Imad Al-Khawaja

Effects of a new vasodilating beta-blocking drug, carvedilol, on left ventricular function in stable angina pectoris

The effects of a new vasodilating beta-blocking drug, carvedilol, were studied in 20 patients with chronic stable angina using a single-blind, placebo-controlled protocol. Two doses of carvedilol, 25 mg twice daily and 50 mg twice daily, were compared with placebo using analysis of variance. The study design consisted of 2 weekly phases of initial placebo followed by carvedilol, 25 mg twice daily and then 50 mg twice daily, and a second placebo period. Supine rest and exercise radionuclide ventriculography was performed at the end of each phase. Carvedilol produced a significant dose-related reduction in rest and exercise heart rate and blood pressure (p less than 0.01 to less than 0.0001). Ejection fraction at rest increased significantly, from a mean (+/- standard error) of 53 +/- 3% with placebo to 58 +/- 3% with carvedilol, 50 mg twice daily, but no improvement was noted in ejection fraction on exercise. Relative, counts-based end-systolic and end-diastolic volumes were significantly reduced at rest (p less than 0.001). Rest peak filling rate index, first-third filling fraction and ejection rate index increased significantly with carvedilol. A dose-related change was observed with rest ejection fraction, peak filling rate index and ejection rate index. Exercise-induced ST-segment depression improved significantly with both doses of carvedilol compared with placebo. Carvedilol was well tolerated and produced significant hemodynamic improvement. This salutary effect on left ventricular function may confer advantages in long-term treatment of patients with chronic stable angina.

Once-and twice-daily bevantolol for systemic hypertension using 24-hour ambulatory intraarterial blood pressure recording

The antihypertensive efficacy of bevantolol, a selective beta 1-adrenoreceptor antagonist, was evaluated in 17 patients with essential hypertension, using continuous ambulatory intraarterial blood pressure (BP) monitoring. The study compared a twice-daily regimen (titrated dose of 200 to 600 mg/day) with the same amount given in a single daily dose. Within-patient comparisons of mean hourly systolic and diastolic BPs and heart rate showed a highly significant effect with twice-daily therapy (p less than 0.001) for all of the 24 hours. Similar significant results were obtained with a single morning dose. There was no difference between the pattern or extent of BP reduction with the 2 regimens. The decrease in BP after bevantolol persisted during the physiologic tests (rest, tilt, isometric and dynamic exercise). Four patients developed minor side effects with the single morning dose, and only 1 patient with the twice-daily regimen. These effects included tiredness, fatigue and dizziness. Unlike pure beta-blocking agents, bevantolol controlled the early morning increase in BP, lending support to the belief that it possesses vasodilatory properties in addition to beta blockade. These results suggest that bevantolol may be useful as first-line therapy in a once-daily dosage for the treatment of essential hypertension.

A comprehensive noninvasive haemodynamic assessment with a single injection of technetium-99M

Summary form only given. In order to identify patients at high risk of subsequent cardiac events after myocardial infarction, 105 patients underwent gated blood pool ventriculography under standard conditions. An automatic program was developed using a mnemonic language and subroutines of a powerful software (F1). Nine-point smoothing and time correction were applied to the raw data and the frames were played in an endless cine display for visual assessment of regional wall motion (RWM). Fourier analysis was used to generate phase and amplitude images. An automatic edge defining algorithm was applied using the second derivative and the local threshold to produce a high-resolution time-activity curve from which the background was subtracted automatically. The analysis was repeated by the same operator and a second operator in 30 cases three months later to assess the reproducibility and repeatability. Patients were followed up for an average period of 19 months. The single most predictive variable of major cardiac events was found to be RWM scores with a sensitivity of 94% and a specificity of 57%.<<ETX>>