Automatic interpretation errors

  Automatic interpretation by the ECG computer may be false and needs confirmation.

  Sometimes ECG computer may fail to diagnose the atrial fibrillation or

      may falsely diagnose as atrial fibrillation.

  Brief episodes of baseline drift may result in a false diagnosis of APC or VPC.

  2:1 atrioventricular (AV) block may be misperceived as QT interval prolongation.

  "Probable Digoxin effect" may be overdiagnosed.

  Many ECG computers usually underdiagnose interatrial block.





ECG 1a. The above ECG shows that a brief
baseline drift may give the impression of a wide QRS complex at first glance.
However, the R wave (initial part of the QRS complex) is not affected by the baseline drift.
Therefore, the R wave morphology is similar to other QRS complexes in the precordial leads.
This finding excludes the presence of a ventricular premature contraction (VPC).

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ECG 1b. Above is the compact report of the ECG 1a including the comment of the computer.
Erroneously, it reports the presence of ventricular premature contraction (VPC).





ECG 2a. The above ECG shows sinus rhythm, tremor artifact and baseline drift.

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ECG 2b. Above is the compact ECG and computer report of the ECG 2a.
Erroneously, it reports the presence of atrial fibrillation.





ECG 3a. The above ECG shows 2:1 atrioventricular block.
The blocked P waves are embedded in the descending limb of the T wave.

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ECG 3b. Above is the compact ECG and computer report of the ECG 3a.
Since it misperceives the blocked P wave as terminal part of the T wave, it erroneously reports the presence of QT interval
prolongation.





ECG 4a. The rhythm in the above ECG is atrial fibrillation.
The patient is NOT under Digoxin therapy.

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ECG 4b. Above is the compact ECG and computer report of the ECG 4a.
It erroneously reports "Moderate ST depresion, probably digitalis effect".
The patient is NOT under Digoxin therapy.





ECG 5a. The above ECG belongs to a 67 years old-man. The rhythm is sinus.
Amplitudes of
the P waves and the T waves are similar.
The PT interval looks similar to the TP interval at first glance.

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ECG 5b. Above is the compact ECG and computer report of the ECG 5a.
Since it misperceives T waves as blocked P wave, it erroneously reports the presence of 2nd degree AV block, Mobitz Type II.
In reality, there is no 2nd degree AV block in this patient.





ECG 6a. The ECG above is from a 81 years-old man who had previous acute myocardial infarction.
After the infarction, left ventricular systolic dysfunction developed (Ejection Fraction of about 35%).
Three-vessel (extensive) coronary artery disease was detected, and his LAD and RCA coronary arteries were stented.

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ECG 6b. Above is the compact ECG and computer report of the ECG 6a.
Diagnosis of old "anteroseptal myocardial infarction" is correct.
However this report does not include "interatrial block".