Naveed Akhtar, Waqas Ahmed, Mehnaz Mehboob


The congenital Long QT Syndrome (LQTS) is characterized by abnormally prolonged ventricular
repolarization due to inherited defect in cardiac sodium and potassium channels, which
predisposes the patients to syncope, ventricular arrhythmias, and sudden cardiac death. Early
diagnosis and preventive treatment are instrumental to prevent sudden cardiac death in patients
with the congenital LQTS. The diagnostic criteria for congenital LQTS are based on certain
electrocardiographic findings and clinical history. Recently genotype specific electrocardiographic
pattern in the congenital LQTS has also been described. Recent studies suggest feasibility of
genotype specific treatment of LQTS and, in near future, mutation specific treatment will probably
become a novel approach to this potentially fatal syndrome. We describe two cases that fulfilled
the electrocardiographic and historical diagnostic criteria with morphology on electrocardiogram
(ECG) suggestive of LQT1 genotype.
Keywords: Congenital LQTS, ECG, genotype, pregnancy

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Chiang CE, Roden DM. The long QT syndromes: genetic basis

and clinical implications. J Am Coll Cardiol 2000; 36:1-12.

Scwartz PJ. The long QT syndrome. Circulation 1993;88:782-

Zhang G, Timothy KW, Vincent GM. Spectrum of ST-T-wave

patterns and repolarization parameters in congenital long-QT

syndrome: ECG findings identify genotypes. Circulation 2000;


Moss AJ, Zareba W, Benhorin J. ECG T-wave patterns in

genetically distinct forms of the hereditary long QT syndrome.

Circulation 1995;92:2929-34.

Moss AJ, Zareba W, Kaufman ES. Increased risk of

arrhythmic events in long QT syndrome with mutations in the

pore region of the human ether-a-a-go-go-related gene

potassium channel. Circulation 2002; 105:794-9.

Priori SG, Napolitano C, Schwartz PJ. Low penetrance in the

long QT syndrome: clinical impact. Circulation 1999; 99:529-

Viskin S. Long QT syndromes and torsades de pointes. Lancet


Donger C, Denjoy I, Berthet M. KVLQT1 C-terminal

missense mutation causes a forme fruste long-QT syndrome.

Circulation 1997;96:2778-81.

Dofetilide product monograph and confirmation of education.

New York, NY: Pfizer Inc; March 2000.

Rashba EJ, Zareba W, Moss AJ, Hall WJ, Robinson J, Locati

EH, et al. Influence of pregnancy on the risk of cardiac events

in patients with hereditary long QTsyndrome. LQTS

investigators. Circulation 1998; 97:451-6.

Zareba W, Moss AJ, Schwartz PJ, Vincent GM, Robinson JL,

Priori SG, et al. Influence of genotype on the clinical course of

the long QT-syndrome. International Long QT Syndrome

Regisrty Research Group. N Engl J Med 1998;339:960-5.

Schwartz PJ, Priori SG, Spazzolini C, Moss AJ, Vincent GM,

Napolitano C, et al. Genotype-phenotype correlation in the

long-QT syndrome: gene-specific triggers for life-threatening

arrhythmias. Circulation 2001;103:89-95.

Moss AJ, Zareba W, Hall WJ, Schwartz PJ, Crampton RS,

Benhorin J, et al. Effectiveness and limitations of beta-blocker

therapy in congenital long-QT syndrome. Circulation


Scwartz PJ, Priori SG, Locati EH, Napolitano C, Cantu F,

Towbin JA, et al. Long QT syndrome patients with mutations

of the SCN5A and HERG genes have differential responses to

Na channel blockade and to increases in heart rate.

Implications for gene-specific therapy. Circulation 1995;



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