Cardiac Contractility Modulation for Patients with Heart Failure

A substantial proportion of patients with heart failure remain either not eligible for cardiac resynchronization therapy (CRT) or do not respond to this therapy. CRT is indicated in patients with prolonged QRS duration (>120 ms). However, up to 60% of patients with heart failure have a normal QRS duration and are not appropriate candidates for CRT. In addition, a significant number of patients (25-30%) who meet the current indications to CRT therapy are non-responders. New device-based therapies including cardiac contractility modulation (CCM) have been developed over the last decade.

Drug-Induced Proarrhythmia: QT Interval Prolongation and Torsades de Pointes

Drug-induced torsades de pointes (TdP), a life-threatening polymorphic ventricular tachycardia associated with prolongation of the QT interval, has been the main safety reason for the withdrawal of non-cardiac agents from clinical use over the last decade. This complication is commonly referred to as drug-induced proarrhythmia. The present review highlights on the mechanisms underlying the drug-induced QT interval prolongation and TdP as well as on the identification of easily recognized risk factors that predispose to this potentially life-threatening condition

Current Ablation Strategies for Persistent and Long-Standing Persistent Atrial Fibrillation

Atrial fibrillation (AF) is associated with an increased risk of cardiac and overall mortality. Restoration and maintenance of sinus rhythm is of paramount importance if it can be accomplished without the use of antiarrhythmic drugs. Catheter ablation has evolved into a well-established treatment option for patients with symptomatic, drug-refractory AF. Ablation strategies which target the pulmonary veins are the cornerstone of AF ablation procedures, irrespective of the AF type. Ablation strategies in the setting of persistent and long-standing persistent AF are more complex. Many centers follow a stepwise ablation approach including pulmonary vein antral isolation as the initial step, electrogram-based ablation at sites exhibiting complex fractionated atrial electrograms, and linear lesions. Up to now, no single strategy is uniformly effective in patients with persistent and long-standing persistent AF. The present study reviewed the efficacy of the current ablation strategies for persistent and long-standing persistent AF

Mid-ventricular obstructive hypertrophic cardiomyopathy

Mid-ventricular obstructive hypertrophic cardiomyopathy was diagnosed in a 72-year-old woman, referred to our hospital because of an episode of syncope. It was characterized by an abnormal ECG (ST segment elevation in leads V3 through V6 ) and the presence of pressure gradient between apical and basal sites in the left ventricle, asymmetric left ventricular hypertrophy and an apical aneurysm on echocardiography

Catheter Ablation of Right Ventricular Outflow Tract Ventricular Tachycardia

Α 57-year-old female with repetitive monomorphic ventricular tachycardia was referred for an electrophysiological study. ECG during sinus rhythm was normal. ECG during tachycardia revealed a left bundle branch block (LBBB) pattern with inferior axis suggestive of an outflow tract tachycardia (Fig. 1). Structural heart disease was excluded. Transthoracic echocardiography and coronary angiography were unremarkable. The tachycardia was easily induced by atrial pacing (Fig. 2). This was suggestive of cyclic adenosine monophosphate (c-AMP) triggered activity as the pathophysiological basis of the arrhythmia. Activation mapping revealed the earliest activity at the posteroseptal region of the right ventricular outflow tract. A systolic pre-potential was recorded in this area, which is rarely seen in these type of arrhythmias (Fig. 3)... (excerpt

Electrocardiographic and Electrophysiologic Characteristics of Ventricular Extrasystoles Arising from the Aortomitral Continuity

Left ventricular outflow tract arrhythmias originating from the aortomitral continuity, the left coronary cusp, the superior basal septum, and the epicardial left ventricular summit display common electrocardiographic and electrophysiological features, probably due to the close proximity of those locations. Catheter ablation of these arrhythmias can be challenging. The case of a 68-year-old male with frequent premature ventricular extrasystoles arising from the aortomitral continuity of the basal left ventricle is described. The electrocardiographic and electrophysiologic characteristics of this arrhythmia are discussed

Catheter Ablation of Ventricular Extrasystoles Originating from the Left Coronary Cusp

We describe the case of a 55-year-old man with frequent premature ventricular extrasystoles displaying inferior axis and positive QRS concordance in precordial leads. The arrhythmia was successfully ablated from the left coronary cusp. The electrocardiographic and electrophysiological characteristics of this arrhythmia are discussed

Cardiology News /Recent Literature Review / First Quarter 2014

Athens Cardiology Update 2014: Athens (Crown Plaza Hotel), 10-12/4/2014HRS Meeting: San Francisco, 7-10/5/2014EuroPCR: Paris, 20-23/5/2014CardioStim: Nice, 18-21/6/2014ESC Congress: Barcelona, 30/8-3/9/14TCT: Washington, 12-17/9/14HCS Annual Meeting: Athens, 23-25/10/2014AHA: Chicago, 15-19/11/14Cutting Inappropriate ICD Shocks: Long Arrhythmia-Detection Time Strategy Confirmed            Programming implantable cardioverter defibrillators (ICDs) to delay the time they take to treat ventricular arrhythmias cuts mortality by 23% and inappropriate shocks by more than one-half in a meta-analysis encompassing ~4900 patients. The included studies were prospective and multicenter and covered both primary and secondary prevention and patients with either ischemic or nonischemic cardiomyopathy. The risk of syncope did not rise significantly with longer detection times, despite traditional concerns that lots of patients would not tolerate prolonged arrhythmia exposure before their ICD is allowed to deliver therapy, either shocks or antitachycardia pacing (ATP). Instead, the extra time frequently gave devices a better chance to exclude non–life-threatening arrhythmias like atrial fibrillation and to let otherwise self-terminating ventricular arrhythmias play out on their own. Current nominal settings used by some ICD manufacturers are likely to be too aggressive, with arrhythmia detection times that in some cases may be as short as 1-3 s. These results highlight the importance of setting longer default ICD detection times. The analysis included 4896 patients from the MADIT-RIT, ADVANCE 3, and PROVIDE randomized trials and the RELEVANT nonrandomized study. Overall, 264 patients received appropriate shocks and 253 experienced inappropriate shocks at follow-up (12 - 17 months). The relative risk (RR) of death from any cause was 0.77 (p=0.02) in the prolonged-detection-time groups compared with controls; the risks of inappropriate shocks and appropriate and inappropriate ATP also fell significantly. Why there were fewer deaths with longer detection times is unclear but it may derive from less exposure to potential hazards of shocks and ATP; inappropriate shocks may up mortality, and ATP poses a small risk of inducing ventricular fibrillation; or it may be due to some other factor, e.g. avoidance of treatment for multiple ICD therapies (e.g., prescription of antiarrhythmic drugs) (Scott PA et al, Heart Rhythm 2014; DOI:10.1016/j.hrthm.2014.02.009. Epub 2014 Feb 12)... (excerpt

Catheter Ablation of Incessant Ventricular Tachycardia in a Patient With Coronary Artery Disease

A 67-year-old male with known coronary artery disease was referred to our hospital for catheter ablation of incessant ventricular tachycardia (VT). Transthoracic echocardiography revealed severe wall motion abnormalities of the left ventricle along with an apical aneurysm. Left ventricular voltage mapping showed a region with low voltage (<1.5 mV) at the left ventricular apex. Propagation mapping revealed a macro-reentry circuit around the apical aneurysm. Mid-diastolic potentials were recorded during the VT (Fig. 1, left panel, arrows), while entrainment mapping was excellent. The first radiofrequency energy application terminated the tachycardia. A circumferential lesion around the aneurysm was finally performed (Fig. 1, right panel, red dots). Ventricular tachycardia became non-inducible, and the patient is free from arrhythmic events during the last six months... (excerpt