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Biomedical subjects

C Marabotti

Publications and source records attributed to C Marabotti.

32 records · Page 2Linked to original sources
PubMed1988

Long-term reproducibility and evaluation of seasonal influences on blood pressure monitoring.

The aim of this study was to evaluate the long-term reproducibility and the possible seasonal influences on casual blood pressure and ambulatory blood pressure monitoring in patients with borderline or mild arterial hypertension. Two sets of measurements were performed at 6-month intervals, one set in the warm and one in the cold season, using the same protocol, consisting of measurements of casual and ambulatory blood pressures, together with the recording of outdoor temperatures. Casual blood pressure was measured by an automatic recorder and 24-h ambulatory blood pressure monitoring was performed by a non-invasive device. For the selected intervals, the reproducibility of most pressure measurements was low; in addition, casual diastolic pressure and 24-h systolic and diastolic pressures were significantly higher in the cold than in the warm season. Taken together, these findings confirm and extend the results obtained in several large-scale studies and support the importance of taking environmental temperature into account, not only in epidemiological studies but also in small-scale studies and probably even in the individual patients, especially when using integrated evaluations by ambulatory monitoring.

Adult↗
PubMed1988

Cardiovascular reactivity to physical and psychologic stress during long-term treatment with nitrendipine in essential hypertension.

Nitrendipine is a second-generation dihydropyridine calcium antagonist selective for hypertension. The aim of this study was to assess whether, in addition to reduce resting blood pressure, nitrendipine also affects the cardiovascular reactivity to physical and psychologic stress. Ten essential hypertensive patients, out of treatment for at least 2 weeks, underwent a symptom-limited dynamic maximal exercise and a mental arithmetic stress test (MAT) after placebo (1 week) and 1 and 5 weeks of active treatment with nitrendipine (20 mg q.i.d.). To evaluate the cardiovascular response to exercise and its changes during treatment, the slope of the regression line (if statistically significant) of the blood pressure, heart rate, and rate-pressure product (RPP) values against workload were considered, together with exercise capacity, blood pressure, and pressure-rate product at the peak of maximal exercise. During mental stress, indexes of stroke volume (SVI), cardiac output (COI), and peripheral resistance (TPRI) were obtained by Doppler transcutaneous aortovelography (TAV). Resting systolic and diastolic BP were significantly reduced during treatment. The average length of exercise was 7.3, 7.64, and 8.0 min after, respectively, placebo, 1, and 5 weeks of treatment. Peak systolic and diastolic BP, peak RPP, and RPP slope were consistently decreased after treatment, significantly for peak DBP and RPP. During mental arithmetics, a significant increase of BP and HR and a decrease of SVI were observed on placebo; both BP and SVI responses disappeared after 5 weeks on nitrendipine, whereas the HR increase was unchanged. Peak values of COI and TPRI during MAT were significantly increased and decreased, respectively, after nitrendipine, whereas basal values showed similar changes, but not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Changes in renal function during physical and mental effort.

Aim of the study was to evaluate the renal responses to physical and mental effort in essential hypertension by means of a non-invasive radioisotopic method. Renal uptake rate of Tc99m-DMSA was evaluated in 10 subjects. Starting from 5 to 15 minutes after dose injection counts over the kidney region were acquired by means of a gamma-camera time-activity curves were obtained for each kidney. In non-stimulated patients DMSA uptake rate increased regularly; in the remaining cases both isometric exercise and mental effort induced an abrupt reduction of the uptake rate which increased again after the end of the test. Although the relation of DMSA uptake rate to renal function is not yet fully understood, we tentatively interpret these results as indicating blood flow reductions during these stressful conditions.

Humans↗
PubMed1987

Long-term hypotensive treatment with nitrendipine in mild to moderate essential hypertension: preliminary results of a placebo-controlled study versus atenolol.

Nitrendipine is a dihydropyridine calcium antagonist suggested to be a new drug for first-line antihypertensive therapy, possibly active in once-daily administration. In the present study the acute and long-term hypotensive effects of nitrendipine have been evaluated in comparison with those of atenolol in a randomized, double-blind, clinical trial. Twenty-four patients have been studied, and the effects of treatment have been evaluated both at rest and during psychological and physiological stresses. Hemodynamic noninvasive parameters have also been obtained, at rest and during mental arithmetic tests, by a continuous-wave Doppler technique. Preliminary results about the first 13 consecutive patients are reported here. Nitrendipine induced a highly significant acute hypotensive effect (2 h after drug administration), whereas no effect was observed for atenolol except for heart rate. During chronic treatment (5 weeks), nitrendipine showed less hypotensive effect than atenolol when BP values 24 h after the last administration were analyzed, but significantly more effect when values obtained 2 h after drug administration were evaluated. These findings confirm that nitrendipine is effective in decreasing blood pressure, but the once-daily administration may not bring about the maximum effect in all patients. Interesting aspects of this drug, which make the clinical use of this compound safe, are represented by apparent lack in tolerance and rebound, and by the moderate increase in cardiac output associated with the treatment.

Adult↗
PubMed1987

Medium-term reproducibility of stress tests in borderline arterial hypertension.

Stress tests are commonly used for an evaluation of blood pressure reactivity, but few data exist in the literature about interindividual variability and intraindividual medium-term reproducibility of blood pressure responses to these tests in borderline hypertension. To this aim we have studied 20 borderline hypertensive patients (age range, 33-59, mean 45). Our data suggest that borderline hypertensive patients cannot be considered a homogeneous group with regard to blood pressure reactivity because they tend to have widely different blood pressure responses to various stress tests. For each test (except for orthostatic stimulation), a fairly good intraindividual reproducibility was found. Considering the poor correlations existing between blood pressure responses to tests for each patient, one test may not be sufficient to characterize blood pressure reactivity to stress in borderline hypertension.

Adult↗
PubMed1986

Acute hypotensive effect of calcium antagonists and endogenous digitalis-like immunoreactivity in human essential hypertension.

Evidence has been provided on the increased presence, in essential hypertension, of endogenous digitalis-like factor(s) [DLIS, digoxin-like immunoreactive substance(s)] able to cross-react with antidigoxin antibodies and to inhibit the membrane-bound sodium-potassium pump. An inhibition of the sodium pump could lead, in smooth muscle cells, to an increase of intracellular calcium ions and to an increase of total peripheral resistances. In this study the relation between plasma levels of DLIS and the acute hypotensive effect of a calcium antagonist (nifedipine) has been evaluated in a group of borderline to severe hypertensive patients and in a control group of normotensive subjects. The results obtained confirm that the hypotensive effect of nifedipine is related to pretreatment blood pressure and show, only in hypertensive patients, a significant relation of DLIS with both pretreatment blood pressure and blood pressure decrement induced by nifedipine. These findings are compatible with a possible role of DLIS in modulating cellular calcium handling.

Adult↗
PubMed1985

Electrocardiogram blood pressure and systolic time intervals long term monitoring in ambulant patients.

Ambulatory monitoring of the intra arterial blood pressure (IBP), through the Selyg-Oxford System, has been used so far primarily for studies on hypertension. Aim of our study is to explore the possibility of obtaining from IBP indications useful to extend its field of application. The study will investigate: the usefulness of the continuous monitoring of the systolic time intervals (STI), measured from IBP as ventricular performance indicators, the increasing of specificity of the ECG allowed by the simultaneous beat by beat estimate of the STI's, the possibility of achieving the same information from non invasive peripheral pressure transducers. In this paper we are presenting the results obtained from the combined analysis of the STI's, ECG and IBP in a first series of 13 patients, selected out of 50 on the basis of the highest number of episodes of IBP variations, to allow the evaluation of the algorithms performances in severe conditions.

Blood Pressure↗
PubMed1985

The intraarterial blood pressure monitoring in the evaluation of patients with dizziness and/or fainting.

Ambulatory blood pressure (BP) monitoring has been extensively utilized, so far, for studying BP profile and hypotensive treatment in arterial hypertension. In this paper, preliminary data will be reported from a clinical study on the possible contribution of the combined ECG and BP monitoring in clarifying mechanisms of dizziness in patients with multiple or complex cardiovascular problems. Results are shown of three patients with ischaemia, arrhythmias and/or episodes of hypotension, and of three patients with borderline hypertension and marked fluctuations of BP.

Arrhythmias, Cardiac↗
PubMedDate not supplied

Left ventricular mass in borderline hypertension, assessed by echocardiography. Relationships with resting and stress blood pressure.

The relationship between clinical measurement of blood pressure (BP) and left ventricular hypertrophy in arterial hypertension appears to be weak in most studies. On the contrary, stronger correlations with target organ damage in general, and left ventricular hypertrophy in particular, have been reported for blood pressure measurements obtained by ambulatory monitoring; this finding may indicate a possible role for blood pressure response to naturally occurring stresses in determining left ventricular hypertrophy. Aim of this study was to investigate, in 18 patients with borderline arterial hypertension, the relationships between echocardiographically assessed left ventricular mass and, respectively, casual BP and BP responses to some standardized stress tests. Only three patients had a diastolic wall thickness of the interventricular septum and of the posterior wall greater than or equal to 1.2 cm and none had a pathologically increased left ventricular mass index. The following statistically significant correlations were found: casual diastolic BP vs. left ventricular mass index (r = 0.53, p less than 0.02), systolic BP response to bicycle exercise test vs. left ventricular mass index (r = 0.55, p less than 0.05). Multiple regression analysis showed that almost fifty percent of the variability of left ventricular mass index could be predicted by these two BP measurements. These findings suggest that besides the chronically increased afterload, also the transient hypertensive responses to naturally occurring physical stresses may have a role in determining the extent of cardiac structural changes in borderline hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗