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Biomedical subjects

R Bolognesi

Publications and source records attributed to R Bolognesi.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Effects of i.v. nicardipine in the treatment of hypertensive crisis].

The availability of i.v. nicardipine has urged us to prove this drug in the treatment of hypertensive attacks (SAP greater than or equal to 210 mmHg and/or DAP greater than or equal to 110 mmHg). Two groups of patients (each made up of ten subjects) were treated with 2 mg and 5 mg respectively of i.v. nicardipine injected for 4 min while mean systolic and diastolic arterial pressure and heart rate were registered until three hours. I.V. nicardipine administration induced in both groups of patients a decrease in systolic pressure from 20 to 30% while diastolic arterial pressure decreased from 15 to 18% in the first group and from 20 to 25% in the second one. Heart rate showed an initial mild increase following arterial vasodilator action of nicardipine whereas it decreased significantly from 120 min in the presence of an unchanged hypotensive effect of the drug. One patient did not respond to nicardipine while another felt chest pain and palpitations. In conclusion our results are satisfactory and argue for the inclusion of nicardipine among the drugs that may be considered useful for the treatment of hypertensive attacks.

Acute Disease↗
PubMed1989

Electrophysiological evaluation of the sinus node in patients with atrioventricular and/or intraventricular conduction defects.

The authors evaluated retrospectively sinoatrial conduction time (SACT), sinus node recovery time (SNRT), and corrected sinus node recovery time (CSNRT) in 272 patients with atrioventricular and/or intraventricular conduction defects without evidence of overt sinus node dysfunction. The study was designed to determine the prevalence of electrophysiologic sinus node abnormalities in patients with overt atrioventricular and/or intraventricular conduction defects. One or more sinus node electrophysiological abnormalities were observed in 133 cases (48.9%). There was a significant prevalence of electrophysiologic sinus node abnormalities only in patients older than 71 years of age. The data suggest that the involvement of the specialized conduction system is much more diffuse than one might expect simply observing the single recorded ECG defect and that the prevalence of associated defects of the conduction system increases with increasing age of patients.

Adolescent↗
PubMed1989

[Effects of intravenous flecainide in the treatment of paroxysmal or recent-onset atrial fibrillations].

Intravenous flecainide (2 mg/Kg for 15 min) was used in 30 patients (18 men and 12 women aged 23 to 85 years: mean 62) with recent or paroxysmal atrial fibrillation: 5 patients returned to sinus rhythm during flecainide administration while other 23 patients did it not later than 2 hours. Treatment with intravenous flecainide proved to be safe without significant side effects. Further investigations are required to define the effects of flecainide in the treatment of atrial fibrillation; at the moment it must be admitted that flecainide acetate is a useful, safe, fast acting drug for the conversion of paroxysmal or recent atrial fibrillation to sinus rhythm.

Adult↗
PubMed1989

[Dynamic obstruction of the left ventricular outflow as a late complication of mitral valve replacement. Case report].

The obstruction of the left ventricular tract outflow following mitral valve surgery, as a late complication, is rarely reported in the literature. The case of a 47-yr-old woman, who, after mitral valve surgery, developed dynamic left ventricular tract outflow obstruction four years later is reported. This alteration was detected by 2D echo-Doppler. The echocardiographic findings were: 1) Normal function of the mitral prosthesis. 2) An equal pressure-gradient of 44 mmHg at rest and of 75 mmHg after amyl nitrite at three examined levels: below, above and at the level of the aortic valve. 3) A hyper-echo image in the peri-annular region, probably representing fibrous degeneration around the valve ring, which was the likely cause of the obstruction. Th data were confirmed by cardiac catheterization. The echocardiographic technique appears to be a useful tool to detect and study this complication of mitral valve surgery.

Echocardiography, Doppler↗
PubMed1989

[Modification of left ventricular filling after acute administration of nifedipine in hypertensive patients. Doppler echocardiographic study].

This study was undertaken to determine the acute effects of nifedipine on left ventricular filling, examined by Doppler echocardiography in patients with arterial hypertension and normal left ventricular systolic function. Twenty-seven patients with mild to moderate systemic hypertension, and 18 normotensive subjects were studied. Pulsed Doppler, M-mode and B-mode measurements were performed before and 30 min after sublingual nifedipine administration (10 mg). Peak E, peak A, area A, area E, ratio area A/area E, E deceleration and E acceleration time were measured. Before administering nifedipine, some of these diastolic filling parameters were significantly different in the hypertensive patients as compared with normal subjects. After nifedipine, in patients with arterial hypertension, peak E and area E increased significantly (p less than 0.01), while ratio peak A/E and ratio area A/area E showed a significant decrease (p less than 0.001). No significant changes were observed in normal subjects. The result of this study demonstrates that the acute administration of nifedipine modifies transmitral flow velocity pattern in hypertensive patients, suggesting that the left ventricular filling abnormalities are in part dynamic and reversible.

Adult↗
PubMed1989

[Effects of digitalis on the left ventricular filling phase in the normal and ischemic heart. Angiographic study in man].

The effects of digitalis on the left ventricular diastolic phase are very scant. In order to gain a better insight into this problem, we measured the hemodynamic effects of an intravenous injection of K-strophantidin (0.005 mg/kg in a bolus given within 5-10 min) during the diastolic phase in 9 normal male subjects and in 9 male patients with coronary artery disease (CAD), maintaining a normal overall ejection fraction despite of the presence of some hypokinetic segments. Administration of K-strophantidin decreased significantly in normal controls the left ventricular volumes at 1/3, 1/2, 2/3 of the diastolic phase, whereas it did not produce significant change in CAD patients. Digitalis decreased the first and increased the second filling peak of the volumetric variable dV/dt in the normal controls, but not in the CAD patients. In the latter group the 2 peaks before digitalis administration were similar. The effects of digitalis on the dV/dt measured during the second filling peak were significantly different in the 2 groups. The increments of pressure in middle and end diastole in CAD patients were significantly greater than those observed in normal controls. Results of the present study suggest that digitalis has a negative influence on the left ventricular filling phase both in normal and CAD subjects. In fact digitalis modifies in normals the pattern of the left ventricular filling phase whereas it induces an untoward increase in the middle and end diastolic pressure in CAD patients.

Adult↗
PubMed1988

Lack of effect of nicardipine and diltiazem on glucose- and arginine-induced insulin release in obese subjects.

The metabolic effects of calcium channels blockers have already been studied both in normal and diabetic humans and results were quite controversial, depending on the drug used, the dose administered, and the type of patient. Little information exists on the use of Ca2+ antagonists in obese people, even if these persons are a population risk group for developing diseases in which these drugs may be requested for treatment. Thus, we evaluated, in obese humans, the metabolic effects of two Ca2+ antagonist drugs recently made commercially available to treat diseases such as hypertension and ischemic heart disease: nicardipine and diltiazem. Sixteen obese subjects were submitted to an intravenous glucose tolerance test (0.33 g/kg) (IVGTT) and an arginine test tolerance (30 g in 30 minutes) (ATT) before and after a week of oral treatment with nicardipine (60 mg/day) or diltiazem (360 mg/day). Plasma values of glucose, insulin, and C-peptide during IVGTT, and of glucose, insulin and glucagon during ATT did not show any modification during treatment with either drug. Thus the Ca2+ antagonists, nicardipine and diltiazem, at therapeutic doses in obese subjects do not significantly affect glucose tolerance or insulin and glucagon release.

Arginine↗
PubMed1987

The effects of intravenous nifedipine on cardiac hemodynamics and contractility in patients with coronary artery disease in the presence or absence of beta adrenergic blockade.

We studied the acute effects of intravenous nifedipine on hemodynamics and left ventricular function of CAD patients without previous treatment (group 1) and of 10 CAD patients receiving acebutolol (9 mg/kg daily) and who had been shown to be adequately beta blocked (reduction in heart rate by 25%) (group 2). Intravenous nifedipine (15 micrograms/kg) significantly reduced systemic peripheral resistances in both groups: this was associated with decreased systolic blood pressure and increased left ventricular cardiac output with a slight nonsignificant increase of ejection fraction. There was a significant increase in heart rate in both groups, the chronotropic response to nifedipine being attenuated in patients receiving acebutolol. Left ventricular end-diastolic pressure did not change in the first group, but it was significantly decreased in the second group, with a concomitant increase of end-diastolic left ventricular volume, suggesting an amelioration of diastolic compliance. The effect of nifedipine on intrinsic myocardial contractility was quite different, depending on the presence of beta adrenergic blockade. When given to patients of group 1, nifedipine significantly increased dP/dtmax, Vcemax, and Vmaxd. The same indices, however, were significantly depressed when nifedipine was given to the patients of group 2 receiving acebutolol. This study shows that intravenous nifedipine can be usefully administered to patients with coronary artery disease who have been on adequate beta-blocking doses of acebutolol with relative safety. Under these conditions nifedipine increases cardiac output in association with arterial dilation, despite evidence for a negative inotropic effect. These data also suggest that such an intrinsic negative inotropic effect would normally be masked by compensatory sympathetic activity.

Acebutolol↗
PubMed1987

Effects of verapamil and nifedipine on rate of left ventricular relaxation in coronary arterial disease patients.

We have evaluated the effects of nifedipine and verapamil on rate of left ventricular relaxation in 26 patients having coronary arterial disease with normal ejection fraction and normal left ventricular contractility. None of the patients had myocardial infarction. All patients showed normal contractile indices and abnormally high values of T constant, neg, dP/dt and left ventricular protodiastolic pressure, suggesting an impairment of left ventricular relaxation. Nifedipine, injected intravenously (15 micrograms/kg) in 14 patients induced a significant reduction of afterload parameters and an increase of contractility. Nifedipine also improved left ventricular relaxation, as it induced a reduction of the T constant from 42 +/- 2 msec to 33 +/- 2 msec (P less than 0.01). It induced a tendency to a reduction of negative dP/dt and protodiastolic pressure without reaching statistical significance. Verapamil, injected intravenously in the remaining 12 patients (0.1 mg/kg as a bolus followed by chronic infusion of 0.005 mg/kg/min for 3 min) induced a reduction of the T constant from 43 +/- 10 to 37 +/- 6 msec (P less than 0.01). It reduced the negativity of dP/dt from 2302 +/- 273 to 2021 +/- 252 mm Hg/sec (P less than 0.05) and of left ventricular protodiastolic pressure from 3.2 +/- 1.4 to 1.5 +/- 1.1 mm Hg (P less than 0.01). Verapamil, like nifedipine, reduced the afterload parameters although to a lesser extent. It did not substantially affect the left ventricular contractility. These data suggest that abnormalities of left ventricular relaxation may precede changes in systolic function and that nifedipine and verapamil favourably modify the indices of left ventricular diastolic function in patients with coronary arterial disease.

Blood Pressure↗
PubMed1986

Inhibitory effect of acute and chronic administration of digitalis on the sick sinus node.

We have determined the effects of the acute administration of intravenous (i.v.) digitalis administration (0.8 mg of digoxin in 5-10 min) on the electrophysiological variables of 12 normal subjects (group 1), 12 patients with asymptomatic sinus node bradycardia (group 2) and 34 patients with symptomatic sinus node dysfunction (SSS) (group 3). The injection of digitalis induced: an increase of sinus node cycle length (SNCL) in all groups; a 10% increase of sinus node recovery time (SNRT) in group 1, no changes in group 2 and a 25% increase in group 3; a tendency to increase, without reaching statistical significance, of corrected sinus node recovery time (CSNRT) and sino-atrial conduction time (SACT) in all groups. In 16 patients of group 3 the effects of oral chronic treatment with digoxin (0.25 mg daily for 7 days) was also determined. The results show that chronic treatment did not further affect SNCL, SNRT or CSNRT, but caused a greater increase of SACT than did the acute i.v. administration. Chronic treatment significantly reduced the sinus rate and increased the number of premature supraventricular and ventricular beats, measured by means of 24 hour-Holter monitoring. These data suggest that digitalis should be used with great caution in patients with SSS.

Administration, Oral↗
PubMed1986

Effects of 17 beta-estradiol on the isolated rabbit heart.

We have studied the effects of 17 beta-estradiol on the left ventricular pressure and on the coronary perfusion pressure in isolated rabbit heart, in order to evaluate the action of this hormone on the myocardial contractility and on the coronary resistances. 17 beta-Estradiol has induced a negative inotropic effect starting from a concentration of 10(-6) M and a vasodilation starting from 10(-7) M when administered on a vasopressin-induced coronary spasm. These effects are not related to sex or to alpha-, beta-adrenergic, histaminergic, anaesthetic-like mechanisms, but seem to interfere with calcium transport.

Animals↗
PubMed1986

[Early changes in ventricular function in diastolic phase in the resting coronary patient].

The aim of this study is to test left ventricular diastolic function in coronary artery disease patients with preserved systolic performance. Two groups of patients (25 coronary artery disease patients with angiographic proved coronary artery stenosis, but with normal hemodynamic and angiographic indices of systolic phase, first group; and 14 normal subjects for control, second group) were tested comparing their systolic and diastolic ventricular function indices, obtained by using a Millar microtip catheter and a computerized program. Systolic ventricular function was similar in the two groups (EF: 0.61 +/- 0.05 vs 0.62 +/- 0.03, p: n.s.; Vmax:120 +/- 28 vs 112 +/- 24 sec-1, p: n.s.), while diastolic indices were significantly different (lowest diastolic pressure: 3.7 +/- 2.4 vs -1.72 +/- 1.45 mmHg, p less than 0.01; end-diastolic pressure: 11.2 +/- 4.2 vs 6.5 +/- 2.8 mmHg, p less than 0.05; T constant: 45 +/- 8 vs 35 +/- 6 mmHg, p less than 0.001; end-diastolic compliance: 2.79 +/- 0.3 X 10(-2) vs 5.68 +/- 0.4 X 10(-2) mmHg-1, p less than 0.001; Kp: 0.041 +/- 0.006 vs 0.003 +/- 0.004 p less than 0.001). In conclusion, impairment of left ventricular diastolic phase may be one of the earliest manifestations of functional alterations of ischemic ventricle.

Cardiac Catheterization↗