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This is simple and straightforward. Look for PR intervals and QT intervals.

A prolonged PR interval on its own is not a major issue. It represents a first degree block. However if combined with a left anterior fascicular block and a RBBB, it is a triphasicular block and the patient requires a pacemaker.

The QT Interval is very important.

It is usually given on the ECG, but can be calculated also. A clue as to a prolonged QT occurs when the end of the T wave is past the midpoint between the R-R Interval.

The QT Interval is measured from the beginning of QRS to end of T wave.

It can be calculated by QTc = QT/sq root of RR

>0.44 seconds concerning

Causes of Prolonged QT

Inherited Lange-Neilsen (AR), Romano-Ward(AD)


Drugs – amiodarone, sotalol, haloperidol, methadone

Other – Hypothyroidism, Hypercalcaemia

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