Figure 5.(.

A) Manifest pre-excitation pattern consisting of short PR interval, delta wave, and wide QRS tirade on 12-channel electrocardiography (ECG); Wolff-Parkinson-White (WPW) pre-excitation. (B) Fast conduction to ventricles of atrial fibrillation in WPW, which can degenerate to ventricular fibrillation. (C) Permanent junctional reciprocal tachycardia (PJRT) recording with long RP interval and negative P waves in the inferior leads (DII-III and aVF) are seen. (D) Very short RP interval in ECG (retrograde p waves seen immediately after the QRS as “pseudo-r” in lead V-1 and a “pseudo-s” in lead D-III) seen in typical AVNRT. (E) Atypical AVNRT ECG with long R-P interval is seen (differential diagnosis includes other long R-P interval SVTs such as focal atrial tachycardia and PJRT). (F) Focal atrial tachycardia ECG; p waves seen on the ground after adenosine administration, returning to the isoelectric line. (G) Atrial flutter ECG with typical saw-tooth-like p waves.