PC

• Palpitations
  • Patient may describe Hx of palpitations and had ways to stop them, e.g. sticking fingers down theoat, pressing hard on eyeballs, dipping his face in cold water
• SOB

2 subtypes:

1. Atrioventricular nodal re-entrant tachycardia (AVNRT)

• Impulses conducted from atria to ventricles through AV node, then travel immediately back into atria (abnormal additional retrograde conduction within the AV node), forming a re-entry circuit through the AV node - triggering tachycardia
• QRS complexes are narrow. But because of the abnormal retrograde conduction, the P wave is merged with QRS / T.
• A narrow complex regular tachycardia

1. Atrioventricular re-entrant (reciprocating) tachycardia (AVRT)

• An additional congenital 'accessory' pathway exists from the atria to the ventricles, outside of the AV node. This also allows impulses to travel round and round, leading to episodes of supraventricular tachycardia. The most common form is Wolff-Parkinson-White syndrome.

Wolf Parkinson White syndrome- extra electrical pathway (bundle of kent) connecting atria to ventricles. Patients are at risk of sudden death

WPW on ECG:

• Short PR interval (< 0.12 seconds)
• Wide QRS complex (> 0.12 seconds)
• “Delta wave” which is a slurred upstroke on the QRS complex