Long-term Prognosis of Short QT Interval in Asian Patients: Multicenter
Retrospective Cohort Study
Introduction: Short QT syndrome is a rare, inherited channelopathy
associated with sudden cardiac arrest (SCA) but characteristics and
prognosis of short QT interval (SQTI) in Asian patients remain unclear.
This study aimed to determine clinical characteristics of and outcomes
in patients with SQTI in an Asian population. Methods: Consecutive
patients with SQTI were recruited. SQTI was defined as a Bazett’s
formula-corrected QT interval (QTc) ≤340 ms in serial
electrocardiograms. Age- and sex-matched patients with a normal QTc and
without overt cardiovascular disease were included at a 1:4 ratio.
Clinical and ECG features and outcomes were compared between patients
with and without SQTI. Results: Thirty-four patients with SQTI [age,
23.5 (21–30.5) years; 31 male] were followed up for 4.8 (2.0–7.8)
years. Early repolarization, tall T wave, and U wave were significantly
more frequent in patients with SQTI than the patients without SQTI. QT
dispersion [44.0 (28.0–73.0) vs. 20.0 (12.0–35.0) ms,
P<0.001] was significantly wider and heart rate [52.0
(47.0–58.0) vs. 70.0 (62.3–84.0) /min, P<0.001] was
significantly slower in patients with SQTI than patients without SQTI.
Atrial fibrillation (AF, 11.8% vs. 2.2%, P=0.030) and ventricular
arrhythmia (VA)/SCA (8.7% vs 0%, P=0.007) were significantly more
frequent in patients with SQTI than patients without SQTI. SQTI was
significantly associated with AF [odds ratio, 5.911; 95% confidence
interval, 1.257–27.808; P=0.025] and VA/SCA. Conclusions: In this
Asian population, SQTI was associated with AF and VA/SCA.