High Frequency of Early Repolarization and Brugada-Type Electrocardiograms in Hypercalcemia.
BACKGROUND
J wave, or early repolarization has recently been associated with an increased risk of lethal arrhythmia and sudden death, both in idiopathic ventricular fibrillation and in the general population. Hypercalcemia is one of the causes of J point and ST segment elevation, but the relationship has not been well studied. The aim of this study was to examine the effects of hypercalcemia on J point elevation.


METHODS
Electrocardiographic findings were compared in 89 patients with hypercalcemia and 267 age- and sex-matched healthy controls with normocalcemia. The association of J point elevation with arrhythmia events in patients with hypercalcemia was also studied.


RESULTS
The PR interval and the QRS duration were longer in patients with hypercalcemia than in normocalcemic controls. Both the QT and the corrected QT intervals were shorter in patients with hypercalcemia compared with normocalcemic controls. Conduction disorders, ST-T abnormalities, and J point elevation were more common in patients with hypercalcemia than normocalcemic controls. Following the resolution of hypercalcemia, the frequency of J point elevation decreased to a level similar to that noted in controls. During hospitalization, no arrhythmia event occurred in patients with hypercalcemia.


CONCLUSIONS
Hypercalcemia was associated with J point elevation.
Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Keiko
K
Sonoda
Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Hiroshi
H
Watanabe
Center for Epidemiologic Research in Asia, Shiga University of Medical Science, Otsu, Japan.|Department of Public Health, Shiga University of Medical Science, Otsu, Japan.|Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan.
Takashi
T
Hisamatsu
Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan.
Takashi
T
Ashihara
Center for Epidemiologic Research in Asia, Shiga University of Medical Science, Otsu, Japan.|Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan.
Seiko
S
Ohno
Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan.
Hideki
H
Hayashi
Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan.
Minoru
M
Horie
Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Tohru
T
Minamino
D000368:Aged; D053840:Brugada Syndrome / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D000075224:Cardiac Conduction System Disease; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000097:blood / Q000150:complications*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
Brugada syndrome; J point elevation; J wave; early repolarization; hypercalcemia