QT Interval: The Proper Measurement Techniques

Jessica is a 23-year-old university student who presents to hospital with anorexia and symptoms of a lower respiratory tract infection. She is otherwise healthy and is on no medications. The remainder of her history is unremarkable except for a family history of sudden, unexplained death in a maternal aunt. Baseline blood work shows mild hypokalemia and a left lower lobe infiltrate on her chest xray. She is admitted to hospital for correction of her electrolytes and is given clarithromycin for her pneumonia. The following day, she suffers a cardiac arrest. Polymorphic wide QRS complex tachycardia is seen on the monitor. A post-resuscitation ECG demonstrates striking QT findings (Figure 1).