[Obstructive sleep apnea syndrome and cardiovascular diseases]. / Syndrome d'apnées obstructives du sommeil (SAOS) et pathologies cardiovasculaires.

Obstructive sleep apnoea syndrome is due to pharyngeal obstruction of inspiratory airflow with preservation of thoraco-abdominal respiratory movements. This disease has been described for about thirty years, but is now the subject of growing interest. According to the increasingly abundant literature on this subject, OSAS is associated with essentially cardiovascular morbidity and mortality (systemic hypertension, pulmonary hypertension, heart failure, coronary heart disease, arrhythmias, cerebral vascular accidents and sudden death). The pathophysiology of its underlying mechanisms and its complications is complex and multifactorial. The diagnosis of this syndrome should be suspected on clinical interview (snoring, excessive daytime drowsiness, and apnoea during sleep) and is confirmed by polysomnography. Nasal continuous positive pressure with elimination of aggravating factors is the reference treatment in 1994. The diagnosis and management of this syndrome requires a multidisciplinary approach with collaboration between general practitioners, neurologists, maxillofacial/ENT surgeons, cardiologists and respiratory physicians.

[Antiarrhythmic treatment after reduction of atrial fibrillation by external shock]. / Traitement antiarythmique après réduction d'une fibrillation auriculaire par choc électrique externe.

Among the drugs recommended to prevent recurrences of atrial fibrillation after external electric shock, antiarrhythmic agents of classes Ia (quinidine, disopyramide), Ic (cibenzoline, flecainide, propafenone) and III (sotalol) seem to have the same effectiveness in maintaining the sinus rhythm in about 50 percent of the cases after 6 months and one year. Amiodarone, seldom used as first-line treatment, appears to be the most effective drug. The percentage of side-effects requiring discontinuation of treatment is the same for all drugs (about 10 percent). All these drugs have potential proarrhythmic effects. In case of recurrence electric shocks can be repeated in some special cases. The therapeutic strategy according to the clinical context (atrial fibrillation of vagal nerve or catecholergic origin, normal or altered left ventricular function) is discussed.

[Value of transesophageal echography in the diagnosis of posterior ventricular septal rupture during the acute phase of myocardial infarction. Apropos of 2 cases]. / Intérêt de l'échographie transoesophagienne dans le diagnostic de rupture du septum interventriculaire postérieur au stade aigu de l'infarctus du myocarde. A propos de 2 observations.

The authors report two cases of posterior ventricular septal defects complicating acute myocardial infarction diagnosed by transesophageal echocardiography. Transesophageal echocardiography was well tolerated confirmed the diagnosis, and enabled accurate evaluation of the shunt in the transgastric view. The anatomical results guided the surgical approach and correlated well with the operative findings.

[Predictive factors of regularization and maintenance of sinus rhythm in chronic atrial fibrillation]. / Les facteurs prédictifs de la régularisation et du maintien en rythme sinusal de la fibrillation auriculaire chronique.

The aim in treating chronic atrial fibrillation, is not limited to simply achieving immediate regularization. What matters, is sustaining the sinus rhythm. The various methods of regularization, using either medical procedures or cardioversion, involve constraints and risks. Investigation of the relapse predicting factor is of great value in evaluating the benefit/risk ratio. For regularization, the absence ultrasound signs of heart disease, an undilated left atrium, recent atrial fibrillation and all forms of heart disease which are curable, albeit surgically, are indicative of success. With regard to prophylaxis, relapses occur more frequently in cases involving mitral valve disease, long-standing atrial fibrillation or a dilated left atrium.

[Embolic complications of chronic atrial fibrillation]. / Les complications emboliques de la fibrillation auriculaire chronique.

Systemic embolism secondary to chronic atrial fibrillation usually affect the cerebral circulation. The risk of a cerebrovascular accident in patients with chronic atrial fibrillation, irrespective of the aetiology, is 1.8 to 7.5 times that of the general population. The embolic risk is 18 times greater in patients with atrial fibrillation related to the rheumatic heart disease. The risk of patients under 60 years of age with idiopathic atrial fibrillation does not seem to be different to that of the general population. The risk of early recurrence of embolism in the first 30 days ranges from 8 to 15%. The risk of late recurrence varies but seems to be higher than that of the general population. The prognosis of embolic cerebrovascular accidents is poor with a 20% mortality rate. The benefits of preventive therapy of embolism with oral anticoagulants have been clearly established in rheumatic atrial fibrillation and in other indications. In non-valvular atrial fibrillation the benefits have to be compared with the risks of treatment. The incidence of hemorrhage due to anticoagulant therapy is between 3 and 5% per year per patient (about 1% of severe haemorrhage). Three randomised studies of primary prevention have shown a significant reduction of the embolic risk in non-valvular atrial fibrillation treated by warfarin compared to patients on placebo. Only one study has shown a significant reduction of the embolic risk in patients under 75 years of age with non-valvular atrial fibrillation treated with 325 mg/day of aspirin. However, anticoagulant therapy does not seem necessary in carefully selected patients under 60 years of age with idiopathic atrial fibrillation (less than 5% of all patients).

[Role of internal cardioversion in the treatment of permanent atrial fibrillation. Early results apropos of 28 cases]. / La place du choc électrique interne dans le traitement de la fibrillation auriculaire permanente. Résultats préliminaires à propos de 28 cas.

Internal cardioversion is a new method of treating atrial fibrillation. It consists in delivering an electric shock between an electrode positioned in the right atrium and a dorsal electrode. A quadripolar electrophysiological catheter is used as the proximal electrode, the two distal poles of which are used to locate the His bundle deflection. Care is taken that the electrode used for cardioversion is not in contact with the atrial wall by using biplane fluoroscopy and unipolar endocavitary recordings. Twenty-eight patients (18 men and 10 women) average age 55 years, underwent this treatment for chronic atrial fibrillation resistant to one or two attempts at external cardioversion. Each patient was given one or two shocks (average 1.68) in the same session. There were 22 immediate reversions to sinus rhythm, giving a primary success rate of 78.57%. Four patients relapsed in the 3 days following the procedure, giving a short term success rate of 64.28%. The minimum effective energy would seem to be 200 joules. The only rhythm complications were sinus bradycardia and/or atrioventricular block lasting a few seconds, both countered by prophylactic ventricular pacing : no traumatic complications due to electric shock were observed. The long term results show sinus rhythm maintained in 66.66% of patients at 6 months and more. In conclusion, internal cardioversion is an effective method of treating cardiac arrhythmias resistant to external cardioversion. The procedure would seem to be reliable and relatively atraumatic. The long term results are promising, particularly the stability of sinus rhythm which seems to be longer than after external cardioversion, by they need further confirmation.