Atrial tachycardia: Difference between revisions

Revision as of 23:01, 27 February 2021

Also known as focal atrial tachycardia, Paroxysmal Atrial Tachycardia (PAT), unifocal atrial tachycardia, ectopic atrial tachycardia
Rate >100 bpm
Electrical focus that originates outside in the sinus node at a single location
- By comparison, reentrant tachycardias (eg. AVRT, AVNRT) involve multiple foci/ larger circuits
Sustained atrial tachycardia can lead to a tachycardia-induced cardiomyopathy.
Differs from sinus tachycardia in that the impulses are generated by an ectopic focus somewhere within the atrial myocardium rather than the sinus node.
Multifocal atrial tachycardia is similar, but has P waves with at least three different morphologies.
The combination of atrial tachycardia plus AV block is particularly common in digoxin toxicity.

Often asymptomatic
Palpitations
- Non-specific finding
- Associated with all tachydysrhythmias, not just AT
- Rapid fluttering/throbbing/pounding sensation in the chest or neck
Syncope
- Patients with AT rarely present with syncope
- Cerebral hypoperfusion is more common with a ventricular rate >200 bpm
Chest pain
- Can present if there is underlying cardiovascular disease
- Represents a worsening of the associated disease
Dyspnea
- Can present if there is underlying cardiovascular disease
- Represents a worsening of the associated disease

P waves inverted in lead II and AVL while upright in III and AVF, suggesting ectopic atrial tachycardia, most likely originating from the left side.

Atrial rate >100 bpm
P-waves
- Morphology abnormal (when compared with sinus P wave due to ectopic origin)
- Has at least three consecutive identical ectopic p waves
- Axis frequently abnormal (e.g. inverted in inferior leads)
QRS complexes
- Usually normal morphology (unless pre-existing bundle branch block, accessory pathway, or rate related aberrant conduction)
Baseline isoelectric (unlike atrial flutter)
AV block may be present

Initial treatment may be aimed at rate control, while later resolution of clinical symptoms usually requires restoration of normal sinus rhythm.

Authors:

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 *Electrical focus that originates outside in the sinus node at a single location
 **By comparison, reentrant tachycardias (eg. AVRT, AVNRT) involve multiple foci/ larger circuits
-*Sustained atrial tachycardia can lead to a tachycardia-induced cardiomyopathy and it is important not to misdiagnose the rhythm as [[sinus tachycardia]] in such cases.
+*Sustained atrial tachycardia can lead to a tachycardia-induced cardiomyopathy.
-*Atrial tachycardia differs from sinus tachycardia in that the impulses are generated by an ectopic focus somewhere within the atrial myocardium rather than the sinus node.
+*Differs from sinus tachycardia in that the impulses are generated by an ectopic focus somewhere within the atrial myocardium rather than the sinus node.
-*The atrial (P wave), is usually 100-250 /min with abnormally shaped P waves. The combination of focal atrial tachycardia with AV block is particularly common in digoxin toxicity.
+*Multifocal atrial tachycardia is similar, but has P waves with at least three different morphologies.
-*Multifocal atrial tachycardia can be mistaken for AF, due to its irregular nature, but closer inspection of the ECG will reveal P waves with at least three different morphologies.
+*The combination of atrial tachycardia plus AV block is particularly common in [[digoxin toxicity]].
 ==Clinical Features==