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Biomedical subjects

A Nigri

Publications and source records attributed to A Nigri.

At least 55 records · Page 3Linked to original sources
PubMed1984

Nomogram for calculation of stenotic cardiac valve areas from cardiac output and mean transvalvular gradient.

In 15 patients (group 1) with isolated mitral stenosis and in 14 patients (group 2) with isolated aortic stenosis the stenotic valve areas were calculated according to: A) Gorlin's formula; B) Hakki's simplified formula, using mean mitral gradient by planimetry or peak-to-peak aortic gradient; C) the three-point simplified formula, using mean gradient calculated by the three-point method for both mitral and aortic valve. The three-point method is definitely easier to use than planimetry. The values (mean +/- SD) of mitral valve areas in group 1 patients were, respectively: 1.56 +/- 0.63 cm2; 1.56 +/- 0.55; 1.51 +/- 0.53. The values of aortic valve areas in group 2 patients were: 0.91 +/- 0.63; 0.77 +/- 0.41; 0.88 +/- 0.52. An excellent correlation was shown between the valve area calculated by Gorlin's formula and both Hakki's simplified formula and the three-point simplified formula. For aortic valve area the correlation is even better if the mean gradient by the three-point method is used instead of the peak-to-peak gradient. On the basis of the simplified formula, a nomogram was constructed which allows an immediate calculation of valve areas from cardiac output and transvalvular gradient.

Adult↗
PubMed1984

Acute hemodynamic effects of acebutolol and propranolol.

The acute hemodynamic effects of intravenous acebutolol, 50 mg, and propranolol, 10 mg, were evaluated in 12 patients undergoing diagnostic cardiac catheterization. Each patient received acebutolol or propranolol according to a list of randomization. Both acebutolol and propranolol depressed left ventricular function. There was a significant increase in left ventricular end-diastolic pressure at rest and after isometric exercise, with a concomitant decrease in cardiac index. Systemic vascular resistance was increased by both drugs. The increment after patients received acebutolol was not statistically significant; however, with propranolol it was statistically significant. The overall hemodynamic effects of acebutolol and propranolol are similar, but a quantitative difference exists in their effect on systemic vascular resistance. Acebutolol, a cardioselective agent, produces less of a peripheral vascular beta 2-blockade than does propranolol.

Acebutolol↗
PubMed1984

[Determination of cardiac output by thoracic electric impedance: comparison with thermodilution].

When an alternating current of high frequency is applied to the thorax, the first derivative of the impedance (dZ/dt) is affected by the cardiac cycle, resulting in a characteristic wave form. The maximum negative of this wave occurring during systole together with the length of ejection time (VET), the blood resistivity, the basal impedance (ZO) and the distance between the inner detecting electrodes (L) makes it possible to calculate stroke volume (SV) and related parameters, as cardiac output (CO) and cardiac index (Cl) by a formula developed by Kubicek. Thoracic electrical impedance has been proposed as a non invasive technique to evaluate cardiac emodinamics. In the present study we have evaluated thoracic electrical impedance by comparing it with thermodilution, simultaneously performed in 21 catheterized patients. Reproducibility was assessed by comparing Cl measured several times in the same patient during ten minutes of rest in the supine position: coefficient of variation, expressed as CV = SD/m X 100 was 8,5 +/- 4,2% and 9,4 +/- 3,2% (p = NS) for thermodilution and thoracic electrical impedance respectively. Cl values obtained by both methods correlated well, with little scatter either baseline (r = 0,784, n = 40, p less than 0,001), either after an handgrip manoeuvre (r = 0,629, n = 15, p less than 0,05). This degree of correlation is similar to that observed comparing invasive techniques (Fick, thermodilution, dye dilution) either among them, or with noninvasive methods (echocardiography, gated equilibrium blood pool scintigraphy and ultrasonic Doppler).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Iliac arteriovenous fistula complicating lumbar laminectomy.

An iliac arteriovenous fistula may rarely complicate lumbar laminectomy, particularly at the L4-L5 level. We present such a complication in a 45-year-old man who presented in our institution with a postlaminectomy iliac arteriovenous fistula and severe congestive heart failure. Repair of the fistulous orifice and tubular reconstruction of the iliac artery were successfully performed.

Journal Article↗
PubMed1983

Pulmonary arteriovenous fistulas: a case report.

An 11 year old boy had a congenital pulmonary arteriovenous fistula, which was previously mistaken for a congenital cyanotic cardiopathy. After the diagnosis was established, the patient was successfully operated. Considering the high mortality of the untreated cases and the recent advances in pulmonary surgery techniques, the importance of a correct diagnosis and an early surgical treatment of these lesions, is reaffirmed.

Arteriovenous Malformations↗
PubMed1980

[Hypertrophic obstructive cardiomyopathy associated with significant coronary artery stenosis. Apropos of 2 cases. Diagnostic and therapeutic considerations and review of the literature].

Hypertrophic obstructive cardiomyopathy (HOCM) is rarely associated with significant coronary artery stenosis. Differential diagnosis may be difficult because of similar symptoms; therefore we suggest coronary arteriography in all patients above 30 years of age having HOCM and angina associated. Obviously, in case the clinical diagnosis is coronary artery occlusive disease, left ventriculography is mandatory to rule out HOCM. Four medical treatment beta-blocking agents are the drugs of choice associated, if needed, with coronary dilators, avoiding nitrates. In case surgical treatment is selected, complete correction of all lesions is indicated.

Adrenergic beta-Antagonists↗
PubMed1979

Acute influence of different beta-blocking agents upon left heart hemodynamics at rest and during exercise in patients with coronary artery disease.

The study investigated the acute hemodynamic changes induced in patients with angiographically confirmed coronary artery disease by 3 beta-blockers: metoprolol, cardioselective without intrinsic sympathomimetic activity (ISA), group I, 11 patients; bunitrolol, noncardioselective with ISA, group II, 11 patients; oxprenolol, noncardioselective with ISA, group III, 11 patients. Hemodynamic variables were obtained at rest and during exercise, before and 45 min after 10 mg i.v. of the drug. Changes in LVEDP and cardiac indexes were such as LV function was improved in 1 patient of group I, 7 patients of group II and 5 patients of group III; impaired in 4 patients of group I and in 1 patient of group III; unchanged in the others. Contractility indexes were less influenced by bunitrolol and oxprenolol. During exercise there was a significant difference between groups for LVEDP which was lower in group II (P less than 0.01). The data seem to indicate that the choice of the beta-blocker may be of importance when it is desirable that an already compromised cardiac function be not further impaired by pharmacological intervention.

Adrenergic beta-Antagonists↗
PubMed1976

Evidence for improved cardiac performance after beta-blockade in patients with coronary artery disease.

The study was undertaken to investigate the acute haemodynamic effects of bunitrolol (0-2-hydroxy-3-(tert.butylamino)-propoxy)-bity. Right and left heart catheterization was performed in eleven patients with documented coronary artery disease. After bunitrolol (10 mg i.v.), there was a statistically significant decrease in left ventricular and aortic systolic pressures left ventricular end-diastolic pressure, aortic diastolic and mean pressures, pressure-rate product and compliance index (delta P/delta V). Left ventricular dp/dt, left ventricular dp/dt over isovolumic pressure, systemic resistance and heart rate tended to decrease, stroke volume and left ventricular stroke work index tended to increase, without statistical significance. Cardiac index showed individual variations, the mean values for the group being unchanged. Correlation of left ventricular end-diastolic pressure and left ventricular stroke work index showed a shift toward improved ventricular function curve in most cases, deterioration in no instance. Supine exercise was performed in ten patients. Angina occurred in nine patients; in five only before and in four before and after beta-blockade. Post-drug exercise heart rate, pressure-rate product and left ventricular end-diastolic pressure were significantly lower, the latter also in the four patients who still presented exercise angina. It is concluded that certain beta-blockers can improve cardiac performance at rest and during exercise in patients with coronary artery disease. This is explainable on the basis of a more favourable balance between oxygen supply and demand, together with a less marked negative inotropic effect due to the partial agonist activity of the agent used in the study.

Adult↗