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 Table of Contents  
Year : 2017  |  Volume : 2  |  Issue : 2  |  Page : 58-61

Multifocal atrial tachycardia: Looking for new solutions to an old problem

Department of Geriatric Rehabilitation, Rehabilitative Cardiology Unit, Italian National Research Center on Aging, 63900 Fermo, Italy

Date of Web Publication31-Jan-2018

Correspondence Address:
Elpidio Santillo
Department of Geriatric Rehabilitation, Rehabilitative Cardiology Unit, Italian National Research Center on Aging, Contrada Mossa 2, Fermo 63900
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/IJHR.IJHR_2_17

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Multifocal atrial tachycardia (MAT) is a cardiac rhythm disorder frequently diagnosed in elderly patients affected by several comorbidities. However, MAT can be observed also in younger ages as an incidental finding or in association with heart and lung diseases. MAT is characterized by heart rate >100 beats/min and at least three different P waves when compared to sinus P wave. Recent guidelines recommend the use of beta-blockers and verapamil for rate control and ongoing management of MAT. Unfortunately, electrical cardioversion and antiarrhythmic drugs have been demonstrated not always effective in MAT treatment. Intravenous magnesium seems a promising therapy in restoring sinus rhythm in patients who developed MAT. Moreover, in the last years, innovative strategies such as atrioventricular junction modification, ablate and pace approach, and electrophysiological isolation of firing sites have been successfully tested as curative treatment in selected cases of MAT resistant to drug therapy.

Keywords: Atrial arrhythmias, multifocal atrial tachycardia, radiofrequency catheter ablation

How to cite this article:
Santillo E. Multifocal atrial tachycardia: Looking for new solutions to an old problem. Int J Heart Rhythm 2017;2:58-61

How to cite this URL:
Santillo E. Multifocal atrial tachycardia: Looking for new solutions to an old problem. Int J Heart Rhythm [serial online] 2017 [cited 2023 Jun 5];2:58-61. Available from: https://www.ijhronline.org/text.asp?2017/2/2/58/224356

  Introduction Top

Multifocal atrial tachycardia (MAT), also known as chaotic atrial tachycardia or multifocal atrial rhythm, is a heart arrhythmia primarily observed in old and diseased patients.[1],[2] In hospital setting, the prevalence of MAT has been estimated to be from 0.05% to 0.40%.[1],[3],[4]

In most participants, especially outpatients, MAT frequently occurs as a harmless condition, which does not impact on mortality and requires no specific treatment.[5] On the other hand, it is well known that elderly patients with MAT are commonly affected by acute illness and several associated chronic diseases such as atherosclerotic heart disease, valvular heart diseases, and chronic obstructive pulmonary disease (COPD) which may heavily impact on their prognosis.[1],[4] In particular, in patients with severe COPD needing mechanical ventilation, MAT presence has proved to be associated with a worse survival.[6]

MAT development has been reported also as a consequence of electrolyte imbalance and drugs' toxicity, especially from digitalis and sympathomimetic amines such as theophylline and aminophylline.[7],[8],[9],[10],[11]

Although it is more frequently diagnosed during senescence, MAT can be detected even in subjects of younger ages, including infants and children, sometimes as an incidental finding in otherwise healthy individuals, while, in a minority of cases, concomitant diseases of heart and lung can be present.[12] The occurrence of sudden cardiac death in infants with chaotic atrial rhythm has been also described.[13]

Hence, finding of MAT represents often a clinical diagnostic challenge for clinicians and imposes to search and treat eventual underlying pathological conditions beyond the arrhythmia itself.[3],[4]

The objectives of the present article are to summarize the available evidences on MAT treatment, including invasive approaches, after briefly reviewing diagnosis criteria and pathophysiological mechanisms of MAT.

  Diagnosis of Multifocal Atrial Tachycardia Top

Electrocardiographic diagnosis of MAT requires a heart atrial rate >100 beats/min and the identification of at least three different P waves with distinct morphology when compared to the sinus one.[14] Moreover, in the course of MAT, P-P and R-R wave intervals exhibit a marked variability as well as PR tract.

Reduction of diagnostic threshold rate to 90 beats/min for definition of MAT has been proposed due to its better association with exacerbations of COPD.[15] Differential diagnosis between MAT and atrial fibrillation (AF) through surface ECG may be challenging. However, in MAT, well-defined isoelectric periods are usually detectable betweenPand R waves. Oppositely, in AF, beyond the evidence of an irregular rhythm, P waves are absent, and “f” waves can be recognized between R waves instead of isoelectric line. Computerized electrocardiography has been suggested as a useful technological tool for the detection of MAT since the arrhythmia is frequently misdiagnosed as AF.[16]

  Pathophysiological Mechanisms of Multifocal Atrial Tachycardia Top

Pathophysiological mechanisms of MAT have not been fully elucidated yet. However, in the genesis of MAT, anatomic factors seem not as important as in AF. Indeed, an echocardiographic study on hospitalized patients showed significantly less structural abnormalities in MAT cases compared to ones with AF.[17] On the other hand, it has been argued that right atrial hypertension and distension could facilitate MAT development.[18]

On the electrophysiological point of view, MAT could originate from triggered activity, ectopic foci, and abnormal automaticity or result from an accelerated wandering pacemaker.[3],[19] Conversely, reentry phenomena appear not a probable mechanism of the arrhythmia for the typical irregularity of cycle length observed in MAT and for its poor response to electrical cardioversion.

According to triggered activity hypothesis, MAT could originate from delayed atrial afterdepolarizations due to intracellular calcium overload, which is a sort of “common ground” of various associated pathological conditions (i.e., catecholamine excess, hypoxemia, acidosis, and hypokalemia).[1] Ectopic foci or a single focus with variable impulse propagation in the atrium are further plausible electrophysiological mechanisms of MAT.[19]

  Therapeutic Recommendations from Guidelines Top

Recent guidelines for the management of patients with supraventricular tachycardias include a specific section on MAT.[20]

According to guidelines, during MAT, heart rate control should be properly obtained using drugs that slow the conduction at atrioventricular node. Intravenous verapamil or metoprolol is recommended for acute treatment of MAT (Class of recommendation: IIa; Level of Evidence: C for limited data). In particular, guidelines underline that verapamil has been shown to facilitate the conversion of the arrhythmia to sinus rhythm. However, the use of intravenous verapamil requires caution for possible hypotension occurring as an adverse effect. On the other hand, the beta-blocker should not be administered in patients with decompensated heart failure for risk of worsening the hemodynamic status as well as in subjects with severe bronchopulmonary disease for the possibility of inducing bronchospasm.

Oral verapamil and diltiazem are recommended for ongoing management of MAT (Class of recommendation IIa). The level of evidence favors verapamil (Level of Evidence B: Data from nonrandomized studies) since data existing on the use of diltiazem are limited (level of evidence C). However, before employing such drugs, relevant sinus dysfunction and conduction anomalies should be excluded.

Electrical cardioversion has proved not useful for MAT while efficacy of antiarrhythmic drugs is still debated.[20] Indeed, in a study of 41 patients with MAT, quinidine, procainamide, lidocaine, and phenytoin did not affect the rhythm.[21] However, more recent evidence suggests that treatment with amiodarone, flecainide, and ibutilide can be effective in suppression of MAT.[10],[22],[23]

  Therapeutic Prospects Top

In few studies, parenteral magnesium has proved to reduce the ventricular rate of MAT and to facilitate reversion to normal sinus rhythm [Table 1].[24],[25],[26] Magnesium's mechanism of action comprises the restoration of ionic equilibrium in atrial cardiomyocytes, so preventing supraventricular ectopic activities. In fact, magnesium is able to antagonize L- and T-type calcium channels antagonism.[27] Moreover, when magnesium is administered in supraphysiological doses, it favors cellular membrane's stabilization through reduction of potassium outward current density.[27]
Table 1: Studies on parenteral magnesium for MAT treatment

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Interestingly, in the last years, various electrophysiological invasive approaches have been tested for treatment of MAT cases refractory to medical therapy [Table 2].[28],[29],[30],[31],[32],[33]
Table 2: Published papers on invasive electrophysiological approaches for MAT treatment

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Tucker et al.[28] observed in three patients with drug-resistant MAT that ablation of atrioventricular junction followed by implantation of permanent transvenous pacemaker resulted safe and effective. More recently, Ueng et al. described the better quality of life and function of left ventriculum in 13 patients with COPD and MAT not responsive to medical therapy after they underwent atrioventricular junction modification.[29] Patients' improvement after AV modification could be explained by the reduction of ventricular response and less need of drugs which impair ventricular function. However, interpretation of such results remains problematic since the study did not provide a control group.[18]

Electrophysiological evidence of atrial multifocality has been considered as criteria that render radiofrequency catheter ablation more difficult or unsuccessful, so ablative option is often excluded for patients with MAT.[34] In fact, in a study of 105 patients with atrial tachycardias, success rate of radiofrequency catheter ablation resulted lower when there was a multifocal origin of the arrhythmia.[30]

However, radiofrequency ablation of MAT has been demonstrated feasible in selected cases in which catheter mapping found easily treatable sites of firing.[31],[32] Of note, it has been observed that such aggressive management can favor the regression of associated tachycardia induced cardiomyopathy.[32] It could be expected that recent three-dimensional mapping systems will confer a great advantage in detection of MAT, in efficacy of ablative procedures, and in limitation of time of exposure to radiations.[33],[35]

  Conclusions Top

Due to the aging of populations worldwide, physicians will face more frequently MAT in their clinical practice. Recent guidelines and evidences from small studies indicate few drugs for management of MAT as effective choices for rate control. Invasive approaches such as “ablate and pace” and atrioventricular junction modification should be reserved to drug-resistant cases. However, further studies should investigate in various age groups which are the optimal medical strategy to adopt, also considering the eventual hemodynamic burden derived from the arrhythmia. Finally, in the near future, technical advancements in radiofrequency catheter ablation procedures of MAT could provide a more effective and safe option for cases of MAT not responsive to medical therapy, but an accurate selection of eligible patients will be always indispensable.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

McCord J, Borzak S. Multifocal atrial tachycardia. Chest 1998;113:203-9.  Back to cited text no. 1
Berlinerblau R, Feder W. Chaotic atrial rhythm. J Electrocardiol 1972;5:135-44.  Back to cited text no. 2
Scher DL, Arsura EL. Multifocal atrial tachycardia: Mechanisms, clinical correlates, and treatment. Am Heart J 1989;118:574-80.  Back to cited text no. 3
Kastor JA. Multifocal atrial tachycardia. N Engl J Med 1990;322:1713-7.  Back to cited text no. 4
Lazaros G, Chrysohoou C, Oikonomou E, Tsiachris D, Mazaris S, Venieri E, et al. The natural history of multifocal atrial rhythms in elderly outpatients: Insights from the “Ikaria study”. Ann Noninvasive Electrocardiol 2014;19:483-9.  Back to cited text no. 5
Tsai YH, Lee CJ, Lan RS, Lee CH. Multifocal atrial tachycardia as a prognostic indicator in patients with severe chronic obstructive pulmonary disease requiring mechanical ventilation. Changgeng Yi Xue Za Zhi 1991;14:163-7.  Back to cited text no. 6
Strickberger SA, Miller CB, Levine JH. Multifocal atrial tachycardia from electrolyte imbalance. Am Heart J 1988;115:680-2.  Back to cited text no. 7
Chung EK. Appraisal of multifocal atrial tachycardia. Br Heart J 1971;33:500-4.  Back to cited text no. 8
Levine JH, Michael JR, Guarnieri T. Multifocal atrial tachycardia: A toxic effect of theophylline. Lancet 1985;1:12-4.  Back to cited text no. 9
Kouvaras G, Cokkinos DV, Halal G, Chronopoulos G, Ioannou N. The effective treatment of multifocal atrial tachycardia with amiodarone. Jpn Heart J 1989;30:301-12.  Back to cited text no. 10
Kim LK, Lee CS, Jeun JG. Development of multifocal atrial tachycardia in a patient using aminophylline – A case report. Korean J Anesthesiol 2010;59 Suppl 1:S77-81.  Back to cited text no. 11
Bradley DJ, Fischbach PS, Law IH, Serwer GA, Dick M 2nd. The clinical course of multifocal atrial tachycardia in infants and children. J Am Coll Cardiol 2001;38:401-8.  Back to cited text no. 12
Yeager SB, Hougen TJ, Levy AM. Sudden death in infants with chaotic atrial rhythm. Am J Dis Child 1984;138:689-92.  Back to cited text no. 13
Shine KI, Kastor JA, Yurchak PM. Multifocal atrial tachycardia. Clinical and electrocardiographic features in 32 patients. N Engl J Med 1968;279:344-9.  Back to cited text no. 14
Kothari SA, Apiyasawat S, Asad N, Spodick DH. Evidence supporting a new rate threshold for multifocal atrial tachycardia. Clin Cardiol 2005;28:561-3.  Back to cited text no. 15
Varriale P, David W, Chryssos BE. Multifocal atrial arrhythmia – A frequent misdiagnosis? A correlative study using the computerized ECG. Clin Cardiol 1992;15:343-6.  Back to cited text no. 16
Santos-Ocampo CD, Sadaniantz A, Elion JL, Garber CE, Malone LL, Parisi AF, et al. Echocardiographic assessment of the cardiac anatomy in patients with multifocal atrial tachycardia: A comparison with atrial fibrillation. Am J Med Sci 1994;307:264-8.  Back to cited text no. 17
Engel TR, Radhagopalan S. Treatment of multifocal atrial tachycardia by treatment of pulmonary insufficiency: Or is it vice versa? Chest 2000;117:7-8.  Back to cited text no. 18
von Alvensleben JC, Bradley DJ. Multifocal atrial tachycardia. In: Dick M 2nd, editor. Clinical Cardiac Electrophysiology in the Young. New York: Springer; 2015.  Back to cited text no. 19
Page RL, Joglar JA, Caldwell MA, Calkins H, Conti JB, Deal BJ, 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:e506-74.  Back to cited text no. 20
Wang K, Goldfarb BL, Gobel FL, Richman HG. Multifocal atrial tachycardia: A clinical analysis in 41 cases. Arch Intern Med 1977;137:161-4.  Back to cited text no. 21
Houyel L, Fournier A, Davignon A. Successful treatment of chaotic atrial tachycardia with oral flecainide. Int J Cardiol 1990;27:27-9.  Back to cited text no. 22
Pierce WJ, McGroary K. Multifocal atrial tachycardia and ibutilide. Am J Geriatr Cardiol 2001;10:193-5.  Back to cited text no. 23
Iseri LT, Fairshter RD, Hardemann JL, Brodsky MA. Magnesium and potassium therapy in multifocal atrial tachycardia. Am Heart J 1985;110:789-94.  Back to cited text no. 24
Cohen L, Kitzes R, Shnaider H. Multifocal atrial tachycardia responsive to parenteral magnesium. Magnes Res 1988;1:239-42.  Back to cited text no. 25
McCord JK, Borzak S, Davis T, Gheorghiade M. Usefulness of intravenous magnesium for multifocal atrial tachycardia in patients with chronic obstructive pulmonary disease. Am J Cardiol 1998;81:91-3.  Back to cited text no. 26
Ho KM. Intravenous magnesium for cardiac arrhythmias: Jack of all trades. Magnes Res 2008;21:65-8.  Back to cited text no. 27
Tucker KJ, Law J, Rodriques MJ. Treatment of refractory recurrent multifocal atrial tachycardia with atrioventricular junction ablation and permanent pacing. J Invasive Cardiol 1995;7:207-12.  Back to cited text no. 28
Ueng KC, Lee SH, Wu DJ, Lin CS, Chang MS, Chen SA, et al. Radiofrequency catheter modification of atrioventricular junction in patients with COPD and medically refractory multifocal atrial tachycardia. Chest 2000;117:52-9.  Back to cited text no. 29
Anguera I, Brugada J, Roba M, Mont L, Aguinaga L, Geelen P, et al. Outcomes after radiofrequency catheter ablation of atrial tachycardia. Am J Cardiol 2001;87:886-90.  Back to cited text no. 30
Yokoshiki H, Mitsuyama H, Watanabe M, Tsutsui H. Swallowing-induced multifocal atrial tachycardia originating from right pulmonary veins. J Electrocardiol 2011;44:395.e1-5.  Back to cited text no. 31
Bevilacqua LM, Rhee EK, Epstein MR, Triedman JK. Focal ablation of chaotic atrial rhythm in an infant with cardiomyopathy. J Cardiovasc Electrophysiol 2000;11:577-81.  Back to cited text no. 32
Hoffmann E, Reithmann C, Nimmermann P, Elser F, Dorwarth U, Remp T, et al. Clinical experience with electroanatomic mapping of ectopic atrial tachycardia. Pacing Clin Electrophysiol 2002;25:49-56.  Back to cited text no. 33
Morady F. Radio-frequency ablation as treatment for cardiac arrhythmias. N Engl J Med 1999;340:534-44.  Back to cited text no. 34
Demir T, Ergül Y, Akdeniz C, Tuzcu V. Electroanatomic mapping-guided radiofrequency ablation of multifocal atrial tachycardia in a child. Anadolu Kardiyol Derg 2013;13:391-3.  Back to cited text no. 35


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