Evaluation of left ventricular mass and diastolic function in the treatment of hypertension with beta blockers [abstract]

Arterial hypertension is associated with left ventricular hypertrophy (LVH), and LVH increases the risk for cardiovascular morbidity and mortality. Selected antihypertensive agents have been shown to reverse LVH. In this study, the effects of celiprolol, a selective á1 blocker with partial agonist activity on á2 receptors and propranolol, a non-selective á-blocker, on blood pressure, left ventricular mass of diastolic function were compared. In a prospective study, twenty-nine patients with mild to moderate hypertension were randomly allocated to treatment with either celiprolol or propranolol for twelve weeks, after a three-week drug washout period. Cross-sectional doppler echocardiography was performed for the measurement of left ventricular mass and pulse doppler studies done for evaluation of left ventricular diastolic function. At the end of the study, both celiprolol and propranolol significantly reduced the diastolic blood pressure, while only celiprolol significantly reduced the systolic blood pressure. In the celiprolol group, there was a greater decrease in the left ventricular mass (7.9 percent) compared to the propranolol group (0.3 percent), but this was not significant. Doppler studies established that propranolol caused no significant change in the E/A ratio, while celiprolol caused a significant increase in the E/A ratio (p= 0.01). Propranolol increased the deceleration time (DT) (p= 0.001), while celiprolol decreased the isovolumetric relaxation time (IVRT) (p= 0.002) and increased the pulmonary venous A wave width (P= 0.02). In conclusion, short-term treatment with celiprolol demonstrated a trend towards decreasing the left ventricular mass, and caused significant improvement in left ventricular diastolic function, while propranolol did not. This may be due to the observation that celiprolol reduces total peripheral resistance by vasodilation. Treatment with celiprolol over a longer interval may result in significant reduction of left ventricular mass. (AU)

Use of magnesium sulphate as adjunctive therapy for resection of phaeochromocytoma

The intraoperative control of cardiovascular disturbances associated with the resection of phaeochromocytoma is traditionally achieved by the use of deep anaesthesia in conjunction with A and B blockers, calcium antagonists, nitroglycerine or sodium nitroprusside. We report the successful use of magnesium sulphate as adjunctive therapy in the control of the cardiovascular consequences associated with surgical resection of a phaeochromocytoma in a patient.(Au)

Use of magnesium sulphate as adjunctive therapy for resection of phaeochromocytoma

The intraoperative control of cardiovascular disturbances associated with the resection of phaeochromocytoma is traditionally achieved by the use of deep anaesthesia in conjunction with A and B blockers, calcium antagonists, nitroglycerine or sodium nitroprusside. We report the successful use of magnesium sulphate as adjunctive therapy in the control of the cardiovascular consequences associated with surgical resection of a phaeochromocytoma in a patient.

Central cholinergic involvement in the mediation of spontaneous motor activity in rats

Spontaneous motor activity of preweanling rats (14-day-old) was examined in an activity cage following the administration of atropine at 1.0, 2.5, 5.0, and 10.0 mg/kg respectively. Compared with saline-control animals, atropine at these dosages, did not significantly affect the activity level of the 14-day-old rat. The motor activity of 14-20-day-old rats was also measured following the administration of atropine (10mg/kg) in the Y-maze and the activity cage. The activity level was significantly decreased in (a) all ages in Y-maze and (b) the 18-day-old animals only in the activity cage. In contrast, amphetamine (2.0, 4.0, and 10.0 mg/kg) induced significant increments in spontaneous motor activity. It is suggested that a cholinergic mechanism concerned with the modulation of central nervous system arousability becomes functional at 18 days of age, that is, subsequent to a more caudal arousal inducing mechanism, which seems to be mediated by a catecholaminergic system (AU)