Congenital long-QT syndrome: a case report illustrating diagnostic pitfalls

Jervell-Lange Nielsen syndrome in a family with the long QT Syndrome (LQTS)

A child with Jervell-Lange Nielsen syndrome is presented from Kolkata. Family study showed that the other family members are suffering from long QT syndrome. The child had frequent syncopal attack and very prolonged QT interval requiring left cardiac sympathetic denervation and beta-blocker therapy as patient could not afford implantable defibrillator and cardiac pacing.

Pediatric cardiac disorders

Although pediatric cardiac disorders are not commonly seen in the Emergency Department, they are important to identify to prevent further morbidity or mortality. Diagnosis may be complicated by the lack of classic complaints such as chest pain or palpitations that are commonly associated with cardiac disorders. In fact, presenting complaints associated with pediatric cardiac disorders, like "fussiness" or "difficulty feeding," may seem quite nonspecific. This article reviews pertinent issues concerning diagnosis and management of pediatric cardiac disorders including supraventricular tachycardia, congenital heart disease, prolonged QT syndrome, pericarditis, myocarditis, rheumatic fever, and endocarditis. It also reviews abnormal findings in pediatric electrocardiograms.

Clinical characteristics of 5 Chinese LQTS families and phenotype-genotype correlation

In order to assess the clinical manifestations and electrocardiogram (ECG) characteristics of Chinese long QT syndrome (LQTS) patients and describe the phenotype-genotype correlation, the subjects from 5 congenital LQTS families underwent clinical detailed examination including resting body surface ECG. QT interval and transmural dispersion of repolarization (TDR) were manually measured. Five families were genotyped by linkage analysis (polymerase chain reacting-short tandem repeat, PCR-STR). The phenotype-genotype correlation was analyzed. Four families were LQT2, 1 family was LQT3. Twenty-eight gene carriers were (14 males and 14 females) identified from 5 families. The mean QTc and TDRc were 0.56 +/- 0.04 s (range 0.42 to 0.63) and 0.16 +/- 0.04 s (range 0.09 to 0.24) respectively. 35.7% (10/28) had normal to borderline QTc (< or = 0.460 s). There was significant difference in QTc and TDRc between the patients with symptomatic LQTS and those with asymptomatic LQTS, and there was significant difference in TDRc between the asymptomatic patients and normal people also. A history of cardiac events was present in 50% (14/28), including 9 with syncope, 2 with sudden death (SD) and occurred in the absence of beta-blocker. Three SDs occurred prior to the diagnosis of LQTS and had no ECG record. Two out of 5 SDs (40%) occurred as the first symptom. Typical LQT2 T wave pattern were found in 40% (6/15) of all affected members. The appearing-normal T wave was found in one LQT3 family. Low penetrance of QTc and symptoms resulted in diagnostic challenge. ECG patterns and repolarization parameters may be used to predict the genotype in most families. Genetic test is very important for identification of gene carriers.

Prolonged QT syndrome in children: an uncommon but potentially fatal entity

Prolonged QT syndrome may be either congenital, as in Jervell and Lange-Nielsen or Romano-Ward syndromes, or acquired in nature. Affected children are at risk for syncope, seizures, dysrhythmias and sudden death. Physicians should consider long QT syndrome (LQTS) in all patients who present with syncope. A thorough personal and family history should be documented, with particular attention to prior syncopal episodes, congenital deafness, and unexplained sudden death. Syncope that is either recurrent or induced by exercise or stress is concerning and also should be noted. An electrocardiogram with manual calculation of the QT interval should be performed on all patients with a suggestive history. Furthermore, the diagnosis of LQTS warrants evaluation of all other family members. With recognition and appropriate treatment of affected patients, the potentially fatal consequences of LQTS may be prevented.

Long QT syndrome manifesting as pulseless epilepsy

A-10-year-old child admitted with repeated seizures due to the long QT syndrome is described. The cardiac origin of the epilepsy was suggested by the fact that during the episode of convulsions his peripheral pulses were not palpable.