Abstract

RUESTA, Víctor. Una forma atípica de síndrome de QT largo: Heraldos de muerte súbita cardíaca. Gac Méd Caracas. [online]. 2008, vol.116, n.1, pp.41-45. ISSN 0367-4762.

The study presents two cases with features related to atypical forms of long QT syndrome. The QT syndrome has been reviewed recently, the presence of autonomic imbalance, the dispersion of repolarization, the heterogeneity of its genetic basis in explaining its clinical presentations have call the atention of the investigators. Two siblings patients (male and female) were studied; both presented ventricular tachycardia under conditions of augmented adrenergic tone (fear and exercise) and their mother died suddenly before age fifty. Electrocardiogram, vectocardiogram, signal average electrocardiogram, bidimensional echo were performed in both, additionally he was studied with coronary angiography. The resting electrocardiogram in him showed nonspecific repolarization anormalities, ventricular tachycardia with right bundle branch configuration in one occasion. Lack of proper shortening of the QT interval during de stress test. Signal average electrocardiogram, bi-dimensional echo and coronary angiography were normal. She had a normal electrocardiogram and echocardiogram but developed a ventricular tachycardia with left bundle branch configuration during the early stages of an stress test. Patients with a positive family history of sudden death, non-specific repolarization anormalities, lack of shortening of the QT interval with increasing heart rate (hypodinamic QT) are suspicious of developing ventricular tachycardia under conditions of augmented adrenergic tone. Preventive measures should be taken in patients with this conditions.

Keywords : Long QT syndrome; Family history of sudden death; Lack of shortening of the QT interval with increasing heart rate; Ventricular tachycardia with augmented adrenergic tone.