Schwartz published criteria for the diagnosis of the idiopathic long QT syndrome in 1985. The author is from the University of Milan in Italy.


Patient preparation: The patient should not be evaluated while taking any medications associated with prolongation of the QT interval.


Major criteria:

(1) prolonged QT interval (corrected QT interval > 440 msec)

(2) stress-induced syncope

(3) family members diagnosed with long QT syndrome


Minor criteria:

(1) congenital deafness

(2) episodes of T wave alternans

(3) low heart rate (in children)

(4) abnormal ventricular repolarization


Diagnosis of the long QT syndrome requires one of the following:

(1) 2 major criteria

(2) 1 major and >= 2 minor criteria


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