A 44-Year-Old Man with Intermittent Dizziness

Differential Diagnosis

• Sinus tachycardia
• AV block 1^st degree
• Multifocal atrial tachycardia
• Wolff-Parkinson-White syndrome
• Third-degree AV block 

Diagnosis
The patient was diagnosed with Wolff-Parkinson-White syndrome (WPW). The ECG reveals a gradual upsloping of the initial reflection of the QRS complex, called delta waves (see arrows). Additional ECG finds may include a shortened PR interval (<120 ms), a widened QRS complex, and ST/T wave changes.

Learnings

• WPW is a supraventricular re-entrant rhythm which may have a normal rate or fast rate