Iatrogenic psychosis
Anne M. Hassett, David Ames, Edmond Chiu in Psychosis in the Elderly, 2005
The antiarrhythmic drugs designated as class 1 are generally thought to act by blocking sodium channels. Cinchonism, a syndrome of quinidine toxicity, includes symptoms of delirium and confusion (Rollo, 1975). Case reports of hallucinations, persecutory delusions, and psychomotor agitation have also been described in patients taking quinidine below therapeutic levels (Deleu and Schmedding, 1987; Johnson et al, 1990). Saravay et al (1987) reported 15 patients with psychiatric complications of lignocaine treatment. The majority of patients had prominent anxiety and depressive symptoms, 53% had symptoms of delirium and 40% had perceptual abnormality including visual illusions and hallucinations. Neuropsychiatric syndromes have also been described with procainamide, disopyramide, tocainide, fle- cainide, and the class III agent amiodarone (see Keller and Frishman, 2003, for recent review).
Left Atrial Scarring Segmentation from Delayed-Enhancement Cardiac MRI Images: A Deep Learning Approach
Ayman El-Baz, Jasjit S. Suri in Cardiovascular Imaging and Image Analysis, 2018
Pharmacological treatment of AF aims to restore and maintain sinus rhythm [6]. However, AF recurrence, side effects of antiarrhythmic drugs, and risks of proarrhythmia may offset the benefits of pharmacological treatment [7]. Consequently, there have been increasing efforts to develop non-pharmacological methods to treat AF patients such as percutaneous catheter ablation (CA) and surgical ablation (SA). Since the importance of pulmonary vein (PV) triggers in the initiation of AF was found [8], CA, which electrically isolates the PVs, has developed into an important interventional therapy [9]. However, despite efforts to improve targeting and delivery of CA, the success rate for a single procedure is just 30–50% at 5 years follow-up [10], [11]. Thoracoscopic SA has shown higher long-term success rates for a single procedure [12]–[14], but this comes with a procedural major adverse event rate of 23% [15].
Arrhythmias
Karim Ratib, Gurbir Bhatia, Neal Uren, James Nolan in Emergency Cardiology, 2010
The onset of AF may be poorly tolerated, producing major symptoms and haemodynamic compromise. Patients with coexistent structural abnormalities (such as valvular heart disease, left ventricular hypertrophy, coronary artery disease or left ventricular dysfunction) or an accessory pathway capable of rapid anterograde conduction are intolerant of AF. When AF is poorly tolerated, many antiarrhythmic drugs are contraindicated or have an unpredictable response. If AF is associated with angina or heart failure, orrate > 200 bpm, orsystolic BP < 90 mmHg,an accessory pathway urgent restoration of sinus rhythm by direct current cardioversion (DCC) is the treatment of choice irrespective of the duration of AF. Emergency treatment in this context should not be delayed by the administration of anticoagulants. As long as the AF is of <48 hours’ duration, the risk of procedure-related thromboembolism is low. Ideally, if there are no contraindications, heparin should be commenced upon presentation if patients have not been previous anticoagulated to a therapeutic level. Oral anticoagulation should be started if sinus rhythm is not re-established, or for those felt to be at risk of recurrent episodes of AF, or for those at high risk of stroke.
New developments in catheter ablation for patients with congenital heart disease
Published in Expert Review of Cardiovascular Therapy, 2021
Mathieu Le Bloa, Sylvia Abadir, Krishnakumar Nair, Blandine Mondésert, Paul Khairy
Antiarrhythmic drugs are the mainstay of therapy for managing tachyarrhythmias. Nevertheless, their use in patients with CHD is limited by moderate efficacy and side effects, including potentially severe pro-arrhythmic consequences. As a result, catheter ablation plays a prominent role in managing a gamut of arrhythmias in this population, with indications that have been elaborated by an expert consensus panel [4]. There are, however, numerous challenges to performing catheter ablation safely and effectively in patients with CHD, including access to the chamber of interest and arrhythmogenic source, understanding complex substrates, and delivery of successful ablation lesions that limit collateral damage [7]. Herein, we provide an overview of developments in catheter ablation strategies for patients with CHD that are helpful in addressing these challenges (Table 1).
Gene therapy to terminate tachyarrhythmias
Published in Expert Review of Cardiovascular Therapy, 2022
Kohei Kawajiri, Kensuke Ihara, Tetsuo Sasano
Gene therapy targeting cardiac arrhythmias has been studied for many years, but few clinical applications have been made. Currently, the most commonly used treatments for cardiac arrhythmia are antiarrhythmic drugs, ablative therapy, and implantable devices. Antiarrhythmic drugs, which have been studied for a long time, have shown some efficacy in treating tachyarrhythmias [1]. Ablative therapy is making progress and is particularly effective in treating paroxysmal and early stage of supraventricular arrhythmias [2]. Implantable devices are used to prevent sudden death [3,4]. However, it is difficult to treat all arrhythmias effectively with these therapies [5]. In particular, persistent atrial fibrillation (AF), which is often encountered in daily practice, is difficult to treat using the methods listed above [6], and the treatment of catheter ablation or antiarrhythmic drugs may lead to iatrogenic arrhythmias [7–9]. Once implanted, Implantable Cardioverter-Defibrillators (ICDs) are effective in preventing sudden death from ventricular tachycardia (VT) and ventricular fibrillation (VF), but it is difficult to treat the arrhythmia itself and suppress its onset. It can also cause device infections in the long term [10].
Indications for mexiletine in the new ESC guidelines and beyond
Published in Expert Opinion on Pharmacotherapy, 2023
Mate Vamos, Elod-Janos Zsigmond, Stefan H. Hohnloser
The first class of the conventional Vaughan-Williams antiarrhythmic drug classification consists of sodium-channel blockers. Blocking Na-channels basically yields a stabilization of the cell membrane thereby achieving an antiarrhythmic effect (i.e. greater depolarization potential is required to open enough Na+ channels to overcome K+ currents at the resting membrane potential) [6]. Of note, there is also a modernized classification of current AADs, but this does not affect the categorization of mexiletine [7]. Unlike class IA or IC drugs, mexiletine rather shortens than prolongs action potential duration; therefore, it is less prone to proarrhythmic effects associated with QT or QRS prolongation (Table 1) [6,7]. This is mainly due to the fact that IB AADs preferentially block the late inward Na+ current [6].
Related Knowledge Centers
- Atrial Fibrillation
- Beta Blocker
- Calcium Channel
- Potassium
- Sodium
- Supraventricular Tachycardia
- Tachycardia
- Sympathetic Nervous System
- Ventricular Tachycardia
- Medication