Molecular Basis of Functional Myocardial Potassium Channel Diversity
Publication date: Available online 24 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Jeanne M. NerbonneTeaser Multiple types of voltage-gated K+ and non–voltage-gated K+ currents have been distinguished in mammalian cardiac myocytes based on differences in time-dependent and voltage-dependent properties and pharmacologic sensitivities. Many of the genes encoding voltage-gated K+ (Kv) and non–voltage-gated K+ (Kir and K2P) channel pore-forming and accessory subunits are expressed in the heart, and a variety of approaches have been, and continue to be, used to define the molecular determinants ...
Source: Cardiac Electrophysiology Clinics - March 23, 2016 Category: Cardiology Source Type: research

Mechanism of Proarrhythmic Effects of Potassium Channel Blockers
Publication date: Available online 24 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Lasse Skibsbye, Ursula RavensTeaser Any disturbance of electrical impulse formation in the heart and of impulse conduction or action potential (AP) repolarization can lead to rhythm disorders. Potassium (K+) channels play a prominent role in the AP repolarization process. In this review we describe the causes and mechanisms of proarrhythmic effects that arise as a response to blockers of cardiac K+ channels. The largest and chemically most diverse groups of compound targets are Kv11.1 (hERG) and Kv7.1 (KvLQT1) channels....
Source: Cardiac Electrophysiology Clinics - March 23, 2016 Category: Cardiology Source Type: research

Dofetilide: Electrophysiologic Effect, Efficacy, and Safety in Patients with Cardiac Arrhythmias
Publication date: Available online 23 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Fatemah Shenasa, Mohammad ShenasaTeaser Dofetilide is a class III antiarrhythmic agent with a selective blockade of rapid component of delayed rectifier potassium current (IKr). Dofetilide was found to be safe in patients after myocardial infarction and those with congestive heart failure and left ventricular systolic dysfunction (ejection fraction of less than 35%). An important adverse effect of dofetilide is its potential proarrhythmic risk of ventricular tachyarrhythmias, mostly torsades de pointes. Because dofetili...
Source: Cardiac Electrophysiology Clinics - March 22, 2016 Category: Cardiology Source Type: research

Proarrhythmic and Torsadogenic Effects of Potassium Channel Blockers in Patients
Publication date: Available online 22 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Mark McCauley, Sharath Vallabhajosyula, Dawood DarbarTeaser The most common arrhythmia requiring drug treatment is atrial fibrillation (AF), which affects 2 to 5 million Americans and continues to be a major cause of morbidity and increased mortality. Despite recent advances in catheter-based and surgical therapies, antiarrhythmic drugs continue to be the mainstay of therapy for most patients with symptomatic AF. However, many antiarrhythmics block the rapid component of the cardiac delayed rectifier potassium current ...
Source: Cardiac Electrophysiology Clinics - March 21, 2016 Category: Cardiology Source Type: research

Potassium Channel Remodeling in Heart Disease
Publication date: Available online 18 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Vincent Algalarrondo, Stanley NattelTeaser Heart disease produces substantial remodeling of K+ channels that in general promotes arrhythmia occurrence. In the case of ventricular arrhythmias, K+ channel remodeling contributes to the arrhythmic risk and increases vulnerability to torsades de pointes with K+ channel inhibiting drugs. Atrial K+ channel remodeling caused by atrial fibrillation promotes arrhythmia stability and presents opportunities for the development of new drugs targeting atrial inward rectifier K+ curre...
Source: Cardiac Electrophysiology Clinics - March 19, 2016 Category: Cardiology Source Type: research

Molecular Basis of Cardiac Delayed Rectifier Potassium Channel Function and Pharmacology
Publication date: Available online 18 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Wei Wu, Michael C. SanguinettiTeaser Human cardiomyocytes express 3 distinct types of delayed rectifier potassium channels. Human ether-a-go-go–related gene (hERG) channels conduct the rapidly activating current I Kr; KCNQ1/KCNE1 channels conduct the slowly activating current I Ks; and Kv1.5 channels conduct an ultrarapid activating current I Kur. Here the authors provide a general overview of the mechanistic and structural basis of ion selectivity, gating, and pharmacology of the 3 types of cardiac delayed rectif...
Source: Cardiac Electrophysiology Clinics - March 19, 2016 Category: Cardiology Source Type: research

Dronedarone
Publication date: Available online 19 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Rafik Tadros, Stanley Nattel, Jason G. AndradeTeaser Dronedarone is the newest antiarrhythmic drug approved for the maintenance of sinus rhythm in patients with nonpermanent atrial fibrillation (AF). It is a multi-channel blocker with diverse electrophysiologic properties. Dronedarone decreases the incidence of AF recurrence and the ventricular rate during recurrence. Dronedarone decreases rates of cardiovascular hospitalizations in patients with paroxysmal and persistent AF. Dronedarone increases mortality in patients...
Source: Cardiac Electrophysiology Clinics - March 19, 2016 Category: Cardiology Source Type: research

Adenosine Triphosphate-Sensitive Potassium Currents in Heart Disease and Cardioprotection
Publication date: Available online 19 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Colin G. NicholsTeaser The subunit makeup of the family of adenosine triphosphate-sensitive potassium channel (KATP) channels is more complex and labile than thought. The growing association of Kir6.1 and SUR2 variants with specific cardiovascular electrical and contractile derangements and the clear association with Cantu syndrome establish the importance of appropriate activity in normal function of the heart and vasculature. Further studies of such patients will reveal new mutations in KATP subunits and perhaps in pro...
Source: Cardiac Electrophysiology Clinics - March 19, 2016 Category: Cardiology Source Type: research

Guidelines for Potassium Channel Blocker Use
This article summarizes recommendations for the clinical use of antiarrhythmic drugs for the treatment and prevention of atrial and ventricular arrhythmias based on current guideline and consensus documents. The choice of antiarrhythmic drug is based on the efficacy and safety profile and influenced by the presence or absence of structural heart disease. Because of its adverse side-effect profile, amiodarone is recommended for the management of atrial fibrillation only when other agents have failed or are contraindicated. For treatment of symptomatic ventricular arrhythmias in the setting of structural heart disease, amiod...
Source: Cardiac Electrophysiology Clinics - March 16, 2016 Category: Cardiology Source Type: research

Iron Overload Leading to Torsades de Pointes in β-Thalassemia and Long QT Syndrome
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Marwan M. Refaat, Lea El Hage, Annette Buur Steffensen, Mostafa Hotait, Nicole Schmitt, Melvin Scheinman, Nitish BadhwarTeaser The authors present a unique case of torsades de pointes in a β-thalassemia patient with early iron overload in the absence of any structural abnormalities as seen in hemochromatosis. Genetic testing showed a novel KCNQ1 gene mutation 1591C>T [Gln531Ter(X)]. Testing of the gene mutation in Xenopus laevis oocytes showed loss of function of the IKs current. The authors hypothesize ...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Brugada Syndrome
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Marwan M. Refaat, Mostafa Hotait, Melvin ScheinmanTeaser Brugada syndrome might stay undetected in patients until surviving cardiac arrest. Despite the prominent advances in exploring the disease in the past 2 decades, many questions remain unanswered and the controversies continue. Despite all mutations identified to be associated with the disease, two-thirds of cases have a negative genetic test. Future studies should be more directed on modulating factors and their impact on patients’ risk for sudden death...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Catecholaminergic Polymorphic Ventricular Tachycardia
This article presents a case with CPVT and discusses the clinical features of the disease, its genetic background, and the management of CPVT. (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

The Muscle-Bound Heart
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Marwan M. Refaat, Akl C. Fahed, Sylvana Hassanieh, Mostafa Hotait, Mariam Arabi, Hadi Skouri, Jonathan G. Seidman, Christine E. Seidman, Fadi F. Bitar, Georges NemerTeaser Hypertrophic cardiomyopathy (HCM) is a familial cardiac disease manifested in a wide phenotype and diverse genotype and, thus, presenting unpredictable risks mainly on young adults. Extensive studies are being conducted to categorize patients and link phenotype with genotype for a better management and control of the disease with all its compli...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Twin Atrioventricular Nodal Reentrant Tachycardia Associated with Heterotaxy Syndrome with Malaligned Atrioventricular Canal Defect and Atrioventricular Discordance
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Akash Patel, Ronn TanelTeaser There are limited data on the experience of transbaffle access for catheter ablation in patients who have undergone a Fontan palliation for complex congenital heart. Nevertheless, these issues will be encountered more frequently, because patients who have undergone Fontan palliation continue to survive into adulthood and develop a variety of arrhythmias that may be refractory to medical therapy. (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Intra-atrial Reentrant Tachycardia in Complete Transposition of the Great Arteries Without Femoral Venous Access
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Ryan T. Borne, Joseph Kay, Thomas Fagan, Duy Thai NguyenTeaser Catheter ablation for patients with transposition of the great arteries (d-TGA) requires multiple considerations and careful preprocedural planning. Knowledge of the patient’s anatomy and surgical correction, in addition to electroanatomic mapping and entrainment maneuvers, are important to identify and successfully treat arrhythmias. This case was unique in that the lack of femoral venous access required transhepatic venous access and bidirectional b...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

A Subclavian Arteriovenous Fistula Associated with Implantable Cardioverter-Defibrillator Implantation
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Salman Rahman, Adam C. Oesterle, Nitish BadhwarTeaser Subclavian arteriovenous fistulas (AVFs) should be considered in the differential diagnosis of a patient presenting with worsening CHF symptoms or unilateral edema immediately after device implantation. A palpable thrill may be present or a bruit may be auscultated in the region of the fistula. Ultrasonography has limitations in the subclavian region and definitive diagnosis is only made by angiogram. Percutaneous occlusion of the AVF is preferred as surgical repair ...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Implantable Cardioverter-Defibrillator Discharge in a Patient with Dilated Cardiomyopathy
This article discusses a case in which the diagnosis of typical atrioventricular nodal reciprocating tachycardia could be firmly established from the implantable cardioverter-defibrillator interrogation alone. (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Concomitant Isolation of the Pulmonary Veins and Posterior Wall Using a Box Lesion Set in a Patient with Persistent Atrial Fibrillation and Variant Pulmonary Venous Anatomy
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Jason D. Roberts, Edward P. GerstenfeldTeaser Variant pulmonary venous anatomy is common and its pre-procedural recognition through cardiac imaging facilitates a personalized approach to ablation tailored to the individual patient. Close juxtaposition of the right and left pulmonary veins is an anatomic variation that serves as an ideal substrate for creation of a single box lesion set that concomitantly isolates the pulmonary veins and posterior wall. Isolation of the posterior wall may serve as an adjunctive ablative s...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Ventricular Tachycardia Arising from Cardiac Crux
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Leila Larroussi, Nitish BadhwarTeaser This case highlights idiopathic ventricular tachycardia (VT) arising from the crux of the heart. It is seen in patients without structural heart disease and can present as rapid hemodynamically unstable VT leading to cardiac arrest. 12 lead ECG showing RBBB with Q waves in inferior leads, precordial MDI>0.55 and R<S in V5 and V6 localized the VT to apical crux. The VT was successfully ablated in the epicardial cardiac crux through percutaneous pericardial access. (Sourc...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Unusual Outflow Tract Ventricular Tachycardia
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): Kara S. Motonaga, Scott R. Ceresnak, Henry H. HsiaTeaser Distinguishing premature ventricular contractions/ventricular tachycardia from the right ventricular outflow tract versus the left ventricular outflow tract can be difficult by electrocardiogram findings alone. A thorough understanding of the outflow tract anatomy and a systematic and meticulous approach to mapping of the ventricular outflow regions and great vessels increases the success rate and decreases the risk of damage to adjacent structures and the conduct...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Implantable Cardioverter-Defibrillator Shock Caused by Uncommon Variety of Nonreentrant Atrioventricular Nodal Tachycardia
This article reports a typical case of incessant double-fire tachycardia resulting in implantable cardioverter-defibrillator discharge caused by the device’s misdiagnosis of ventricular tachycardia. At electrophysiology study, the presence of double-fire physiology was confirmed, and modification of the slow pathway resulted in elimination of repetitive double fires. Although this is an unusual entity, it is important to recognize, because it may be misdiagnosed as atrial fibrillation, resulting in inappropriate anticoagulation and/or antiarrhythmic therapy. Modification of the slow pathway and elimination of double-...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Diagnostic and Prognostic Implications of Surface Recordings from Patients with Atrioventricular Block
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): William P. NelsonTeaser The atrioventricular (AV) bridge is vulnerable to many circumstances that depress conduction. Abnormal impulse transmission may be caused by drugs, autonomic effects, or destructive processes. Type 1 (Wenckebach) AV block is owing to depressed AV nodal conduction and is recognized by a prolonging PR interval ending in a “dropped beat.” Type II (Mobitz) AV block is owing to abnormal infranodal conduction, and is usually accompanied by bundle branch block. Second-degree AV block with 2:1 ...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Use of the Surface Electrocardiogram to Define the Nature of Challenging Arrhythmias
Publication date: March 2016 Source:Cardiac Electrophysiology Clinics, Volume 8, Issue 1 Author(s): David K. Singh, C. Thomas PeterTeaser Despite unprecedented advances in technology, the electrocardiogram (ECG) remains essential to the practice of modern electrophysiology. Since its emergence at the turn of the nineteenth century, the form of the ECG has changed little. What has changed is our ability to understand the complex mechanisms that underlie various arrhythmias. In this article, the authors review several important principles of ECG interpretation by providing illustrative tracings. The authors also highligh...
Source: Cardiac Electrophysiology Clinics - February 24, 2016 Category: Cardiology Source Type: research

Atrial Fibrillation During Cardiac Resynchronization Therapy
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Mariëlle Kloosterman, Alexander H. Maass, Michiel Rienstra, Isabelle C. Van GelderTeaser The landmark trials on cardiac resynchronization therapy (CRT) have focused on patients with sinus rhythm at inclusion. Little data are available on the efficacy of CRT in patients with atrial fibrillation (AF), while AF has a high prevalence (20–40%) among patients receiving CRT. This review focuses on the detrimental effect of AF on CRT response and discusses management of patients with AF during CRT. Uncertainty re...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Cardiac Resynchronization Therapy in Women
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Maria Rosa CostanzoTeaser The benefits of cardiac resynchronization therapy (CRT) on the outcomes of patients with heart failure are unquestionable. Women are under-represented in all CRT studies. Most of the available data show that CRT produces a greater clinical benefit in women than men. In several studies, women have left bundle branch block more frequently than men. Women have a remarkably high (90%) CRT response over a wide range of QRS lengths (130–175 milliseconds). Use of a QRS duration of 150 milliseco...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Why We Have to Use Cardiac Resynchronization Therapy–Pacemaker More
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Jean-Claude Daubert, Raphaël Martins, Christophe LeclercqTeaser Both cardiac resynchronization therapy with a pacemaker (CRT-P) and with a biventricular implantable cardioverter-defibrillator (CRT-D) are electrical treatment modalities validated for the management of chronic heart failure. There is no strong scientific evidence that a CRT-D must be offered to all candidates. Common sense should limit the prescription of these costly and complicated devices. The choice of CRT-P is currently acceptable. A directio...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Why the Authors Use Cardiac Resynchronization Therapy with Defibrillators
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Edward Sze, James P. DaubertTeaser Cardiac resynchronization therapy (CRT) improves left ventricular function, especially in patients with left bundle branch block or those receiving chronic right ventricular pacing. CRT is typically accomplished by placing a right ventricular endocardial pacing lead and a left ventricular pacing lead via the coronary sinus to a coronary vein overlying the lateral or posterolateral left ventricle. CRT can be combined with an implantable defibrillator or with a pacemaker. Limited data ...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Coronary Sinus Lead Extraction
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Edmond M. Cronin, Bruce L. WilkoffTeaser Expanded indications for cardiac resynchronization therapy and the increasing incidence of cardiac implantable electronic device infection have led to an increased need for coronary sinus (CS) lead extraction. The CS presents unique anatomical obstacles to successful lead extraction. Training and facility requirements for CS lead extraction should mirror those for other leads. Here we review the indications, technique, and results of CS lead extraction. Published success rates ...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Robotic-Assisted Left Ventricular Lead Placement
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Advay G. Bhatt, Jonathan S. SteinbergTeaser Robot-assisted left ventricular lead implantation for cardiac resynchronization therapy is a feasible and safe technique with superior visualization, dexterity, and precision to target the optimal pacing site. The technique has been associated with clinical response and beneficial reverse remodeling comparable with the conventional approach via the coronary sinus. The lack of clinical superiority and a residual high nonresponder rate suggest that the appropriate clinical rol...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Coronary Sinus Lead Positioning
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Attila Roka, Rasmus Borgquist, Jagmeet SinghTeaser Although cardiac resynchronization therapy improves morbidity and mortality in patients with cardiomyopathy, heart failure, and electrical dyssynchrony, the rate of nonresponders using standard indications and implant techniques is still high. Optimal coronary sinus lead positioning is important to increase the chance of successful resynchronization. Patient factors such as cause of heart failure, type of dyssynchrony, scar burden, coronary sinus anatomy, and phrenic...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

The Role of Cardiovascular Magnetic Resonance in Cardiac Resynchronization Therapy
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Francisco LeyvaTeaser Randomized, controlled trials have shown that cardiac resynchronization therapy (CRT) is beneficial in patients with heart failure, impaired left ventricular (LV) systolic function, and a wide QRS complex. Other studies have shown that targeting the LV pacing site can also improve patient outcomes. Cardiovascular magnetic resonance (CMR) is a radiation-free imaging modality that provides unparalleled spatial resolution. In addition, emerging data suggest that targeted LV lead deployment over viabl...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Newer Echocardiographic Techniques in Cardiac Resynchronization Therapy
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): John Gorcsan, Bhupendar TayalTeaser Echocardiographic imaging plays a major role in patient selection for cardiac resynchronization therapy (CRT). One-third of patients do not respond; there is interest in advanced echocardiographic imaging to improve response. Current guidelines favor CRT for patients with electrocardiographic (ECG) QRS width of 150 milliseconds or greater and left bundle branch block. ECG criteria are imperfect; there is interest in advanced echocardiographic imaging to improve patient selectio...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Exploring the Electrophysiologic and Hemodynamic Effects of Cardiac Resynchronization Therapy
This article explores the electrophysiologic and hemodynamic changes that occur during CRT in patient and animal studies. It also addresses how novel techniques, such as multipoint and endocardial pacing, can further improve the electromechanical response. (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Cellular and Molecular Aspects of Dyssynchrony and Resynchronization
This article reviews current understanding of these cellular and subcellular mechanisms, arguing that these aspects are key to improving CRT use, as well as translating its benefits to a wider HF population. (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Understanding Heart Failure
This article reviews the current understanding of the pathophysiology, cause, classification, and treatment of HF and describes areas of uncertainty that demand future study. (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Cardiac Resysnchronization Therapy: State of the Art
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Ranjan K. Thakur, Andrea Natale (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Cardiac Resynchronization Therapy: State of the Art
Publication date: December 2015 Source:Cardiac Electrophysiology Clinics, Volume 7, Issue 4 Author(s): Luigi Padeletti, Martina Nesti, Giuseppe Boriani (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Interpretation of Complex Arrhythmias: A Case-based Approach
Publication date: Available online 29 December 2015 Source:Cardiac Electrophysiology Clinics Author(s): Ranjan Thakur, Andrea Natale (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Ventricular Arrhythmias from the Left Ventricular Summit
Publication date: Available online 8 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Saurabh Kumar, Usha B. Tedrow, William G. StevensonTeaser Ventricular arrhythmias arising from the region of the left ventricular summit can be challenging for catheter-based percutaneous ablation. A detailed knowledge of the anatomy of this region and the need of high-density mapping of surrounding structures are critical in ensuring safe and effective ablation. This case-based review focuses on the particular challenges with ablation in this region. (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Implantable Cardioverter-Defibrillator Shock Caused by Uncommon Variety of Nonrenetrant Atrioventricular Nodal Tachycardia
This article reports a typical case of incessant double-fire tachycardia resulting in implantable cardioverter-defibrillator discharge caused by the device’s misdiagnosis of ventricular tachycardia. At electrophysiology study, the presence of double-fire physiology was confirmed, and modification of the slow pathway resulted in elimination of repetitive double fires. Although this is an unusual entity, it is important to recognize, because it may be misdiagnosed as atrial fibrillation, resulting in inappropriate anticoagulation and/or antiarrhythmic therapy. Modification of the slow pathway and elimination of double-...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Supraventricular Tachycardia in a Patient with an Interrupted Inferior Vena Cava
Publication date: Available online 8 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Jaime E. Gonzalez, Duy Thai NguyenTeaser The noncoronary cusp and aortomitral continuity should be evaluated for early atrial activation when atrial tachycardias are noted to arise near the His bundle region, especially when the activation is diffuse around the His and when the P-wave morphology predicts a left atrial focus. In patients with congenital anomalies, alternate routes for catheter position need to be explored, including retrograde access for left atrial tachycardias and positioning of intracardiac echocardi...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Incessant Palpitations and Narrow Complex Tachycardia
Publication date: Available online 8 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Frederick T. HanTeaser Junctional tachycardia (JT) is rare cause of supraventricular tachycardia. The intracardiac activation sequence is similar to atrioventricular nodal reentrant tachycardia (AVNRT). Premature atrial contractions inserted during tachycardia can help distinguish JT from AVNRT. As noted in this case, slow pathway ablation for JT may not always be effective for termination of JT. Activation mapping during JT identified a low-amplitude potential in the region of the coronary sinus ostium and the inferior...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Atrioventricular Nodal Reentrant Tachycardia with 2:1 Atrioventricular Block
This report illustrates an interesting case of atrioventricular nodal reentrant tachycardia that presented with 2 different ventricular cycle lengths due to a 2:1 block in the lower common pathway. At the induction of the tachycardia, a long-short sequence above the His creates a phase 3 block resulting in a 2:1 conduction in the lower common pathway. A premature ventricular contraction, by retrograde penetration of the His, eliminates the long-short sequence and brings the conduction back to 1:1. (Source: Cardiac Electrophysiology Clinics)
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Catheter Ablation of Ventricular Arrhythmias Arising from the Left Ventricular Summit
Publication date: Available online 8 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Pasquale Santangeli, David Lin, Francis E. MarchlinskiTeaser The left ventricular summit is a common site of origin of idiopathic ventricular arrhythmias. These arrhythmias are most commonly ablated within the coronary venous system or from other adjacent structures, such as the right ventricular and left ventricular outflow tract or coronary cusp region. When ablation from adjacent structures fails, a percutaneous epicardial approach can be considered, but is rarely successful in eliminating the arrhythmias due to pr...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Ablation of Ventricular Tachycardia in Patients with Ischemic Cardiomyopathy
Publication date: Available online 8 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Paul Garabelli, Stavros Stavrakis, Sunny S. PoTeaser Ventricular tachycardias (VTs) occurring after prior myocardial infarction are usually caused by reentrant circuits formed by surviving myocardial bundles. Although part of the reentrant circuits may be located in the midmyocardium or epicardium, most of the VTs can be safely and successfully ablated by endocardial ablation targeting the late potentials/local abnormal ventricular activation, which are surrogates for the surviving myocardial bundles. A combination of...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Anatomical Ablation Strategy for Noninducible Fascicular Tachycardia
Publication date: Available online 8 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Ahmed Karim Talib, Akihiko NogamiTeaser The presence of structural heart disease does not exclude fascicular ventricular tachycardia (VT), especially if the VT is verapamil sensitive. An empirical anatomic approach is effective when fascicular VT is noninducible or if diastolic Purkinje potential (P1) cannot be recorded during VT mapping. Pace mapping at the successful ablation site is usually not effective because selective pacing of P1 is difficult and there is an antidromic activation of the proximal P1 potential. (...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Antidromic Atrioventricular Reciprocating Tachycardia Using a Concealed Retrograde Conducting Left Lateral Accessory Pathway
Publication date: Available online 11 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Jaime E. Gonzalez, Matthew M. Zipse, Duy T. Nguyen, William H. SauerTeaser Atrioventricular reciprocating tachycardia is a common cause of undifferentiated supraventricular tachycardia. In patients with manifest or concealed accessory pathways, it is imperative to assess for the presence of other accessory pathways. Multiple accessory pathways are present in 4% to 10% of patients and are more common in patients with structural heart disease. In rare cases, multiple accessory pathways can act as the anterograde and r...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Atrial Fibrillation Ablation Without Pulmonary Vein Isolation in a Patient with Fontan Palliation
Publication date: Available online 12 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Emily Ruckdeschel, Joseph Kay, William Sauer, Duy Thai NguyenTeaser In a patient with Fontan palliation and persistent atrial fibrillation two triggers were identified that initiated atrial fibrillation (AF) from the superior vena cava (SVC) and the right atrium. SVC triggers are more common in patients with a normal-sized left atrium. Eliminating these triggers prevented AF from being sustained in this patient and thus pulmonary vein isolation was not pursued. The patient has remained AF free for 3 years witho...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

A Case of Cough-induced Ventricular Tachycardia in a Patient with a Left Ventricular Assist Device
Publication date: Available online 12 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Emily Sue Ruckdeschel, Eugene Wolfel, Duy Thai NguyenTeaser In this case, the patient’s ventricular tachycardia (VT) was specifically induced by coughing, which has not previously been described. Decreasing the rotational speed of the left ventricular assist device (LVAD) and increasing preload by stopping the patient’s nitrates and reducing diuretic dose allowed improved filling of the left ventricle (LV) and increased LV volumes. When coughing recurred, the effects on the LV cavity were less pronounced ...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research

Incessant Long R-P Tachycardia
Publication date: Available online 12 January 2016 Source:Cardiac Electrophysiology Clinics Author(s): Bernard Abi-Saleh, Marwan M. Refaat, Fadi F. Bitar, Maurice Khoury, Mariam ArabiTeaser A 13-year-old boy had a positive P wave in V1 with a negative P wave in lead I, aVL, and aVR, as well as a positive P wave in the inferior leads, which correlated with a left atrial appendage (LAA) atrial tachycardia (AT) focus. P-wave morphologies can provide clues regarding an AT’s origin, and this P-wave negative in lead I favored LAA AT. Careful mapping along the atria and coronary sinus to determine the earliest site o...
Source: Cardiac Electrophysiology Clinics - February 8, 2016 Category: Cardiology Source Type: research