Errors in ECG recording

Errors in ECG recording

ECG is a widely available simple test to detect heart attack and gives important information in many other heart diseases.

Still human error during recording can cause difficulty and errors in interpretation sometimes. The commonest error is misplacement of ECG electrodes used for recording.

Of these, the most common one is placing the electrode meant for right arm in the left arm and vice versa. This will cause the waves which are expected to be upright to be inverted.

This same pattern can occur in birth defects in which the heart is on the right side than on the left side of the chest. It can be easily identified by checking the recordings from chest leads, which will show normal pattern if only limb leads have been reversed.

Errors during recording can be easily identified by getting the ECG recorded under direct observation of the medical personnel when there is a doubt.
If there is a source of strong electrical interference in the vicinity, it will show up in the ECG as a 50 Hz alternating current tracing in the ECG baseline.

This usually occurs in the intensive care units where several electrically operated devices are connected to the individual. Simple method to avoid this is to switch off all other electrical equipment in the vicinity temporarily and operate the ECG machine on battery.

Errors due to picking up of electrical activity from the muscles can occur in those who are restless or quite anxious and having tremors. This can be taken care of by pacifying and occasionally by using sedation if unavoidable, especially in case of children.