[Cardiac ion channel disorders--diagnosis and treatment]. / Kardiale kanalopatier--diagnostikk og behandling.

BACKGROUND: Inherited arrhythmogenic disorders are a group of genetically determined diseases characterised by ventricular tachyarrhythmias sometimes leading to sudden death. The molecular bases of these disorders are mutations in genes coding for various cardiac ion channels. The most common cardiac ion channel disease is the long QT syndrome. This syndrome is rare, but probably more common in Norway than previously expected. We have recently started genetic testing for cardiac ion channel disorders at Rikshospitalet University Hospital in Oslo. This review describes the current understanding of the etiology, prognosis and management of cardiac ion channel disorders, based on literature and our own clinical experience. INTERPRETATION: Cardiac ion channel disorders may lead to sudden cardiac death. Prophylactic and life-saving therapies are available for many of these disorders. Therapy and risk stratification depend on the clinical presentation, the ECG pattern, and which gene is mutated. Genetic testing offers the opportunity to exclude individual family members as mutation carriers.

Congenital absence of the pericardium: case presentation and review of literature.

Congenital absence of the pericardium is an uncommon finding that may or may not be symptomatic. Asymptomatic patients are discovered incidentally during cardiac surgery for an unrelated condition or postmortem. However, symptomatic patients may experience non-exertional paroxysmal stabbing chest pain. It may occur with other cardiac or extracardiac abnormalities and a variety of imaging modalities may identify the condition. Complete cases are more rare than partial effects. However, complications are more common with partial absence due to strangulation of the heart into the defect thus requiring surgical intervention.

Brugada syndrome: from cell to bedside.

Since its introduction as a new clinical entity in 1992, the Brugada syndrome has attracted great interest because of its high incidence in many parts of the world and its association with high risk for sudden death in infants, children, and young adults. Recent years have witnessed an exponential rise in the number of reported cases and a striking proliferation of articles serving to define the clinical, genetic, cellular, ionic, and molecular aspects of the disease. A consensus report published in 2002 delineated diagnostic criteria for the syndrome. A second consensus conference was held in September 2003. This review provides an in-depth overview of the clinical, genetic, molecular, and cellular aspects of the Brugada syndrome, incorporating the results of the two consensus conferences, and the numerous clinical and basic publications on the subject. The proposed terminology, diagnostic criteria, risk stratification schemes, and device and pharmacologic approach to therapy discussed are based on available clinical and basic studies and should be considered a work-in-progress that will without doubt require fine-tuning as confirmatory data from molecular studies and prospective trials become available.

The electrocardiogram during sinus rhythm and tachycardia in patients with Mahaim fibers: the importance of an "rS" pattern in lead III.

OBJECTIVES: The purpose of the study was to identify the electrocardiographic (ECG) characteristics of the Mahaim fiber. BACKGROUND: Mahaim fibers are slowly conducting accessory pathways reaching into the right ventricle. They often play a role in tachycardias. METHODS: We retrospectively analyzed 40 patients with Mahaim fibers. Five patients had associated Wolff-Parkinson-White syndrome and were excluded from the study. Two patients had a short atrioventricular decremental accessory pathway and were also excluded. The remaining 33 patients had a tachycardia with anterograde conduction over a Mahaim fiber. Twenty were female. Their mean age was 24 +/- 10 years. RESULTS: The most common pattern of minimal preexcitation during sinus rhythm was an rS pattern in lead III. This was found in 20 patients. There was a match between the presence of rS in lead III during sinus rhythm and left axis deviation during tachycardia with anterograde conduction over the Mahaim fiber. After ablation, a different QRS pattern emerged in lead III, indicating the absence of conduction over the Mahaim fiber. To obtain information on the prevalence of an rS pattern in lead III in age-matched controls with palpitations and without structural heart disease, the 12-lead ECG of 200 young individuals were examined. An rS pattern in lead III was found in 6%. CONCLUSIONS: A narrow QRS with an rS pattern in lead III during sinus rhythm in a patient with a history of palpitations should alert the physician to the possibility of a Mahaim fiber. During tachycardia, these patients typically show a left bundle branch block-like QRS complex with left axis deviation.

Pulmonary hypertension due to spontaneous premature ductal constriction in fetal life: association with right bundle branch block.

We describe a case of fetal pulmonary hypertension and tricuspid regurgitation due to non pharmacologically induced ductal constriction observed at 36 weeks' gestational age. The hypertension resolved spontaneously soon after birth, with no functional consequences. Right bundle branch block is the only permanent anomaly, still being seen on the electrocardiogram at the age of 34 months.

Progressive disease of the atrioventricular conduction axis in an infant of an anti-Ro positive mother.

A child of a mother with maternal anti-Ro and anti-La antibodies presented antenatally with abnormal myocardial function, and was found to have a first degree heart block at birth. The extent of the abnormality in the conduction system progressed, with appearance of left bundle branch block in addition to further prolongation of PR interval. A pacemaker was implanted prophylactically, but patient has remained well, with no further deterioration in her atrioventricular conduction.

[Clinical and molecular genetics of familial bundle branch block related to chromosome 19]. / Génétique clinique et moléculaire d'un bloc de branche familial lié au chromosome 19.

Four large Lebanese families were observed for several years and over several generations which enabled the authors to describe the clinical electrocardiographic and prognostic features of a hereditary conduction defect and to locate the culprit gene at 19q 13.3. The ECG showed a healthy group and an affected group (mainly right bundle branch block, hemiblocks or complete AV block) and an undetermined group with minor QRS changes in the right precordial leads. The mode of transmission was autosomal dominant. The estimation of penetration in the observed pedigrees and in previously published pedigrees gave a value of 70% in men and 50% in women. There were, therefore, many healthy carriers of the mutation. The onset was congenital (8 babies aged 15 days to one year were affected). Healthy carriers followed up for 10 to 20 years remained normal. The clinical and ECG features progressed in 19% of subjects in the undetermined group. The changes progressed to complete AV block in 8% of affected subjects, both babies and adults. Several cases of sudden infant death were reported but were not documented. The detection of the culprit gene was made by genetic mapping. Markers situated at q 13.3 on chromosome 19 showed linkage. The haplotype related to the pathology was always present in the affected subjects. The genetic interval was 7 centiMorgans.

[Malignant ventricular arrhythmia in congenital aneurysms of the left ventricle in adulthood]. / Maligne ventrikuläre Arrhythmien bei kongenitalen Aneurysmen des linken Ventrikels im Erwachsenenalter.

Congenital aneurysms of the left ventricle (ALV) are rare cardiac lesions. Beyond that an association with malignant ventricular arrhythmias (MVA, symptomatic ventricular tachycardia--VT or ventricular fibrillation--VF) is reported only in sporadic cases. Since 1988 we had the opportunity to study 5 patients (pts) with MVA (4 sustained VT, 1 VF; 1 female, 4 males; mean age 38 years) without cardiovascular risk factors, history of myocardial infarction, trauma or inflammatory disease. Left ventricular contrast angiography and echocardiography disclosed ALV's. At programmed electrical stimulation clinically documented MVA (4 VT, 1 resuscitated VF) were reproducible in all 5 cases, the respective VT was located in the area of the ALV in 4 cases. In 2 pts aneurysmectomy combined with subendocardial resection and cryotherapy (1 apical, 1 posterobasal ALV) was performed. In both pts histopathology confirmed a congenital disorder, without evidence of inflammatory lesions. In 2 pts MVA was controlled with antiarrhythmic therapy. The pt with VF and an ALV adjacent to the anulus of the aortic valve received an implantable cardioverter defibrillator. In congenital aneurysms of the left ventricle complicated by malignant ventricular arrhythmias surgical intervention offers a potential cure in selected cases.

Concealed paroxysmal atrioventricular block: diffuse congenital atrioventricular conduction system disorder with nonpropagated His bundle depolarizations.

A 2 1/2-year-old girl with bradycardia and left bundle branch block at birth began to experience "night cries" when deeply asleep. Electrophysiological study demonstrated congenital diffuse atrioventricular conduction disease with concealed paroxysmal atrioventricular block, nonpropagated His bundle depolarizations, severe sinus node abnormality, and a low atrioventricular junctional escape rhythm with probable reciprocation. After pacemaker implant, the "night cries" ceased.

Incidência da transmissäo congênita na doença de Chagas / Incidence of congenital transmission in Chagas' disease

Estudou-se a incidência da transmissäo congênita da doença de Chagas em um grupo de 129 indivíduos que näo tiveram possibilidade de contrair a doença pelos meios habituais, filho de 45 mäes portadoras da forma crônica da moléstia. Observou-se que apenas quatro apresentaram as três reaçöes sorológicas positivas (reaçäo de fixaçäo do complemento, teste de hemaglutinaçäo e teste de imunofluorescência), dando uma incidência percentual de 3%, vista na populaçäo estudada. Um deles encontra-se na forma cardíaca e outros três na forma indeterminada. Chama-se a atençäo para a falta de relaçäo entre o quadro clínico do filho em relaçäo ao da mäe e para esta forma, que poderá vir a ter maior importância no futuro, na medida em que as outras formas de transmissäo sejam controladas