[Prognostic significance of second and third degree atrioventricular block in acute inferior wall myocardial infarction]. / Valeur pronostique du bloc auriculoventriculaire du deuxième et du troisième degré au cours de la phase aiguë de l'infarctus du myocarde inférieur.

High degree atrioventricular block complicates inferior wall acute myocardial infarction in 10 to 15% of cases. Its significance is still controversial. In this study, we have analysed 152 observations of acute inferior wall myocardial infarction during hospitalisation period. The mean age of our patients is 60 years, 48.7% of them have received fibrinolytic treatment. Second or third degree atrioventricular block was detected in 33 cases (21.7%). Mortality is higher in inferior wall myocardial infarctions with atrioventricular block than in those without atrioventricular block (12% versus 2.5%, p < 0.05). Hemodynamic complications like cardiogenic shock due to the extension of the infarction to the right ventricle and left ventricle insufficiency are more frequent (18% versus 3.4%, p < 0.01 and 12% versus 3.5%, p < 0.01 respectively). It appears that the infracted mass of myocardium is larger in case of atrioventricular block, this is assessed by comparing the average value of the peak of creatine Kinase in the two groups with and without atrioventricular block (1534 IU versus 1096 IU, p < 0.02) and by considering the rate of low ejection fraction (EF < 40%) in each group (44.6% versus 16%, p < 0.01). In our study, we note that thrombolysis does not affect the incidence of atrioventricular block (19% and 24% in thrombolyed and not thrombolyzed patients respectively) but it seems that thrombolysis improves the outcome of these patients. The occurrence of atrioventricular block in acute inferior wall myocardial infarction is related to the presence of an important right coronary artery that is occluded, the recanalisation of this vessel leads often to rapid regression of the block that is no longer pejorative.

[Indications for definitive cardiac stimulation]. / Indications de la stimulation cardiaque definitive.

Within less than a half-century, after the early rising of cardiac pacing, we witness a dramatical in crease of its indications. After the initial aim, which was to prevent transient ischaemic events, and sudden death due to bradycardia, some more physiological objectives have--progressively appeared, such as improvement of patient's quality of life, and optimization of the cardiac performance to fulfill the metabolic needs. The indications of cardiac pacing are nowadays extended to the fields of haemodynamics and rythmology. Numerous studies are advocating the interest of the cardiac pacing in pathologies such as obstructive and dilated cardiomyopathies specially for the improvement of the NYHA functional status, life comfort and effort sustain. On another hand, newly discovered antiarrhythmic virtues of atrial pacing are of a great interest for a certain type of atrial fibrillations such as vagal induced fibrillations, atrial diseases and atypical flutters. For conclusion: after becoming mandatory for bradycardias, cardiac pacing is conquering new indications on the fields of arrhythmias and cardiomyopathies. Within a close future, scientific evidences could definitely validate çardiac pacing using on these new fields.