Management of patients with atrial tachycardia: a clinical consensus statement of the European Heart Rhythm Association (EHRA) of the ESC, endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), and the Association for European Paediatric and Congenital Cardiology (AEPC)

Figures

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  Figure 1. Mechanisms of AT. Schematic drawing showing different mechanisms of AT. Left, non-reentrant AT with its focal activation pattern is shown; right, reentrant AT are shown, including localized reentrant AT (LRAT; with its subforms of small circuit reentry (SRAT) and micro-reentry (MiRAT)) and macro-reentrant AT (MRAT, with an example of clockwise perimitral MRAT; for other classical MRAT including LA roof-dependent and peritricuspid MRAT see text). Abbreviations: AT, atrial tachycardia.

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  Figure 2. Characteristics for the differentiation between AT and AF. Electrocardiographic and EGM criteria, diagnostic challenges, key EGM features during electrophysiological study, and approaches to distinguish AT from AF are summarized. In AF, a cut-off of 20 ms for beat-to-beat variability in CL has been used and is widely accepted. Abbreviations: AAD, antiarrhythmic drug; AF, atrial fibrillation; AT, atrial tachycardia; AV, atrioventricular; CL, cycle length; CS, coronary sinus; ECG, electrocardiogram; EGM, electrogram; HF, high-frequency; and SR, sinus rhythm. * A change in activation sequence may be seen in AT with different loops.

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  Figure 3. Single-lead vs. multi-lead ECG for AT detection and diagnosis to improve symptom-rhythm correlation and therapy guidance. (A) Recording from lead I, as usually provided by most wearable devices, can be of limited diagnostic accuracy in patients with AT. (B) Multi-lead ECG by (1.) placing a single-lead device on an alternative position, such as the ankle or the precordium,10,11 or (2.) using wearable multi-lead devices (6-lead ECG in the example shown) can facilitate the detection of P waves and clinical decision-making. Abbreviations: AT, atrial tachycardia; and ECG, electrocardiogram.

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  Figure 4. Differentiation between DDAT and DDAF. Careful review of intracardiac tracings, including cycle length, signal morphology, and amplitude, is advised to differentiate between DDAF and DDAT. (A) Overview of the marker channel (upper panel) and morphology of intracardiac electrograms (lower panel) might distinguish DDAT from DDAF. (B) Combining cycle length, electrogram morphology, and amplitude over time in this example confirms DDAF. In case of an ongoing device-detected tachyarrhythmia, a 12-lead electrocardiogram is mandatory for arrhythmia detection and diagnosis. Abbreviations: DDAF, device-detected atrial fibrillation; and DDAT, device-detected atrial tachycardia.

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  Figure 5. Symptoms of AT. Subject to patient history, AT should be evaluated as a potential cause in the differential diagnosis of patients with various symptoms. Depending on AV conduction, especially in the elderly, AT might be underdiagnosed. Symptoms emerge earlier at higher tachycardia rates, especially in patients with persistent AT with 2:1 AV conduction or rates exceeding 150 bpm. Abbreviations: AiCMP, Arrhythmia-induced cardiomyopathy; AT, atrial tachycardia; and AV, atrioventricular.

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  Figure 6. Electroanatomy for AT management. (A) Anatomy of the atria illustrating crucial details, including delicate and thick, trabeculated areas relevant for safe and successful localization, characterization, and treatment of AT. The V1 and I leads of the surface ECG can aid in the rapid distinction between left- and right-sided AT origins in most scenarios. For details, see text and Panel B. Note the antero-inferior muscular buttress along the septum representing several potential closely related paraseptal anatomic sites for FAT origin (coronary sinus ostium, left septum, septal mitral annulus, septal TA, right septum, perinodal region, non-coronary cusp, aorto-mitral continuity; not all shown in anatomical detail), potentially challenging ECG diagnosis and ablation. The authors thank the Amara Yad Project led by K. Shivkumar and S. Mori at the UCLA Cardiac Arrhythmia Centre for permission to use the anatomical image. (B) P wave algorithm for FAT localization. This P wave algorithm offers a simplified and accurate method of localizing the responsible site for FAT. Adapted from Kistler et al.66 Abbreviations: AMC, aorto-mitral continuity; AT, atrial tachycardia; CS, coronary sinus;…

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  Figure 7. Workflow for the performance of TOE prior to reentrant AT ablation. Flow chart suggesting a workflow for the performance of TOE prior to AT catheter ablation. Please refer to the text for details. *Evaluate variables like prior LAA thrombus/sludge/decreased LAA velocity/increased LAA orifice size, and other clinical variables like chronic kidney disease, which may be associated with thromboembolic events.111–113 + Depending on thromboembolic risk factors, including CHA2DS2-VA and *. In adequately anticoagulated patients with AF/AT undergoing TOE before cardioversion or catheter ablation, a prevalence of LA thrombus of 6.3% in patients with CHA2DS2-VASc scores ≥3 vs. 1.1% in patients with scores ≤2 has been demonstrated.114 Abbreviations: AT, atrial tachycardia; CA, catheter ablation; LAA, left atrial appendage; OAC, oral anticoagulation; and TOE, transoesophageal echocardiography.

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  Figure 8. Indicators of clinical complexity. Patient-related factors increasing clinical complexity with a special focus on frequent comorbidities are visualized.

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  Figure 9. Management of procedural complexity in patients undergoing AT ablation. Potential challenges and respective solutions for patients undergoing AT ablation are visualized. The combination of some comorbidities and age-related factors might come along with additionally increased clinical complexity (see Figure 9), potentially aggravating procedural complexity. Others, like back-pain-related conditions alone or in combination with the mentioned comorbidities, can increase patient incompliance, which needs to be evaluated for post-procedural patient management. Abbreviations: AT, atrial tachycardia; EP, electrophysiological; ICE, intracardiac echocardiography; RF, radiofrequency; SHD, structural heart disease; TOE, transesophageal echocardiography; and TSP, transseptal puncture.

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  Figure 10. Neural control of atrial electrophysiology. Neurally mediated AT, the underlying mechanisms, physiological as well as electrical interventions under development for modulation of cardiac neural control, as well as potential pitfalls that might occur during diagnostic manoeuvres are presented. Abbreviations: AF, atrial fibrillation; Ao, Aorta; AT, atrial tachycardia; CL, cycle length; CS, coronary sinus; ET-GP, ectopy-triggering ganglionated plexus; GP, ganglionated plexus area; HFS, high-frequency stimulation; IVC, vena cava inferior; LA, left atrium; PT, pulmonary trunk; PV, pulmonary vein; and RA, right atrium.

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  Figure 11. Risk stratification for the prediction of AT/AF recurrences after AT ablation. Classification of patients into a high and low risk group predicting AT/AF recurrences after AT ablation. Abbreviations: AF, atrial fibrillation; AT, atrial tachycardia; CV, conduction velocity; FAT, focal AT; LA, left atrial; LVEF, left ventricular ejection fraction; MRAT, macro-reentrant AT; and SR, sinus rhythm.

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  Figure 12. Overdrive pacing for AT characterization. Schematic illustration of the diagnostic implications of atrial overdrive pacing in the evaluation of AT mechanisms. Upper panel: Entrainment for the characterization of reentrant AT. A PPI-TCL <30 ms indicates pacing within the active loop. Entrainment with PPI–TCL < 30 ms at ≥2 anatomically distinct atrial sites (>2 cm apart) confirms a macro-reentrant mechanism. AT termination without global atrial propagation suggests capture within a narrow critical isthmus, whereas PPI–TCL > 30 ms indicates pacing from a passive loop or outside the circuit. Middle panel: Overdrive pacing from a single reference site, typically the proximal CS, to differentiate reentrant from non-reentrant AT, independent of the site’s proximity to the circuit or focus. Lower panel: Overdrive pacing in non-reentrant AT. When pacing is delivered close to the focal origin, the PPI after overdrive suppression may approximate the TCL, depending on the automatic or triggered characteristics of the tachycardia. Abbreviations: CS, coronary sinus; MRAT, macro-reentrant AT; NRAT, non-reentrant AT; PPI, post-pacing interval; TCL, tachycardia cycle length; and w/o, without.