Triggers of atrial fibrillation

  Atrial premature beats - APC ( the most frequent )

  Atrial flutter

  Supraventricular tachycardias

  Bradycardia

  Acute atrial stretch.







ECG 1a. Above is a 3-channel Holter tracing from a middle-aged woman with attacks of palpitation.
Holter recording showed multiple episodes of paroxysmal atrial fibrillation.
Atrial premature beat initiates atrial fibrillation.
Atrial premature beat is the most frequent trigger of atrial fibrillation.

Click here for a more detailed ECG





ECG 1b. Above is another strip from her Holter recording.
Atrial premature beat initiates atrial fibrillation.
The first 2 QRS complexes are
aberrantly conducted (Ashman phenomenon).

Click here for a more detailed ECG





ECG 1c. Above is another strip from her Holter recording.
The first atrial premature beat is aberrantly conducted , but it cannot initiate atrial fibrillation.
Second atrial premature beat initiates atrial fibrillation. The first 2 QRS complexes are aberrantly conducted
(
Ashman phenomenon).

Click here for a more detailed ECG





ECG 1d. Above is another strip from her Holter recording.
Every atrial premature beat
cannot initiate atrial fibrillation.
The first and second atrial premature beats are conducted aberrantly, but they cannot initiate atrial fibrillation.
The third atrial premature beat initiates atrial fibrillation of which the first 2 QRS complexes show aberration.
(
Ashman phenomenon).

Click here for a more detailed ECG





ECG 1e. Above is another strip from her Holter recording.
Sometimes paroxysms of atrial fibrillation may last very short(as seen above).
The first atrial premature beat initiates atrial fibrillation.
The following two QRS complexes are
aberrantly conducted (Ashman phenomenon).
Sinus rhythm resumes after 6 beats of atrial fibrillation.

Click here for a more detailed ECG





ECG 1f. Above is another strip from her Holter recording.
Fibrilloflutter.
While the left left side of the ECG shows atrial flutter, the rhythm then changes to atrial fibrillation on the right side of the ECG.

Click here for a more detailed ECG





ECG 2. The Holter rhythm tracing above is from another middle-aged woman.
This is another example of a very short lasting episode of atrial fibrillation.
The first atrial premature beat initiates atrial fibrillation.
The first 2 QRS complexes are conducted
aberrantly (Ashman phenomenon).
Sinus rhythm resumes in a very short time.

Click here for a more detailed ECG






ECG 3a. The above rhythm tracing is from a middle-aged man who had undergone aortic valve replacement for severe
aortic stenosis.
The very first beat on the left side is a sinus beat.
The first atrial premature beat is blocked since it is "too" premature.
It also could not initiate atrial fibrillation.
It is followed by a short-lasting episode of ectopic atrial tachycardia with negative P waves.
The ectopic atrial tachycardia is followed by a
sinus beat and then atrial fibrillation starts.
The sweep speed of this Holter recording is 25 mm/second.

Click here for a more detailed ECG





ECG 3b. The above rhythm Holter tracing is the continuation of the tracing in ECG 3a.
The last beat of the ectopic atrial tachycardia is followed by a sinus beat. Meanwhile, a pause of 1.1 seconds developes.
Then,
the following atrial premature beat initiates atrial fibrillation.
The sweep speed of this Holter recording is 25 mm/second.

Click here for a more detailed ECG





ECG 3c. The above rhythm tracing is derived from the ECG 3b, but it is displayed at a sweep speed of 50 mm/second.
The calibration is also increased.
The last beat of the ectopic atrial tachycardia is followed by a sinus beat. Meanwhile, a pause of 1.1 seconds developes.
Then,
the following atrial premature beat initiates atrial fibrillation.

Click here for a more detailed ECG





ECG 4. The above rhythm Hoter tracing belongs to another middle-aged man.
An
atrial premature beat during sinus tachycardia initiates atrial fibrillation.
The sweep speed of this Holter recording is 25 mm/second.

Click here for a more detailed ECG