Short QT

HPI:  55 y/o male with no past medical history presents with vague symptoms including nausea, lethargy, and weakness. Vital signs are within normal limits. Before labs come back you obtain this EKG:

EKG:

EKG Interpretation:
Normal sinus rhythm, rate 67 bpm. Normal axis. Narrow QRS, no ST elevation or depression. --> “Normal ECG”.

**On closer inspection you notice the QT interval appears shortened, calculated at 350 ms**

Discussion:
Initial labs show total calcium of 15.0 mg/dL and PTH of 400 pg/mL (nl 7-53 pg/mL). A single large parathyroid adenoma was diagnosed and subsequently removed.

EKG signs of Hypercalcemia: 
·   Short QT interval, usually less than 350 ms
·   In severe hypercalcemia, can see Osborn waves (J waves)
·   In extreme hypercalcemia, ventricular irritability and ventricular fibrillation have been reported

Remember, degree of EKG findings usually signify severity of hypercalcemia! Administer fluid resuscitation and treat the underlying cause. 
Simplified DDx for shortened QT interval: 
1) Hypercalcemia
2) Congenital short QT syndrome
3) Digitalis toxicity
4) Normal variant. 

By Dr. Blake Johnson