Double-blind controlled study of rilmenidine versus hydrochlorothiazide in mild hypertension: clinical and renal haemodynamic evaluation.

Clinical and renal haemodynamic parameters were evaluated in 20 mild hypertensive patients after rilmenidine (RIL) administration during a one month double-blind randomised study compared with hydrochlorothiazide (HCT). At the beginning and at the end of the study, BP, heart rate and renal haemodynamic parameters were evaluated. Renal haemodynamic parameters included effective renal plasma flow (ERPF) evaluated by radionuclide study utilising 131I-Hippuran according to Schlegel's method, effective renal blood flow (ERBF = ERPF/(1-Ht)), glomerular filtration rate (GFR) by creatinine clearance, filtration fraction (FF = GFR/ERPF) and renal vascular resistances (RVR = DBP x 80/ERBF). RIL and HCT significantly (P < 0.01) reduced systolic, diastolic and mean blood pressure without relevant change in ERPF, ERBF, GFR and FF. RVR was significantly reduced both in the RIL group (P < 0.002 vs. baseline) and in the HCT group (P < 0.001 vs. baseline). No relevant side-effects were observed in either group. In conclusion, rilmenidine was effective in reducing BP in mild hypertensive patients and produced favourable effects on renal function.

Clinical and haemodynamic effects of ketanserin in lean and obese hypertensive patients.

Systemic and central haemodynamics were evaluated in 10 lean and 10 obese hypertensive patients (World Health Organization stage I-II) after treatment for 8 weeks with a serotoninergic antagonist, such as ketanserin. Blood pressure and heart rate were recorded and first-pass radionuclide angiocardiography was performed to determine cardiac output, cardiac index and ejection fraction of the left ventricle; total peripheral resistance was also calculated. In both obese and lean patients, ketanserin significantly reduced diastolic (P less than 0.05) and mean (P less than 0.005) blood pressure but no significant changes in systolic blood pressure, cardiac output, cardiac index and ejection fraction were observed in lean and obese hypertensive patients. Total peripheral resistance was significantly (P less than 0.05) reduced in lean patients but in obese hypertensives it was only moderately reduced. It is concluded that monotherapy with ketanserin is effective in treating mild to moderate hypertension in both lean and obese hypertensive patients, without interfering with left ventricular performance.

Effect of obesity on left ventricular function studied by radionuclide angiocardiography.

Several studies have shown a significant association of obesity with cardiovascular morbidity and mortality. The present study was carried out to investigate central and systemic haemodynamics in overweight and moderate obese, but otherwise healthy subjects, and in a lean control group to determine whether obesity can influence left ventricular performance per se. In this study an attempt has been made to eliminate misleading factors, such as diabetes, lipid abnormalities and hypertension. A total of 67 subjects, 44 with overweight or moderate obesity and 23 lean healthy subjects, were included. Patients were divided into three groups according to BMI levels and Garrow's criteria as follows: lean control group (BMI less than 25 kg/m2); overweight (BMI from 25 to 30 kg/m2); moderate obese (BMI greater than 30 less than 40 kg/m2). Overweight and moderate obese subjects were further subgrouped according to duration of obesity (DO) in subgroup A (DO less than 98 months) and in subgroup B (DO greater than 98 months). Haemodynamic assessment was performed using first pass radionuclide angiocardiography. When compared with lean subjects, overweight and moderate obese subjects were characterized by a significant increase in cardiac output (CO), stroke volume (SV), end diastolic volume (EDV), end systolic volume (ESV), total blood volume (TBV) and total plasma volume (TPV) and by a significant decrease in left ventricular ejection fraction (EF); some of these changes appeared to be related to the degree of obesity. In overweight and moderate obese subjects, total peripheral resistance (TPR) was lower than in lean controls, but this difference was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical and hemodynamic effects of medium-term ketanserin treatment in 2 compared groups of obese and non-obese hypertensive patients]. / Effetti clinici ed emodinamici del trattamento a medio termine con ketanserina in due gruppi di ipertesi obesi o non obesi posti a confronto.

We evaluated systemic and central hemodynamics in 10 lean hypertensives and in 10 obese hypertensives (WHO stage I-II) after 8 weeks treatment regimen with a serotoninergic antagonist such as ketanserin. At the beginning and at the end of the study, body weight, BMI, blood pressure and heart rate were measured and a first pass radionuclide angiocardiography was performed to determine cardiac output, cardiac index and ejection fraction of left ventricle. Total peripheral resistances were also calculated. In both hypertensive groups ketanserin significantly reduced diastolic (p less than 0.05) and mean (p less than 0.005) blood pressure. No significant change in systolic blood pressure, cardiac output, cardiac index and ejection fraction of left ventricle has been observed in lean and obese hypertensives. Total peripheral resistance values significantly (p less than 0.05) decreased in lean hypertensives; in obese hypertensives total peripheral resistance moderately reduced. Our results indicated that monotherapy with ketanserin is effective in treating mild to moderate hypertension both in lean and in obese hypertensives and did not interfere with left ventricular performance. At last the effectiveness of ketanserin treatment appears moderately higher in lean than in obese hypertensives.

Antihypertensive efficacy and effects of nitrendipine on cardiac and renal hemodynamics in mild to moderate hypertensive patients: randomized controlled trial versus hydrochlorothiazide.

In this study antihypertensive efficacy, safety, and the effects of short-term nitrendipine administration on central and renal hemodynamics were evaluated in mild to moderate hypertensives. Our final goal was to ascertain whether the reduction in blood pressure induced by nitrendipine treatment was associated with maintained renal function. After a run-in period with placebo, 26 hypertensives without cardiac or renal disease were randomly assigned to a double-blind 8-week controlled trial with nitrendipine (N) 20 mg once a day (13 pts) or hydrochlorothiazide (HCT) 25 mg once a day (13 pts). Renal hemodynamic measurements included effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) by radionuclide study using I-131 hippuran and Tc-99m, according to the methods described by Schlegel and Gates, respectively. Effective renal blood flow [ERBF = ERPF/(1-Ht)], filtration fraction (FF = GFR/ERPF), and renal vascular resistance (RVR = MBP x 80/ERBF) were also calculated. Other hemodynamic measurements included cardiac index (CI), left ventricular (LV) ejection fraction (EF), and total peripheral resistance (TPR) measured by the first-pass radionuclide angiography technique. At the end of N or HCT administration significant decreases (p less than 0.001) in SBP, DBP, and MBP vs. baseline values were observed in both hypertensive groups. In the N group a significant decrease (p less than 0.01) in TPR and RVR, and significant increases (p less than 0.05) in CI, ERPF, and ERBF were observed. In the HCT group a significant decrease (p less than 0.05) in RVR was found without significant changes in other hemodynamic parameters. No important side effects were observed with either therapy. In conclusion, nitrendipine was effective in reducting blood pressure in mild to moderate hypertensive patients and exerted favorable effects on cardiac and renal function.

Left ventricular diastolic and systolic function in normotensive obese subjects: influence of degree and duration of obesity.

The present study was carried out to evaluate systolic and diastolic parameters in overweight and moderately obese, but otherwise healthy subjects, and in a lean control group, to determine whether degree and duration of obesity can influence left ventricular function. A total of 27 subjects, 17 overweight or with moderate obesity and 10 lean, healthy subjects were included. Patients were divided into three groups according to their body mass index (BMI) and to Garrow's criteria as follows: lean control group (BMI less than 25 kg.m-2); overweight subjects (BMI from 25 to 30 kg.m-2); moderately obese subjects (BMI greater than 30 less than 40 kg.m-2). Systolic and diastolic parameters were measured using blood pool gated radionuclide angiography. Left ventricular (LV) ejection fraction (EF), peak ejection rate (PER), time to PER (tPER), peak filling rate (PFR) and time to PFR (tPFR) were evaluated. PER and PFR values were normalized for end-diastolic volume (EDV). EF and PFR were significantly lower (P less than 0.05) both in moderately obese and in overweight subjects and tPFR was significantly (P less than 0.05) prolonged in both groups in comparison to lean controls. Only in moderately obese subjects was PER significantly (P less than 0.05) decreased and tPER significantly (P less than 0.05) prolonged in comparison to lean controls. As compared to overweight individuals, moderately obese subjects were characterized by a significant decrease (P less than 0.05) in LVEF and PER and by a significant increase (P less than 0.05) in tPER, without relevant change in PFR and in tPFR.(ABSTRACT TRUNCATED AT 250 WORDS)

The nature and origin of interstellar diamond.

Microscopic diamond was recently discovered in oxidized acid residues from several carbonaceous chondrite meteorites (for example, the C delta component of the Allende meteorite). Some of the reported properties of C delta seem in conflict with those expected of diamond. Here we present high spatial resolution analytical data which may help to explain such results. The C delta diamond is an extremely fine-grained (0.5-10 nm) single-phase material, but surface and interfacial carbon atoms, which may comprise as much as 25% of the total, impart an 'amorphous' character to some spectral data. These data support the proposed high-pressure conversion of amorphous carbon and graphite into diamonds due to grain-grain collisions in the interstellar medium although a low-pressure mechanism of formation cannot be ruled out.