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Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

Background Patients with atrial fibrillation are increasingly prescribed a direct oral anticoagulant (DOAC) over warfarin and seek to avoid anticoagulation even without a history of major bleeding. This study explores the outcomes of patients implanted with a Watchman device in relation to anticoagulation choice (warfarin versus DOAC) in the post-procedure period and a history of bleeding. Methods Patients implanted with a Watchman device at a single center were retrospectively analyzed. Characteristics including anticoagulation in the first 45 days and history of major bleed were assessed and efficacy (thromboembolism) and safety (bleeding) outcomes compared by Kaplan-Meier analysis. Results 209 patients were implanted (57% male, age 74.6  7.8 years) and followed for 23.5 ± 7.1 months. In the first half of patients, 98% were prescribed warfarin, which dropped to 51% in the second half (p

IntroductionSimulation technology has an established role in teaching technical skills to cardiology fellows, but their impact on teaching trainees to interpret coronary angiographic (CA) images has not been systematically studied. The aim of this randomized controlled study was to test whether structured simulation training in addition to traditional methods would improve CA image interpretation skills in a group of novices to advanced medical trainees.MethodsWe prospectively randomized 105 subjects comprising of medical students (N=20), residents (N=68) and fellows (N=17) from the University of Arizona. Subjects were randomized into a simulation training group which received simulation training in addition to didactic teaching (n=53) and a control training group which received didactic teaching alone (n=52). The change in pre and post-test score (delta score) was analyzed by a two-way ANOVA for education status and training arm.ResultsSubjects improved in their post-test scores with a mean change of 4.6 ± 4.0 points. Subjects in the simulation training arm had a higher delta score compared to control (5.4 ± 4.2 versus 3.8 ± 3.7, p=0.04), with greatest impact for residents (6.6 ± 4.0 versus 3.5 ± 3.4) with a p=0.02 for interaction of training arm and education status.ConclusionsSimulation training complements traditional methods to improve CA interpretation skill, with greatest impact on novice trainees. This highlights the importance of incorporating high-fidelity simulation training early in cardiovascular fellowship curricula.

Patients with atrial fibrillation are increasingly prescribed a direct oral anticoagulant (DOAC) over warfarin and seek to avoid anticoagulation even without a history of major bleeding. This study explores the outcomes of patients implanted with a Watchman device in relation to anticoagulation choice (warfarin versus DOAC) in the post-procedure period and a history of bleeding.Patients implanted with a Watchman device at a single center were retrospectively analyzed. Characteristics including anticoagulation in the first 45 days and history of major bleed were assessed and efficacy (thromboembolism) and safety (bleeding) outcomes compared by Kaplan-Meier analysis.Two hundred nine patients were implanted (57% male, age 74.6 ± 7.8 years) and followed for 23.5 ± 7.1 months. In the first half of patients, 98% were prescribed warfarin, which dropped to 51% in the second half (p0.0001). A history of major bleed was present in 80.8% of the first half of patients and decreased to 60% in the second half (p = 0.001). There were 16 safety and 4 efficacy events. There was no difference in safety outcomes according to history of major bleeding or anticoagulant choice in the first 45 days. There was no difference in efficacy outcomes over the duration of follow-up according to anticoagulation choice in the first 45 days.Patients implanted with a Watchman device were increasingly over time prescribed a DOAC and implanted without a history of major bleeding. Bleeding and thromboembolic events were infrequent and related neither to choice of anticoagulant nor to prior major bleeding.

Previous reports indicate that IL18 is a novel candidate gene for diastolic dysfunction in sickle cell disease (SCD)–related cardiomyopathy. We hypothesize that interleukin-18 (IL-18) mediates the development of cardiomyopathy and ventricular tachycardia (VT) in SCD. Compared with control mice, a humanized mouse model of SCD exhibited increased cardiac fibrosis, prolonged duration of action potential, higher VT inducibility in vivo, higher cardiac NF-κB phosphorylation, and higher circulating IL-18 levels, as well as reduced voltage-gated potassium channel expression, which translates to reduced transient outward potassium current (Ito) in isolated cardiomyocytes. Administering IL-18 to isolated mouse hearts resulted in VT originating from the right ventricle and further reduced Ito in SCD mouse cardiomyocytes. Sustained IL-18 inhibition via IL-18–binding protein resulted in decreased cardiac fibrosis and NF-κB phosphorylation, improved diastolic function, normalized electrical remodeling, and attenuated IL-18–mediated VT in SCD mice. Patients with SCD and either myocardial fibrosis or increased QTc displayed greater IL18 gene expression in peripheral blood mononuclear cells (PBMCs), and QTc was strongly correlated with plasma IL-18 levels. PBMC-derived IL18 gene expression was increased in patients who did not survive compared with those who did. IL-18 is a mediator of sickle cell cardiomyopathy and VT in mice and a novel therapeutic target in patients at risk for sudden death.

Background Observational studies have explored the safety of magnetic resonance (MR) scanning of patients with cardiac implantable electronic devices (CIEDs) that are not Food and Drug Administration approved for MR scanning ("nonconditional"). However, concern has been raised that MR scanning that includes the thoracic region may pose a higher risk. This study examines the safety of MR scanning of thoracic versus nonthoracic regions of patients with CIEDs. Methods Patients underwent MR scanning utilizing an institutional protocol. CIED variables examined included sensing value, pacing capture threshold, lead impedance, and battery voltage. Regression analysis of the CIED variable differences (pre- to immediately post-MR and pre-MR to long-term follow-up) was performed to determine if CIED variable differences were dependent on region scanned (thoracic vs nonthoracic), time from CIED implant to MR scanning, or CIED type (pacemaker vs implantable cardioverter defibrillator). Results 238 patients (38% female, age 65 ± 15 years) underwent 339 MR scans, including 99 MR scans of the thoracic region. CIED variable differences to immediately post-MR or to long-term follow-up were not significantly different from zero (P > 0.05) and there was no dependence upon region scanned (thoracic vs nonthoracic), time from CIED implant to MR scan, or CIED type. One power-on reset occurred in a patient that underwent a cardiac MR and the CIED was successfully reprogrammed. There were no clinical adverse effects. Conclusions CIED variable differences following MR scan were not dependent on the region scanned (thoracic vs nonthoracic) and there were no clinical adverse effects in this prospective cohort.

Eric S. Williams, MD, MACC, Chair Jonathan L. Halperin, MD, FACC, Co-Chair Jesse E. Adams III, MD, FACC James A. Arrighi, MD, FACC Eric H. Awtry, MD, FACC[†][1] Eric R. Bates, MD, FACC[†][1] John E. Brush, Jr, MD, FACC Lori Daniels, MD, MAS, FACC[†][1] Ali Denktas, MD, FACC Susan

Cardiac implanted electronic devices (CIEDs) have historically been regarded as a contraindication for performing magnetic resonance imaging (MRI), limiting the availability of this exam for large numbers of patients who may have otherwise benefited from the unique diagnostic capabilities of MRI. Interactions between CIEDs and the magnetic field associated with MRI systems have been documented, and include potential effects on CIED function, lead heating, and force/torque on the generator. Several device manufacturers have developed "MR-Conditional" CIEDs with specific hardware and software design changes to optimize the device for the MR environment. However, a substantial body of evidence has been accumulating that suggests that MRI may be safely performed in patients with either conditional or nonconditional CIEDs. Institutional policies and procedures, including preexam screening and assessment by skilled electrophysiology personnel and intraexam monitoring, allow MRI to be safely performed in CIED patients, as evidenced by at least two, large multicenter prospective studies and multiple smaller, single-institution studies. Cross-departmental collaboration and a robust safety infrastructure at sites that perform MRI should allow for the safe imaging of CIED patients who have a clinical indication for the study, regardless of the conditionality status of the device. LEVEL OF EVIDENCE 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;47:595-603.

The American College of Cardiology In-Training Exam (ACC-ITE) is incorporated into most U.S. training programs, but its relationship to performance on the American Board of Internal Medicine Cardiovascular Disease (ABIM CVD) Certification Examination is unknown. ACC-ITE scores from third-year fellows from 2011 to 2014 (n = 1,918) were examined. Covariates for regression analyses included sex, age, medical school country, U.S. Medical Licensing Examination Step, and ABIM Internal Medicine Certification Examination scores. A secondary analysis examined fellows (n = 511) who took the ACC-ITE in the first and third years. ACC-ITE scores were the strongest predictor of ABIM CVD scores (p < 0.0001), and the most significant predictor of passing (p < 0.0001). The change in ACC-ITE scores from first to third year was a strong predictor of the ABIM CVD score (p < 0.001). The ACC-ITE is strongly associated with performance on the ABIM CVD Certification Examination.

International audience; Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.

A sudden cardiac arrest in school or at a school event is potentially devastating to families and communities. An appropriate response to such an event—as promoted by developing, implementing, and practicing a cardiac emergency response plan (CERP)—can increase survival rates. Understanding that a trained lay-responder team within the school can make a difference in the crucial minutes between the time when the victim collapses and when emergency medical services arrive empowers school staff and can save lives. In 2015, the American Heart Association convened a group of stakeholders to develop tools to assist schools in developing CERPs. This article reviews the critical components of a CERP and a CERP team, the factors that should be taken into account when implementing the CERP, and recommendations for policy makers to support CERPs in schools.

Preamble e472 1. Introduction e473 2. General Principles e475 3. Sinus Tachyarrhythmias e480 4. Nonsinus Focal Atrial Tachycardia and MAT e481 5. Atrioventricular Nodal Reentrant Tachycardia e482 6. Manifest and Concealed Accessory Pathways e483 7. Atrial Flutter e485 8. Junctional Tachycardia e487 9. Special Populations e487

Jonathan L. Halperin, MD, FACC, FAHA, Chair Glenn N. Levine, MD, FACC, FAHA, Chair-Elect Jeffrey L. Anderson, MD, FACC, FAHA, Immediate Past Chair [¶][1] Nancy M. Albert, PhD, RN, FAHA[¶][1] Sana M. Al-Khatib, MD, MHS, FACC, FAHA Kim K. Birtcher, PharmD, AACC Biykem Bozkurt, MD, PhD, FACC

Eric S. Williams, MD, MACC, Chair Jonathan L. Halperin, MD, FACC, Co-Chair James A. Arrighi, MD, FACC Eric H. Awtry, MD, FACC Eric R. Bates, MD, FACC John E. Brush, Jr, MD, FACC Salvatore Costa, MD, FACC Lori Daniels, MD, MAS, FACC Akshay Desai, MD, FACC[‡][1] Douglas E. Drachman, MD

Left ventricle (LV) lead misplacement is a rare complication of cardiovascular implantable electronic device (CIED) placement, mainly due to an inadvertent access to the subclavian artery. A frail 81 year-old woman (BMI of 15) received a single chamber pacemaker at an outside institution for

See Article by Orgeron et al Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive disorder characterized by morphological changes in the myocardium that place the patient at risk for lethal ventricular arrhythmias. A genetic mutation involving desmosomes is seen in most patients1 that affects myocyte cell-to-cell adhesion. Athletes are likely to express this disease at an earlier age as exercise promotes progression of the disease. Because either ventricle can be affected, the term arrhythmogenic cardiomyopathy has been proposed.1,2 Diagnosis is based on criteria as set out in the 2010 Task Force document,3 encompassing ventricular structure, histology, electrocardiographic features, arrhythmias, and genetic features. In 2015, an International Task Force published a consensus statement to provide clinical practice guidance based on available evidence and expert opinion.4 For implantable cardioverter defibrillator (ICD) implantation, the Task Force assigned a class I recommendation to patients who had been resuscitated from hemodynamically unstable ventricular tachycardia (VT) or ventricular fibrillation (VF) and for patients with severe right ventricular or left ventricular systolic dysfunction because these patients were felt to have life-threatening arrhythmic events >10% per year.4 The Task Force advised that an ICD should be considered (class IIa) for patients with hemodynamically stable sustained VT, syncope, nonsustained VT, or moderate ventricular dysfunction.4 A class IIb (may be considered) designation was assigned for those with minor risk factors, such as male sex, proband status, inducibility on electrophysiological study, or at least 3 precordial leads with T-wave inversion.4 Finally, class III (not recommended) was assigned to asymptomatic patients with no risk factors or healthy gene carriers.4 Since the publication of the International Task Force consensus statement, larger observational studies have added to our understanding of this disease. In 416 …

Objective In out-of-hospital cardiac arrest (OHCA) with ventricular fibrillation (VF) the frequency-based waveform characteristic, amplitude-spectral area (AMSA) is associated with hospital discharge and good neurological outcome, yet AMSA is also known to increase in response to chest compressions (CC). In addition to rate and depth, well performed CC provides good chest recoil without leaning, reflected in the release velocity (RV). We hypothesized that AMSA is associated with hospital discharge and good neurological outcome independent of CC quality. Methods OHCA patients (age≥18), with initial rhythm of VF from an Utstein-Style database were analyzed. AMSA was measured prior to each shock, and averaged for each subject (AMSA-avg). Primary endpoint was hospital discharge and secondary endpoint was a good neurological outcome. Univariate and stepwise multivariable logistic regression, and receiver–operator–characteristic (ROC) analyses were performed. Factors analyzed were age, sex, witnessed status, time from dispatch to monitor/defibrillator application, number of shocks, first shock AMSA (AMSA 1 ), AMSA-avg, averaged pre-shock pause, CC rate, depth, and RV. Results 140 subjects were analyzed. Hospital discharge was 31% and with good neurological outcome in 24% (77% of those discharged). AMSA-avg ( p p =0.002), and age ( p =0.029) were independently associated with hospital discharge, with a non-significant trend for witnessed status ( p =0.069), with AUC=0.846 for the multivariate model. For good neurological outcome, AMSA-avg ( p =0.001) and RV ( p =0.001) remained independently significant, with AUC=0.782. Conclusion In OHCA with an initial rhythm of VF, AMSA-avg and CC RV are both highly and independently associated with hospital discharge and good neurological outcome.

Since the advent of the non-vitamin K antagonist oral anticoagulant (NOAC) agents, which act as direct thrombin inhibitors or inhibitors of Factor Xa, clinicians are provided with valuable alternatives to vitamin K antagonists (VKAs). At the same time, electrophysiologists frequently perform more invasive procedures, increasingly involving the left chambers of the heart. Thus, they are constantly faced with the dilemma of balancing the risk for thromboembolic events and bleeding complications. These changes in the rapidly evolving field mandate an update of the European Heart Rhythm Association (EHRA) 2008 consensus document on this topic.1 The present document covers the antithrombotic management during different ablation procedures, implantation or exchange of cardiac implantable electronical devices (CIEDs), as well as the management of peri-interventional bleeding complications. The document is not a formal guideline and due to the lack of prospective randomized controlled trials (RCTs) for many of the clinical situations encountered, the recommendations are often ‘expert opinion’. The document strives to be practical for which reason we subdivided it in the three main topics: ablation procedure, CIED implantation or generator change, and issues of peri-interventional bleeding complications on concurrent antiplatelet therapy. For quick reference, every subchapter is followed by a short section on consensus recommendations. Many RCTs are ongoing in this field and it is hoped that this document will help to prompt further well-designed studies. ### Ablation of atrial fibrillation, left atrial arrhythmias and right sided atrial flutter In patients with symptomatic paroxysmal or even persistent atrial fibrillation (AF), catheter ablation is indicated when antiarrhythmic drugs have failed in controlling recurrences or even as a first-line therapy in selected patients.2–4 Patients with AF have an increased risk of thromboembolic events, which varies according to the presence of several risk factors.5,6 Apart from their intrinsic thromboembolic risks, ablation in these patients increases thromboembolic risk due to the introduction and manipulation …

Background The American College of Cardiology (ACC), in collaboration with the National Board of Medical Examiners (NBME), developed the first standardized in-training examination (ITE) for cardiovascular disease fellows-in-training (FITs). In addition to testing knowledge, this examination uses the newly developed ACC Curricular Milestones to provide specific, competency-based feedback to program directors and FITs. The ACC ITE has been administered more than 5,000 times since 2011. Objectives This analysis sought to report the initial experience with the ITE, including feasibility and reliability of test development and implementation, as well as the ability of this process to provide useful feedback in key content areas. Methods The annual ACC ITE has been available to cardiovascular disease fellowship programs in the United States since 2011. Questions for this Web-based, secure, multiple-choice examination were developed by a group of cardiovascular disease specialists and each question was analyzed by the NBME to ensure quality. Scores were equated and standardized to allow for comparability. Trainees and program directors were provided detailed feedback, including a list of the curricular competencies tested by those questions answered incorrectly. Results The ITE was administered 5,118 times. In 2013, the examination was taken by 1,969 fellows, representing 194 training programs. Among the 3 training years, there was consistency in the examination scores. Total test scores and scores within each of the content areas increased with each FIT year (there was a statistically significant difference in each cohort’s average scale score across administration years). There was also significant improvement in examination scores across the fellowship years. Conclusions The ACC ITE is a powerful tool available to all training programs to assess medical knowledge. This examination also delivers robust and timely feedback addressing individual knowledge gaps, and thus, may serve as a basis for improving training curricula.

In retrospective swine and human investigations of ventricular fibrillation (VF) cardiac arrest, the amplitude-spectral area (AMSA), determined from the VF waveform, can predict defibrillation and a return of spontaneous circulation (ROSC).We hypothesized that an algorithm using AMSA in real time to direct postshock chest compression (CC) duration would shorten the time to ROSC and improve neurological outcome in a swine model of VF cardiac arrest with acute myocardial infarction (AMI) or nonischemic myocardium.AMI was induced by occlusion of the left anterior descending artery. VF was untreated for 10 min. Animals were randomized to either traditional resuscitation with 2 min of CC after each shock or to an AMSA-guided algorithm where postshock CCs were shortened to 1 min if the preshock AMSA exceeded 20 mV-Hz.A total of 48 animals were studied, 12 in each group (AMI vs. normal, and traditional vs. AMSA-guided). There was a nonsignificant shorter time to ROSC with an AMSA-guided approach in AMI swine (17.2 ± 3.4 vs. 18.5 ± 4.7 min, p = NS), and in normal swine (13.5 ± 1.1 vs. 14.4 ± 1.2, p = NS). Neurological outcome was similar between traditional and AMSA-guided animals. AMSA predicted ROSC (p0.001), and a threshold of 20 mV-Hz gave a sensitivity of 89%, with specificity of 29%.Although AMSA predicts ROSC in a swine model of VF arrest in both AMI and normal swine, a waveform-guided approach that uses AMSA to direct postshock CC duration does not significantly shorten the time to ROSC or alter neurological outcome.

Coronary arterial spasm has long been recognized to cause chest pain and myocardial ischemia, with attacks occurring predominantly at rest and during the night. In 1959, Prinzmetal et al. [(1)][1] described a “variant form of angina pectoris” that occurred at rest with ST-segment elevation or

Observational studies have explored the safety of magnetic resonance (MR) scanning of patients with cardiac implantable electronic devices (CIEDs) that are not Food and Drug Administration approved for MR scanning ("nonconditional"). However, concern has been raised that MR scanning that includes the thoracic region may pose a higher risk. This study examines the safety of MR scanning of thoracic versus nonthoracic regions of patients with CIEDs.Patients underwent MR scanning utilizing an institutional protocol. CIED variables examined included sensing value, pacing capture threshold, lead impedance, and battery voltage. Regression analysis of the CIED variable differences (pre- to immediately post-MR and pre-MR to long-term follow-up) was performed to determine if CIED variable differences were dependent on region scanned (thoracic vs nonthoracic), time from CIED implant to MR scanning, or CIED type (pacemaker vs implantable cardioverter defibrillator).238 patients (38% female, age 65 ± 15 years) underwent 339 MR scans, including 99 MR scans of the thoracic region. CIED variable differences to immediately post-MR or to long-term follow-up were not significantly different from zero (P 0.05) and there was no dependence upon region scanned (thoracic vs nonthoracic), time from CIED implant to MR scan, or CIED type. One power-on reset occurred in a patient that underwent a cardiac MR and the CIED was successfully reprogrammed. There were no clinical adverse effects.CIED variable differences following MR scan were not dependent on the region scanned (thoracic vs nonthoracic) and there were no clinical adverse effects in this prospective cohort.

Cardiac implanted electronic devices (CIEDs) have historically been regarded as a contraindication for performing magnetic resonance imaging (MRI), limiting the availability of this exam for large numbers of patients who may have otherwise benefited from the unique diagnostic capabilities of MRI. Interactions between CIEDs and the magnetic field associated with MRI systems have been documented, and include potential effects on CIED function, lead heating, and force/torque on the generator. Several device manufacturers have developed "MR-Conditional" CIEDs with specific hardware and software design changes to optimize the device for the MR environment. However, a substantial body of evidence has been accumulating that suggests that MRI may be safely performed in patients with either conditional or nonconditional CIEDs. Institutional policies and procedures, including preexam screening and assessment by skilled electrophysiology personnel and intraexam monitoring, allow MRI to be safely performed in CIED patients, as evidenced by at least two, large multicenter prospective studies and multiple smaller, single-institution studies. Cross-departmental collaboration and a robust safety infrastructure at sites that perform MRI should allow for the safe imaging of CIED patients who have a clinical indication for the study, regardless of the conditionality status of the device.5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;47:595-603.

1. Introduction 95 2. Current Guidelines that Address ICD Use 95 3. Randomized Controlled Trials of ICD Therapy for Primary Prevention of Sudden Cardiac Death 96 4. ICD Implantation in the Context of an Abnormal Troponin that Is Not Due to a Myocardial Infarction 100 5. ICD Implantation Within 40 Days of a Myocardial Infarction 101 6. ICD Implantation Within 90 Days of Revascularization 105 7. ICD Implantation < 9 Months from the Initial Diagnosis of Nonischemic Cardiomyopathy 110 8. Dual-Chamber vs Single-Chamber ICD Recommendations 114 9. Documentation of Clinical Decisions 116 10. Future Research and Directions 117 The implantable cardioverter defibrillator (ICD) has emerged as an important treatment option for selected patients who are at risk of sudden cardiac death. Randomized trials have consistently shown that ICD implantation reduces mortality in patients with heart failure and reduced left ventricular function, as well as in patients who have suffered a cardiac arrest.1–3 Recommendations on the use of the ICD in clinical practice have been provided in four important guideline documents sponsored by the American College of Cardiology (ACC), the American Heart Association (AHA), Heart Rhythm Society (HRS), and the European Society of Cardiology (ESC).4–7 For each indication for ICD therapy, both a Class of indication (I, II, or III) and level of evidence for the indication (A, B, or C) are provided. To ensure that recommendations are evidence-based, Class I recommendations are typically based on the results of prospective randomized clinical trials. For example, in the ACC/AHA/HRS 2012 Focused Update of the …

BackgroundPrevious 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.ObjectivesTo determine whether AMSA computed from the ventricular fibrillation (VF) waveform is associated with pre-hospital ROSC, hospital admission, and hospital discharge.MethodsAdults 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.ResultsEighty-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.ConclusionsAMSA 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.

Eric S. Williams, MD, MACC, Chair Jonathan L. Halperin, MD, FACC, Co-Chair James A. Arrighi, MD, FACC Eric H. Awtry, MD, FACC Eric R. Bates, MD, FACC Salvatore Costa, MD, FACC Lori Daniels, MD, FACC Akshay Desai, MD, FACC Douglas E. Drachman, MD, FACC Susan Fernandes, LPD, PA-C Rosario

For almost the past decade, recommendations for the use of implantable cardioverter defibrillators (ICDs) for primary prevention of sudden cardiac death have been based upon the left ventricular ejection fraction (LVEF). Current guidelines recommend an ICD for heart failure patients with LVEF ≤35% and NYHA functional class of II or III; however, because the majority of heart failure patients who qualify for ICD implantation based on these criteria will never have an event requiring ICD therapy over several years of follow-up, additional methods of risk stratification for sudden death are clearly needed. Additionally, most of the nearly 300,000 cardiac arrests that occur each year occur in patients without heart failure or significant left ventricular dysfunction. To improve the identification of patients at risk for sudden death, several criteria other than ejection fraction have been proposed and studied. Markers of autonomic tone, including heart rate turbulence and QT dynamicity, have shown some ability to predict total mortality but not arrhythmic events. Microvolt T-wave alternans testing was initially thought to be highly predictive of life-threatening arrhythmias, but prospective large sub-studies of the MADIT II and SCD-HeFT trials have failed to show a predictive value for T-wave alternans testing. Newer markers for risk are based upon the detection of myocardial fibrosis, which forms the substrate for re-entrant and malignant ventricular tachyarrhythmias. Markers of collagen turnover or quantification of myocardial scar by MRI may hold the best promise for identifying patients at highest risk for sudden cardiac death and may also identify patients at high risk but with an ejection fraction above 35%, who are not currently recommended for ICD implantation.

Imaging of the right ventricle (RV) for the diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is commonly performed by echocardiography or magnetic resonance imaging (MRI). Angiography is an alternative modality, particularly when MRI cannot be performed. We hypothesized that RV volume and ejection fraction computed by angiography would correlate with these quantities as computed by MRI. RV volumes and ejection fraction were computed for subjects enrolled in the North American ARVC/D Registry, with both RV angiography and MRI studies. Angiography was performed in the 30° right anterior oblique (RAO) and 60° left anterior oblique (LAO) views. Angiographic volumes were computed by RAO view and two-view (RAO and LAO) formulae. 17 subjects were analyzed (11 men and 6 women), with 15 subjects classified as affected, and two as unaffected by modified Task Force criteria. The correlation coefficient of MRI to the two-view angiographic analysis was 0.72 (P = 0.003) for end-diastolic volume and 0.68 (P = 0.005) for ejection fraction. Angiographically derived volumes were larger than MRI derived volume (P = 0.009) and with the slope in a linear relationship equal to 0.8 for end diastolic volume, and 0.9 for RV ejection fraction (P < 0.001), computed by the two view formula. End-diastolic volumes and ejection fractions of the RV obtained by dual view angiography correlate with these quantities by MRI. RV end-diastolic volumes are larger by RV angiography in comparison with MRI.

Background— In cardiac arrest, the ventricular fibrillation (VF) waveform, particularly amplitude spectral area (AMSA) and slope, predicts the return of spontaneous circulation (ROSC), but it is unknown whether the predictive utility differs in an acute myocardial infarction (MI), prior MI, or normal myocardium and if the waveform can distinguish the underlying myocardial state. We hypothesized that in a swine model of VF cardiac arrest, AMSA and slope predict ROSC after a shock independent of substrate and distinguish an acute from nonacute MI state. Methods and Results— MI was induced by occlusion of the left anterior descending artery. Post MI swine recovered for a 2-week period before induction of VF. VF was untreated for 8 minutes in 10 acute MI, 10 post MI, and 10 control swine. AMSA and slope predicted ROSC after a shock independent of myocardial state. For AMSA >31 mV-Hz, the odds ratio was 62 ( P ≤0.001) compared with AMSA 3.1 mV/s, odds ratio was 52 ( P ≤0.001) compared with slope 33.5 mV-Hz, the sensitivity to identify an acute from nonacute (control or post MI) state was 83%. Conclusions— In a swine model of VF cardiac arrest, AMSA and slope predict ROSC independent of myocardial substrate. Furthermore, with chest compressions, the VF waveform evolves differently and may offer a means to distinguish an acute MI.

We have demonstrated that a return of spontaneous circulation in the first 3 mins of resuscitation in swine is predicted by ventricular fibrillation waveform (amplitude spectral area or slope) when untreated ventricular fibrillation duration or presence of acute myocardial infarction is unknown. We hypothesized that in prolonged resuscitation efforts that return of spontaneous circulation immediately after a second or later shock with postshock chest compression is independently predicted by end-tidal CO2, coronary perfusion pressure, and ventricular fibrillation waveform measured before that shock in a swine model of ischemic and nonischemic ventricular fibrillation arrest.Animal intervention study with comparison to a control group.University animal laboratory.Twenty swine.Myocardial infarction was induced by steel plug occlusion of the left anterior descending coronary artery. Ventricular fibrillation was untreated for 8 mins in normal swine (n=10) and acute myocardial infarction swine (n=10).End-tidal CO2, coronary perfusion pressure, and ventricular fibrillation waveform characteristics of amplitude spectral area and slope were analyzed before second or later shocks. For an amplitude spectral area35 mV-Hz, the odds ratio for achieving return of spontaneous circulation after that shock was 72 (95% confidence interval, 3.8-1300; p=.004) compared with an amplitude spectral area28 mV-Hz and with an area under the receiver operator characteristic curve of 0.86. For slope3.6 mV/s, the odds ratio for achieving return of spontaneous circulation was 36 (95% confidence interval, 2.7-480; p=.007) compared with slope2.72 mV/s with an area under the curve of 0.86. End-tidal CO2 and coronary perfusion pressure were not predictive of return of spontaneous circulation after a shock, although coronary perfusion pressure was significantly related to both amplitude spectral area (p.001) and slope (p.001).: In prolonged untreated ventricular fibrillation arrest, the waveform characteristics of amplitude spectral area and slope predict the attainment of return of spontaneous circulation with a second or later shock. This has implications for the ideal means to customize the timing of shocks and chest compressions when return of spontaneous circulation is not promptly obtained.

Introduction: Changes due to biventricular pacing have been documented by shortening of QRS duration and echocardiography. Compared to normal ventricular activation, the presence of left bundle branch block (LBBB) results in a significant change in cardiac cycle time intervals. Some of these have been used to quantify the underlying cardiac dyssynchrony, assess the effects of biventricular pacing, and guide programming of ventricular pacing devices. This study evaluates a simple noninvasive method using accelerometers attached to the skin to measure cardiac time intervals in biventricularly paced patients. Methods: Ten patients with biventricular pacemakers previously implanted for congestive heart failure were paced in the AAI mode, then in atrioventricular (AV) sequential mode from the right and left ventricles followed by biventricular pacing. Simultaneous recordings were obtained by 2D, Doppler echocardiography as well as by accelerometers. Similar recordings were obtained from 10 gender, aged matched, normal controls during sinus rhythm. Results: Compared to normals, heart failure patients paced in AAI mode had prolonged isovolumetric contraction time (IVCT), shorter ventricular ejection time (LVET), and prolonged isovolumetric relaxation (IVRT). With biventricular pacing the IVCT decreased, but the LVET and IVRT did not change significantly. There was excellent correlation between the echo and accelerometer-measured intervals. Conclusions: Shortening of the IVCT measured by an accelerometer is a consistent time interval change due to biventricular pacing that probably reflects more rapid acceleration of left ventricular ejection. The accelerometer may be useful to assess immediate efficacy of biventricular pacing during device implantation and optimize programmable time intervals such as AV and interventricular (VV) delays. (PACE 2007; 30:1476‐1481)

Objective: Future automated external defibrillators are being designed to direct rescue efforts (chest compressions first vs. defibrillation) by inferring the duration of ventricular fibrillation based on its waveform characteristics such as frequency content. This approach assumes that the ventricular fibrillation waveform is an appropriate surrogate for ventricular fibrillation duration and is not affected by structural heart disease. We hypothesized that an acute myocardial infarction may alter the frequency content of ventricular fibrillation. Design: Animal intervention study with comparison to control group. Setting: University animal laboratory. Subjects: Twenty-seven swine. Interventions: Acute myocardial infarction was induced by occlusion of the mid-left anterior descending artery. Ventricular fibrillation was induced in swine with acute myocardial infarction and control swine. Measurements and Main Results: Ventricular fibrillation was induced in 11 swine with an acute myocardial infarction and in 16 control swine. Ventricular fibrillation waveforms were analyzed for mean, median, and dominant frequency, as well as bandwidth and amplitude. All frequency characteristics were significantly (p

Preamble e472 1. Introduction e473 2. General Principles e475 3. Sinus Tachyarrhythmias e480 4. Nonsinus Focal Atrial Tachycardia and MAT e481 5. Atrioventricular Nodal Reentrant Tachycardia e482 6. Manifest and Concealed Accessory Pathways e483 7. Atrial Flutter e485 8. Junctional Tachycardia e487 9. Special Populations e487

Preamble 1523 1. Introduction 1524 2. General Standards 1526 3. Training Components 1526 4. Training Requirements 1528 5. Evaluation of Proficiency 1542 6. Maintenance of Competency 1543 References 1543 Appendix 1. Author Relationships with Industry and Other Entities (Relevant) 1545 Appendix 2. Reviewer Relationships with Industry and Other Entities (Relevant) 1548 Appendix 3. Abbreviations 1551 Since the 1995 publication of its Core Cardiovascular Training Statement (COCATS), the American College of Cardiology (ACC) has played a central role in defining …

Jonathan L. Halperin, MD, FACC, FAHA, Chair Glenn N. Levine, MD, FACC, FAHA, Chair-Elect Jeffrey L. Anderson, MD, FACC, FAHA, Immediate Past Chair [¶][1] Nancy M. Albert, PhD, RN, FAHA[¶][1] Sana M. Al-Khatib, MD, MHS, FACC, FAHA Kim K. Birtcher, PharmD, AACC Biykem Bozkurt, MD, PhD, FACC

1.1 Document Development Process #### 1.1.1 Writing Committee Organization The writing committee was selected to represent the American College of Cardiology (ACC) and included a cardiovascular training program director; a director of a coronary care unit; experts in advanced interventional

The QT interval on the ECG is prolonged by more than 50 marketed drugs, an effect that has been associated with syncope and/or sudden cardiac death due to an arrhythmia. Because changes in heart rate also change the QT interval, it has become standard practice to use a correction formula, such as the Bazett formula, to normalize the QT interval to a heart rate of 60 bpm, that is, the rate-corrected QT or QTc. Numerous other formulas have been devised to make this correction, including the Fridericia, Hodges, and Framingham formulas.The purpose of this study was to investigate how the Bazett formula and three other formulas influence assessment of the QT-prolonging effect of the potassium channel-blocking drug ibutilide.Using a standardized physical activity protocol, the QT interval was assessed over a broad range of heart rates before and after an infusion of ibutilide (4.75 microg/kg) that produced a stable 15- to 20-ms QT prolongation in consenting normal subjects (9 men and 9 women). The QT interval was measured digitally over a range of heart rates from 60 to 120 bpm, and then four correction formulas (Bazett, Fridericia, Framingham, or Hodges) were applied. The uncorrected change in QT interval due to ibutilide was compared with the change using each of the formulas by repeated measures analysis of variance.At heart rates from 60 to 120 bpm, the Bazett and Fridericia correction formulas overestimated the change in QT in both men and women (P.001). However, the Framingham and Hodges formulas did not alter the accuracy of the assessment of QT interval change.Rate correction of QT intervals using the standard Bazett and Fridericia formulas can introduce significant errors in the assessment of drug effects on the QT interval. This has implications for the clinical assessment of drug effects and for the safety assessment of new drugs under development.

Summary Background For prolonged VF, perfusion of the myocardium by pre-shock chest compressions can improve myocardial readiness for successful defibrillation. Characteristics of the VF waveform correlate with the duration of VF when there is no structural heart disease. A "smart" automated external defibrillator (AED) could therefore analyze the VF waveform, determine if VF has been prolonged, and then direct rescuers to either deliver a shock first or chest compressions first. We hypothesized that ischemic heart failure might alter the waveform content of ventricular fibrillation compared with normal hearts, complicating the determination of VF duration. Methods Myocardial infarction was induced by ligating the proximal left coronary artery. Six weeks later, VF was then induced in 10 rats with myocardial infarction and heart failure (MI-CHF) and 9 control rats. Waveforms were analyzed for total signal amplitude, median frequency, dominant frequency and bandwidth (the frequency interval containing 50% of the total amplitude about the median frequency). Results All of these VF waveform characteristics were altered substantially in MI-CHF rats compared to normal controls. In particular, MI-CHF rats had decreased signal amplitude early in VF ( p =0.02), a broader bandwidth ( p =0.001) and different frequency characteristics over time ( p Conclusions VF waveforms vary over time in a typical manner among rats with and without ischemic heart failure. However, the time-course and waveform characteristics of ventricular fibrillation are altered in rats with myocardial infarctions and ischemic heart failure compared to normal controls. These findings have important implications regarding the use of waveform analyses to determine the duration of VF.