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Biomedical subjects

C Longhini

Publications and source records attributed to C Longhini.

At least 73 records · Page 4Linked to original sources
PubMed1980

Mechanographic evaluation of left atrial activity in mitral valve prolapse.

Twenty-five patients suffering from mitral valve prolapse were studied to demonstrate any diagnostic modifications of the indirect (esophageal) left atrial pulse (ESO). Valvular prolapse is demostrated on the ESO by a sudden change in slope of the curve after the "x" point, in coincidence with a midsystolic click. Late systolic mitral insufficiency, when associated with prolapse is illustrated on the ESO tracing in two ways: a) an abnormally tall "v" wave; b) a late systolic plateau which begins immediately after the click and continues beyond the second heart sound. After the infusion of methoxamine or isometric exercise the ESO is usually of the a) conformation, while after the inhalation of amyl nitrite the tracing tends to be of the b) type. The "c" wave is at times altered but not always. This alteration is characterized by a greater amplitude and sharper peak. Based on the physiopathogenesis of the alterations of the ESO, it can be stated that they are specific, and sensitive enough to be both qualitative and quantitative.

Electrocardiography↗
PubMed1980

[Different cardiovascular and hormonal consequences of A-V fistula in uremic patients (author's transl)].

The Authors studied 11 uremic patients for whom it was necessary to make an arterio-venous (A-V) fistula for dialysis purposes. Before and after creation of the fistula, the following parameters were determined: arterial pressure (PA) heart rate (HR), peripheral vascular resistances (PVR), renin, adrenalin and nor-adrenalin blood levels. The patients were divided in two groups according to the increase of the systolic output (SO) and o the cardiac index (CI) after the fistula (1st group of 5 patients: less than 30% increase of these values as compared to those before the fistula; 2nd group: more than 30% increase. By using Wilcoxon distribution free test it was possible to demonstrate the existence of a different condition, statistically significant in the two groups. In the 1st group of older patients (P < 0.05) where the systolic pressure values were greater (P < 0.05) and the indexes of the mechanical events of the left ventricle were altered, there was an increase of heart rate (P < 0.05), a moderate reduction of PVR (P < 0.01) and a very small increase of the systolic output and cardiac index (P < 0.01). Furthermore, in the 1st group, a left ventricular hypertrophy was observed, except in one case whereas this condition was constantly absent in the patients of the 2nd group. Patients of the 1st group had high nor-adrenalin blood levels, which did not change after the significantly after the creation of the fistula. In conclusion, an A-V fistula provokes two different hemodynamic behaviours which are related to age, pressure values, myocardial performance, presence of a left ventricular hypertrophy, PVR variations, and renin and nor-adrenalin blood levels.

Adolescent↗
PubMed1980

[Spectral analysis of a "sea gull cry" murmur (author's transl)].

"Precordial honk" is a loud, high pitched, musical and usually intermittent systolic noise. The concept of extracardiac origin and "inocence" of this finding is superseded and today its valvular origin during mitral prolapse, mitral or tricuspidal insufficiency - due to rheumatic or ischaemic disease - or during cardiomiopathy is demonstrated. The acoustic characterization of this finding was based on phonocardiographic registration. All the authors describe the "precordial honk" as a high frequency murmur without specifying the acoustic characteristics of the phenomenon. A spectral analysis technique applied to the acoustic cardiac signal (Fourier analysis) has been employed in order to study the "precordial honk" of a 15-year-old boy with mitral valve prolapse. This made possible to show that this sound had only one fundamental frequency at 300 Hz. without harmonics; a "sea gull cry" murmur (as the cry of many birds is) justifying the name given by clinicians. The spectral analysis of phonocardiography signal allow to study, more precisely, the cardiac acoustic phenomenon.

Adolescent↗
PubMed1979

The fast Fourier transform in the analysis of the normal phonocardiogram.

The present study is focused on spectrum analysis as a useful method of processing the PCG in order to obtain the frequency spectral distribution of normal heart sounds. Thirty normal subjects aged from 17 to 34 were studied. PCG was recorded on the fourth intercostal space at the left sternal border using a sound level meter coupled with a standard 6 ml cavity. The microphone had a linear response from 0.2 to 8,000 Hz. The signal was filtered with the standard B network according to the ANSI specifications and was registered on a four track FM tape recorder. A four channel analyzer with a microprocessor for off-line elaborations was used with 10 KHz sampling frequency. The PCG signal was triggered by a QRS detector on the R wave of the simultaneously recorded ECG. Fast Fourier transform was performed employing either a four channel analyzer with a microprocessor, or an A/D converter with a computer. Finally the results of the analysis were statistically elaborated. The described procedures permit to obtain a direct and exact tracing of the acoustic features of the heart, thus representing an attempt to come closer to the standardization and automatic analysis of the phonocardiographic technique.

Adolescent↗
PubMed1979

Diagnosis of mitral valve diseases using indirect (esophageal) left atrial pulse.

The diagnostic usefulness of the indirect (esophageal) left atrial pulse (ESO) has been analyzed in: 1) 25 patients (pts) with mitral insufficiency (MI), 2) 18 pts with mitral stenosis, 3) 29 pts with combined valvular disease, 4) 10 normal subjects. In addition, in 1) and 4), the ESO was recorded under the following dynamic conditions: a) during isometric exercise (handgrip), b) after inhalation of amyl nitrite, c) after intravenous infusion of methoxamine. The ESO tracing demonstrated estimates of the severity of the disease. Under dynamic conditions no modification from the resting morphology was obtained in the control group, whereas in MI the following modifications were observed: a) increased, progressive, positive elevation of the systolic phase of the ESO during the handgrip and the administration of the methoxamine; b) tendency to return to normal morphology after amyl nitrite.

Heart Atria↗
PubMed1979

[Technical and methodological aspects concerning the application of Fourier's analysis to phonocardiography (author's transl)].

The frequency spectrum analysis (Fourier's analysis) has recently been applied to phonocardiography. Using this mathematical approach instead of the current empirical analysis, it is possible to obtain -- on a less subjective basis -- more precise pathophysiological and diagnostic information from the acoustic cardiac phenomena. On the other hand, this refinement of the method of analysis stresses the need for better technical and methodological solutions, in order to reach the standardization of both the transduction and the recording of the acoustic signal at higher level of sensibility, fidelity and reproducibility. With this in mind, and on the basis of their experience, the Authors suggest the adoption of devices with specific technical characteristics, and propose a suitable method of application of Fourier's analysis to the phonocardiogram.

Fourier Analysis↗
PubMed1979

Cardiomechanical effect of k-strophanthoside administered to healthy volunteers by the rectal route.

Eight healthy volunteers were given k-strophanthoside (Strofopan) 1 mg rectally in order to evaluate changes in the cardiac function. Cardiomechanical measurements were performed by the polygraphic method before administering the drug and 1, 2, 3, 4, 5 and 6 h later. Three of the eight subjects continued to receive k-strophanthoside 1 mg daily for a further 6 days. Similar evaluations were made at the same times on day 3 and on day 7 of treatment. All indices considered varied to a statistically significant extent and showed the maximum effect at about the 4th h. The most evident changes were observed in the ICT and the PEP/LVET ratio. Here, the maximum variations were 46.3% and 29.5%, respectively, as compared with baseline values (P less than 0.01). When treatment was given for 7 days, the baseline values measured on day 3 and day 7 before administration showed a moderate and constant decrease in all parameters as compared with the first baseline value. This proves that k-strophanthoside administered rectally possesses steady-state activity with time. From a comparison of the changes in the same parameters as observed in a previous investigation after administering digoxin 0.50 mg orally there is reason to conclude that the effects obtained after administering k-strophanthoside 1 mg rectally were of the same magnitude.

Adult↗
PubMed1979

An improvement in digoxin bioavailability. Studies with soft gelatin capsules containing a solution of digoxin.

A study of relative bioavailability of two digoxin formulations was carried out on 28 healthy volunteer human subjects of both sexes. A commercial digoxin in tablet form was compared with a new commercial formulation which contains a solution of digoxin in soft gelatin capsules. The parameters investigated were: plasma levels, area under the plasma level-time curve, daily urinary excretion of digoxin and a series of polycardiographic measurements, all the parameters being evaluated in a steady-state condition (14 days of treatment). All the parameters investigated demonstrated better bioavailability in the capsules than in the tablets, the average improvement being 26.1%. The better bioavailability of digoxin capsules also resulted in more rapid and wider variations in the polycardiographic parameters.

Adult↗