Coronary artery compression by a dilated pulmonary artery is a rare complication in patients with tetralogy of Fallot with absent pulmonary valve. We present a case in which this condition manifested at two months of age, with ventricular fibrillation as the initial symptom of myocardial ischaemia. It is important to recognise that this potentially fatal complication can occur in early infancy.

Japanese whalers use the electric lance as a secondary method of killing minke whales (Balaenoptera acutorostrata). The lances are dropped into the body, and currents varying between 2.2 and 14. OA, with a mean of 6.8A, are applied.

When currents of 5A were applied to the carcasses of dead whales, varying in size from 1.8 to 15.7m in length, no current densities induced in the target organs were sufficient to cause either insensibility (10mA cm−2 in the brain), or to cause ventricular fibrillation (0.5mA cm−2 in the heart), except in a few cases where electrodes were specifically placed to span the heart. When electrodes were placed in positions normally used in whaling operations, no current densities were produced which would have been sufficient to cause brain and cardiac dysfunction.

Further investigations on changes in current density with time post mortem after application of a controlled current of 5A showed, during a 60 hour period, a fourfold increase in the current density in the heart, and more than a twofold increase in the brain. Thus contrary to previous criticisms, if these studies had been carried out on live animals, all current densities would have been below threshold values.

There are no records of signs of epileptic form seizure, which are associated with an effective electrical stun, in whales subjected to the electric lance.

It is concluded that the electric lance as used in whaling operations is ineffective and likely to cause extra pain and suffering to an already distressed animal.

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

In young patients with unexplained ventricular fibrillation, coronary occlusion may be missed by echocardiogram and misinterpreted by CT. We report two patients presenting with ventricular fibrillation and initially negative workup, later identified to have occlusion of left main coronary artery. We demonstrate the importance of angiography to rule out coronary occlusion in patients with unexplained ventricular fibrillation.

We present a young soldier presenting with aborted sudden cardiac death, who was found to have concomitant hypertrophic cardiomyopathy and Wolff–Parkinson–White syndrome. Along with pathological haemodynamic features of hypertrophic cardiomyopathy, an easily-inducible re-entrant tachycardia was clearly documented in our patient. Given the fatal potential of supraventricular tachycardia in hypertrophic cardiomyopathy, we postulated that his tachyarrhythmia could potentially trigger the event. Upon his refusal to receive implantable cardioverter/defibrillator therapy, we ablated anatomical arrhythmogenic substrate instead, and he remained uneventfully over 3 years on β-blocker.

Introduction: Patients in ventricular fibrillation (VF) who do not respond to standard Advanced Cardiac Life Support treatments are deemed to be in refractory VF (rVF). The ideal prehospital treatment for patients with rVF remains unknown. Double sequential external defibrillation (DSED) has been proposed as a viable option for patients in rVF. Although the mechanism by which DSED terminates rVF remains unknown, one theory is that the change in defibrillation vector that occurs may contribute. The objective of this study was to describe clinical outcomes for patients presenting in rVF during out-of-hospital cardiac arrest (OOHCA) for those who underwent vector change defibrillation, compared to those who received standard treatment. Methods: This was a retrospective chart review of adult (18 years) patients presenting in rVF during OOHCA over 15 months beginning in March 2016. Patients who underwent vector change defibrillation had a change in pad position (anterior-anterior to anterior-posterior) after 3 or more consecutive shocks. Termination of rVF was defined as the absence of VF after a vector change or standard shock during the next rhythm analysis. Results: There were 372 OOHCA, with 25 (6.7%) patients meeting our definition of rVF. Of these, 16 (64.0%) patients (median age 62 years, 81.3% male) had vector change after a median (IQR) of 3 (3.0-4.0) paramedic defibrillation attempts. Median (IQR) time to vector change defibrillation was 8.8 (7.1-11.1) minutes. Eight (50%) patients had termination of rVF after the first vector change shock, 6 (37.5%) had prehospital return of spontaneous circulation (ROSC) and 5 (31.3%) patients survived to hospital discharge. Of the 9 rVF patients who did not have vector change, median age was 63 years and 88.9% were male. The median (IQR) number of defibrillations within this group was 5 (4.5-7.0). No patients converted after the 4th defibrillation. Prehospital ROSC was achieved in 3 (33.3%) patients and 5 (55.5%) patients were transported while in rVF . Three patients (33.3%) survived to hospital discharge. Conclusion: This is preliminary evidence that vector change defibrillation in patients with rVF may result in VF termination. A randomized controlled trial is warranted to test whether or not vector change has a role in the termination of rVF.

RottenbergEM. Can Gasping be Used as a Tool to Determine Whether to Perform Compression-Only CPR versus Conventional CPR?Prehosp Disaster Med. 2018;33(2):225–226.

Dual sequential external defibrillation (DSED) is the process of near simultaneous discharge of two defibrillators with differing pad placement to terminate refractory arrhythmias. Previously used in the electrophysiology suite, this technique has recently been used in the emergency department and prehospital setting for out-of-hospital cardiac arrest (OHCA). We present a case of successful DSED in the emergency department with neurologically intact survival to hospital discharge after refractory ventricular fibrillation (RVF) and review the putative mechanisms of action of this technique.

Introduction: When ventricular fibrillation (VF) cannot be terminated with conventional external defibrillation, it is classified as refractory VF (RVF). There is a paucity of information regarding prehospital or patient factors that may be associated with RVF. The objectives of this study were to determine factors that may be associated with RVF, the initial ED rhythm for patients with prehospital RVF, and the incidence of survival in patients who had RVF and were transported to hospital. Methods: Ambulance Call Records (ACRs) of patients with out of hospital cardiac arrest between Mar. 1 2012 and Apr. 1 2016 were reviewed. Cases of RVF (≥5 consecutive shocks delivered) were determined by manual review of the ACR. ED and hospital records were analyzed to determine outcomes of patients who were in RVF and transported to hospital. Descriptive statistics were calculated and all variables were tested for an association with initial ED rhythm, survival to admission, and survival to discharge. Results: Eighty-five cases of RVF were identified. A history of coronary artery disease (47.10%) and hypertension (50.60%) were the most common comorbidities in patients transported to the ED with RVF. Upon arrival to the ED, 24 (28.2%) remained in RVF, 38 (44.7%) had a non-shockable rhythm, and 23 (27.1%) had return of spontaneous circulation. Thirty-four (40%) survived to admission, while only 18 (21.2%) survived to discharge. Pre-existing comorbidities, time to first shock, time on scene, and transport time were not statistically associated with initial ED rhythm, survival to admission or discharge. Patient age was statistically associated with improved rhythm on ED arrival (p=0.013) and survival to discharge (58.24 yrs vs 67.40 yrs, Δ9.17, 95% CI 1.82 to 16.52, p=0.015). Conclusion: The majority of patients with prehospital RVF have a rhythm deterioration by the time care is transferred to the ED. Of these patients with a rhythm deterioration, few survive to hospital discharge. Younger patients are more likely to remain in RVF and survive to discharge. Further research is required to determine prehospital treatment strategies for RVF, as well as patient populations that may benefit from those treatments.

Introduction: Emergency Medical Services (EMS) care confers distinct impact upon survivability from sudden cardiac arrest. Many studies have been conducted regarding EMS interventions for cardiac arrest, though fewer studies have been published detailing specific analysis of paramedic compliance with standing orders, particularly those involving a novel energy strategy in defibrillation. Methods: Adults in sudden cardiac arrest with resuscitation initiated, including at least one defibrillation, between July 1, 2016 and December 1, 2016 were enrolled. Education on a novel defibrillation strategy, involving weight-based joule settings and double sequential external defibrillation (DSED) was delivered in classroom and internet-accessed settings. Paramedics then performed hands-on practice in DSED. All resuscitations were reviewed from electronic medical records (EMRs) completed by treating paramedics, alongside telemetry and defibrillation events recorded, transmitted, and analyzed in proprietary software (CODE-STAT™, Physio-Control Corporation, Redmond, WA). All ECGs and defibrillation events were reviewed by an emergency physician to determine energy settings used by paramedics for determining the accuracy of compliance with protocol-based standing orders. Results: During the 5 month study period, the paramedics involved treated 133 adults in sudden cardiac arrest involving perceived ventricular fibrillation that was treated with at least one defibrillation. 76/90 (84.4%) with estimated weight <100 kg were treated with correct joule settings, though only 7/43 (16.3%) with estimated weight ≥100kg received all defibrillations at 360J as protocol-specified. 26/44 (59.1%) in refractory ventricular fibrillation, defined as requiring a fourth defibrillation, received DSED as protocol-specified. Conclusion: Paramedics, when specifically trained on a novel defibrillation strategy, involving both weight-based joule settings and use of DSED for refractory ventricular fibrillation, are inconsistently able to quickly and successfully incorporate that strategy in EMS resuscitation care. Further educational endeavours are warranted to achieve higher defibrillation strategy protocol compliance.

Following the sudden death of a friend in 1966, Dr Michel Mirowski began pioneering work on the first implantable cardioverter-defibrillator. By 1969 he had developed an experimental model and performed the first transvenous defibrillation. In 1970 he reported on the use of a “standby automatic defibrillator” that was tested successfully in dogs. He postulated that such a device “when adapted for clinical use, might be implanted temporarily or permanently in selected patients particularly prone to develop ventricular fibrillation and thus provide them with some degree of protection from sudden coronary death”. In 1980 he reported on the first human implants of an “electronic device designed to monitor cardiac electrical activity, to recognise ventricular fibrillation and ventricular tachyarrhythmias … and then to deliver corrective defibrillatory discharges”. Through innovations in circuitry, battery, and capacitor technologies, the current implantable cardioverter-defibrillator is 10 times smaller and exponentially more sophisticated than that first iteration. This article will review the inner workings of the implantable cardioverter-defibrillator and outline several features that make it the wonder in technology that it has become.

Accidental hypothermia can lead to untoward cardiac manifestations and arrest. This report presents a case series of severe accidental hypothermia with cardiac complications in three emergency patients who were treated with extracorporeal membrane oxygenation (ECMO) and survived after re-warming. The aim of this discussion was to encourage more clinicians to consider ECMO as a re-warming therapy for severe hypothermia with circulatory collapse and to prompt discussion about decreasing the barriers to its use.

NiehausMT, PechulisRM, WuJK, FreiS, HongJJ, SandhuRS, GreenbergMR. Extracorporeal Membrane Oxygenation (ECMO) for Hypothermic Cardiac Deterioration: A Case Series. Prehosp Disaster Med. 2016;31(5):570–571.

Anabolic androgenic steroids are synthetic derivatives of testosterone that promote the growth of skeletal muscles and have many recognised cardiovascular effects. We report the clinical presentation and pathological findings of an adolescent male whose sudden cardiac arrest following ventricular fibrillation was attributed to anabolic androgenic steroid use. The age of our patient reflects the usage of anabolic androgenic steroids among younger athletes and highlights the need for increased awareness among practitioners.

Fatal arrhythmias in asymptomatic Kawasaki disease patients with normal left ventricular function have rarely been reported. In this study, we report the cases of two adult patients with largely unpredictable sudden cardiac arrest, despite almost-normal left ventricular function even after the diagnosis of presumed Kawasaki disease, as well as consider the mechanisms involved with reference to the literature.

Objectives: The objectives of this systematic literature review were to identify all published literature on wearable defibrillators, assess the wearable defibrillator's efficacy and effectiveness in general and among specific patient groups, including post-myocardial infarction, post coronary artery bypass grafting or percutaneous coronary intervention, non-ischemic cardiomyopathy, and ischemic cardiomyopathy, and to evaluate the quality of evidence.

Methods: The search and synthesis was informed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, and the quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation and the Newcastle Ottawa Scale.

Results: A total of thirty-six articles and conference abstracts from thirty-three studies were included in the review. It appears that wearable defibrillator use compared with no defibrillator use reduces the chance of ventricular tachycardia and ventricular fibrillation (VT/VF) associated deaths by an absolute risk reduction of approximately 1 percent, achieved by averting approximately 4/5th of all VT/VF associated deaths. The quality of evidence was low to very low quality, such that our confidence in the reported estimates is weak.

Conclusions: To validate beneficial results, further investigation using robust study designs conducted by independent researchers is warranted.