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Biomedical subjects

C Longhini

Publications and source records attributed to C Longhini.

At least 19 recordsLinked to original sources
PubMed1997

Estimating mean pulmonary wedge pressure in patients with chronic atrial fibrillation from transthoracic Doppler indexes of mitral and pulmonary venous flow velocity.

OBJECTIVES: We sought to obtain a noninvasive estimation of mean pulmonary wedge pressure (MPWP) in patients with chronic atrial fibrillation (AF). BACKGROUND: It has previously been demonstrated that MPWP can be reliably estimated from Doppler indexes of mitral and pulmonary venous flow (PVF) in patients with sinus rhythm. Doppler estimation of MPWP has not been validated in patients with AF. METHODS: MPWP was correlated with variables of mitral and pulmonary venous flow velocity as assessed by Doppler transthoracic echocardiography in 35 consecutive patients. The derived algorithm was prospectively tested in 23 additional patients. RESULTS: In all patients the mitral flow pattern showed only a diastolic forward component. A significant but relatively weak correlation (r = -0.50) was observed between MPWP and mitral deceleration time. In 12 (34%) of 35 patients, the pulmonary vein flow tracing demonstrated only a diastolic forward component; a diastolic and late systolic forward flow was noted in the remaining 23 patients (66%). A strong negative correlation was observed between MPWP and the normalized duration of the diastolic flow (r = -0.80) and its initial deceleration slope time (r = -0.91). Deceleration time > 220 ms predicted MPWP < or = 12 mm Hg with 100% sensitivity and 100% specificity. When estimating MPWP by using the equation MPWP = -94.261 PVF deceleration time -9.831 Interval QRS to onset of diastolic PVF -16.337 Duration of PVF + 44.261, the measured and predicted MPWP closely agreed with a mean difference of -0.85 mm Hg. The 95% confidence limits were 4.8 and -6.1 mm Hg. CONCLUSIONS: In patients with chronic AF, MPWP can be estimated from transthoracic Doppler study of PVF velocity signals.

Age Factors↗
PubMed1997

Age-related differences of blood pressure profile in essential hypertension.

The purpose was to assess age-related circadian changes of blood pressure profile (BPP) employing a truncated Fourier series with four harmonics (tFs) in patients with essential hypertension. The study was performed on 32 patients with essential hypertension divided in two groups: (A) 15 patients younger than 55 years and (B) 17 patients older than 60 years. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were monitored every 20 minutes for 24 h with a noninvasive portable device (SpaceLabs 90202). To evaluate the existence of SBP and DBP circadian rhythms a one-sample runs-test was performed and the mesor, amplitude, and acrophase from the overall curve of each patient were obtained by tFs. In both groups, SBP and DBP profiles showed a first peak in the late morning and a second peak in the early evening around the same hours. The two peaks in the SBP profile were higher and the two peaks in the DBP profile were lower in older patients than in younger ones (p < .01, p < .05, p < .3, p < .05). The truncated Fourier series with four harmonics evidences different age-related BP profiles characterized by two peaks with higher SBP and lower DBP in elderly patients. These changes of BPP are in accordance with the reported higher risk of cardiovascular events observed around the same hours.

Adult↗
PubMed1996

The mechanism of the physiologic disappearance of the third heart sound with aging.

The third heart sound (S3) is often present in children and adolescents but is not present in most adults. Applying at the left ventricle a mathematical model, the mechanism of the disappearance of S3 was studied employing the frequency analysis of the sound and echocardiographic data. The existence of a significant correlation between the spectrum energy of S3 and the diameter and thickness of the left ventricle at the moment of S3 in 25 healthy subjects (aged 21 +/- 7 years) allowed us to interpret the origin of S3 based on a viscoelastic oscillating system. Once the left ventricle starts vibrating it behaves as a simple physical model composed of a mass (m), a spring (k) and a viscous element. The abrupt deceleration of the blood mass (m) against the left ventricular walls (k) triggers the vibration of the system according to the equation Fd = 1/2 pi.square root of k/m.square root of 1 - zeta 2, where Fd is the natural damped frequency and zeta is the damping factor. The equation shows that the vibrating system can oscillate only if zeta is < 1. During the growth of the individual the increased myocardial mass may lead to augmented viscous forces causing a gradual increase in zeta until the system becomes overdamped and consequently unable to vibrate causing the disappearance of S3.

Adult↗
PubMed1995

The response of the ageing heart to regular physical exercise. An echo and Doppler study.

In upper middle age healthy subjects the functional cardiac reserve is known to be decreased (Port et al., 1980; Aubert et al., 1994). On the other hand regular physical exercise improves the cardiovascular function (Nishimura et al., 1980). The aim of this study was to establish whether regular physical exercise is associated with a significant change in the ageing process of the cardiovascular system.

Aging↗
PubMed1995

An estimation of the left ventricular diastolic function from the spectral analysis of the fourth heart sound. A Doppler validated study in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a typical primary cardiac disease characterized by diastolic abnormal function due to both prolonged relaxation and decreased compliance (Sanderson et al., 1977; Spirito & Maron, 1990). Since the contribution of the atrial systole to ventricular filling is usually increased, the appearance of a fourth heart sound (S4) is a common finding in HCM. This sound is related to the ventricular compliance and to the atrial contractility. It is generated during the rapid setting into vibration of the left ventricular walls that results from the rapid rush of the blood due to the atrial contraction (Nishimura et al., 1989; Tavel, 1978). The aim of this study is to look for relationships between the frequency peak of S4 and various mono- and two-dimensional echocardiographic parameters in order to identify those cardiac structures involved in its genesis and obtaining an estimation of the stiffness of the acoustic vibrating system with a simply vibratory model (Baracca et al., 1991).

Cardiomyopathy, Hypertrophic↗
PubMed1995

Genesis and acoustic quality of the physiological fourth heart sound.

The genesis of the fourth heart sound (S4) is commonly related to the rapid set in vibration of the left ventricular walls, resulting from the rapid inflow of the blood due to the atrial contraction (Nishimura et al., 1989). S4 can be recorded in normal young subjects as an expression of physiologic atrial dynamics but it is more common in pathologic conditions characterized by decreased ventricular distensibility (Tavel, 1978). Employing the spectral analysis of heart sounds (Longhini et al., 1979; Longhini et al., 1981; Aubert et al., 1984) we searched for the relationship between different components of the frequency spectrum of S4 and various echocardiographic parameters, with the aim of identifying the cardiac structures involved in its genesis (Longhini et al., 1989; Baracca et al., 1991).

Acoustics↗
PubMed1994

Comparative diagnostic value of transesophageal echocardiography and retrograde aortography in the evaluation of thoracic aortic dissection.

The aim of this study was to assess the comparative diagnostic value of transesophageal echocardiography (TEE) and retrograde aortography for morphologic evaluation and anatomic mapping of aortic dissection. Seventy patients (aged 18 to 79 years) were prospectively evaluated with both techniques for suspected aortic dissection. In 64 patients, findings on aortography and TEE could be validated against intraoperative (n = 53) and postmortem (n = 11) findings. Examination time was significantly shorter for TEE (9 +/- 6 vs 48 +/- 25 minutes; p < 0.001). For the detection of aortic dissection, aortography showed lower sensitivity (87.5% vs 97.5%) and negative predictive value (85.3% vs 96.7%; both trends did not reach statistical significance) due mostly to the inability to identify noncommunicating dissection (dissection without intimal tears). For the epiphenomena of aortic dissection, aortography was significantly more accurate (97.2% vs 78%; p < 0.05) in assessing the site of entry, and TEE was more accurate in identifying thrombus formation (90% vs 65%; p < 0.05). There was no significant difference between aortography and TEE with regard to assessing secondary tears, aortic regurgitation, coronary dissection, and extension of the dissection. Thus, both TEE and aortography offer detailed anatomic mapping for guided surgical interventions. In elective patients, integration of both techniques seems the best approach; in unstable patients, TEE may be preferential because it is less invasive, requires no contrast injection, and provides accurate diagnosis in a short time at the bedside.

Adult↗
PubMed1994

Estimation of left ventricular diastolic pressures from precordial pulsed-Doppler analysis of pulmonary venous and mitral flow.

Because analysis of pulmonary venous flow (PVF) will be extensively used in comprehensive Doppler assessment of left ventricular diastolic function, this study was designed to (1) evaluate the feasibility of PVF measurement in 116 consecutive patients with various cardiac abnormalities by using precordial pulsed Doppler echocardiography; (2) Estimate mean pulmonary capillary pressure (MPCP) and left ventricular end-diastolic pressure (LVEDP) from Doppler variables of PVF and mitral inflow; and (3) evaluate the influence of clinical and hemodynamic variables on PVF Doppler patterns. We adequately recorded anterograde PVF in 96 (82.7%) patients and retrograde PVF in 45 (38.7%) patients. The strongest correlation between MPCP and Doppler variables of PVF was found with systolic fraction (the systolic velocity time integral expressed as a fraction of total anterograde PVF) (r = -0.88; p < 0.001). Age influenced this relation, with progressive increase of the systolic fraction in older patients. A good correlation (r = 0.72; p < 0.001) was found between LVEDP and the difference in duration of the reversal PVF and the mitral a wave. In conclusion, (1) PVF can be recorded adequately in most patients with precordial Doppler echocardiography; (2) left ventricular diastolic pressures can be estimated reliably by precordial Doppler echocardiography; and (3) the clinical meaning of Doppler-derived indexes of left ventricular diastolic performance is age-related.

Adult↗
PubMed1993

Biliary cyst. A case report.

A case of type-IA biliary cyst, according to the Todani classification, is reported in a 44-years-old man admitted to hospital with epigastric pain. Ultrasound was misleading; CT scanning and preoperative cholangiography confirmed the biliary duct's dilatation. Cyst excision and hepaticojejunostomy were performed with a view to avoiding possible cyst cancerization.

Adult↗
PubMed1992

A new, noninvasive method to monitor the aging of bioprosthetic valves in the mitral position.

Bioprosthetic valves undergo a tissue degeneration of unpredictable onset and amount. This process alters the structure and function of the valve and consequently shortens its lifespan. The echocardiographic technique usually used in the follow-up of these patients does not provide accurate information concerning the amount of prosthesis tissue degeneration. A new technique has been developed based on the spectral analysis of the first heart sound, which enables the evaluation of prosthetic leaflet stiffness. The Young's modulus (E) and stress (s) of the valve leaflets were derived as functions of the inner diameter of the heterograft and its primary vibration frequency, which can be obtained from the frequency spectrum of the first heart sound. Thirty-six patients with a mitral bioprosthetic valve were studied. Fifteen had thickening or calcification, or both, of the valvular leaflets at echocardiographic examination. In patients with a normal valve, E and s showed a good correlation with the duration of implantation (r = 0.909, p < 0.001; and r = 0.828, p < 0.001; respectively). Patients with abnormal leaflets had values of E and s that were greater than the theoretical values expected for their duration of implantation. The procedure is sensitive, accurate and easy to perform, and enables monitoring of the aging of the prosthetic valve and early identification of valve tissue degeneration. Together with echocardiography, this procedure yields a more complete evaluation of prosthetic valves for the follow-up of patients.

Aged↗
PubMed1992

Acute and chronic nitrendipine administration in essential hypertension: a chronobiologic study.

To evaluate the chronobiologic pattern of the hypotensive effect of nitrendipine, 10 patients with mild-to-moderate arterial hypertension were studied. They received a randomized single dose (20 mg) of nitrendipine and placebo, and 20 mg of nitrendipine daily for 2 months. Systolic and diastolic blood pressure (SBP and DBP, respectively) and heart rate (HR) were measured for 24 h using an automatic noninvasive device. The data were analyzed by single and mean cosinor methods and by ANOVA and Student's paired t test. Chronic administration of nitrendipine resulted in a more effective lowering of the SBP and DBP mesor, compared with placebo and acute administration, preserving the circadian rhythms. The preservation of the HR circadian rhythm agrees with the lack of interference of the drug with neurohormonal mechanisms.

Adult↗
PubMed1991

Non-invasive estimation of the diastolic elastic and viscoelastic properties of the left ventricle.

The present study applies a non-invasive method to the quantitative evaluation of left ventricular stiffness in normal subjects and in patients with ischaemic heart disease (IHD). We have studied 20 patients with IHD and 25 healthy subjects. The third heart sound (S3) was detectable in all patients. We have correlated the energy spectrum of S3, divided into 15 Hz bands, with a series of echocardiographic parameters. The existence of a significant correlation between the spectrum energy and the diameter and thickness of the left ventricle at the moment of S3 allowed us to explore the possibility of interpreting the origin of S3 based on a mathematical model. Our hypothesis has been that, once the left ventricle starts vibrating, it behaves as a simple physical model composed of a mass and an elastic element. To this purely elastic model one can add a factor accounting for viscosity, with a damping effect, to obtain a more complex viscoelastic model. The stiffness coefficient 'k' was computed in both models from the peak frequency of S3 and the left ventricular mass at the moment of S3. Furthermore, in the viscoelastic model, the damping element 'c' was also computed. Both parameters--k and c--were significantly increased in the group with IHD compared with the control group. Although a simplification of the vibrating system, these models make it possible to obtain non-invasively information on the characteristics of the left ventricle through the combined use of echocardiography and spectral analysis of S3.

Adolescent↗
PubMed1991

Circadian rhythm of blood pressure and calcium entry blockade: a chronobiologic study with nitrendipine in essential hypertension.

In order to evaluate the chronobiologic effect of nitrendipine, 27 patients with mild-to-moderate arterial essential hypertension were studied. After randomized administration of 20 mg of nitrendipine and placebo, systolic and diastolic blood pressure (SBP and DBP, respectively) and heart rate (HR) were measured for 24 h using an automatic noninvasive device. The data of the time series were statistically analyzed by single and mean cosinor methods (obtaining mesor, amplitude, and acrophase) and by ANOVA and Student's paired t test. Nitrendipine significantly reduced the SBP and DBP mesors without affecting the HR mesor, and reduced the SBP and DBP amplitudes while increasing the HR amplitude. After placebo, group circadian rhythms were observed for SBP, DBP, and HR and maintained after nitrendipine. In conclusion, a single-dose administration of nitrendipine is effective in lowering blood pressure. The increased HR amplitude is probably due to a tachycardic reaction. The preservation of the SBP, DBP, and HR group circadian rhythms agrees with the lack of interference of the drug with the neurohormonal mechanisms.

Adult↗
PubMed1991

Peripheral vascular circulation in trained athletes.

Modifications in the neurogenic control are important in cardiovascular adaptation to physical training. To examine the influence of such variations on arterial blood pressure, heart rate and limb blood flow the Authors have studied the reaction to cardiovascular stress tests of soccer players and sedentary controls. No difference was found in the blood flow response between athletes and sedentary subjects. However, the tests inducing sympathetic activation determined blood pressure response of different intensity, possibly related to the differences in the autonomic nervous system control.

Adult↗
PubMed1990

The effect of captopril on peripheral hemodynamics in patients with essential hypertension: comparison between oral and sublingual administration.

A comparative study of the effects of oral and sublingual captopril on the hemodynamics of the peripheral musculocutaneous vasculature was carried out on ten patients with essential hypertension. Both routes of administration of captopril lead to lower blood pressure and decreased regional resistance, and to an increased arterial blood flow at rest. The first measurable effect and the peak effect on blood pressure and peripheral hemodynamics appear slightly earlier with sublingual administration. The data provided in this study support the usefulness of the sublingual route in clinical situations in which oral administration of captopril is not feasible.

Administration, Oral↗