Left ventricular longitudinal function predicts life-threatening ventricular arrhythmia and death in adults with repaired tetralogy of fallot

Abstract

Background: Sudden cardiac death and life-threatening ventricular arrhythmia remain a concern in adult patients with repaired tetralogy of Fallot. Longitudinal left ventricular (LV) function is sensitive in detecting early myocardial damage and may have prognostic implications in this setting.

Methods and results: We included 413 tetralogy of Fallot patients (age, 36 ± 13 years; QRS duration, 148 ± 27 milliseconds; LV ejection fraction, 55 ± 10%). A composite end point of sudden cardiac death/life-threatening ventricular arrhythmia (sustained ventricular tachycardia, resuscitated sudden cardiac death, or appropriate implantable cardioverter-defibrillator discharge) was used. During a median follow-up of 2.9 years, 5 patients died suddenly, 9 had documented sustained ventricular tachycardia, and another 5 had appropriate implantable cardioverter-defibrillator shocks. On univariate Cox analysis, QRS duration (hazard ratio [HR], 1.02 per 1 ms; P=0.046), right atrial area (HR, 1.05 per 1 cm(2); P=0.02), right ventricular fractional area change (HR, 0.94 per 1%; P=0.02), right ventricular outflow tract diameter (HR, 1.08 per 1 mm; P=0.01), mitral annular plane systolic excursion (HR, 0.84 per 1 mm; P=0.03), and LV global longitudinal 2-dimensional strain (HR, 0.87 per 1%; P=0.03) were related to the combined end point. On bivariable analysis, mitral annular plane systolic excursion and LV global longitudinal 2-dimensional strain were related to outcome independently of QRS duration (P=0.002 and P=0.01, respectively). In addition, a combination of echocardiographic variables, including right atrial area, right ventricular fractional area change, and LV global longitudinal 2-dimensional strain or mitral annular plane systolic excursion, was also found to be significantly related to outcome (P<0.001; c statistic, 0.70).

Conclusions: LV longitudinal dysfunction was associated with greater risk of sudden cardiac death/life-threatening ventricular arrhythmias. In combination with echocardiographic right heart variables, also available from routine echocardiography, these measures provide important outcome information and should be considered a useful adjunct to established markers such as QRS duration in the estimation of prognosis in this challenging population.