A Covid patient with cough and Fever. Why does the ST-T wave look so abnormal?

I was reading through a stack of ECGs and saw this one.  What is going on here?At first glance, it looks like a low atrial rhythm, with a negative P-wave in inferior leads.  There appear to be inferior QS-waves and and intraventricular conduction delay (computer measure QRS at 120 ms).There appear to be very strange down up T-waves.On closer inspection, the P-wave in V1 appears biphasic, which should not happen in a low atrial rhythm.Then we see that there is another P-wave inbetween, superimposed on the T-wave, in V1.Then we see that in lead II, the negative P-waves have another negative P-wave between the QRS and the T-wave, which accounts for the abnormal appearing ST-T.So this is an extremely slow atrial flutter with 2:1 conduction.  Atrial rate 146, ventricular rate 73.It turns out that this patient has cardiac amyloidosis.  I suspect that the amyloid slows the conduction of the atrial flutter.I later found out that the patient complained of cough and fever, and was diagnosed with Covid.It turned out that he had a history of slow atrial flutter.  His cough and fever was from mild Covid pneumonia.  All troponins were negative.Diagnosis: Extremely slow Atrial flutter===================================MY Comment by KEN GRAUER, MD (11/16/2020):===================================Some of the most interesting ECG cases I have seen have been picked up “reading through a stack of ECGs”  — in the same manner that Dr...
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