refresh your CVS - kallastro

[ArchivalUser]

A 48-year-old man is brought to the emergency department after passing out at home. He had been arguing with his wife when he suddenly collapsed. ECG shows sinus rhythm, with a corrected QT (QTc) interval of 500 ms. What other ECG sign would indicate that this patient is at high risk for cardiac events?

A. T-wave alternans
B. U wave
C. Peaked T waves
D. Osborne waves

[ArchivalUser]

c.

[ArchivalUser]

A.

This patient has a long QT interval. The upper limit of the normal QTc is 460 ms for women and 440 ms for men. T-wave alternans, an alternation in the polarity and amplitude of the T wave, is associated with an increased risk of adverse cardiac events. The U wave is associated with hypokalemia. Peaked T waves can indicate MI or hyperkalemia. Osborne waves (J waves) are usually seen in hypothermia.

Sources
Meyer JS, Mehdirad A, Salem BI, et al. Sudden arrhythmia death syndrome: importance of the long QT syndrome. Am Fam Physician. 2003;68:483-488.