[Relations between antihypertensive and vascular effects of nitrendipine]. / Relations entre les effets antihypertenseurs et vasculaires de la nitrendipine.

We have realized an unicentric prospective study to assess the effects of Nitrendipine on carotid circulation and arterial blood pressure (BP) in essential, permanent, uncomplicated arterial hypertension. This randomized, double blind versus placebo trial concerned 21 mild to moderate hypertensive patients (pts) (WHO advices) aged from 35 to 65 years. After a 15 days washout, the pts were randomized in two groups: 11 pts received a 20 mg Nitrendipine tablet once a day and 10 pts received a placebo. BP control and ultrasonic carotid flowmetry were performed at J0 and J30. At J30, BP was normalized for 55% of pts under NT (versus 30% for placebo). This result correspond to a very significative decrease for systolic and diastolic BP and differential BP (Dif BP) without reflex tachycardia, under Nitrendipine, opposite to placebo. Ultrasonic carotid flowmetry variations are not significative excepting common carotid vasodilation under Nitrendipine. Under Nitrendipine, at J30, 5 pts show a decrease of a least 15% of the cerebral vascular resistances (responding patients); and 6 pts do not show any significative decrease of cerebral vascular resistances. For the responding pts, arteriolar vasodilation is then correlated to the decrease of BP and Dif BP, to the increase of carotid blood flow and to the arterial vasodilation; while there is no significative decrease of BP for non responding pts. It suggests an improvement of arterial compliance by a direct action on the arterial wall. Furthermore, inspite of a drop in diastolic parietal tension, there is not any group showing reflex tachycardia. Thus, antihypertensive efficacy of Nitrendipine seem to be principally subordinated to the improvement of arterial compliance.(ABSTRACT TRUNCATED AT 250 WORDS)

[Rhythm complications of radiotherapy. Apropos of a case]. / Complications rythmologiques de la radiothérapie. A propos d'un cas.

We are reporting a case of complete atrio-ventricular block following radiotherapy; this diagnosis was made after ruling out other etiologies. In relation with this case, we are discussing the different rhythm complications of radiotherapy. Therefore, we are presenting tissue involvements, revealed either by minimal electrocardiographic alterations, or by rhythm or conduction disorders, insisting on atrio-ventricular blocks. Finally, we are insisting on a recent disease, cardiac pacemaker dysfunctions, induced by radiotherapy, from in vitro studies and clinical cases.

[Prinzmetal's syncopal angina during an electroencephalogram. Triggering role of the hyperpnea test]. / Angor de prinzmetal syncopal au cours d'un électroencéphalogramme. Rôle déclenchant de l'épreuve d'hyperpnée.

We are reporting a cardiac arrest occurring during an electroencephalogram with hyperventilation. The diagnosis is made on the Holter recording which shows a Prinzmetal's angor tracing followed with ventricular arrhythmias, leading to asystoly. The physiopathology of the spasm is not clear and we are discussing the possible mechanisms. We stress again the harmful role of beta-blockers in this pathology. In addition, we insist on electrocardiographic manifestations surrounding sudden death. As for the hyperventilation test, its potential risks call for caution during its performance.

[Veno-occlusive disease of the lung]. / La maladie veino-occlusive du poumon.

This paper is a review of current data on a rare pathology which causes primary pulmonary arterial hypertension: pulmonary veno-occlusive disease. The manifestations of the disease consist of dyspnoea of progressive onset, crepitations in the lower pulmonary lobes and diffuse interstitial syndrome with Kerley's B lines. These signs are associated with severe hypoxia and severe pulmonary arterial hypertension with paradoxically normal wedge pressure. Pathological specimens must be obtained to confirm the diagnosis. They show thrombosis of pulmonary veins less than 2 mm in diameter and sometimes of arterioles, presence of connective tissue with few cells and images of recanalization, muscularization of pulmonary arterioles, lesions of interstitial nodular fibrosis and presence of haemosiderin-rich macrophages. The disease is frequently associated with other pathologies, including heart disease, blood disease and pulmonary capillary haemangiomatosis. In recent years, veno-occlusive disease has been found to occur immediately after chemotherapy for cancer and bone marrow or kidney transplantation. Three physiopathological hypotheses have been put forward to explain the disease: infection, autoimmune reaction and toxic reaction.

[Effects of nifedipine on carotid blood flow and baroreflex response in essential arterial hypertension. Preliminary results]. / Effet de la nifédipine sur le débit carotidien et la réponse baroréflexe, au cours de l'hypertension artérielle essentielle. Résultats préliminaires.

The objective of this prospective study was to evaluate the effect of nifedipine administered at usual daily doses of 30 to 40 mg on the carotid flow in arterial hypertension. The study included 15 patients (8 men and 7 women), 50 to 79 (mean 59.5) years old suffering from long-standing, fixed essential hypertension becoming instable under central antihypertensive drug therapy. For calculating the carotid blood flow, vascular echotomography combined with Doppler ultrasonography and spectral analysis (Duplex probe) determining the vascular section and flow velocity were used. Arterial pressure using a mercury tonometer, flow velocity, common carotid artery diameter, carotid blood flow, Pourcelot's index, parietal tension and heart rate were measured before treatment and at the 8th day of nifedipine administration. It could be shown that the drug produced a significantly (p less than 0.001) increased carotid blood flow, in spite of a marked (p less than 0.001) decrease in systolic (p less than 0.001) and diastolic (p less than 0.005) blood pressure. The increase in carotid blood flow was directly related to the increase in flow velocity (p less than 0.001) and in the diameter of common carotid artery (p less than 0.01) and was associated with a significant decrease in the Pourcelot's index. Analysis of two groups of patients isolated from the total group according to the elevation of carotid blood flow, showed that the degree of hypotensive effect of nifedipine is negatively correlated with the baroreflex response determined by the variation of parietal tension.(ABSTRACT TRUNCATED AT 250 WORDS)