation may improve outcomes. The initial rhythm and ROSC may help select patients for extracorporeal-CPR.

Propranolol Versus Metoprolol for Treatment of Electrical Storm in Patients With Implantable Cardioverter-Defibrillator

BACKGROUND

Electrical storm (ES), characterized by unrelenting recurrences of ventricular arrhythmias, is observed in approximately 30% of patients with implantable cardioverter-defibrillators (ICDs) and is associated with high mortality rates.

OBJECTIVES

Sympathetic blockade with β-blockers, usually in combination with intravenous (IV) amiodarone, have proved highly effective in the suppression of ES. In this study, we compared the efficacy of a nonselective β-blocker (propranolol) versus a β₁-selective blocker (metoprolol) in the management of ES.

METHODS

Between 2011 and 2016, 60 ICD patients (45 men, mean age 65.0 ± 8.5 years) with ES developed within 24 h from admission were randomly assigned to therapy with either propranolol (160 mg/24 h, Group A) or metoprolol (200 mg/24 h, Group B), combined with IV amiodarone for 48 h.

RESULTS

Patients under propranolol therapy in comparison with metoprolol-treated individuals presented a 2.67 times decreased incidence rate (incidence rate ratio: 0.375; 95% confidence interval: 0.207 to 0.678; p = 0.001) of ventricular arrhythmic events (tachycardia or fibrillation) and a 2.34 times decreased rate of ICD discharges (incidence rate ratio: 0.428; 95% CI: 0.227 to 0.892; p = 0.004) during the intensive care unit (ICU) stay, after adjusting for age, sex, ejection fraction, New York Heart Association functional class, heart failure type, arrhythmia type, and arrhythmic events before ICU admission. At the end of the first 24-h treatment period, 27 of 30 (90.0%) patients in group A, while only 16 of 30 (53.3%) patients in group B were free of arrhythmic events (p = 0.03). The termination of arrhythmic events was 77.5% less likely in Group B compared with Group A (hazard ratio: 0.225; 95% CI: 0.112 to 0.453; p < 0.001). Time to arrhythmia termination and length of hospital stay were significantly shorter in the propranolol group (p < 0.05 for both).

CONCLUSIONS

The combination of IV amiodarone and oral propranolol is safe, effective, and superior to the combination of IV amiodarone and oral metoprolol in the management of ES in ICD patients.

A case of refractory ventricular fibrillation successfully treated with low-dose esmolol

Current advanced cardiac life support (ACLS) guidelines for the management of ventricular fibrillation (VF) and pulseless ventricular tachycardia is defibrillation. However, refractory VF, which is defined as VF that persists despite three defibrillation attempts, is challenging for all ACLS providers; the best resuscitation strategy for patients that persist in refractory VF remains unclear. We report on a 51-year-old man who presented to the emergency department with chest pain and subsequently went into witnessed VF cardiac arrest. Despite standard ACLS management consisting of high-quality cardiopulmonary resuscitation, serial epinephrine and serial defibrillation, the return of spontaneous circulation (ROSC) was unable to be achieved. Double sequential defibrillation (DSD) was attempted multiple times unsuccessfully. After administration of low-dose esmolol, he immediately achieved ROSC. DSD and β-blockade are increasingly recognised in the literature and practice for refractory VF. However, to the best of our knowledge, this is the first case of refractory VF that responded to low-dose esmolol β-blockade.

Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest

Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO₂-mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG) and electroencephalogram (EEG) signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients.

Milrinone and esmolol decrease cardiac damage after resuscitation from prolonged cardiac arrest

BACKGROUND

Long-term survival after cardiac arrest (CA) due to shock-refractory ventricular fibrillation (VF) is low. Clearly, there is a need for new pharmacological interventions in the setting of cardiopulmonary resuscitation (CPR) to improve outcome. Here, hemodynamic parameters and cardiac damage are compared between the treatment group (milrinone, esmolol and vasopressin) and controls (vasopressin only) during resuscitation from prolonged CA in piglets.

METHODS

A total of 26 immature male piglets were subjected to 12-min VF followed by 8-min CPR. The treatment group (n=13) received i.v. (intravenous) boluses vasopressin 0.4 U/kg, esmolol 250 μg/kg and milrinone 25 μg/kg after 13 min, followed by i.v. boluses esmolol 375 μg/kg and milrinone 25 μg/kg after 18 min and continuous esmolol 15 μg/kg/h infusion during 180 min reperfusion, whereas controls (n=13) received equal amounts of vasopressin and saline. A 200 J monophasic counter-shock was delivered to achieve resumption of spontaneous circulation (ROSC) after 8 min CPR. If ROSC was not achieved, another 200 J defibrillation and bolus vasopressin 0.4 U/kg would be administered in both groups. Direct current shocks at 360 J were applied as one shot per minute over maximally 5 min. Hemodynamic variables and troponin I as a marker of cardiac injury were recorded.

RESULTS

Troponin I levels after 180 min reperfusion were lower in the treatment group than in controls (P<0.05). The treatment group received less norepinephrine (P<0.01) and had greater diuresis (P<0.01). There was no difference in survival between groups.

CONCLUSION

The combination of milrinone, esmolol and vasopressin decreased cardiac injury compared with vasopressin alone.

Use of beta-blockers for the treatment of cardiac arrest due to ventricular fibrillation/pulseless ventricular tachycardia: a systematic review

INTRODUCTION

Advanced Life Support guidelines recommend the use of epinephrine during Cardiopulmonary Resuscitation (CPR), as to increase coronary blood flow and perfusion pressure through its alpha-adrenergic peripheral vasoconstriction, allowing minimal rises in coronary perfusion pressure to make defibrillation possible. Contrasting to these alpha-adrenergic effects, epinephrine's beta-stimulation may have deleterious effects through an increase in myocardial oxygen consumption and a reduction of subendocardial perfusion, leading to postresuscitation cardiac dysfunction.

OBJECTIVE

The present paper consists of a systematic review of the literature regarding the use of beta-blockade in cardiac arrest due to ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT).

METHODS

Studies were identified through MEDLINE electronic databases research and were included those regarding the use of beta-blockade during CPR.

RESULTS

Beta-blockade has been extensively studied in animal models of CPR. These studies not only suggest that beta-blockade could reduce myocardial oxygen requirements and the number of shocks necessary for defibrillation, but also improve postresuscitation myocardial function, diminish arrhythmia recurrences and prolong survival. A few case reports described successful beta-blockade use in patients, along with two prospective human studies, suggesting that it could be safe and effectively used during cardiac arrest in humans.

CONCLUSION

Even though the existing literature points toward a beneficial effect of beta-blockade in patients presenting with cardiac arrest due to VF/pulseless VT, high quality human trials are still lacking to answer this question definitely.

Does prearrest adrenergic integrity affect pressor response? A comparison of epinephrine and vasopressin in a spontaneous ventricular fibrillation swine model

OBJECTIVES

Coronary perfusion pressure (CPP) during resuscitation from cardiac arrest has been shown to correlate with return of spontaneous circulation. Adrenergic blockade of beta-1 and alpha-1 receptors is common in the long-term management of ischemic heart disease and congestive heart failure. We sought to compare the CPP response to vasopressin vs. epinephrine in a swine model of cardiac arrest following pre-arrest adrenergic blockade.

METHODS

Eight anesthetized and instrumented swine were administered 0.1mg epinephrine and arterial pressure and heart rate response were measured. An infusion of labetalol was then initiated and animals periodically challenged with epinephrine until adrenergic blockade was confirmed. The left anterior descending coronary artery was occluded to produce ventricular fibrillation (VF). After 7min of untreated VF, mechanical chest compressions were initiated. After 1min of compressions, 1mg epinephrine was given while CPP was recorded. When CPP values had returned to pre-epinephrine levels, 40U of bolus vasopressin was given. Differences in CPP (post-vasopressor-pre-vasopressor) were compared within animals for the epinephrine and vasopressin response and with eight, non-adrenergically blocked, historical controls using Bayesian statistics with a non-informative prior.

RESULTS

The CPP response following epinephrine was 15.1mmHg lower in adrenergically blocked animals compared to non-adrenergically blocked animals (95% Highest Posterior Density [HPD] 2.9-27.2mmHg lower). CPP went up 18.4mmHg more following vasopressin when compared to epinephrine (95% HPD 8.2-29.1mmHg). The posterior probability of a higher CPP response from vasopressin (vs. epinephrine) in these animals was 0.999.

CONCLUSIONS

Pre-arrest adrenergic blockade blunts the CPP response to epinephrine. Superior augmentation of CPP is attained with vasopressin under these conditions.

Improving the outcome of in-hospital cardiac arrest: the importance of being EARNEST

Cardiopulmonary resuscitation techniques were introduced more than 50 years ago, yet the rate of survival from cardiac arrest, particularly in the hospital setting, remains dismally low. This article reviews the prevalence, etiology, and outcome of in-hospital cardiac arrest, with a focus on the determinants of outcome that are amenable to improvement. These include principally components of basic life support that may be supported by either prompting or mechanical assistance (eg, chest compression, ventilation, and defibrillation). Also reviewed are preevent and postevent effectors such as medical staff skills and recognition of impending arrest, induction of mild hypothermia, and stabilization after return of spontaneous circulation.