Hemodynamics, biochemical and reflexive changes produced by atenolol in hypertension

Hemodynamic (systemic and regional), metabolic and cardiovascular reflexive variables were measured before and after 4 weeks of beta blockade with atenolol in 10 patients with mild essential hypertension. Atenolol reduced mean arterial pressure, heart rate, cardiac index (all p less than 0.005) and renal vascular resistance (p less than 0.01) and increased total peripheral resistance (p less than 0.005). Glomerular filtration rate and renal blood flow were unchanged; plasma renin activity fell 43%. Reflexive cardioacceleration during the Valsalva maneuver and upright passive tilt was blunted. No changes were observed in circulating fluid volumes. In six patients followed for 1 year, blood pressure and heart rate were maintained at levels similar to those during the first 4 weeks. Atenolol was shown to be an effective oral antihypertensive that has no apparent deleterious hemodynamic effects on the renal and splanchnic circulations.     

Hybrid intravenous digital subtraction angiography of the carotid bifurcation

A hybrid digital subtraction angiography technique and noise-reduction algorithm were used to evaluate the carotid bifurcation. Temporal, hybrid, and reduced-noise hybrid images were obtained in right and left anterior oblique projections, and both single- and multiple-frame images were created with each method. The resulting images were graded on a scale of 1 to 5 by three experienced neuroradiologists. Temporal images were preferred over hybrid images (average score = 3.2 and 2.4, respectively). The percentage of nondiagnostic examinations, as agreed upon by two readers, was higher for temporal alone than temporal + hybrid (4 and 1, respectively). In addition, also by agreement between two readers, temporal + hybrid images significantly increased the number of bifurcations seen in two views (87%) compared to temporal subtraction alone (64%).