Frontal QRS-T angle and ventricular mechanics in congenital heart disease.

BACKGROUND: The QRS-T angle has been associated with adverse cardiovascular events and sudden cardiac deaths. We determined frontal QRS-T angle in patients with complete transposition of the great arteries (TGA) after atrial switch operation and repaired tetralogy of Fallot (TOF) and explored its relationships with ventricular mechanics. METHODS: Thirty TGA patients aged 32.3 +/- 4.4 years after atrial switch operation and 47 repaired TOF patients aged 28.7 +/- 6.0 years were studied. The frontal planar QRS-T angle and QRS duration were measured from 12-lead electrocardiograms. Right (RV) and left ventricular (LV) strain parameters were determined using speckle tracking echocardiography. RESULTS: Compared with TOF patients, TGA patients after atrial switch operation had significantly greater frontal QRS-T angle (136.3 degrees +/- 43.5 degrees vs 74.5 degrees +/- 59.6 degrees , p /= 100 degrees (83.3% vs 29.8%, p 0.05). CONCLUSION: Increased frontal QRS-T angle is prevalent in TGA patients after atrial switch operation and is related to worse systemic RV mechanics.