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Biomedical subjects

P Cinelli

Publications and source records attributed to P Cinelli.

At least 37 records · Page 2Linked to original sources
PubMed1986

Relationship between systolic time intervals and arterial blood pressure.

It has been suggested that systolic time intervals (STI) can be used to monitor the cardiac effects of antihypertensive treatments and also to evaluate hypertensive patients. STI changes observed in hypertensives have been ascribed to myocardial disease, although they could be due to the existence of a relationship between STI and blood pressure. A group of 37 subjects (18 normotensives and 19 hypertensives) with no signs of heart failure and left ventricular dysfunction were studied to examine the relationship of STI to blood pressure. Pacing with an external battery pulse generator was performed at the rate of 95 beats/min in order to eliminate differences in heart rate. STI were measured from good quality high speed (100 mm/s) recordings and the average value of 10 consecutive cardiac cycles was used for statistical analysis. Normal subjects showed significantly lower values of pre-ejection period (PEP), electromechanical systole (QS2), and pre-ejection period/left ventricular ejection time ratio (PEP/LVET). Moreover, a significant inverse relationship between diastolic pressure and LVET and significant direct relationships between diastolic pressure and PEP, systolic pressure and PEP, diastolic pressure and PEP/LVET, and between systolic pressure and PEP/LVET were demonstrated. We suggest to consider the relation of STI to blood pressure to provide regression equations to best appreciate and use STI.

Adult↗
PubMed1986

Muscular blood flow in patients with heart failure.

We studied reactive hyperemia in a group of patients with heart failure before and after therapy, since changes in the characteristics of muscular blood flow may influence the functional class of these patients. At the same time we evaluated some echocardiographic parameters too. When the patients improved clinically, they showed an increase in muscular blood flow at rest and in percent of fractional shortening and a decrease in peripheral vascular resistance. The reactive hyperemia did not change significantly. This fact probably depends on a maximal response to the postischemic hyperemia and represents the integrity of autoregulatory mechanisms.

Aged↗
PubMed1986

[Circadian and ultradian rhythms of the heart rate in the neonate].

Few papers deal with the chronobiologic characteristics of heart rate in neonates. A better knowledge of this topic could be useful under both clinical and therapeutical point of view. We studied the circadian and ultradian rhythms of heart rate in 10 healthy neonates (5 males and 5 females). Six of them (60%) show a well defined circadian rhythm of heart rate such as adult subjects even if with an obviously higher mesor and with acrophases dispersed throughout the 24 hours. We also demonstrated one or more ultradian rhythms of heart rate for each neonate. The most frequent have a period between 4 hours and 6 minutes and 4 hours and 36 minutes. These rhythms are out of phase with the world outside which is the best evidence that they are not imposed by some undetected external factors.

Circadian Rhythm↗
PubMed1985

A chronobiologic study on some cardiovascular parameters.

We studied the chronobiologic pattern of heart rate, R and T wave voltage, QT interval, and ST segment displacement. Premature atrial and ventricular beats obtained by dynamic electrocardiography, as well as arterial blood pressure measurements obtained by autometry, have also been studied in 131 untreated subjects (25 with hypertension, 28 with major risk factors for coronary artery disease, 9 with coronary artery disease, 37 presumably healthy and 11 shift workers). Our results show the existence of circadian rhythms in heart rate, in the duration of the QT interval and also in the voltage of R and T waves. Our data for R and T wave voltages do not completely agree with those from other authors. We demonstrated also that smoking may influence the circadian acrophase of the rhythm in R wave voltage while sleeping does not show any relationship with R and T wave voltages although it seems related to the displacement of the ST segment. We could point out only small differences in the chronobiologic behavior of patients with coronary disease and that of normal subjects, unlike the results previously reported by other authors. Our study demonstrated the existence of circadian and ultradian rhythms in premature atrial and ventricular beats as well as circadian and circaseptan rhythms in arterial blood pressure. Further studies are needed to improve our chronobiologic knowledge in order to optimize dosage and time of administration of the drugs used in the long term management of arrhythmias and hypertension.

Adult↗
PubMed1985

Reduction of cardiac toxicity of anthracyclines by L-carnitine: preliminary overview of clinical data.

Doxorubicin is one of the most effective antineoplastic agents but its limited use is due to acute and chronic cardiotoxicity. These side-effects are irreversible and dose-dependent, occurring in one-third of the patients treated after a cumulative dose of 300 mg/m2. It has been suggested that the problem of acute and chronic cardiotoxicity may be prevented by using L-carnitine. Hence nine patients receiving a cumulative dose (200-490 mg/m2) of doxorubicin have been studied. Acute cardiotoxicity has been evaluated by creatine kinase---marsh bender (MB) serum levels before and 15 h after treatment. Data demonstrated no significant increase of isoenzyme-MB after doxorubicin administration. Chronic cardiotoxicity has been monitored studying the electrocardiograph and the left ventricular performance by computerized M-Mode echocardiography measuring the maximal velocity of circumferential fibre shortening (VCF Max) which is considered a reliable and very sensitive non-invasive parameter to evaluate myocardial contractility. The results show a decrease in VCF Max (measured in diameter/cardiac cycle) from 1.7 +/- 0.4 to 1.4 +/- 0.3 but still within normal values. So the systematic use of L-carnitine as adjuvant therapy is proposed during doxorubicin administration.

Adolescent↗
PubMed1985

Effects of isoproterenol and methoxamine on the electrocardiogram.

The effects of isoproterenal (ISP) and methoxamine (MTX) infusion in 20 asymptomatic subjects with labile T wave were studied. In those treated with ISP the T wave showed an early negative trend and later became clearly positive in 5 subjects. In the majority of the subjects treated with MTX the T wave became positive. T wave changes match variations of both the ventricular gradient and, to a lesser degree, the QRS area. These changes were not related to heart rate or, in the subjects treated with MTX, to the baroreceptorial sensitivity deduced from the slope of the regression equation between R-R internal and systolic arterial pressure. The results of this study confirm the existence of a neurogenic mechanism affecting the electrocardiographic changes in T wave.

Adult↗
PubMed1984

Heart rate and premature beats: a chronobiologic study.

Sixteen subjects, mean age 59 +/- 18, 11 normal and 5 with coronary artery disease, all having premature ventricular and/or atrial beats in the standard resting electrocardiogram (ECG), were studied to analyse the chronobiologic parameters of these arrhythmias. Single cosinor analysis of the data obtained by 96-hour ECG performed according to the Holter system, demonstrated: A) significant circadian rhythm in heart rate for all the subjects, with acrophases occurring between 12.56 and 17.36; B) significant circadian rhythms of premature ventricular beats for the majority of the subjects, with acrophases distributed along the 24 hours; C) significant circadian rhythms in premature atrial beats for 8 subjects, with acrophases occurring between 04.24 and 18.12; D) a spectrum of significant ultradian rhythms in heart rate with various periodicities, both in normal and in coronary patients; E) significant ultradian rhythms in premature ventricular beats for 8 subjects with periods ranging from 5h 15' to 17h. Population mean cosinor analysis demonstrated: A) significant circadian group rhythm in heart rate for all the 16 subjects and for the group of 11 normal subjects; B) no significant circadian group rhythm for premature ventricular and atrial beats. These findings suggest that the study of the individual chronobiologic pattern of premature beats may help to optimize antiarrhythmic therapy.

Cardiac Complexes, Premature↗
PubMed1984

Clinical electrophysiological effects of chronic administration of verapamil: the phenomenon of overdrive excitation of junctional pacemaker.

The electrophysiological effects of chronic administration of verapamil were studied in 10 patients with normal sinus node function, who received 160 mg of the drug every eight hours for at least two weeks. Uncorrected and corrected sinus node recovery time, sino-atrial conduction time, effective and functional refractory periods were normal in each case. In three patients, at the cessation of atrial pacing, an overdrive excitation of junctional pacemaker with short lasting A-V dissociation was observed.

Electric Stimulation↗
PubMed1984

Computerized M-mode echocardiography in the assessment of cardiovascular effects during intravenous administration of amiodarone.

Antianginal and antiarrhythmic long term therapy with amiodarone may be associated with side effects, therefore it should be used mainly in short term treatment of severe arrhythmias and acute coronary insufficiency. It is important to assess if any inotropic effect may be produced after intravenous administration of this drug in commonly accepted therapeutic doses (5 mg/kg body weight). To investigate this possibility we studied the effects of amiodarone on blood pressure (BP), on heart rate (HR) and on the maximal velocity of circumferential fiber shortening (Vcf Max). Simultaneous echocardiogram (UCG), electrocardiogram (lead DII) (ECG) and BP cuff measurement were performed on 12 subjects without cardiomegaly and clinical evidence of heart failure, immediately before a 30 second intravenous injection of amiodarone and every 30 seconds over a period of 6 minutes after drug administration. Amiodarone administration markedly raised HR within the first 30 seconds from the beginning of the injection and concomitantly decreased diastolic BP. No significant lowering of systolic BP was observed. Vcf Max (circ/sec) raised during the test concomitantly with HR increase, showing a significant relationship between left ventricular performance and HR. The same was also true during atrial pacing performed on one subject. No significant changes in any of the parameters studied were demonstrated after placebo (saline solution) administration to two presumable healthy subjects. Amiodarone does not seem to have any positive or negative intrinsic inotropic effect when administered intravenously at a dose of 5 mg/kg body weight.

Adolescent↗
PubMed1983

Circadian rhythms in dynamic electrocardiography.

A group of ten healthy subjects aged 32-58 years was studied by dynamic electrocardiography. An electrocardiogram (ECG) was recorded on CM 5 lead for 14 seconds every 15 minutes during the 24 hours. All the subjects were under a similar nyctohemeral schedule, sleeping between 23.30 and 06.45, and all followed their spontaneous diet without any restriction. "Mean Cosinor" analysis of the data revealed statistically significant circadian rhythms of heart rate (HR), R and T-wave voltages, duration of the QT interval and ST segment displacement, but not of the duration of the corrected QT (QTc).

Adult↗
PubMed1982

Systolic time intervals during isometric exercise in supine position should be corrected also for arterial pressure.

In this paper we have studied the relationship between the systolic time intervals (STI) and the heart rate (HR) and systolic arterial pressure (SAP) in a group of 24 healthy subjects at three different effort levels during an isometric exercise in supine position and in basal conditions. We observed a decrease of the non corrected STI values during the exercise. Then we corrected STI using the regression equations obtained by plotting STI values versus the corresponding HR values at rest and during the exercise. We showed an increase of corrected left ventricular ejection time (LVET) during the whole exercise, and an increase of corrected total electromechanical systole (QS2c) at 50% effort level and then a return to the basal values. We also derived the multiple regression equations correlating QS2 and LVET with HR and SAP. Notwithstanding these equations show a significant positive correlation between the two STI considered and SAP only at the maximum effort, we corrected LVET and QS2 values by these equations assuming that the relationship between these parameters exists also in basal conditions and during the remaining stages of the exercise. By this correction we found a decrease of LVETc and QS2c in accordance with hemodynamic data reported by other authors. We may conclude that it seems useful to correct the STI obtained during isometric exercise in supine position both for HR and SAP.

Adult↗
PubMed1982

STI usefulness during isometric exercise in labile hypertensive patients.

Measurement of the left ventricular systolic time intervals (STI) was considered a valid method in demonstrating the presence of a state of beta-drenergic hyperstimulation. The authors used this method during isometric exercise to differentiate between a group of 16 normal subjects (N) and 16 random labile hypertensives (LH), and between the N and 16 fixed hypertensives (FH). Exercise resulted in a general shortening (p less than 0.01) of the STI, an increase (p less than 0.01) in the systolic arterial pressure (SAP), and an increase (p less than 0.01) in the heart rate (HR) in all the groups studied. The study also demonstrated that the state of blood pressure (diagnosis) alone does not significantly influence the course of the exercise test, and that the interaction diagnosis-exercise gives quantitatively different results in the three groups, to the extent that it is possible to recognize a specific polygraphic pattern for the LH. In this group there is a greater shortening of the Q--S2 and the non-corrected LVET (p less than 0.01) than for the N. The behaviour for the FH falls between the other groups, but it is not possible to distinguish clearly between this group and its neighbour on either side. We conclude that the measurement of the STI during isometric exercise could be useful in determining a diagnostic pattern for subjects who show a lability in their blood pressure.

Adult↗
PubMed1982

[The normal values of systolic time intervals must be reviewed?].

A study of the relation between left ventricular ejection time (LVET) and arterial blood pressure (BP), was carried out in 26 healthy volunteers divided into 2 groups. A rise in BP was achieved in the first group of 2 subjects by venous infusion of 0.02% methoxamine solution. The heart rate was held constant by right atrial pacing and the arterial blood pressure was measured by catheterization of the right radial artery. A simultaneous recording of the electrocardiogram, the carotid arterial pulse and the arterial blood pressure tracings, was obtained. The relationship between LVET and the corresponding values of BP was examined by plotting LVET against BP. The second group of 24 subjects underwent a session of maximal isometric exercise. When the maximum of the effort was reached, the carotid arterial pulse tracing was recorded and the blood pressure of the arteria dorsalis pedis was measured by doppler technique. In both groups we plotted LVET against BP and HR. Simple and multiple regression equations were obtained. Our data show that LVET correlates with BP during the maximal isometric exercise and during venous infusion of methoxamine, suggesting that the normal values of systolic time intervals (STI) should be revised.

Blood Pressure↗
PubMed1978

[An echocardiographic study of the anatomo-functional alterations of the left ventricle in patients with different degrees of systemic hypertension (author's transl)].

An evaluation of the functional state of the left ventricle through an estimate of the mean Vcf (Vcf) and the ejection fraction (EF) was made i- 30 patients, subdivided into groups according to average blood pressure rate, degree of severity of the retinographic alterations and ECG pattern. In addition, the thickness of the interventricular septum (S), the posterior wall (PP) and the S/PP were measured. Lastly, the mass of the left ventricle was determined through the following formula: mass = (h1+h2+Dd)3 -- Dd3X1,050. Only one patient was under treatment with beta-blocking drugs, and no patient presented clinical symptoms of cardiac decompensation. The Vcf and the EF did not deteriorize when the hypertensive pattern worsened, while there was an expansion of the thickness of the S and an increase in the mass of the left ventricular. The increase of the ventricular mass, however, was not always found to be associated with normal functionality, nor was an increase of the mass always present even in cases of highly evident hypertension. It is likely, therefore, that other factors not taken into consideration (time factor, for example) play an important role in determining the functional state of the left ventricle and degree of hypertrophy.

Adult↗
PubMed1976

[Normal echogram of the mitral valve. Study of 50 normal, military-age subjects].

The mitral echograms of 50 normal subjects of military age were studied and basic parameters compared with anthropometric data and heart frequency; unlike what has been found by other workers, no significant statistical correlation was observed. Mean values of the parameters used are not substantially different to those reported in the literature consulted although deeper statistical studies are required if more valid standards are to be found.

Adolescent↗
PubMed1976

Bioavailability of digoxin and beta-methyl-digoxin.

In a randomized crossover study the bioavailability of a single dose of digoxin and of beta-methyl-digoxin tablets was tested in four normal volunteers. No difference was found between the two products in the rate and extent of drug absorption using 6 day cumulative urinary excretion and serial serum concentration measurements.

Adult↗
PubMed1975

[Haemodynamic effects of nitroglycerin (author's transl)].

The haemodynamic effects of nitroglycerin (0.6 mg sublingual) have been studied in eleven patients with coronary artery disease, by means of the thermodilution method which enables cardiac output to be repeatedly measured at short time intervals (1-2 minutes). The following data have been studied: blood pressure (BP), pulmonary arterial pressure (PA), left ventricular filling pressure (LVFP), cardiac output (CO), stroke volume (SV), heart rate (HR), total systemic resistance (TSR), total pulmonary resistance (TPR), tension-time index (TTI) and left ventricular stroke work index (LVSWI). Within 1 minute following nitroglycerin (NG) administration the patients showed a decrease in TSR, TPR, and an increase in CO, SV, HR and LVCWI. TTI was reduced at the 5th minute. LVFP, PA and BP decreased after 3-5 minutes. CO increase at the 1st minute often compensated the fall in TSR, and blood pressure remained unchanged. The LVSWI/LVFP curve showed a transitory shift to the left at the 1st minute. In eleven normal subjects NG induced a minor increase in CO and SV, and a minor decrease in TSR at the 1st minute. The mechanism of action of NG in angina pectoris is briefly discussed.

Angina Pectoris↗