Brugada syndrome: Diagnosis, risk stratification and management.

Brugada syndrome is a rare inherited arrhythmia syndrome leading to an increased risk of sudden cardiac death, despite a structurally normal heart. Diagnosis is based on a specific electrocardiogram pattern, observed either spontaneously or during a sodium channel blocker test. Among affected patients, risk stratification remains a challenge, despite recent insights from large population cohorts. As implantable cardiac defibrillators - the main therapy in Brugada syndrome - are associated with a high rate of complications in this population, the main challenge is risk stratification of patients with Brugada syndrome. Aside from the two main predictors of arrhythmia (symptoms and spontaneous electrocardiogram pattern), many risk factors have been recently suggested for stratifying risk of sudden cardiac death in Brugada syndrome. We have reviewed these data and discuss current guidelines in light of recent progress in this complex field.

Part 3: Adult Basic Life Support and Automated External Defibrillation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations.

This review comprises the most extensive literature search and evidence evaluation to date on the most important international BLS interventions, diagnostics, and prognostic factors for cardiac arrest victims. It reemphasizes that the critical lifesaving steps of BLS are (1) prevention, (2) immediate recognition and activation of the emergency response system, (3) early high-quality CPR, and (4) rapid defibrillation for shockable rhythms. Highlights in prevention indicate the rational and judicious deployment of search-and-rescue operations in drowning victims and the importance of education on opioid-associated emergencies. Other 2015 highlights in recognition and activation include the critical role of dispatcher recognition and dispatch-assisted chest compressions, which has been demonstrated in multiple international jurisdictions with consistent improvements in cardiac arrest survival. Similar to the 2010 ILCOR BLS treatment recommendations, the importance of high quality was reemphasized across all measures of CPR quality: rate, depth, recoil, and minimal chest compression pauses, with a universal understanding that we all should be providing chest compressions to all victims of cardiac arrest. This review continued to focus on the interface of BLS sequencing and ensuring high-quality CPR with other important BLS interventions, such as ventilation and defibrillation. In addition, this consensus statement highlights the importance of EMS systems, which employ bundles of care focusing on providing high-quality chest compressions while extricating the patient from the scene to the next level of care. Highlights in defibrillation indicate the global importance of increasing the number of sites with public-access defibrillation programs. Whereas the 2010 ILCOR Consensus on Science provided important direction for the "what" in resuscitation (ie, what to do), the 2015 consensus has begun with the GRADE methodology to provide direction for the quality of resuscitation. We hope that resuscitation councils and other stakeholders will be able to translate this body of knowledge of international consensus statements to build their own effective resuscitation guidelines.

[A brief history of resuscitation - the influence of previous experience on modern techniques and methods]. / Krótka historia resuscytacji - wplyw doswiadczen z przeszlosci na obecnie stosowane techniki i metody.

Cardiopulmonary resuscitation (CPR) is relatively novel branch of medical science, however first descriptions of mouth-to-mouth ventilation are to be found in the Bible and literature is full of descriptions of different resuscitation methods - from flagellation and ventilation with bellows through hanging the victims upside down and compressing the chest in order to stimulate ventilation to rectal fumigation with tobacco smoke. The modern history of CPR starts with Kouwenhoven et al. who in 1960 published a paper regarding heart massage through chest compressions. Shortly after that in 1961Peter Safar presented a paradigm promoting opening the airway, performing rescue breaths and chest compressions. First CPR guidelines were published in 1966. Since that time guidelines were modified and improved numerously by two leading world expert organizations ERC (European Resuscitation Council) and AHA (American Heart Association) and published in a new version every 5 years. Currently 2010 guidelines should be obliged. In this paper authors made an attempt to present history of development of resuscitation techniques and methods and assess the influence of previous lifesaving methods on nowadays technologies, equipment and guidelines which allow to help those women and men whose life is in danger due to sudden cardiac arrest.

The use of imaging for electrophysiological and devices procedures: a report from the first European Heart Rhythm Association Policy Conference, jointly organized with the European Association of Cardiovascular Imaging (EACVI), the Council of Cardiovascular Imaging and the European Society of Cardiac Radiology.

Implantations of cardiac devices therapies and ablation procedures frequently depend on accurate and reliable imaging modalities for pre-procedural assessments, intra-procedural guidance, detection of complications, and the follow-up of patients. An understanding of echocardiography, cardiovascular magnetic resonance imaging, nuclear cardiology, X-ray computed tomography, positron emission tomography, and vascular ultrasound is indispensable for cardiologists, electrophysiologists as well as radiologists, and it is currently recommended that physicians should be trained in several imaging modalities. There are, however, no current guidelines or recommendations by electrophysiologists, cardiac imaging specialists, and radiologists, on the appropriate use of cardiovascular imaging for selected patient indications, which needs to be addressed. A Policy Conference on the use of imaging in electrophysiology and device management, with representatives from different expert areas of radiology and electrophysiology and commercial developers of imaging and device technologies, was therefore jointly organized by European Heart Rhythm Association (EHRA), the Council of Cardiovascular Imaging and the European Society of Cardiac Radiology (ESCR). The objectives were to assess the state of the level of evidence and a first step towards a consensus document for currently employed imaging techniques to guide future clinical use, to elucidate the issue of reimbursement structures and health economy, and finally to define the need for appropriate educational programmes to ensure clinical competence for electrophysiologists, imaging specialists, and radiologists.

Defibrillation success is not associated with near field electrogram complexity or shock timing.

BACKGROUND: It has been suggested that more-complex fibrillation requires higher energy shocks to terminate. Furthermore, animal studies have demonstrated that shock timing also plays a role. The objective of this study was to test these assertions in a clinical context. METHODS: Near- and far-field electrograms were collected during defibrillation threshold testing. Fibrillation complexity was measured by quantifying the organization in the signals with wavelet-based methods, scaling exponent, and cross-correlation analysis. Receiver operator characteristic curves were used to determine predictive value. The effect of the phase at which defibrillation shocks were applied was also determined. RESULTS: No measure was able to classify whether a particular shock would be successful. All performed very poorly. Shock timing played no role in defibrillation outcome. CONCLUSIONS: Signal organization of a local electrogram and phase of shock delivery do not relate to minimum defibrillation shock energy immediately after ventricular fibrillation onset.

Take Heart America: A comprehensive, community-wide, systems-based approach to the treatment of cardiac arrest.

OBJECTIVES: To determine out-of-hospital cardiac arrest survival rates before and after implementation of the Take Heart America program (a community-based initiative that sequentially deployed all of the most highly recommended 2005 American Heart Association resuscitation guidelines in an effort to increase out-of-hospital cardiac arrest survival). PATIENTS: Out-of-hospital cardiac arrest patients in Anoka County, MN, and greater St. Cloud, MN, from November 2005 to June 2009. INTERVENTIONS: Two sites in Minnesota with a combined population of 439,692 people (greater St. Cloud and Anoka County) implemented: 1) widespread cardiopulmonary resuscitation and automated external defibrillator skills training in schools and businesses; 2) retraining of all emergency medical services personnel in methods to enhance circulation, including minimizing cardiopulmonary resuscitation interruptions, performing cardiopulmonary resuscitation before and after single-shock defibrillation, and use of an impedance threshold device; 3) additional deployment of automated external defibrillators in schools and public places; and 4) protocols for transport to and treatment by cardiac arrest centers for therapeutic hypothermia, coronary artery evaluation and treatment, and electrophysiological evaluation. MEASUREMENTS AND MAIN RESULTS: More than 28,000 people were trained in cardiopulmonary resuscitation and automated external defibrillator use in the two sites. Bystander cardiopulmonary resuscitation rates increased from 20% to 29% (p = .086, odds ratio 1.7, 95% confidence interval 0.96-2.89). Three cardiac arrest centers were established, and hypothermia therapy for admitted out-of-hospital cardiac arrest victims increased from 0% to 45%. Survival to hospital discharge for all patients after out-of-hospital cardiac arrest in these two sites improved from 8.5% (nine of 106, historical control) to 19% (48 of 247, intervention phase) (p = .011, odds ratio 2.60, confidence interval 1.19-6.26). A financial analysis revealed that the cardiac arrest centers concept was financially feasible, despite the costs associated with high-quality postresuscitation care. CONCLUSIONS: The Take Heart America program doubled cardiac arrest survival when compared with historical controls. Study of the feasibility of generalizing this approach to larger cities, states, and regions is underway.

Airway interventions in the cardiac electrophysiology laboratory: a retrospective review.

OBJECTIVE: To quantify the incidence of airway interventions during cardiac electrophysiology laboratory procedures. DESIGN: A retrospective chart review. SETTING: A tertiary care teaching hospital. PARTICIPANTS: Two-hundred eight adult patients undergoing cardiac electrophysiology laboratory procedures during a 2-year period, March 2006 to March 2008. The patients underwent the following procedures: supraventricular tachycardia ablation, atrial tachycardia ablation, atrial flutter ablation, premature ventricular contraction ablation, and ventricular tachycardia ablation. Patients who were intubated (in the intensive care unit or emergency department) before the ablation began, patients with ventricular assist devices or intra-aortic balloon pumps, and patients receiving inotropic support before the procedure were excluded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The data were summarized by using the mean and standard deviation. Of the 208 patients, 186 were planned monitored anesthesia care, and 22 were planned general anesthetics. Of the monitored anesthesia care cases, 20 were converted to general anesthesia, and 54 received some type of airway intervention including oral-pharyngeal airway or nasal airway insertion. Therefore, 40% (74/186) of the non-general anesthesia cases required an airway intervention. CONCLUSIONS: These results suggest that a significant proportion of the authors' patients undergoing cardiac electrophysiology laboratory procedures required deep sedation if not general anesthesia, although a non-general anesthetic was planned. The issue of depth of sedation has implications for patient safety, privileging, and regulatory compliance. Based on the present results, the authors believe sedation for these procedures is best given by anesthesia providers; furthermore, caregivers should be aware that these procedures are likely to require deep sedation if not general anesthesia.

ICD patients with elevated defibrillation threshold: clinical behavior and therapeutic alternatives.

BACKGROUND: The ideal programming of the implantable cardioverter defibrillator (ICD) shock energy should be at least 10J above the defibrillation threshold (DFT), requiring alternative techniques when the DFT is elevated. OBJECTIVE: To assess the clinical behavior of ICD patients with DFT>25J and the efficacy of the chosen therapy. METHODS: Patients who had undergone ICD implantation between Jan/00 and Aug/04 (prospective database) and presented intraoperative DFT>25J were selected. The analyzed variables were: clinical characteristics, LVEF, rescue of arrhythmic events from ICD and causes of deaths. RESULTS: among 476 patients, 16 (3.36%) presented DFT>25J. The mean age was 56.5 years, and 13 patients (81%) were men. According to the baseline cardiomyopathy, 09 patients had Chagas' disease, 04 had ischemic cardiomyopathy and 03 had idiopathic cardiomyopathy. Mean LVEF was 0.37 and amiodarone was used by 94% of the patients. Mean follow-up (FU) period was 25.3 months. DFT was higher than maximum energy shock (MES) in 2 patients and it was necessary to implant an additional shock electrode (array). It was programmed MES in ventricular fibrillation zone of ICD therapy in the other patients. In the FU, 03 patients had 67 successful appropriate shock therapies (AST). There were 05 noncardiac and 02 heart failure deaths. The patients who died showed higher DFT levels (p=0.044) without correlation with death because there wasn't unsuccessful AST. CONCLUSION: In this cohort of ICD patients, the occurrence of elevated DFT (>25J) was low, leading to alternative therapies. There was an association with severe ventricular dysfunction, although without correlation to the causes of death.

Portadores de CDI com limiar de desfibrilação elevado: evolução clínica e alternativas terapêuticas / ICD patients with elevated defibrillation threshold: clinical behavior and therapeutic alternatives

FUNDAMENTO: A programação ideal da energia de choque do CDI deve ser pelo menos 10 J acima do limiar de desfibrilação (LDF), necessitando de técnicas alternativas quando o LDF é elevado. OBJETIVO: Avaliar o comportamento clínico dos portadores de CDI com LDF>25 J e a eficácia da terapêutica escolhida. MÉTODOS: Foram selecionados portadores de CDI, entre janeiro de 2000 e agosto de 2004 (banco de dados prospectivo), com LDF>25 J intra-operatório, e analisaram-se: características clínicas, FEVE, resgate de eventos arrítmicos pelo CDI e óbitos. RESULTADOS: dentre 476 pacientes, 16 (3,36 por cento) apresentaram LDF>25J. Idade média de 56,5 anos, sendo 13 pacientes (81 por cento) do sexo masculino. Quanto à cardiopatia de base 09 eram chagásicos, 04 isquêmicos e 03 com etiologia idiopática. A FEVE média dos pacientes foi 37 por cento e 94 por cento utilizavam amiodarona. O seguimento médio foi de 25,3 meses. Em 02 pacientes com LDF > Choque Máximo (CM), foi necessário implante de eletrodo de choque adicional (array), sendo mantido programação com CM em zona de FV (>182bpm) nos demais. Durante o seguimento 03 pacientes apresentaram 67 terapias de choque apropriadas (TCA) com sucesso. Ocorreram 07 óbitos sendo 5 por causas não cardíacas e 2 por insuficiência cardíaca avançada. Os pacientes que foram a óbito apresentaram níveis de LDF maiores (p=0,0446), entretanto sem relação com a causa dos mesmos tendo em vista que não ocorreram TCA sem sucesso. CONCLUSÃO: Nessa coorte de pacientes com CDI, a ocorrência de LDF elevado foi baixa, implicando terapêuticas alternativas. Houve associação com disfunção ventricular grave, entretanto sem correlação com as causas de óbito.

BACKGROUND: The ideal programming of the implantable cardioverter defibrillator (ICD) shock energy should be at least 10J above the defibrillation threshold (DFT), requiring alternative techniques when the DFT is elevated. OBJECTIVE: To assess the clinical behavior of ICD patients with DFT>25J and the efficacy of the chosen therapy. METHODS: Patients who had undergone ICD implantation between Jan/00 and Aug/04 (prospective database) and presented intraoperative DFT>25J were selected. The analyzed variables were: clinical characteristics, LVEF, rescue of arrhythmic events from ICD and causes of deaths. RESULTS: among 476 patients, 16 (3.36 percent) presented DFT>25J. The mean age was 56.5 years, and 13 patients (81 percent) were men. According to the baseline cardiomyopathy, 09 patients had Chagas' disease, 04 had ischemic cardiomyopathy and 03 had idiopathic cardiomyopathy. Mean LVEF was 0.37 and amiodarone was used by 94 percent of the patients. Mean follow-up (FU) period was 25.3 months. DFT was higher than maximum energy shock (MES) in 2 patients and it was necessary to implant an additional shock electrode (array). It was programmed MES in ventricular fibrillation zone of ICD therapy in the other patients. In the FU, 03 patients had 67 successful appropriate shock therapies (AST). There were 05 noncardiac and 02 heart failure deaths. The patients who died showed higher DFT levels (p=0.044) without correlation with death because there wasn't unsuccessful AST. CONCLUSION: In this cohort of ICD patients, the occurrence of elevated DFT (>25J) was low, leading to alternative therapies. There was an association with severe ventricular dysfunction, although without correlation to the causes of death.

Orthogonal field calibration analysis for myocardial electrode arrays used in defibrillation studies.

Mapping the myocardial electric field during a defibrillation pulse requires the recording of potential differences between electrodes. The field is then calculated from these quantities and the corresponding calibration matrix. One straightforward calibration technique involves alignment of a known electric field along each of the orthogonal axes of an electrode array and recording the resulting potential differences. However, no results have been reported to support the efficacy of this technique. This study performs a detailed error analysis including a one-to-one comparison to a precision calibration technique, and quantitatively establishes the efficacy of the orthogonal field technique.

Determination of the upper limit of vulnerability using implantable cardioverter-defibrillator electrograms.

BACKGROUND: The upper limit of vulnerability (ULV) correlates with the defibrillation threshold and can be determined with 1 episode of ventricular fibrillation (VF). To automate the ULV in an implantable cardioverter-defibrillator (ICD), the most vulnerable intervals must be identified from an ICD electrogram rather than the latest-peaking surface T wave (Tpeak). We hypothesized that the recovery time (TR), defined as the maximum derivative (dV/dt) of the T wave of the shock electrogram, correlates with the most vulnerable intervals. METHODS AND RESULTS: We determined ULV, defibrillation threshold, and the most vulnerable intervals in 25 patients at ICD implantation. The ULV was the weakest T-wave shock that did not induce VF. The most vulnerable intervals were the ones associated with the strongest shocks that induced VF. Telemetered shock electrograms were stored on digital tape and differentiated offline to measure TR. Tpeak and TR were highly correlated (Tpeak-TR=-2+/-11 ms; rho=0.80, P<0.001). At least 1 most vulnerable interval timed between -20 ms and +20 ms relative to Tpeak in all patients and between -40 ms and +20 ms relative to TR in 96% of patients. CONCLUSIONS: The recovery time of shock electrograms provides accurate information about global repolarization. TR closely approximates Tpeak. The ULV method may be automated in an ICD by timing T-wave shocks relative to TR.