Diagnostic Considerations
The differential diagnosis of atrial tachycardia is the differential diagnosis of supraventricular tachycardia (SVT) and includes the following:
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Sinus tachycardia
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Atrial flutter (see the image below)
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Atrial fibrillation
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Atrioventricular (AV) junction–dependent reentrant tachycardias (AV nodal reentrant tachycardia and AV reentrant tachycardia using an accessory pathway)
Atrial tachycardia. This image shows an example of rapid atrial tachycardia mimicking atrial flutter. A single radiofrequency application terminates the tachycardia. The first three tracings show surface electrocardiograms, as labeled. AblD and AblP = distal and proximal pair of electrodes of the mapping catheter, respectively; HBED and HBEP = distal and proximal pair of electrodes in the catheter located at His bundle, respectively; HRA = high right atrial catheter; MAP = unipolar electrograms from the tip of the mapping catheter; RVA = catheter located in right ventricular apex.
Note that "non-paroxysmal” junctional tachycardia is not an atrial tachycardia, but it can easily be confused with one. The distinction is made either on the basis of an electrophysiologic study or by a spontaneous tracing showing atrial dissociation, but with a QRS complex that is identical with that observed in sinus rhythm. With the popularity and rise in ingestion of "energy drinks," it is possible that the incidence of non-paroxysmal junctional tachycardia may increase.
Differentiating among these diagnoses requires electrocardiographic (ECG) analysis of the tachycardia for P wave activity. In SVT, the ECG typically has narrow QRS complexes (unless aberrant conduction with typical left or right bundle-branch block occurs or a bystander preexcitation is seen).
Assessment of the relationship of the P waves to the QRS complex (R waves) can help to guide diagnosis. A short RP interval (P wave immediately following the QRS) suggests different causes of the tachycardia than does a long RP interval (interval wave preceding QRS).
In short RP interval SVT, the differential diagnosis includes the following:
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Typical AV nodal reentrant tachycardia
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AV reentrant tachycardia using accessory pathways
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Atrial tachycardia with long first-degree AV block
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Atrial tachycardia originating from the os of the coronary sinus or junctional tachycardia
To determine the diagnosis requires additional maneuvers, such as vagal stimulation (eg, carotid sinus massage, Valsalva maneuver), or adenosine.
In long RP interval SVT, the differential diagnosis includes the following:
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Atypical (fast-slow) AV nodal reentrant tachycardia
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Permanent junctional reciprocating tachycardia (PJRT) due to a slowly conducting retrograde accessory pathway
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Atrial tachycardia
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Sinus tachycardia
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Sinus node reentry
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Atrial flutter
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AV reentrant tachycardia
Diagnosis requires assessment of the patient condition, vagal maneuvers, adenosine, and cardioversion—namely, procedures that may not only be diagnostic but also therapeutic.
For multifocal atrial tachycardia (MAT), the differential diagnosis includes atrial fibrillation because both can manifest with an irregular pulse. MAT with aberration or preexisting bundle branch block may be misinterpreted as ventricular tachycardia (VT).
However, if the patient also has new signs or symptoms (eg, chest pain, unexplained dyspnea, inappropriate hypotension) or a recent illness, perform a more extensive workup because atrial tachycardia may not be the primary problem; acute pulmonary embolus, acute noncardiac illness, thyroid disease, or drugs (especially sympathomimetics or bronchodilators) can cause atrial tachycardia. In addition, with frequent or incessant tachycardia, tachycardia-induced cardiomyopathy may develop.
Another tachycardia that mimics atrial tachycardia is inappropriate sinus tachycardia. Strictly speaking, inappropriate sinus tachycardia and postural orthostatic tachycardia syndrome (POTS) are not atrial tachycardias, because their origin is not abnormal. They are sinus tachycardias related to enhanced sinus automaticity, abnormal autonomic function (dysautonomia), or physiologic reflexes
Differential Diagnoses
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Atrial tachycardia. This 12-lead electrocardiogram demonstrates an atrial tachycardia at a rate of approximately 150 beats per minute. Note that the negative P waves in leads III and aVF (upright arrows) are different from the sinus beats (downward arrows). The RP interval exceeds the PR interval during the tachycardia. Note also that the tachycardia persists despite the atrioventricular block.
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Atrial tachycardia. This propagation map of a right atrial tachycardia originating from the right atrial appendage was obtained with non-contact mapping using the EnSite mapping system.
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Atrial tachycardia. Note that the atrial activities originate from the right atrium and persist despite the atrioventricular block. These features essentially exclude atrioventricular nodal reentry tachycardia and atrioventricular tachycardia via an accessory pathway. Note also that the change in the P-wave axis at the onset of tachycardia makes sinus tachycardia unlikely.
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Atrial tachycardia. An anterior-posterior mapping projection is shown. This is an example of activation mapping using contact technique and the EnSite system. The atrial anatomy is partially reconstructed. Early activation points are marked with white/red color. The activation waveform spreads from the inferior/lateral aspect of the atrium through the entire chamber. White points indicate successful ablation sites that terminated the tachycardia. CS = shadow of the catheter inserted in the coronary sinus; TV = tricuspid valve.
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Atrial tachycardia. These intracardiac tracings showing atrial tachycardia breaking with the application of radiofrequency energy. Before ablation, the local electrograms from the treatment site preceded the surface P wave by 51 ms, consistent with this site being the source of the tachycardia. Note that postablation electrograms on the ablation catheter are inscribed well past the onset of the sinus rhythm P wave. The first three tracings show surface electrocardiograms as labeled. Abl = ablation catheter (D-distal pair of electrodes); CS = respective pair of electrodes of the coronary sinus catheter; CS 1,2 = distal pair of electrodes; CS 7,8 = electrodes located at the os of the coronary sinus.
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Atrial tachycardia. This image shows an example of rapid atrial tachycardia mimicking atrial flutter. A single radiofrequency application terminates the tachycardia. The first three tracings show surface electrocardiograms, as labeled. AblD and AblP = distal and proximal pair of electrodes of the mapping catheter, respectively; HBED and HBEP = distal and proximal pair of electrodes in the catheter located at His bundle, respectively; HRA = high right atrial catheter; MAP = unipolar electrograms from the tip of the mapping catheter; RVA = catheter located in right ventricular apex.
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Atrial tachycardia. This electrocardiogram shows multifocal atrial tachycardia (MAT).
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Atrial tachycardia. This electrocardiogram belongs to an asymptomatic 17-year-old male who was incidentally discovered to have Wolff-Parkinson-White (WPW) pattern. It shows sinus rhythm with evident preexcitation. To locate the accessory pathway (AP), the initial 40 milliseconds of the QRS (delta wave) are evaluated. Note that the delta wave is positive in lead I and aVL, negative in III and aVF, isoelectric in V1, and positive in the rest of the precordial leads. Therefore, this is likely a posteroseptal AP.
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Atrial tachycardia. This is a 12-lead electrocardiogram from an asymptomatic 7-year-old boy with Wolff-Parkinson-White (WPW) pattern. Delta waves are positive in leads I and aVL; negative in II, III, and aVF; isoelectric in V1; and positive in the rest of the precordial leads. This again predicts a posteroseptal location for the accessory pathway (AP).
Tables
Type of Tachycardia |
Treatment (Grade) |
Not Mentioned in 2019 Guidelines |
Narrow QRS tachycardias |
Verapamil and diltiazem; beta-blockers (now all are grade IIa) |
Amiodarone, digoxin |
Wide QRS tachycardias |
Procainamide, adenosine (both grade IIa); amiodarone (IIb) |
Sotalol, lidocaine |
Inappropriate sinus tachycardia |
Beta-blockers (IIa) |
Verapamil/diltiazem, catheter ablation |
Postural orthostatic tachycardia syndrome |
Salt and fluid intake (IIb) |
Head-up tilt sleep, compression stockings, selective beta-blockers, fludrocortisone, clonidine, methylphenidate, fluoxetine, erythropoietin, ergotaminel octreotide, phenobarbitone |
Focal atrial tachycardia |
Acute: beta-blockers (IIa); flecainide/propafenone, amiodarone (IIb) |
Acute: procainamide, sotalol, digoxin |
Chronic: beta-blockers; verapamil and diltiazem (all IIa) |
Chronic: amiodarone, sotalol, disopyramide |
|
Atrial flutter |
Acute: ibutilide (I); verapamil and diltiazem, beta-blockers (all IIa); atrial or transesophageal pacing (IIb); flecainide/propafenone (III) |
Acute: digitalis |
Chronic: — |
Chronic: dofetilide, sotalol, flecainide, propafenone, procainamide, quinidine, disopyramide |
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Atrioventricular nodal re-entrant tachycardia (AVNRT) |
Acute: — |
Acute: amiodarone, sotalol, flecainide, propafenone |
Chronic: verapamil and diltiazem; beta-blockers (all IIa) |
Chronic: amiodarone, sotalol, flecainide, propafenone, “pill-in-the-pocket” approach |
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Atrioventricular re-entrant tachycardia (AVRT) |
Beta-blockers (IIa); flecainide/propafenone (IIb) |
Amiodarone, sotalol, “pill-in-the-pocket” approach |
SVT in pregnancy |
Verapamil (IIa); catheter ablation (IIa when fluoroless ablation is available) |
Sotalol, propafenone, quinidine, procainamide |
Adapted from Brugada J, Katritsis DG, Arbelo E, et al, for the ESC Scientific Document Group. 2019 ESC Guidelines for the management of patients with supraventricular tachycardia. The Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). Eur Heart J. 2019 Aug 31;ehz467. https://academic.oup.com/eurheartj/advance-article/doi/10.1093/eurheartj/ehz467/5556821 |
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