Electrocardiogram screening of deaf children for long QT syndrome: An Egyptian experience.

BACKGROUND: Jervell and Lange-Nielsen syndrome is an autosomal recessive form of long QT syndrome (LQTS), clinically manifested by long QT interval and bilateral sensorineural hearing loss (SNHL) with the highest prevalence in Norway and Sweden. No data are available about the prevalence of such syndrome in Egypt. OBJECTIVES: This study aimed to assess by electrocardiogram (ECG) the prevalence of LQTS among Egyptian children with SNHL. METHODS: One thousand and twelve patients, aged ≤ 10 years (mean age 5.8 ± 2.6), were included in this study, 578 male patients (57%) and 434 female patients (43%). A 12-lead ECG was recorded for all patients and the corrected QT interval (QTc) was calculated by Bazett's formula. The probability of LQTS was evaluated by Schwartz criteria and laboratory investigations were done on all patients with long QT interval. RESULTS: In the current study, the mean QTc interval was 411.7 ± 25.3 ms (range 343-675 ms). Twenty-one patients (2.1 %) had probable LQTS; of these, 11 patients had intermediate probability (Schwartz score 1.5-3 points) and 10 patients had high probability (Schwartz score ≥ 3.5 points). CONCLUSION: This study shows that 2.1% of Egyptian children with SNHL in a tertiary care setting have LQTS.

Scar characteristics for prediction of ventricular arrhythmia in ischemic cardiomyopathy.

BACKGROUND: Better risk-stratification tools are needed to identify the best candidates for implantable cardioverter defibrillator implantation. Infarct characterization by cardiac magnetic resonance (CMR) has become an evolving potential tool for risk stratification. OBJECTIVE: We assessed the ability of scar characteristics by CMR in patients with postinfarction left ventricular (LV) dysfunction to predict sustained monomorphic ventricular tachycardia (SMVT). METHODS: Forty-eight patients with postinfarction LV dysfunction underwent CMR study. Twenty-four patients had history of SMVT and the other 24 were control group and underwent electrophysiological study to assess SMVT inducibilty. Various scar characteristics were assessed in the spontaneous SMVT group and were compared with the inducible and noninducible SMVT groups. RESULTS: Only six patients in the control group had inducible SMVT. In univariable analysis, total scar (absolute and as percent of LV), scar core (absolute and as percent of LV), peri-infarct zone (absolute and as percent of LV), mean infarct transmurality, and number of segments with late gadolinium enhancement (LGE) were statistically significant predictors of spontaneous SMVT experience and SMVT inducibility. In multivariable analysis, total infarct as percent of LV mass was the only significant independent predictor of spontaneous SMVT experience (odds ratio [OR] 1.33 per% change, 95% confidence interval [CI] 1.12-1.6, P = 0.001) and SMVT inducibility (OR 1.3 per% change, 95% CI 1.1-1.6, P = 0.004). CONCLUSION: Characterization of myocardial infarct by LGE-CMR, specifically total infarct size, is better predictor of spontaneous SMVT experience and SMVT inducibility than LV ejection fraction.

Idiopathic left ventricular outflow tract ectopy: a single focus with extremely divergent breakouts.

BACKGROUND: Idiopathic ventricular tachycardia (VT) and/or premature ventricular contractions (PVCs) arise most commonly from the right ventricular outflow tract and less frequently from the left ventricular outflow tract (LVOT), either below or above the semilunar valves. CASE PRESENTATION: We report a case of 24-year-old man with idiopathic ventricular tachycardia from a single focus in the supravalvular left ventricular outflow tract with two extremely divergent breakouts observed during the ablation procedure. CONCLUSION: Focal sources of ventricular arrhythmia in the aortic root may have different preferential exits and meticulous activation sequence mapping is the preferable strategy to delineate the site of origin.