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Biomedical subjects

L Spinelli

Publications and source records attributed to L Spinelli.

At least 73 records · Page 4Linked to original sources
PubMed1990

Alinidine in chronic stable angina: the effect on diastolic perfusion time.

The present study has been performed to assess the effects of alinidine on diastolic duration during exercise in chronic coronary artery disease. Twelve male patients with stable effort angina and without previous myocardial infarction were studied. They received alinidine or placebo in a double-blind randomized crossover trial for 3 days after a wash-out period of 4 days. Alinidine was administered at a dosage of 30 mg 3 times a day. At the end of each treatment the patients underwent upright bicycle exercise. Left ventricular time intervals were obtained by means of carotid thermistor plethysmography. Diastolic duration was calculated by subtracting the electromechanical systole from the R-R interval and expressed as a percentage of the cardiac cycle (%D). Alinidine increased both total exercise duration from 246.7 +/- 120.7 to 346.6 +/- 114.1 s (p less than 0.05) and time to 0.1-mV ST segment depression from 98.3 +/- 53 to 187.2 +/- 105 s (p less than 0.05). Similarly the drug induced a reduction of the rate-pressure product and of the extent of ischemic ST segment depression during exercise. %D was increased by alinidine both at rest and during exercise. A direct linear regression between R-R and %D was found after both alinidine and placebo treatments either at rest or during exercise. Nevertheless, no difference was observed between both slopes and intercepts. Therefore, since the relationship between R-R interval and %D was unaffected by alinidine, it was possible to hypothesize that the changes in diastolic duration were due only to the bradycardic action of the drug.

Angina Pectoris↗
PubMed1989

Problems in the design of anticancer agents.

Theoretically, two predominant paths for obtaining more selective anticancer agents may be envisaged. These are: (a) to make compounds which distribute only or preferentially in cancer cells; (b) to make compounds that are able selectively to kill or to differentiate cancer cells. Although in the last two decades research into new anticancer drugs has not produced satisfactory results, there is solid ground on which novel strategies can be developed, mainly based on a much greater biological knowledge of human tumours. This article does not review all the possible approaches that may be followed, but simply discusses some ideas and problems mainly taken from the current research of our laboratory.

Animals↗
PubMed1989

Non-invasive assessment of left ventricular performance in patients with coronary artery disease after chronic diltiazem therapy.

To evaluate the effects of diltiazem (240 mg/day) on the left ventricular function, we studied 13 patients with coronary artery disease (CAD). Comparison with placebo was made in a double-blind randomized crossover study. Both placebo and diltiazem were administered for 5 weeks. We assumed left ventricular systolic time intervals assessed by polycardiography as parameter of ventricular function. Diltiazem induced a significant decrease in pre-ejection period (p less than 0.01) as well as pre-ejection period/left ventricular ejection time ratio (p less than 0.01). Thus, our results suggest that diltiazem improves the contractile state of ischemic myocardium in CAD patients.

Blood Flow Velocity↗
PubMed1988

Electromechanical events during spontaneous angina.

The electromechanical events occurring during acute myocardial ischemia were assessed in 10 patients who developed spontaneous angina during cardiac catheterization. Aortic pressure and electrocardiogram were recorded, and heart rate and systolic and diastolic time intervals were measured under control conditions, at the onset of angina and during the relief of chest pain. In 5 patients spontaneous angina was accompanied by an increase in heart rate and systemic arterial pressure and by ST segment changes in anterior or anterolateral precordial leads. Diastolic time, expressed as percent of cardiac cycle, shortened from 48.8 +/- 3.6% at rest to 33.6 +/- 4.8% (p less than 0.01) at the onset of angina, as a consequence of a significant increase in both electromechanical systole and heart rate, and returned to control values within 10 min after sublingual nitroglycerin. In the remaining 5 patients, spontaneous angina was accompanied by a decrease in heart rate and systemic arterial pressure and by ST segment changes in the inferior or inferolateral leads. The diastolic time increased significantly (p less than 0.05) from 39.4 +/- 6.1% at rest to 47.8 +/- 9% at the onset of angina, as a consequence of a significant decrease in heart rate and a slight decrease in electromechanical systole. Since coronary perfusion takes place mainly during diastole, our results suggest that the reflex increase in adrenergic tone may worsen myocardial ischemia by affecting diastolic perfusion time. In contrast, the increase in vagal tone may contribute to spontaneous relief of angina by prolonging diastolic perfusion time.

Adult↗
PubMed1988

[Influence of posture on exercise-induced electrocardiographic and hemodynamic changes in patients with stable effort angina pectoris].

The present work was performed in order to assess the differences in electrocardiographic and hemodynamic responses to supine and upright dynamic exercise of patients with coronary artery disease. Changes in heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure, rate-pressure product (RPP) and ST segment depression during supine and upright bicycle stress test were compared in twenty patients suffering from stable effort angina and without previous myocardial infarction. In the supine posture lower values of HR were observed at rest, during stress test and during three minutes of the recovery period. Conversely, in all patients both SBP and DBP were higher during the stress test in the supine position decubitus. No significant changes in RPP was observed between the two different postures. Finally, ST segment didn't show differences at rest between the upright and supine position. All the patients had a lower ischemic threshold during exercise in the supine position than in the upright one. In fact an ST segment depression greater than 1 mm was observed during stress test in the supine position at lower work-load levels and at lesser HR values. Consequently for given HR, SBP and DBP ST segment, depression was greater in the supine rather than in the upright position.

Adult↗
PubMed1987

Early diastolic time intervals during hypertensive pregnancy.

Early diastolic time intervals have been assessed by means of the echopolycardiographic method in 17 pregnant women who developed hypertension during pregnancy (HP) and in 14 normal pregnant women (N). Systolic time intervals (STI), stroke volume (SV), ejection fraction (EF), and mean velocity of myocardial fiber shortening (VCF) were also evaluated. Recordings were performed in the left lateral decubitus (LLD) and then in the supine decubitus (SD). In LLD, isovolumic relaxation period (IRP) was prolonged in the hypertensive pregnant women compared with normal pregnant women (HP 51 +/- 12.5 ms, N 32.4 +/- 15 ms p less than 0.05), whereas time of the mitral valve maximum opening (DE) was not different in the groups. There was no difference in SV, EF, and mean VCF, whereas STI showed only a significant (p less than 0.05) lengthening of pre-ejection period (PEP) in HP. When the subjects shifted from the left lateral to the supine decubitus position, left ventricular ejection time index (LVETi) and SV decreased significantly (p less than 0.05) in both normotensive hypertensive pregnant women. IRP and PEP lengthened significantly (p less than 0.05) only in normals, whereas they were unchanged in HP. DE time did not vary in either group. In conclusion, hypertension superimposed on pregnancy induces lengthening of IRP, as well as of PEP, and minimizes the effects of the postural changes in preload on the above-mentioned time intervals.

Adolescent↗
PubMed1984

Systolic and diastolic time intervals during spontaneous angina.

In 5 patients who suffered spontaneous angina during cardiac catheterization, aortic pressure and electrocardiographic lead (V5) were recorded at rest, at the onset of anginal pain, 5 and 10 min after 0.6 mg sublingual nitroglycerin (NTG). Heart rate, systemic arterial pressure, systolic, and diastolic time intervals were measured. Heart rate and systemic arterial pressure rose significantly immediately after the onset of angina and declined progressively within 10 min from NTG administration. Preejection period did not change during angina, while left ventricular ejection time and electromechanical systole lengthened. As a consequence, diastolic time, expressed as percent of cardiac cycle, shortened sharply. All parameters considered went back to basal values within 10 min from NTG administration, and were preceded by relief or reduction of anginal pain. We concluded that a fall in diastolic time, secondary to a prolongation of electromechanical systole occurring during angina, may further increase the degree of ischemia resulting in a vicious cycle than can be interrupted by NTG administration.

Angina Pectoris↗
PubMed1982

Changes of systolic time intervals in asymptomatic patients with primary hyperlipoproteinemia.

Previous studies have focused on the usefulness of systolic time intervals to assess changes of myocardial function. In a recent report, hyperlipoproteinemia (HLP) was shown to induce early signs of vascular disease in asymptomatic subjects. By means systolic time intervals (STI) we studied left ventricular functions in normal subjects and asymptomatic patients with HLP, who showed normal response to exercise on a bicycle ergometer. The results showed mean values of STI for the population in the normal range, according to standards accepted in North American reports. Different values of STI were found when we compared the data of controls with the STI of HLP patients with higher values of PEPI and PEP/LVET and lower values of LVETI in HLP patients. These results suggest that hyperlipoproteinemia affects STI in asymptomatic patients, probably as a sign of early impairment of left myocardial function.

Adult↗
PubMed1980

Effects of intravenous disopyramide on myocardial function in patients with different degrees of cardiac failure.

The effects of intravenous disopyramide phosphate on myocardial function were evaluated by non-invasive indices of cardiac performance (systolic time intervals, STI) in 15 patients with atherosclerotic heart disease and different degrees of cardiac failure. Disopyramide (1.5 mg/Kg) was given intravenously over a period of 5 min. This drug induced in patients in I-II classes of NYHA a significant decrease of LVETc, while PEP, ICT, and PEP/LVET ratio rose significantly. STI were affected much more markedly in patients in III-IV classes of NYHA. Particularly affected were contractility indices (PEP, ICT, PEP/LVET), which were reduced significantly more in patients in III-IV classes as compares to patient in I-II classes. In contrast, LVETc, which correlates to stroke volume and cardiac output, was similarly worsened by the drug in the 2 groups of patients. Therefore, this study shows that disopyramide has relevant depressant effects on myocardial performance, simultaneously reducing stroke volume and contractility, and that the effect on contractility is more marked in patients with severe left ventricular impairment.

Arrhythmias, Cardiac↗
PubMed1980

Left ventricular function after coronary artery bypass. Non-invasive study by systolic time intervals.

Left ventricular function was evaluated with serial recording of STI intervals in 78 patients with stable angina on effort undergoing coronary and left ventricular cineangiography. On the basis of these data the patients were divided into four groups: OV) nor or mild coronary disease (n. 11); 1V) 70% stenosed vessel; 2V) two significantly affected vessels (n. 32); 3V) three significantly affected vessels (n. 18). Thirty-six patients (9 with one stenosis, 17 with 2, 10 with 3) underwent coronary artery bypass. Thirty-one 8 with one, 15 with 2, 8 with 3) refused the treatment in spite of the same clinical situation and were medically treated. Recordings were performed before medical and surgical treatment and after 6 and 12 months. Initial average values of the patients of 2V and 3V groups showed a shorter LVETI, longer PEPI and higher PEP/LVET ratio than those of 1V and 0V groups. Subjects of 2V group and abnormal left ventricular wall motion showed longer PEPI and higher PEP/LVET than patients of 2V without abnormal wall motion. On first evaluation no differences were observed between surgical and medical groups. The latter did not show any difference after 6 and 12 months. Surgical patients of 2V and 3V showed a longer LVETI, shorter PEPI and a lower PEP/LVET than the medical group. In the surgical group PEPI and PEP/LVET were significantly decreased after surgery while LVETI was prolonged. Our results suggest an improvement of left ventricular performance by coronary artery bypass in patients with coronary artery disease.

Coronary Artery Bypass↗