Sotalol

  is both a Class III antiarrhythmic agent and a beta adrenergic blocker.



Sotalol MAY be used for

  the treatment of ventricular tachycardia (some patients with VT may not be suitable for sotalol).

  the conversion of atrial fibrillation and atrial flutter to sinus rhythm (in certain patients only).

  the maintenance of sinus rhythm after conversion of atrial fibrillation / atrial flutter (in certain patients only).



ECG abnormalities that may be observed in patients under Sotalol therapy

  Sinus bradycardia

  QT interval prolongation

  Prolonged PR interval



ECG abnormalities that may be observed in patients with Sotalol overdose

  Torsades de pointes



References

  Chou's Electrocardiography in Clinical Practice. Adult and Pediatric. 5th ed. Philadelphia. WB Saunders. 2001.

  Ned Tijdschr Geneeskd 2007;151:2214-2218.

  Prog Cardivasc Dis 1988;31:115.

  2012 focused update of the ESC Guidelines for the management of atrial fibrillation

  ACC/AHA/ESC Guidelines for the Management of Patients With Supraventricular Arrhythmias 2003




ECG 1. This patient is under Sotalol therapy of 2 x 80mg/daily. Her ECG shows sinus bradycardia.

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ECG 2a. The ECG above belongs to a 66 years-old man with coronary artery disease. He complained of recent onset palpitation.
The rhythm is atrial flutter with 2:1 AV block. Flutter waves with "sawtooth-like" appearance is best seen in leads II, III and aVF.
The atrial rate is 300/minute. After this ECG, oral Sotalol therapy (2 x 80mg tablets) was started.

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ECG 2b. The ECG above was recorded 6 hours after ingestion of the first tablet of Sotalol 80mg.
The AV block is frequently 2:1, and rarely the level of block increases due to the effect of Sotalol.

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ECG 2c. His ECG next day (while under 2 x 80mg/day of Sotalol therapy) shows atrial flutter with variable AV block.
The effect of Sotalol on the level of AV block is more pronounced in the above ECG.
Now, increased level of AV block is seen more frequently.
After this ECG, the dose of oral Sotalol therapy was increased to 2 x 160mg /day (suggested maximum daily dose).


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ECG 2d. Next day, 24 hours after switching to Sotalol 2 x 160mg tablets, the ECG shows sinus rhythm.

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ECG 3a. The ECG above belongs to a 16 years-old male who had previously undergone Fontan operation.
He has been under Sotalol therapy for a long time.
Do you think the PR interval is prolonged when you look at leads V1 and V2?
In fact, the rhythm is not sinus rhythm and we cannot talk about PR interval.
The seemingly "P waves" in leads V1 and V2 are actually flutter waves.
The flutter waves are best seen in lead II.
The rhythm is 2:1 atrial flutter and half of the flutter waves are buried in QRS complexes.
The ventricular rate is 104/minute. When a patient with atrial flutter is under Sotalol or Amiodarone therapy,
even if the rhythm is not converted to sinus, ventricular rate is usually lower than pre-treatment levels.
Don't let the "relatively slow" heart rate deceive you in diagnosing the rhythm.
In a patient with 2:1 atrial flutter, if pre-treatment ventricular rate is about 125-150/min, it may decrease to 100-110/minute
after treatment with Sotalol or Amiodarone.

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ECG 3b. The ECG above belongs to the same patient. It was recorded 2 years after the ECG 3a.
He is still taking 2 x 80 mg Sotalol per day.
The rhythm is sinus and we can talk about PR interval now. The PR interval is normal. No flutter waves are seen.
Unlike the ECG 3a, P wave, QRS complex and T wave in lead II are clearly identifiable in ECG 3b.
The ventricular rate is 57/minute now. If a patient with sinus rhythm is under Sotalol or Amiodarone therapy,
generally expect to see low heart rates (as is the case in this patient).
The last beat is an atrial premature beat.

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