China
Africa
Explore chapters and articles related to this topic
Cardiovascular Disease
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
Approximately 1–2% of the population have dual AV node physiology with a second pathway between the atria and ventricle within the AV node. A re-entry tachycardia (atrioventricular nodal re-entrant tachycardia [AVNRT]) (Figure 7.29a) occurs within the AV node due to fast and slow conduction. This precipitates a tachycardia by simultaneously activating both the atrium and ventricle.
Ablation of SVT (AVNRT and AVRT)
Published in Andrea Natale, Oussama M. Wazni, Kalyanam Shivkumar, Francis E. Marchlinski, Handbook of Cardiac Electrophysiology, 2020
Kushwin Rajamani, Patrick Tchou
In the common form of typical AtrioVentricular Nodal Reentrant Tachycardia (AVNRT), anterograde conduction occurs through the slow AV nodal pathway, typically localized along the tricuspid annulus just anterior to the coronary sinus (CS) os, while retrograde conduction occurs through the fast pathway localized more superiorly along the mid to anterior part of the septum. Earlier attempts at ablation targeted the fast AV nodal pathway,1,2 proved to be effective in 80%–90% of patients. However, the risk of complete AV block ranged up to 22% due to its close proximity to the compact AV node. Therefore fast pathway ablation is rarely performed now, especially in the context of the safer approach of slow pathway ablation. There are rare and unusual circumstances when fast pathway ablation may be necessary. Those would be described later in the chapter.
Ventricular arrhythmias in the elderly
Published in Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich, Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
Jason T. Jacobson, Sei Iwai, Wilbert S. Aronow
Successful radiofrequency ablation was performed in 22 of 84 patients with an ICD who had inappropriate shocks from atrial tachycardia, atrial flutter, or atrioventricular nodal reentrant tachycardia (166). Of 22 patients who underwent successful radiofrequency ablation for supraventricular tachycardia 95% had no inappropriate ICD shocks at 21-month follow-up compared to 63% of patients with inappropriate shocks for supraventricular tachycardia who did not have radiofrequency ablation (p = 0.04) (166).
Association between atrial septal aneurysm and arrhythmias
Published in Scandinavian Cardiovascular Journal, 2020
Ertan Yetkin, Mehmet Ileri, Ahmet Korkmaz, Selcuk Ozturk
After getting informed consent, patients with suspected and non-documented arrhythmia either by electrocardiography or ambulatory 24-h rhythm monitoring, and patients with documented arrhythmia to identify and treat the arrhythmia were scheduled for electrophysiological study (EPS) and radiofrequency ablation. EPS was performed in the fasted state, at least 5 half-lives after discontinuation of antiarrhythmic medications. Three catheter electrodes (USCI 6F) were introduced percutaneous under fluoroscopic control into the femoral vein and positioned in the high right atrium, across the tricuspid valve for His bundle recording, and at the right ventricular apex. When an atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reentrant tachycardia (AVRT) or atrial tachycardia (AT) was induced, subsequent ablation procedures were performed. The ablation itself was performed in sinus rhythm in most cases or under continuing tachycardia if required for mapping. Successful ablation was defined as the absence of reinducibility of the native tachycardia, disappearance of dual AV node physiology or the loss of the delta wave in AVRT. Subsequently, further electrophysiological testing for additional tachycardias, which could potentially have been masked by the ablated primary tachycardia, was performed.
Biological therapies targeting arrhythmias: are cells and genes the answer?
Published in Expert Opinion on Biological Therapy, 2018
Debbie Falconer, Nikolaos Papageorgiou, Emmanuel Androulakis, Yasmin Alfallouji, Wei Yao Lim, Rui Providencia, Dimitris Tousoulis
Atrioventricular Nodal Re-entrant Tachycardia is also caused by a re-entrant mechanism. It occurs secondary to the presence of two pathways within the atrioventricular node (AVN) which have different electrophysiological properties. It occurs as the fast pathway that exists has rapid conduction and a longer refractory period in comparison to the AVN, creating a substrate for re-entry. The impulse will travel through both pathways in normal conditions. In the presence of a premature stimulate, the stimulus blocks in the faster pathway due to a longer refractory period and travels through the slower accessory pathway. If slow enough, the blocked pathway can have time to recover, setting the state for re-entry. In response to a premature stimulation, the stimulus can block the fast pathway due to a longer refractory period and travel through the slow pathway. If conduction is slow enough, the blocked fast pathway can have time to recover, thus setting the stage for a re-entrant circuit, translating into atrioventricular nodal tachycardia (AVRT) when perpetuated.
Atrial fibrillation in young patients
Published in Expert Review of Cardiovascular Therapy, 2018
Jean-Baptiste Gourraud, Paul Khairy, Sylvia Abadir, Rafik Tadros, Julia Cadrin-Tourigny, Laurent Macle, Katia Dyrda, Blandine Mondesert, Marc Dubuc, Peter G. Guerra, Bernard Thibault, Denis Roy, Mario Talajic, Lena Rivard
Several studies have emphasized the association between SVT and AF in young patients [8,10,37,95,96]. Rapid atrial activation during SVT may induce AF. Elimination of SVT, such as atrioventricular nodal reentrant tachycardia (AVNRT) or atrioventricular reentrant tachycardia (AVRT), may prevent AF recurrence[97,98].