require chronic suppressive therapy. (See 'Chronic or maintenance therapy' above.) For frequent symptomatic episodes Initial therapy For patients with frequent, symptomatic AT, we suggest chronic management with an oral beta blocker or nondihydropyridine calcium channel blocker (ie, diltiazem or verapamil) as the initial treatment rather than an antiarrhythmic drug or catheter ablation (Grade 2C). (See 'Chronic or maintenance therapy' above.) For recurrent or refractory episodes Patients with frequent, symptomatic AT who have failed initial medical therapy or require long-term medical therapy are candidates for catheter ablation. (See 'Chronic or maintenance therapy' above.) For incessant AT For few or no symptoms For patients with incessant AT with preserved left ventricular function and few or no symptoms, an initial trial of rate-controlling medications or antiarrhythmic medications may be reasonable. The efficacy of this approach should be reassessed within two weeks and, if unsuccessful, the patient should be referred for catheter ablation. (See 'Treatment of incessant AT' above.) For cardiomyopathy related to incessant AT For patients with cardiomyopathy felt to be related to incessant AT, we recommend aggressive attempts to restore a normal ventricular heart rate rather than rate control alone (Grade 1B). This can be accomplished in most patients by catheter ablation of the AT focus. In the unusual likelihood that catheter ablation is unsuccessful, pacemaker implantation, preferably including biventricular or his bundle pacing followed by atrioventricular nodal ablation, typically provides symptomatic relief. (See 'Catheter ablation' above and "Arrhythmia-induced cardiomyopathy", section on 'Treatment'.) https://www.uptodate.com/contents/focal-atrial-tachycardia/print 13/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate Use of UpToDate is subject to the Terms of Use. REFERENCES 1. Saoudi N, Cos o F, Waldo A, et al. A classification of atrial flutter and regular atrial tachycardia according to electrophysiological mechanisms and anatomical bases; a Statement from a Joint Expert Group from The Working Group of Arrhythmias of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Eur Heart J 2001; 22:1162. 2. Medi C, Kalman JM, Haqqani H, et al. Tachycardia-mediated cardiomyopathy secondary to focal atrial tachycardia: long-term outcome after catheter ablation. J Am Coll Cardiol 2009; 53:1791. 3. Chen SA, Chiang CE, Yang CJ, et al. Sustained atrial tachycardia in adult patients. Electrophysiological characteristics, pharmacological response, possible mechanisms, and effects of radiofrequency ablation. Circulation 1994; 90:1262. 4. Roberts-Thomson KC, Kistler PM, Kalman JM. Atrial tachycardia: mechanisms, diagnosis, and management. Curr Probl Cardiol 2005; 30:529. 5. Roberts-Thomson KC, Kistler PM, Kalman JM. Focal atrial tachycardia I: clinical features, diagnosis, mechanisms, and anatomic location. Pacing Clin Electrophysiol 2006; 29:643. 6. Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation 2016; 133:e506. 7. Higa S, Tai CT, Lin YJ, et al. Focal atrial tachycardia: new insight from noncontact mapping and catheter ablation. Circulation 2004; 109:84. 8. De Groot NM, Schalij MJ. Fragmented, long-duration, low-amplitude electrograms characterize the origin of focal atrial tachycardia. J Cardiovasc Electrophysiol 2006; 17:1086. 9. Kistler PM, Sanders P, Hussin A, et al. Focal atrial tachycardia arising from the mitral annulus: electrocardiographic and electrophysiologic characterization. J Am Coll Cardiol 2003; 41:2212. 10. Kistler PM, Roberts-Thomson KC, Haqqani HM, et al. P-wave morphology in focal atrial tachycardia: development of an algorithm to predict the anatomic site of origin. J Am Coll Cardiol 2006; 48:1010. 11. Wong MC, Kalman JM, Ling LH, et al. Left septal atrial tachycardias: electrocardiographic and electrophysiologic characterization of a paraseptal focus. J Cardiovasc Electrophysiol 2013; https://www.uptodate.com/contents/focal-atrial-tachycardia/print 14/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate 24:413. 12. Ouyang F, Ma J, Ho SY, et al. Focal atrial tachycardia originating from the non-coronary aortic sinus: electrophysiological characteristics and catheter ablation. J Am Coll Cardiol 2006; 48:122. 13. Akhtar, M. Supraventricular tachycardias. Electrophysiologic mechanisms, diagnosis and ph armacologic therapy. In: Tachycardias: Mechanisms, Diagnosis, Treatment, Josephson, ME, Wellens, H (Eds), Lea & Febiger, Philadelphia 1984. p.137. 14. Levine HD, Smith C Jr. Repetitive paroxysmal tachycardia in adults. Cardiology 1970; 55:2. 15. Sung RJ. Incessant supraventricular tachycardia. Pacing Clin Electrophysiol 1983; 6:1306. 16. Gillette PC, Smith RT, Garson A Jr, et al. Chronic supraventricular tachycardia. A curable cause of congestive cardiomyopathy. JAMA 1985; 253:391. 17. Gillette PC, Wampler DG, Garson A Jr, et al. Treatment of atrial automatic tachycardia by ablation procedures. J Am Coll Cardiol 1985; 6:405. 18. Packer DL, Bardy GH, Worley SJ, et al. Tachycardia-induced cardiomyopathy: a reversible form of left ventricular dysfunction. Am J Cardiol 1986; 57:563. 19. Bertil Olsson S, Blomstr m P, Sabel KG, William-Olsson G. Incessant ectopic atrial tachycardia: successful surgical treatment with regression of dilated cardiomyopathy picture. Am J Cardiol 1984; 53:1465. 20. Doig JC, McComb JM, Reid DS. Incessant atrial tachycardia accelerated by pregnancy. Br Heart J 1992; 67:266. 21. Chen SA, Tai CT, Chiang CE, et al. Focal atrial tachycardia: reanalysis of the clinical and electrophysiologic characteristics and prediction of successful radiofrequency ablation. J Cardiovasc Electrophysiol 1998; 9:355. 22. Koike K, Hesslein PS, Finlay CD, et al. Atrial automatic tachycardia in children. Am J Cardiol 1988; 61:1127. 23. Kistler PM, Sanders P, Fynn SP, et al. Electrophysiological and electrocardiographic characteristics of focal atrial tachycardia originating from the pulmonary veins: acute and long-term outcomes of radiofrequency ablation. Circulation 2003; 108:1968. 24. O'Neill MD, Wright M, Knecht S, et al. Long-term follow-up of persistent atrial fibrillation ablation using termination as a procedural endpoint. Eur Heart J 2009; 30:1105. 25. Verma A, Jiang CY, Betts TR, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med 2015; 372:1812. 26. Tisdale JE, Chung MK, Campbell KB, et al. Drug-Induced Arrhythmias: A Scientific Statement From the American Heart Association. Circulation 2020; 142:e214. https://www.uptodate.com/contents/focal-atrial-tachycardia/print 15/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate 27. Zipes DP, Gaum WE, Genetos BC, et al. Atrial tachycardia without P waves masquerading as an A-V junctional tachycardia. Circulation 1977; 55:253. 28. Qian ZY, Hou XF, Xu DJ, et al. An algorithm to predict the site of origin of focal atrial tachycardia. Pacing Clin Electrophysiol 2011; 34:414. 29. Kistler PM, Chieng D, Tonchev IR, et al. P-Wave Morphology in Focal Atrial Tachycardia: An Updated Algorithm to Predict Site of Origin. JACC Clin Electrophysiol 2021; 7:1547. 30. Cappato R, Castelvecchio S, Ricci C, et al. Clinical efficacy of ivabradine in patients with inappropriate sinus tachycardia: a prospective, randomized, placebo-controlled, double- blind, crossover evaluation. J Am Coll Cardiol 2012; 60:1323. 31. Brugada J, Katritsis DG, Arbelo E, et al. 2019 ESC Guidelines for the management of patients with supraventricular tachycardiaThe Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). Eur Heart J 2020; 41:655. 32. Kang KT, Etheridge SP, Kantoch MJ, et al. Current management of focal atrial tachycardia in children: a multicenter experience. Circ Arrhythm Electrophysiol 2014; 7:664. 33. Chieng D, Lahiri A, Sugumar H, et al. Multipolar mapping with the high-density grid catheter compared with conventional point-by-point mapping to guide catheter ablation for focal arrhythmias. J Cardiovasc Electrophysiol 2020; 31:2288. 34. Lesh MD. Radiofrequency catheter ablation of atrial tachycardia and flutter. In: Cardiac Elect rophysiology: From Cell to Bedside, 2nd ed, Zipes DP, Jalife J (Eds), WB Saunders, Philadelphi a 1995. p.1461. 35. Iwai S, Markowitz SM, Stein KM, et al. Response to adenosine differentiates focal from macroreentrant atrial tachycardia: validation using three-dimensional electroanatomic mapping. Circulation 2002; 106:2793. 36. Berns E, Rinkenberger RL, Jeang MK, et al. Efficacy and safety of flecainide acetate for atrial tachycardia or fibrillation. Am J Cardiol 1987; 59:1337. 37. Brugada P, Abdollah H, Wellens HJ. Suppression of incessant supraventricular tachycardia by intravenous and oral encainide. J Am Coll Cardiol 1984; 4:1255. Topic 900 Version 36.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 16/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate GRAPHICS Electrocardiogram showing an ectopic atrial tachycardia originating from the tricuspid annulus Electrocardiographic tracing showing a narrow complex tachycardia with uniform P waves consistent with an ectopic atrial tachycardia originating from the tricuspid annulus. Prior to the final QRS complex, there is spontaneous return to normal sinus rhythm with P wave of a different morphology. Courtesy of Peter Kistler, MBBS, FRACP, PhD. Graphic 74611 Version 10.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 17/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate Relationship between fast sodium-mediated myocardial action potential and surface electrocardiogram Each phase of the myocardial action potential (numbers, upper panel) corresponds to a deflection or interval on the surface ECG (lower panel). Phase 4, the resting membrane potential, is responsible for the TQ segment; this segment has a prominent role in the ECG manifestations of ischemia during exercise testing. ECG: electrocardiogram. Graphic 64133 Version 4.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 18/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate A schematic representation of the anatomic distribution of focal atrial tachycardias The atrioventricular valvular annuli have been removed. %: percent; CS: coronary sinus; CT: crista terminalis; LA: left atrium; LAA: left atrial appendage; MA: mitral annulus; PV: pulmonary vein; RA: right atrium; RAA: right atrial appendage; TA: tricuspid annulus. Reproduced with permission from: Kistler, PM, Roberts-Thomson, KC, Haqqani, HM, et al. P- wave morphology in focal atrial tachycardia: development of an algorithm to predict the anatomic site of origin. J Am Coll Cardiol 2006; 48:1010. Copyright 2006 Elsevier. Graphic 62431 Version 1.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 19/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate Electrocardiogram (ECG) showing atrial tachycardia originating from the crista terminalis. Electrocardiographic tracing showing a narrow complex tachycardia with uniform P waves consistent with atrial tachycardia originating from the crista terminalis. Following the third beat there is spontaneous return to normal sinus rhythm with uniform P waves of a different morphology. Courtesy of Dr. Peter M Kistler. Graphic 50523 Version 7.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 20/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate Electrocardiogram (ECG) showing atrial tachycardia originating from the left superior pulmonary vein. Electrocardiographic tracing showing a narrow complex tachycardia with uniform P waves consistent with atrial tachycardia originating from the left superior pulmonary vein. The initial QRS complex shows a normal sinus beat, followed by the development of atrial tachycardia. Courtesy of Dr. Peter Kistler. Graphic 57390 Version 3.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 21/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate P-wave algorithm to predict anatomic origin of atrial tachycardia A P-wave algorithm constructed on the basis of findings from 130 atrial tachycardias correctly localized the focus in 93%. The algorithm begins with assessment of the P-wave morphology in lead V1 on the surface electrocardiogram, then utilizes other leads as needed. Neg: negative P-wave morphology; Pos: positive P-wave morphology; Iso: isoelectric P-wave morphology; CT: crista terminalis; CS: coronary sinus ostium; LS: left superior pulmonary vein; SMA: superior mitral annulus; TA: tricuspid annulus; RAA: right atrial appendage; LPV: left inferior pulmonary vein; LAA: left atrial appendage; RPV: right inferior pulmonary vein. Reproduced with permission from: Kistler PM, Roberts-Thomson KC, Haqqani HM, et al. P-wave morphology in focal atrial tachycardia: development of an algorithm to predict the anatomic site of origin. J Am Coll Cardiol 2006; 48:1010. Copyright 2006 Elsevier. Graphic 53718 Version 6.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 22/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate Electrophysiology study (EPS) tracing showing atrial tachycardia onset and termination From top to bottom, surface ECG leads I, II, III, and VI and intracardiac recordings in the high right atrium (2 leads) and His bundle, obtained during electrophysiologic study performed in a 79-year-old with an incessant atrial tachycardia with a rate of 130 beats per minute. This figure shows that a tachychycardia similar to the spontaneous tachycardia could be induced using programmed electrical stimulation with one stimulus (St) and terminated with one stimulus, which favors a reentrant mechanism. This tachycardia was successfully ablated by detecting the earliest atrial activation in reference to the onset or the P wave on the surface ECG. Note during the tachycardia that the QRS complexes are preceded (lead II) by a P wave with a configuration different of that of the sinus P wave (last beat). Graphic 90888 Version 1.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 23/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate Approach to adenosine dosing in stable adults with suspected supraventricular tachyarrhythmia This figure summarizes the initial dosing, administration, and need for repeat dosing of adenosine in a hemo stable adult with suspected AV node-dependent SVT. Adenosine can be used as a diagnostic aid to identify th rhythm or as a therapy to terminate SVTs that rely on AV node conduction. AV node-dependent SVTs include A reentrant tachycardia (AVNRT) and AV reentrant (or reciprocating) tachycardia (AVRT). The management of su node-dependent SVT in hemodynamically stable adults commonly starts with a trial of 1 or more vagal mane proceeding to adenosine therapy. If the patient has hemodynamically unstable SVT, cardioversion is indicate UpToDate content for details on management of SVTs. https://www.uptodate.com/contents/focal-atrial-tachycardia/print 24/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate AV: atrioventricular; SVT: supraventricular tachycardia; IV: intravenous; ACC: American College of Cardiology; American Heart Association; HRS: Heart Rhythm Society; ECG: electrocardiogram. Lower adenosine doses are indicated in certain clinical settings. If central venous administration is perform adenosine dose is 3 mg; if needed (SVT persists and there is no AV block), the dose may be increased to 6 mg mg for subsequent doses. For heart transplant recipients, the initial adenosine dose is 1 mg; if needed (SVT p there is no AV block), the dose may be increased to 2 mg and then 3 mg for subsequent doses. An 18 mg dose is more likely to be required to produce AV block in patients with a body weight >70 kg, par [1] those weighing >110 kg. When a third dose is indicated, an alternative approach is to administer 12 mg (in mg) as described in the 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients with Supraventr Tachycardia. [2] SVT termination in response to adenosine includes SVT termination closely followed by SVT recurrence. Refer to UpToDate content on treatment of SVT for dosing of second-line AV nodal blockers. If the SVT pers second-line AV nodal blocker therapy, electrical cardioversion is performed, as discussed in UpToDate conten treatment of SVT. SVTs that are not AV node dependent include atrial flutter, atrial fibrillation, and atrial tachycardia. When AV is induced by adenosine, the ECG may reveal atrial activity diagnostic of these rhythms. References: 1. Prabhu S, Mackin V, McLellan AJA, et al. Determining the optimal dose of adenosine for unmasking dormant pulmonary vein co following atrial brillation ablation: Electrophysiological and hemodynamic assessment. DORMANT-AF study. J Cardiovasc Electr 28:13. 2. Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Hea Society. Circulation 2016; 133:e506. Graphic 141417 Version 3.0 https://www.uptodate.com/contents/focal-atrial-tachycardia/print 25/26 7/5/23, 10:24 AM Focal atrial tachycardia - UpToDate Contributor Disclosures Peter Kistler, MBBS, FRACP, PhD Consultant/Advisory Boards: Biosense Webster [Advanced mapping technologies in arrhythmias]. Speaker's Bureau: Biosense Webster [Atrial fibrillation]; St Jude Medical/Abbott [Atrial fibrillation]. All of the relevant financial relationships listed have been mitigated. Samuel L vy, MD No relevant financial relationship(s) with ineligible companies to disclose. Susan B Yeon, MD, JD, FACC No relevant financial relationship(s) with ineligible companies to disclose. Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence. Conflict of interest policy https://www.uptodate.com/contents/focal-atrial-tachycardia/print 26/26