ECG recorded from a 17-year-old man with<unk><unk><unk>  syndrome<unk>  syndrome is diagnosed in a person who has experienced episodes of abnormal heart racing (arrhythmias) who has a PR interval less than or equal to 0.12 second (120 ms) with normal QRS complex configuration and duration on their resting ECG. A short PR interval found incidentally on an ECG without episodes of tachycardia is simply a benign ECG variant.<unk>  can be distinguished from WPW syndrome because the delta waves seen in WPW syndrome are not seen in<unk>  syndrome. The QRS complex will also be narrow in<unk>  syndrome, as opposed to WPW, because ventricular conduction is via the His-Purkinje system.<unk>  is a clinical diagnosis that came about before the advent of electrophysiology studies. It is important to be aware that not all WPW ECGs have a delta wave; the absence of a delta wave does not conclusively rule out WPW.
Lown–Ganong–Levine syndrome
Wolff–Parkinson–White syndrome
Lucey–Driscoll syndrome
Morgagni Stewart Morel syndrome
Bhaskar–Jagannathan syndrome
Claude's syndrome
Witteveen–Kolk syndrome
Townes–Brocks syndrome