Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology.

WRITING GROUP MEMBERS Emelia J. Benjamin, MD, SCM, FAHA Michael J. Blaha, MD, MPH Stephanie E. Chiuve, ScD Mary Cushman, MD, MSc, FAHA Sandeep R. Das, MD, MPH, FAHA Rajat Deo, MD, MTR Sarah D. de Ferranti, MD, MPH James Floyd, MD, MS Myriam Fornage, PhD, FAHA Cathleen Gillespie, MS Carmen R. Isasi, MD, PhD, FAHA Monik C. Jiménez, ScD, SM Lori Chaffin Jordan, MD, PhD Suzanne E. Judd, PhD Daniel Lackland, DrPH, FAHA Judith H. Lichtman, PhD, MPH, FAHA Lynda Lisabeth, PhD, MPH, FAHA Simin Liu, MD, ScD, FAHA Chris T. Longenecker, MD Rachel H. Mackey, PhD, MPH, FAHA Kunihiro Matsushita, MD, PhD, FAHA Dariush Mozaffarian, MD, DrPH, FAHA Michael E. Mussolino, PhD, FAHA Khurram Nasir, MD, MPH, FAHA Robert W. Neumar, MD, PhD, FAHA Latha Palaniappan, MD, MS, FAHA Dilip K. Pandey, MBBS, MS, PhD, FAHA Ravi R. Thiagarajan, MD, MPH Mathew J. Reeves, PhD Matthew Ritchey, PT, DPT, OCS, MPH Carlos J. Rodriguez, MD, MPH, FAHA Gregory A. Roth, MD, MPH Wayne D. Rosamond, PhD, FAHA Comilla Sasson, MD, PhD, FAHA Amytis Towfighi, MD Connie W. Tsao, MD, MPH Melanie B. Turner, MPH Salim S. Virani, MD, PhD, FAHA Jenifer H. Voeks, PhD Joshua Z. Willey, MD, MS John T. Wilkins, MD Jason HY. Wu, MSc, PhD, FAHA Heather M. Alger, PhD Sally S. Wong, PhD, RD, CDN, FAHA Paul Muntner, PhD, MHSc On behalf of the American Heart Association Statistics Committee and Stroke Statistics Subcommittee Heart Disease and Stroke Statistics—2017 Update

Heart Disease and Stroke Statistics—2017 Update: A Report From the American Heart Association

Author(s): Writing Group Members; Mozaffarian, Dariush; Benjamin, Emelia J; Go, Alan S; Arnett, Donna K; Blaha, Michael J; Cushman, Mary; Das, Sandeep R; de Ferranti, Sarah; Despres, Jean-Pierre; Fullerton, Heather J; Howard, Virginia J; Huffman, Mark D; Isasi, Carmen R; Jimenez, Monik C; Judd, Suzanne E; Kissela, Brett M; Lichtman, Judith H; Lisabeth, Lynda D; Liu, Simin; Mackey, Rachel H; Magid, David J; McGuire, Darren K; Mohler, Emile R; Moy, Claudia S; Muntner, Paul; Mussolino, Michael E; Nasir, Khurram; Neumar, Robert W; Nichol, Graham; Palaniappan, Latha; Pandey, Dilip K; Reeves, Mathew J; Rodriguez, Carlos J; Rosamond, Wayne; Sorlie, Paul D; Stein, Joel; Towfighi, Amytis; Turan, Tanya N; Virani, Salim S; Woo, Daniel; Yeh, Robert W; Turner, Melanie B; American Heart Association Statistics Committee; Stroke Statistics Subcommittee

Heart Disease and Stroke Statistics—2016 Update: A Report From the American Heart Association

March 5, 2019 e1 WRITING GROUP MEMBERS Emelia J. Benjamin, MD, ScM, FAHA, Chair Paul Muntner, PhD, MHS, FAHA, Vice Chair Alvaro Alonso, MD, PhD, FAHA Marcio S. Bittencourt, MD, PhD, MPH Clifton W. Callaway, MD, FAHA April P. Carson, PhD, MSPH, FAHA Alanna M. Chamberlain, PhD Alexander R. Chang, MD, MS Susan Cheng, MD, MMSc, MPH, FAHA Sandeep R. Das, MD, MPH, MBA, FAHA Francesca N. Delling, MD, MPH Luc Djousse, MD, ScD, MPH Mitchell S.V. Elkind, MD, MS, FAHA Jane F. Ferguson, PhD, FAHA Myriam Fornage, PhD, FAHA Lori Chaffin Jordan, MD, PhD, FAHA Sadiya S. Khan, MD, MSc Brett M. Kissela, MD, MS Kristen L. Knutson, PhD Tak W. Kwan, MD, FAHA Daniel T. Lackland, DrPH, FAHA Tené T. Lewis, PhD Judith H. Lichtman, PhD, MPH, FAHA Chris T. Longenecker, MD Matthew Shane Loop, PhD Pamela L. Lutsey, PhD, MPH, FAHA Seth S. Martin, MD, MHS, FAHA Kunihiro Matsushita, MD, PhD, FAHA Andrew E. Moran, MD, MPH, FAHA Michael E. Mussolino, PhD, FAHA Martin O’Flaherty, MD, MSc, PhD Ambarish Pandey, MD, MSCS Amanda M. Perak, MD, MS Wayne D. Rosamond, PhD, MS, FAHA Gregory A. Roth, MD, MPH, FAHA Uchechukwu K.A. Sampson, MD, MBA, MPH, FAHA Gary M. Satou, MD, FAHA Emily B. Schroeder, MD, PhD, FAHA Svati H. Shah, MD, MHS, FAHA Nicole L. Spartano, PhD Andrew Stokes, PhD David L. Tirschwell, MD, MS, MSc, FAHA Connie W. Tsao, MD, MPH, Vice Chair Elect Mintu P. Turakhia, MD, MAS, FAHA Lisa B. VanWagner, MD, MSc, FAST John T. Wilkins, MD, MS, FAHA Sally S. Wong, PhD, RD, CDN, FAHA Salim S. Virani, MD, PhD, FAHA, Chair Elect On behalf of the American Heart Association Council on Epidemiology and Prevention Statistics Committee and Stroke Statistics Subcommittee

Heart Disease and Stroke Statistics—2019 Update: A Report From the American Heart Association

Author(s): Go, Alan S; Mozaffarian, Dariush; Roger, Veronique L; Benjamin, Emelia J; Berry, Jarett D; Borden, William B; Bravata, Dawn M; Dai, Shifan; Ford, Earl S; Fox, Caroline S; Franco, Sheila; Fullerton, Heather J; Gillespie, Cathleen; Hailpern, Susan M; Heit, John A; Howard, Virginia J; Huffman, Mark D; Kissela, Brett M; Kittner, Steven J; Lackland, Daniel T; Lichtman, Judith H; Lisabeth, Lynda D; Magid, David; Marcus, Gregory M; Marelli, Ariane; Matchar, David B; McGuire, Darren K; Mohler, Emile R; Moy, Claudia S; Mussolino, Michael E; Nichol, Graham; Paynter, Nina P; Schreiner, Pamela J; Sorlie, Paul D; Stein, Joel; Turan, Tanya N; Virani, Salim S; Wong, Nathan D; Woo, Daniel; Turner, Melanie B; American Heart Association Statistics Committee and Stroke Statistics Subcommittee

Heart Disease and Stroke Statistics—2013 Update A Report From the American Heart Association

Sensing characteristics of first- and second-generation endocardial (non-thoracotomy) lead systems for implantable cardioverter-defibrillators

The ICE CHIP study is a sequential Phase I and Phase II pilot study comparing the cardiac imaging capabilities of intracardiac echocardiography (ICE) with with transesophageal echocardiography (TEE) followed by a randomized comparison of ICE guided cardioversion with a conventional cardioversion strategy in patients with atrial fibrillation. It is a prospective open label randomized multi-center investigation performed in two phases designed to initially compare two distinct imaging modalities (Phase 1) and subsequently two different strategies (ICE guided Cardioversion and Conventional) in the management of AF in patients undergoing invasive cardiac procedures in whom electrical cardioversion is indicated (Phase 2). This study will examines two hypotheses in AF patients undergoing invasive cardiac procedures: (1) ICE has comparable efficacy to TEE in visualization of left atrial pathology including thrombi or interatrial septal defects. This will be evaluated during the Phase I component of the study. (2) ICE can identify low risk patients in whom immediate cardioversion during the procedure is safe and comparably effective to electrical cardioversion performed based on a conventional strategy of a minimum of 3 weeks of preceding anticoagulation therapy. Phase 1 will enroll 100 patients at 12 centers, who will undergo a clinically indicated TEE procedure and cardiac catheterization procedure. Each patient will be imaged by TEE & ICE and a core echo laboratory will perform a blinded comparison of the two imaging modalities. In Phase 2, a total of 300 patients (3:2 randomization) will be enrolled in the study at up to 15 investigational sites in USA and Europe. The composite incidence rate of major cardiac and bleeding complications (stroke, TIA, peripheral embolism, major hemorrhagic event) will be compared between the two treatment groups over the duration of the study.

Intra-cardiac echocardiography guided cardioversion to help interventional procedures (ICE-CHIP) study: study design and methods.

In 1996, the report of the MADIT I study moved the field of implantable cardioverter defibrillator therapy towards prophylactic applications [1]. While this concept had existed for considerable period of time, this particular trial validated it. Around the same time, an AVID study subanalysis defined patients with left ventricular dysfunction as a prime beneficiary of ICD intervention [2]. The debate on the shape of the technology suitable for this application was on. One manufacturer introduced a limited feature ICD (AirbagTM, Biotronik, Erlangen, Germany), which required standard implant procedures including leads. However, even earlier, one of the original developers of the ICD was thinking ahead and outside the box by introducing a defibrillation vest (Wearable DefibrillatorTM, Lifecor, Pittsburgh, PA) using large cutaneous electrodes for energy delivery with an external power source. This was offered for high risk heart transplant patients as an alternative to ICD insertion awaiting an appropriate donor heart [3]. The original implanted ICD used a configuration developed at our center combining a transvenous lead with a cutaneous or subcutaneous electrode [4,5]. In the eighties and early nineties, a variety of non-thoracotomy lead positions were tested using these cutaneous or subcutaneous electrodes [6]. These eventually resulted in the use of the ICD generator shell as a subcutaneous electrode, a development that is the core standard for current ICD lead systems.It was then a matter of time that a totally subcutaneous lead system would be re-evaluated without intracardiac leads. This concept has been reduced to practice in a new device developed and recently tested in pilot clinical studies (Cameron Health, San Jose, CA).The attractiveness of this concept stems from several viewpoints. Intracardiac leads are often the Achilles heel of any ICD system, being prone to late infection, fracture and thrombosis with a variety of acute complications at implant. In the AVID study, lead related complications averaged 4.7%, by far the most common complication [7]. Implant technique now required a different skill set that did not involve cardiac catheterization. Finally, leads are costly and ICD system costs could decrease. Clinical trials of a prototoype device have been recently reported [8]. These trials examined the defibrillation energy requirements acutely in humans undergoing standard ICD testing. The two electrodes (an active shell and a subcutaneous elongated electrode) were implanted without thoracotomy or cardiac catheterization. Defibrillation thresholds, as could have been anticipated from prior human studies of over a decade ago, were considerably higher with mean DFTs of 36.1 J. While the concept was reduced to practice, important questions remain regarding its viability and role in clinical practice. Among the most important is the cost of the concept in losing an intracardiac electrode. This includes sensing for intracardiac atrial and ventricular activity, pacing for bradycardias and tachycardias and reduced energies for defibrillation. While temporary support pacing with cutaneous or subcutaneous electrodes is possible, long term demand pacing is difficult. Knowing that over 30% of ICD patients use this function in current systems is an important issue, particularly when drug induced bradycardias or spontaneous bradycardias cannot be anticipated at implant in many. Discrimination of supraventricular arrhythmias remains a challenge without dedicated bipolar intracardiac electrograms. Antitachycardia pacing, which painlessly terminated over 80% of events in many series, is not feasible or likely to be effective without intracardiac leads at this time. Mean defibrillation energies vary with electrode configuration and earlier studies have indicated that mean energy requirements in humans approximate 10 joules [9]. While increasing the number of extrathoracic leads to produce multiple shock vectors can reduce DFTs this would definitely complicate a simpler implant procedure. Finally, in a previous clinical experience with extrathoracic subcutaneous leads, these proved vulnerable to erosion, deformation and infection as well as lead fracture. The current device uses a different electrode and may well offer some resistance to some of these problems but chronic implant data over a long term (>one device generator life expectancy) is required. Similar data is

The leadless defibrillator or the return of the subcutaneous electrode: episode III in the ICD saga?

Implantable cardioverter defibrillators (ICDs) have proven highly successful in the treatment of recurrent ventricular and atrial arrhythmias. Despite their high efficacy in terminating arrhythmias, concomitant therapy with antiarrhythmic drugs in ICD recipients remains common. Antiarrhythmic drugs are employed in an attempt to to limit patient exposure to high-energy shocks, primarily by reducing the number of arrhythmia reccurrences, suppressing coexisting arrhythmias, affecting rate and organization of tachycardias, and increasing efficacy of painless pacing therapies. Data regarding interaction of antiarrhythmic drugs with ICDs are incomplete and mostly based on animal models; however, it is clear that antiarrhythmic drugs affect all aspects of function of devices such as defibrillation threshold, pacing threshold, and sensing of both atrial and and ventricular arrhythmias. Because significant change in any of these functions may result in a nonfunctional device, and magnitude of drug effect in an individual patient is unpredictable, careful assessment of ICD function after an institution of therapy with antiarrhythmic drugs is mandatory.

Sanjeev Saksena

Papers

Sensing characteristics of first- and second-generation endocardial (non-thoracotomy) lead systems for implantable cardioverter-defibrillators

Intra-cardiac echocardiography guided cardioversion to help interventional procedures (ICE-CHIP) study: study design and methods.

The leadless defibrillator or the return of the subcutaneous electrode: episode III in the ICD saga?

Interactions of antiarrhythmic drugs with implantable defibrillator therapy for atrial and ventricular tachyarrhythmias.

Optimal pacing and sensing lead systems for implantable hybrid pacemaker-cardioverter-defibrillators