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Biomedical subjects

F Rengo

Publications and source records attributed to F Rengo.

At least 73 records · Page 4Linked to original sources
PubMed1995

Comparison of the safety and efficacy of delapril with enalapril in patients with congestive heart failure.

To evaluate the safety and efficacy of delapril versus enalapril in patients with congestive heart failure (CHF), New York Heart Association (NYHA) class II and III, 198 patients were enrolled in a study in 13 centers involving a double-blind parallel group design. After completing a 2-week run-in period on placebo, patients were randomized to receive delapril 7.5 mg twice daily or enalapril 2.5 mg twice daily for 2 weeks. The dose was then doubled for the remaining 6 weeks. In this phase, 1 patient in each group experienced orthostatic hypotension; the dose was then reduced to the initial dose for study completion. A total of 195 patients received active treatment (96 delapril, 99 enalapril). After 8 weeks' treatment, bicycle ergometry demonstrated a significant increase in exercise duration (p < 0.01) and workload (p < 0.01). Echo Doppler investigations showed a significant reduction (p < 0.01) in left ventricular end-systolic volume associated with a significant increase (p < 0.01) in ejection fraction and cardiac output. No clinically significant changes in blood pressure, heart rate, electrocardiogram, or biochemical and hematologic tests were found. There were no significant differences between treatment groups. Three patients in each group experienced adverse reactions requiring withdrawal of 1 patient in each group. Delapril 15 mg twice daily, like enalapril 5 mg twice daily, was effective in improving signs and symptoms of CHF and was well tolerated.

Administration, Oral↗
PubMed1995

Congestive heart failure in elderly patients: controlled study of delapril versus captopril.

In this controlled trial, 30 elderly patients with congestive heart failure, New York Heart Association (NYHA) classes II and III, were randomly assigned to treatment with captopril 25 mg three times daily or delapril 15 mg twice daily. At the end of an 8-week treatment period, clinical symptoms of heart failure were significantly relieved by both drugs, with a consistent and statistically significant improvement in patients' quality of life evaluated using a symptoms/activity scale (p < 0.001). None of the patients was judged NYHA class III at the end of the trial and 40% were assigned to class I (p < 0.01). There was a relevant, but not statistically significant, increase in exercise duration in both treatment groups (10% captopril group, 14% delapril group), but the number of patients discontinuing the exercise test for dyspnea was 50% less in the delapril group. Neither drug had evident effects on echocardiographic left ventricular parameters. Two patients treated with captopril and 3 with delapril complained of mild-to-moderate adverse reactions. The safety of both drugs was confirmed by laboratory tests.

Aged↗
PubMed1995

Age-response effectiveness of gallopamil for the treatment of myocardial exertional ischemia. A medium-term randomized cross-over double-blind placebo-controlled trial.

We evaluated the efficacy and safety of gallopamil 150 mg daily in middle-aged and elderly patients with stable exertional ischemia, using a medium-term randomized double-blind cross-over placebo-controlled trial. Twenty middle-aged patients (52.8 +/- 6 years; range 38-61 years) and 14 elderly patients (67.4 +/- 2.8 years; range 65-73 years) with stable exertional ischemia underwent a bicycle exercise test. After a run-in period, both groups received treatment with either placebo or gallopamil 50 mg tid for 28 days. At the end of this time, each patient crossed over to the alternate regimen. Gallopamil significantly reduced heart rate, blood pressure and rate pressure product (from 15.37 +/- 2.7 to 13.65 +/- 4.16 U x 10(-3); p < 0.01) in elderly patients at submaximal exercise, but had no effect in middle-aged patients (from 14.52 +/- 4.45 to 13.49 +/- 3.77 U x 10(-3); p = NS). At peak exercise, none of the hemodynamic parameters was modified with gallopamil in either group. At peak exercise, both middle-aged and elderly patients achieved rate-pressure products similar to those reached during placebo at higher work loads. Exercise duration and maximal work load significantly increased in both groups. Electrocardiographic signs of ischemia were favorably influenced by gallopamil in both groups (from 1.39 +/- 0.5 mm to 0.76 +/- 0.73 mm; p < 0.001 in the middle-aged patients and from 1.5 +/- 0.34 mm to 1 +/- 0.76 mm; p < 0.01 in the elderly patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Reduced left ventricular mechanical efficiency in elderly patients with coronary artery disease.

We evaluated left ventricular (LV) mechanical efficiency in 23 elderly patients (mean age 67 +/- 2) with coronary artery disease (CAD) and in 22 patients younger than 65 years (mean age 49 +/- 8) with similar severity of CAD (2.4 +/- 0.8 and 2.2 +/- 0.8 vessels per patient, respectively) and history of myocardial infarction (34% and 41%, respectively). LV mechanical efficiency was calculated as the ratio of LV work per minute and myocardial O2 consumption. LV stroke volume was calculated from left ventriculography. Coronary blood flow was measured by thermodilution. Older patients had lower values of LV stroke volume (49 +/- 16 vs 73 +/- 16 mL, p < 0.005), ejection fraction (41 +/- 17 vs 58 +/- 17%, p < 0.05), LV stroke work (93 +/- 26 vs 131 +/- 41 g.m., p < 0.02) and LV work per minute (6.7 +/- 2.6 vs 9.3 +/- 2.7 kg.m./min, p < 0.05). Since myocardial O2 consumption was similar in the two groups, LV mechanical efficiency was lower in older CAD patients (16.2 +/- 15 vs 23.8 +/- 12%, p < 0.05). Thus, elderly patients with CAD show a reduced LV mechanical pump performance and efficiency, compared with younger patients with similar disease severity and history of myocardial infarction. These observations may contribute to understanding the higher frequency of congestive heart failure in elderly patients with CAD.

Adult↗
PubMed1995

Left ventricular diastolic filling in diabetes mellitus with and without hypertension.

Left ventricular diastolic filling by Doppler echocardiography was investigated in 84 diabetic patients without evidence of heart disease and in 84 normotensive nondiabetic age- and sex-matched control subjects. Diabetic patients were subdivided into two groups on the basis of the presence of arterial hypertension. Group 1 comprised 41 normotensive diabetic patients (19 men, 22 women, mean age 63.7 +/- 9.1 years); Group 2 comprised 43 hypertensive diabetics (15 men, 28 women, mean age 65.6 +/- 9.6 years). Doppler measures of diastolic filling were significantly altered in the two groups as compared with control subjects. Peak atrial flow velocity, velocity integral for the atrial filling period, and atrial filling fraction were increased, whereas the ratio of peak early to peak atrial flow velocity and the ratio of flow velocity integrals were decreased, especially in Group 2 patients. Thirteen patients in Group 1 (32%) and 17 in Group 2 (40%) had evidence of diastolic dysfunction, as assessed by the presence of at least two independent abnormal indices (outside age-corrected 95% confidence interval). In each group, patients with altered diastolic filling differed slightly from diabetic patients with normal Doppler indices, tending to increased wall thickness and left ventricular mass. In conclusion, diastolic filling of the left ventricle is frequently altered in diabetic patients and is adversely affected by arterial hypertension whose coexistence further impairs left ventricular relaxation.

Aged↗
PubMed1995

Effects of age and hypertension on adrenoceptor-sensitivity evaluated with CD25 and QT/QS2.

BACKGROUND: We studied the effects of age and hypertension on responses to chronotropic dose (CD25) and standing-induced changes in the ratio of electrical systole (QT) to electromechanical systole (QS2) in order to identify their role on beta adrenoceptor sensitivity and to verify the value of QT/QS2 ratio as a noninvasive parameter of beta-adrenoceptor sensitivity. METHODS: We enrolled 33 normal subjects and 37 hypertensive patients (WHO stage I and II) (age range 21-82 years). RESULTS: CD25 was significantly age-related in normotensive and hypertensive subjects, whereas standing-induced QT/QS2 changes were age-related in normotensive subjects only When we divided subjects into three age groups, beta-adrenoceptor sensitivity was found to be lower in hypertensives than normotensives in the two groups under age 60, but was not affected in those over age 60. This suggests that hypertension influences beta-adrenoceptor sensitivity in younger subjects, but not in elderly patients, whose beta-adrenoceptor sensitivity is already reduced. CONCLUSIONS: CD25 does not predict standing-induced QT/QS2 ratio changes; therefore, during autonomic stimulation, QT/QS2 ratio seems not to be significantly related to beta adrenergic sensitivity.

Adult↗
PubMed1995

Protective effect of beta-blockade on dipyridamole-induced myocardial ischaemia. Role of heart rate.

This study was designed to investigate the effect of heart rate changes on dipyridamole echocardiographic tests in patients with coronary artery disease treated with propranolol. We prospectively studied 12 patients (8 men and 4 women; mean age 56.5 +/- 8.7 years) selected by: (a) angiographic evidence of significant coronary artery disease; (b) adequate echocardiographic window; (c) positive dipyridamole echocardiography test results in baseline conditions (step I); (d) test reproducibility in the absence of treatment; (e) negative dipyridamole echocardiography test results after 7 days of treatment with propranolol (120 mg.day-1) in twice divided doses daily (step II). In all patients treated with propranolol, dipyridamole echocardiographic testing was repeated 24 h after the last negative test. In these patients, transoesophageal atrial pacing was performed at peak dipyridamole infusion to increase heart rate to values similar to those observed at baseline (step III). At baseline, heart rate and rate-pressure product were significantly lower in patients treated with propranolol (-20.3% and -22.5% in group II, P < 0.001 vs step I; -24.3% and -26.4% in group III, P < 0.05 vs step I), but the different treatments did not produce significant differences in systolic and diastolic blood pressure. At peak dipyridamole infusion, heart rate and rate-pressure product increased with either placebo or propranolol treatments with respect to baseline, while remaining significantly lower with propranolol as compared to placebo (-29.6% and -29.5% in step II, P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1995

Reduced aerobic metabolic efficiency in postischemic myocardium dysfunction in rats: role of aging.

It has been suggested that aging may enhance the deleterious effects of myocardial ischemia-reperfusion. This study evaluates the relationship between oxygen consumption and functional impairment during reperfusion following myocardial ischemia in adult and senescent rat hearts. Global ischemia induced a marked impairment of contractile function which was significantly higher in senescent than in adult hearts. During reperfusion postischemic dysfunction was more evident in senescent hearts: at the 10th minute, the developed pressure recovered less (p < 0.05) and end-diastolic pressure increased more (p < 0.05) in senescent than in adult hearts. However, oxygen consumption per unit of work was significantly higher throughout 60 min of reperfusion when compared to controls with no significant difference between adult and senescent hearts. This study demonstrates that following ischemia and reperfusion depression of function and inappropriately high oxygen consumption were observed in both adult and senescent hearts. However, aging was associated with greater contractile impairment, which occurred in the absence of further deterioration of metabolic efficiency of contraction.

Adenosine Triphosphate↗
PubMed1995

Relation between age, left ventricular mass and ventricular arrhythmias in patients with hypertension.

To evaluate the effect of age on left ventricular hypertrophy-related arrhythmias in patients with essential arterial hypertension, 68 hypertensives (47 men and 21 women, mean age 59.4 +/- 9.5 years) without other cardiovascular disorders were studied. All patients underwent M-mode and two-dimensional echocardiogram and 24 h ambulatory electrocardiographic monitoring to measure left ventricular internal dimension, septum and posterior wall thickness, left ventricular mass index, premature ventricular beats and modified Lown grade. Premature ventricular beats (PVB) and modified Lown grade were significantly related to left ventricular mass index, but not to left ventricular internal dimension, fractional shortening, systolic and diastolic blood pressure. There was no relation between age and number of PVB, or severity of arrhythmias. In conclusion, in hypertensive patients only left ventricular hypertrophy, and not age, plays a significant role in the pathophysiology of the increased incidence of ventricular arrhythmias by a different mechanism than age-related increased ventricular arrhythmias.

Adult↗
PubMed1995

Protective role of chronic ubiquinone administration on acute cardiac oxidative stress.

Previous studies have shown that acute exogenous administration of coenzyme ubiquinone (CoQ10) can protect the heart against oxidant-mediated injury. The aim of this study was to investigate whether protection against cardiac oxidative stress could be obtained by increasing tissue levels of CoQ10, as achieved by chronic CoQ10 supplementation. Wistar rats were randomly divided into two groups: a control group given standard diet and a test group receiving diet supplemented with CoQ10 (5 mg/kg/day) for 4 weeks. Functional and metabolic changes induced by oxidative stress were investigated in isolated perfused hearts and in papillary muscles. Tissue concentrations of ubiquinones were significantly higher in the left ventricle of treated rats than in controls. H2O2 infusion (60 microM for 60 min) induced marked alterations of both developed pressure, which decreased to -58.8 +/- 16.8% of base line and end-diastolic pressure which increased almost 13-fold. These effects were reduced significantly (P < .05) in hearts from CoQ10-supplemented rats (-13.8 +/- 2.3 and +375.0 +/- 42.5%, respectively). In the same hearts, cumulative release of oxidized glutathione (a specific marker of oxidative stress) was 450.2 +/- 69.2 nmol/g of wet weight in the control group and only 89.6 +/- 22.3 nmol/g of wet weight in treated hearts (P < .01). In papillary muscles, after 60 min of perfusion with H2O2, active tension decreased, largely in controls whereas it was almost unchanged in the treated group (-34.4 +/- 7.5% of baseline vs. -0.1 +/- 0.05%, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

[Reduced endothelium-dependent peripheral vasodilation in the aged].

Endothelial dysfunction may be present years before the clinical manifestations of atherosclerosis, which is particularly frequent in the late decades of life. Therefore, we have evaluated the presence of endothelial dysfunction in the elderly by measuring, by echo-Doppler technique, the vasodilatation of brachial artery in response to the hyperemia following forearm occlusion and decompression, a response that is dependent on endothelial function. We studied 10 subjects > 65 years (mean 72 +/- 8) and 10 subjects < 65 years (mean 40 +/- 6) all without clinical signs and without risk factors for atherosclerosis. The increase in brachial arterial flow during reactive hyperemia was similar in the young and elderly subjects (152 +/- 74% vs 129 +/- 63%, NS). While in the young at peak hyperemia we found a significant increase in brachial artery diameter from 3.4 +/- 0.9 to 4.1 +/- 1.0 mm (p < 0.005), there was no significant change in the elderly (from 3.0 +/- 0.7 to 3.1 +/- 0.7 mm, NS). In both groups sublingual glyceryl trinitrate produced a significant increase in brachial artery diameter (from 3.0 +/- 0.7 to 3.5 +/- 0.8 mm in the elderly, p < 0.01, and from 3.4 +/- 0.9 to 3.9 +/- 0.9 mm in the young subjects, p < 0.01, NS among groups), showing the absence in the elderly of structural vascular changes potentially responsible for absence of dilatation. In conclusion, elderly subjects without clinical signs or risk factors for atherosclerosis have a vascular endothelial dysfunction that may play an important role in pathologic processes of the cardiovascular system in the late decades of life.

Adult↗
PubMed1994

Regression of left ventricular hypertrophy and improvement of renal hemodynamics in hypertensive patients treated with quinapril.

Of 17 patients with mild to moderate essential hypertension, 8 showed echocardiographic evidence of left ventricular hypertrophy. Cardiac and renal function evaluated by glomerular filtration rate (GFR) were studied in all patients before and after 20 weeks of quinapril treatment. Systolic pressure decreased from 174.7 +/- 16.7 to 131.7 +/- 7.7 mmHg (p < .0001) and diastolic pressure decreased from 101.8 +/- 9.8 to 80 +/- 4.3 mmHg (p < .0001). Left ventricular mass index decreased in the eight patients with left ventricular hypertrophy (p < .01). Basal values of GFR were lower than normal in 41% of all patients; GFR increased significantly after 20 weeks of treatment (from 96.5 +/- 32.3 to 108.6 +/- 31.12 ml/min, p < .01); it decreased in only one patient. Patients reported few adverse effects to quinapril, and no important clinical laboratory abnormality was observed. Quinapril not only lowered arterial pressure, but it had a distinct effect on regression of left ventricular hypertrophy and favorable effects on renal function.

Adult↗
PubMed1994

Role of aging on electrical, mechanical, and coronary modification induced by ouabain and epinine in isolated rat heart.

OBJECTIVE: The contractile response to digitalis and beta adrenoceptor agonists is lower in the senescent than in the adult myocardium, while the development of ventricular arrhythmias is increased. The aim of this study was to examine the effects of aging on cardiac response to digitalis and an adrenergic agonist used clinically. METHODS: The electrical and mechanical responses were tested in isolated and perfused hearts from 3-24 month old rats receiving 15 min infusion of digitalis drug (ouabain, 6 x 10(-5) M) alone, and after 5 min of beta adrenoceptor agonist drug (epinine, 1.5 x 10(-7) M). RESULTS: Ouabain action was associated with a rise in left ventricular end diastolic pressure (p < 0.01) which increased progressively with aging, and with an elevation of left ventricular developed pressure (p < 0.01) which decreased progressively with aging. Epinine induced a reduction of left ventricular end diastolic pressure (p < 0.01) and a rise in left ventricular developed pressure (p < 0.01) but both effects decreased progressively with aging. Ouabain reduced coronary flow and this decrease was more pronounced with aging (p < 0.01), while epinine caused an increase (p < 0.01) that diminished in older hearts. Ouabain given after epinine resulted in a greater increase in left ventricular end diastolic pressure than epinine (p < 0.01) but lower than that caused by ouabain alone (p < 0.01), a greater increase in left ventricular developed pressure than epinine and ouabain (p < 0.01), and a smaller reduction of coronary flow rate than ouabain alone (p < 0.01). All these effects, however, diminished progressively with aging. Arrhythmia scores were higher during ouabain than in control (p < 0.01) and in epinine treated hearts (p < 0.01); pretreatment with epinine did not modify arrhythmia score during ouabain administration. The number and severity of arrhythmias, however, increased with aging in all groups. CONCLUSIONS: Aging has a negative effect on both the positive inotropic and the arrhythmogenic effects of ouabain and epinine, although these phenomena are more pronounced during ouabain administration. However, when the two drugs are given simultaneously, epinine does not modify the arrhythmogenic effect of ouabain but reduces some of its deleterious haemodynamic effects.

Aging↗
PubMed1994

[Comparison of nisoldipine and diltiazem in the treatment of effort angina pectoris].

BACKGROUND: In order to evaluate the benefits of a calcium-antagonist medium-term treatment, 20 patients with effort stable angina pectoris were treated with nisoldipine in comparison to diltiazem. METHODS: Twenty patients with stable effort angina completed a double-blind, placebo controlled trial, comparing 10 twice daily nisoldipine per os and diltiazem 120 three times daily per os for 28 days. After wash-out, placebo and drug period, ergometer stress tests were performed. Exercise tolerance, angina frequency, nitrate consumption and side effects were evaluated. RESULTS: Our results showed that both drugs significantly increased exercise tolerance. Exercise duration was 330 +/- 107 sec after placebo, 397 +/- 106 sec after nisoldipine (p < 0.05) and 378 +/- 99 sec after diltiazem (p < 0.05). Effort angina episodes decreased from 20 after placebo to 8 after nisoldipine and diltiazem. Both drugs reduced rate-pressure product at submaximal exercise in comparison to placebo. There were no differences at peak exercise between placebo or drug periods. Both drugs similarly reduced nitrate consumption and weekly effort angina attacks. No patients referred serious side-effects. CONCLUSIONS: nisoldipine, like diltiazem, is an effective drug in the treatment of stable effort angina. Moreover, the therapeutic effects of nisoldipine during medium-term treatment are probably related to decrease in oxygen consumption.

Administration, Oral↗
PubMed1993

Role of metabolic therapy in cardiovascular disease.

The pathophysiological basis for the use of metabolic therapy in the treatment of heart failure is analyzed. Bioenergetical processes related to ATP bioavailability play a central role in regulating myocardial contractility at rest and on effort. Furthermore, a significant correlation has been demonstrated in diseased heart between ATP content, revealed at endomyocardial biopsy, and systolic and diastolic left ventricular indexes evaluated with invasive and noninvasive methods. Several international investigations demonstrate the beneficial effects of ubiquinone (coenzyme Q10) in the treatment of heart failure. Here the results of a study are reported that was conducted on patients with heart failure treated with ubiquinone. After 7 months of oral drug administration (100 mg/day), a significant improvement was observed in echocardiographic indexes of systolic function, cardiothoracic ratio, and clinical signs and symptoms of congestive heart failure. In conclusion, the introduction of metabolic drugs, such as ubiquinone, in the treatment of heart failure opens new horizons in the therapeutic approach to an ailment that entails substantial human and social costs.

Female↗
PubMed1993

Relationship between ventricular ectopic beat frequency and heart rate: study in patients with severe arrhythmias.

To evaluate and quantify the relationship between premature ventricular contractions (PVCs) and heart rate (HR), 57 patients (48 men and 8 women, mean age 59.8 +/- 7.9 years) with severe PVCs (Lown-Wolf grade > or = 3a) over 24 hours of Holter monitoring were studied. Twenty had no coronary artery disease (CAD), 25 had angiographically documented CAD, and 12 had acute myocardial infarction. All parameters of the 24-hour recordings from two ECG leads were measured by a Holter analyzer designed in our laboratory, based on fast microprocessors and controlled by a microcomputer. Scatter diagrams of the number of PVCs per minute as a function of HR and correlation coefficient were computed for various HR values corresponding to a total number of minutes greater than five. A positive correlation (r > or = 0.35) was found in most patients without CAD (85%); there was a complex relationship between the strength of the correlation and the presence of CAD or acute myocardial infarction because of a greater variability in the results of correlation coefficient analysis (coefficient of variation 62%, 208%, and 145% in patients without CAD, with CAD, and with acute myocardial infarction, respectively). The incidence of a positive correlation was similar in patients with Lown-Wolf grade III (63%), IVa (82%), or > or = IVb (67%) arrhythmias. The reproducibility of the correlation coefficient of the relationship between PVC frequency and HR was tested in 15 patients. The mean value of the correlation coefficient was 0.801 +/- 0.169 for the first test and 0.805 +/- 0.22 (p = NS) for the second test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗