Mitochondrial tRNA glutamine variant in hypertrophic cardiomyopathy.

BACKGROUND: Mitochondria play critical roles in both the life and death of cardiac myocytes. Pathogenic mitochondrial DNA (mtDNA) mutations leading to mitochondrial dysfunction can cause cardiomyopathies (CMPs). Our aim was to investigate the underlying mitochondrial defect in a patient with hypertrophic cardiomyopathy (hCMP). A detailed clinical and molecular genetic analysis was performed. PATIENTS AND METHODS: Total DNA was extracted from lymphocytes in a 14-year-old index male patient with hCMP, preexcitation syndrome, and severe ventricular arrhythmias. Direct sequencing of the PCR fragments was performed. To distinguish deleterious from functionally neutral variants, the ClustalW program, RNAfold software, and PolyPhen algorithm were applied, which predict the pathogenicity of a particular variant by using a set of empirical rules based on the nature of the mutation, the phylogenetic conservation of the variant, and the physicochemical property of the amino acid. RESULTS: The mutational analysis of mtDNA genes revealed four variants. The m.4395A>G transition (C6G) in the MT-TQ gene, which altered an evolutionary conserved nucleotide, with a conservation index of 85.7 % and affected a highly conserved U.G base pair in the secondary structure of MT-TQ. Additionally, the previously reported polymorphisms m.14757T>A, m.15236A>G, and m.15314G>A resulting in the replacement of amino acid residues in the MT-CYB gene were detected. CONCLUSION: The m.4395A>G variant was scored as possibly pathogenic and may exert a negative effect on heart function to generate hCMP.

[Interruption of the aortic arch with no patent ductus arteriosus: is survival possible?]. / Interruption de l'arche sans canal artériel : la survie est-elle possible ?

Interruption of the aortic arch is a rare congenital disease. It is defined by the complete interruption between the ascending and descending aorta. A patent ductus arteriosus is necessary to maintain flow from the pulmonary to the descending aorta. Its closure leads to a cardiovascular collapse and this malformation is therefore duct-dependent. However, in rare cases, survival remains possible even after ductus arteriosus closure. We report such a case.

Successful pregnancy and delivery in a woman with a single ventricle and Eisenmenger syndrome.

BACKGROUND: Patients with a single ventricle represent a rare abnormality found in 1% of patients with congenital heart disease, often discovered during childhood. Without pulmonary stenosis, the disease can progress to fixed pulmonary hypertension. Both pregnancy and delivery are risky events capable of increasing the right-to-left shunt. Pregnancy is contraindicated. CASE: We report the case of a 27-year-old woman with a single ventricle without pulmonary protection and fixed pulmonary hypertension at 60 mmHg, discovered during a pregnancy. The delivery was obtained by cesarean section with epidural anesthesia and the patient was perioperatively treated with nitric oxide. Though contraindicated, pregnancy and delivery were successfully achieved in this patient. COMMENT: Patients with single ventricle and Eisenmenger syndrome rarely reach adult life. Pregnancy with this condition is exceptional and fundamentally perturbs hemodynamic stability. In spite of the development of anesthesia and resuscitation and the description of some cases in literature, pregnancy with Eisenmenger syndrome is contraindicated.

HLA class II polymorphisms in Tunisian patients with dilated cardiomyopathy.

Cardiomyopathies (CMs) are primary disorders of cardiac muscle. They are a major cause of morbidity and mortality for all ages and, like acquired forms of cardiovascular disease, often result in heart failure. Molecular genetic studies have made remarkable progress in defining the pathogenesis of CM. The present study was the first report to evaluate the relationship between class II major histocompatibility complex (MHC) genes (HLA-DRB1 and HLA-DQB1) and the genetic susceptibility to primary dilated cardiomyopathy (DCM) in Tunisian patients. The human leukocyte antigen (HLA)-DRB1 and -DQB1 alleles were analyzed in 76 patients with primary DCM and 111 ethnically matched healthy controls using polymerase chain reaction-sequence specific primers technique. An increased frequencies of HLA-DRB1*0401 (OR = 2.67, P < 0.001), HLA-DQB1*0302 (OR = 3.28, P = 0.001) and HLA-DQB1*0401 (OR = 6.26, P = 0.005) alleles were found in the patients with primary DCM compared with healthy controls. Individuals with HLA-DRB1*1301 (OR = 0.24, P < 0.001) and HLA-DQB1*0201 (OR = 0.49, P = 0.002) alleles have a protective effect against primary DCM. Two haplotypes were associated with increased risk of primary DCM: DRB1*0401/DQB1*0302 (OR = 4.53, P = 0.002) and DRB1*0401/DQB1*0401 (OR = 9.42, P = 0.004). In conclusion, our data suggest that the variation in class II HLA alleles could be a genetic factor involved in the susceptibility to primary DCM in the Tunisian population.

[Diverticulum of the left atrium detected antenatally. Management of a case]. / Diverticule de l'oreillette gauche découvert en anténatal. Conduite a tenir a propos d'un cas.

Cardiac diverticulae are rare, most often affecting the ventricles rather than the atria. We report the case of a diverticulum of the left atrium discovered during routine fetal echocardiography. The diagnosis was confirmed at birth with cardiac echography and an MRI. In view of the patient's age and asymptomatic nature, it was decided to defer surgery and to observe the infant with regular echocardiography. Surgery was eventually performed via a left thoracotomy after the appearance of signs of cardiac compression, and there were no complications in the post-operative period.

[Predictive factors for late complete atrio-ventricular block after surgical treatment for congenital cardiopathy]. / Facteurs prédictifs de bloc auriculo-ventriculaire complet tardif après traitement chirurgical des cardiopathies congénitales.

The late occurrence of complete atrio-ventricular block (CAVB) after cardiac surgery is rare but potentially responsible for cases of late sudden death. We searched for factors allowing prediction of this complication, retrospectively reviewing the case notes of 11 patients in hospital with complete AVB, 2 months to 10 years after correction of a cardiac malformation. All had a normal pre-operative ECG. The diagnosis had been made based on symptoms in 8 patients: syncope or collapse (4 cases) symptoms on effort (3 cases) or fatigue (1 case). In the others the diagnosis had been made on ECG. The block was infra-His in 5 patients who had electrophysiology. ECG analysis showed that all the patients had CAVB immediately post-operatively lasting 3-14 days. After restoration of conduction the ECGs showed the following anomalies compared to the pre-operative ECGs: long PR (1 case), long PR + right bundle branch block (2 cases), long PR + left axis deviation (1 case), RBBB + left deviation or rotation of the QRS axis (3 cases), long PR + RBBB + left axis deviation (4 cases). All of these patients had been fitted with a cardiac stimulator. In conclusion, the children who had CAVB immediately post-operatively lasting more than 48 hours and who then had an ECG showing different QRS compared to the pre-operative QRS and/or long PR had a risk of late complete AVB. These patients should have electrophysiology and a stimulator must be implanted in those who have an infra-His block.

[Complete repair of a corrected transposition of the great vessels by double switch. A case report]. / Réparation complete de la transposition corrigée des gros vaisseaux par double switch. A propos d'un cas.

We report the observation of a female patient with a corrected transposition of the great arteries, ventricular septal defect and complete atrio-ventricular block. This complex cardiac disease originated heart failure and was discovered at the age of 4 months. This baby has been operated at the age of 7 months, in April 1998. She had a complete repair by the double switch, closure of the ventricular septal defect and implantation of a permanent pace-maker. Short term results are favorable. Total repair of the corrected transposition of the great arteries is currently possible thanks to the recent technique of the double switch. It remains a difficult operation but with satisfactory short term results.

[Cavopulmonary shunts: apropos of 40 observations]. / Derivations cavopulmonaires: a propos de 40 observations.

Fourty patients with univentricular heart, underwent a cavopulmonary shunt procedure. The majority have an excellent hemodynamic status with ventricular end diastolic pressure > 12 mmHg and a mean pulmonary artery pressure > 15 mmHg. However, 11 patients have ventricular dysfunction, 9 have an incompetent systemic atrio-ventricular valve and 6 have mean pulmonary artery pressure > 15 mmHg. The pulmonary arteries were of a good size in all cases with a Nakata index > 100 mm2/m2. Cavopulmonary connections are satisfactory palliative procedures in the treatment of univentricular cardiac disease.