ECG 1a. Above is an ECG from a middle-aged woman.
She was transferred to our hospital with the diagnosis of sinus arrest.
What is your diagnosis? Is there a real pause?

Dr. Sinan Altan Kocaman has donated the above ECG to our website.

Click here for a more detailed ECG



ECG 1b. Above is the explanation for the same ECG:
The deflections mimicking P waves on the left side are in fact T waves.
If they are T waves, then where are their preceding QRS complexes? They are not seen.
It is "not because that they do not exist". They are not depicted because of the artifact.
There are 3 clues to suggest artifact in this patient:
1- T waves cannot be formed without preceding QRS complexes.
2- Lead I shows baseline drift due to artifact.
3- Also, this artifact deforms the simultaneous P waves resulting in the appearence of subtle deflections.
The second P wave from the left side is not seen where it should be.
In conclusion, there is no sinus pause in this ECG, but artifact mimicking pause.
Her heart rate is 58/minute.

Dr. Sinan Altan Kocaman has donated the above ECG to our website.

Click here for a more detailed ECG