[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.