Atrial tachycardia: Difference between revisions
| Line 24: | Line 24: | ||
==Evaluation== | ==Evaluation== | ||
[[File:PMC3665213 CRIM.MEDICINE2013-430862.002.png|thumb|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.]] | |||
===Workup=== | ===Workup=== | ||
*[[ECG]] | *[[ECG]] | ||
Revision as of 22:18, 27 February 2021
Background
- Also known as focal 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
Clinical Features
- 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
Differential Diagnosis
Narrow-complex tachycardia
- Regular
- AV Node Independent
- Sinus tachycardia
- Atrial tachycardia (uni-focal or multi-focal)
- Atrial fibrillation
- Atrial flutter
- Idiopathic fascicular left ventricular tachycardia
- AV Node Dependent
- AV Node Independent
- Irregular
- Multifocal atrial tachycardia (MAT)
- Sinus tachycardia with frequent PACs, PJCs, PVCs
- Atrial fibrillation
- Atrial flutter with variable conduction
- Digoxin Toxicity
Evaluation
Workup
Diagnosis
- 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.
- 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 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.
Management
- Non-sustained episodes of focal tachycardia are commonly seen on ambulatory ECG monitoring and are often asymptomatic.
- 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.
- Focal atrial tachycardia should be treated with urgent electrical cardioversion if the patient is unstable.
- Stable patients may cardiovert with adenosine or with beta blockers.
- If digoxin toxicity is the cause of the atrial tachycardia the drug should be stopped.
- Rate control and or prophylaxis against recurrent episodes can be attained usually with beta blockers, or calcium channel blockers.