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Biomedical subjects

G Baciarello

Publications and source records attributed to G Baciarello.

At least 19 recordsLinked to original sources

Cardiovascular reactivity of mitral valve prolapse patients during experimental stress exposure: evidence for a functional nature of cardiovascular symptoms.

We studied a group of 18 patients with mitral valve prolapse (MVP) and a group of 20 healthy controls. Subjects in both groups were subjected to a 1-h experimental stress exposure during which Holter-ECG monitoring was performed and was then continued for the following 24 h. MVP patients complained of significant cardiac palpitation during the stress session, but ECG examination did not reveal significant inter-group differences. However, the two groups did show statistically significant differences in some psychometric measurements (Toronto Alexithymia Scale, Anxiety Sensitivity Index, Fear Questionnaire, Beck Depression Inventory, and Harm Avoidance subscale of Tridimensional Personality Questionnaire) that underlie personality traits known to be important in the process fostering functional somatic symptoms, according to the somatosensory amplification model. As no objective signs of cardiac rhythm modification were found in MVP patients under stress, we postulate that the symptoms for which these patients were referred have a functional nature, and that there is no pathogenetic link with the underlying valvular defect.

Adult↗

Automatic analysis of high resolution atrial activation in mitral valve stenosis.

High resolution P-waves of 28 patients having a mean age of 45 years and affected by isolated mitral valve stenosis (nine of whom showed paroxysmal atrial fibrillation) have been compared with those obtained from 30 healthy subjects about 35 years old. Our primary aim was to characterize the signal-averaged P-wave in mitral valve stenosis. Parameters which differed between the two groups in time domain analysis were the P-wave duration, the abscissa of the maximum positive voltage amplitude, the peak-to-peak amplitude and the integrated voltage-time product, which turned out to be greater in the patient class than in the healthy set; furthermore, in the frequency domain analysis, amplitudes in the range from 37 to 60 Hz were greater in healthy subjects than in patients. A successive analysis carried out to predict those patients with mitral valve stenosis who are at risk of developing paroxysmal atrial fibrillation showed that the P-wave duration and the amplitudes (in the range 60-106 Hz) were the most distinctive parameters, but, unfortunately, without any significant difference with respect to those of patients with mitral valve stenosis alone. Finally, some correlations between the age, the P-wave duration and the left atrial diameter of patients, were revealed to exist only in patients affected by episodes of atrial fibrillation.

Adult↗

[Ventricular late potentials in hypertrophic cardiomyopathy: personal contribution and analysis of the literature].

BACKGROUND: Patients with hypertrophic cardiomyopathy are at increased risk of sudden death. Recently it has been investigated whether late potentials can be useful markers of that risk in such patients, with discordant results. The aim of our study was to detect a correlation, if any, between late potentials, ventricular tachycardia and the hypertrophy extension. METHODS: Twenty-five patients were enrolled, 19 males and 6 females, mean age 40.40 +/- 15.02 years. Each underwent 24h Holter monitoring, averaged ECG, M-Mode and 2-D Echo. The hypertrophy was considered extensive (septum and free wall) or non extensive (septum and/or apex). RESULTS: Late potentials of a mean duration of 37 +/- 14.83 ms were recorded in 5/7 patients with documented ventricular tachycardia vs in none of the non tachycardia group. Sensibility was 100%, specificity 71% and predictive value 100%. Late potentials were present in 8.3% of patients with non extensive and in 30.8% of patients with extensive hypertrophy (p = NS). CONCLUSIONS: From our data it seems that extensive hypertrophy is present in about half of patients with hypertrophic cardiomyopathy, and this roughly correlates with a more frequent ventricular tachycardia and with late potentials. Furthermore, late potentials are strictly related to the incidence of ventricular tachycardia in this disease, just as in ischemic heart disease or in idiopathic dilated cardiomyopathy. The small number of our cases may not be sufficient to reach a significant statistical correlation between late potentials and hypertrophy, but we believe that the trend is very promising.

Action Potentials↗

[Paroxysmal atrial fibrillation in patients with chronic ischemic cardiopathy: a study of high-resolution atrial activation].

BACKGROUND: Patients with ischemic heart disease and episodes of paroxysmal atrial fibrillation are at major risk of stroke. In order to prevent such episodes, through the identification of patients prone to atrial fibrillation, we investigated the high-resolution atriogram of 65 patients with chronic ischemic heart disease, 54 male and 11 female, mean age 60.22 +/- 9.04 years. Based on previous documented episodes of atrial fibrillation, the patients were divided into two groups: group A, 45 males and 3 females, mean age 58.92 +/- 7.68 years, without atrial fibrillation; group B, 9 males and 8 females, mean age 63.88 +/- 11.6 years, with atrial fibrillation. RESULTS: High resolution atrial duration (100-300 Hz) in group B (with atrial fibrillation) was higher than in group A (without atrial fibrillation) (140.59 +/- 16.85 ms vs 121.77 +/- 11.27 ms, p < 0.001); Non filtered atrial duration (0-300 Hz) was not different between the two groups, A and B (118.54 +/- 10.96 ms vs 123.53 +/- 18.77 ms, p = NS); The prevalence of late atrial potentials was higher in group B than in group A (60.8% vs 7.1%, p < 0.001); No relation was observed between high resolution atriogram data and echocardiographic measurements; Sensibility was 82%, specificity 81%, and predictivity 60%. CONCLUSIONS: Data from our study show that high resolution electrocardiography is a valid tool for identifying patients prone to atrial fibrillation. Such patients can be identified by the presence of "late atrial potentials" that, like late ventricular potentials for ventricular tachycardia, are correlated with atrial fibrillation. Nevertheless, a larger cohort of patients is necessary to confirm these results.

Aged↗

Late potentials in idiopathic dilated cardiomyopathy.

Twenty-five patients with idiopathic dilated cardiomiopathy were investigated in order to evaluate the role of late ventricular potentials as possible markers of ventricular tachycardia or sudden cardiac death. Holter monitoring showed ventricular tachycardia in 9 patients (group A) all of whom had late ventricular potentials, (mean +/- SD length 37.22 +/- 15.83 ms and mean +/- SD voltage 5.62 +/- 2.78 microV). Mean +/- SD ejection fraction in this group was 20 +/- 9.39%. In 16 patients (group B), without ventricular tachycardia, means +/- SD ejection fraction 27.5 +/- 8.17%; late ventricular potentials were recorded in 2 patients. During the follow-up period (means +/- SD 11.53 +/- 7.19 months), 3 patients underwent heart transplantation, 2 patients underwent pace-maker implantation and 2 patients from the ventricular tachycardia group died one from sudden cardiac death and the other from progressive heart failure. No significant differences were found in the ejection fraction either between the ventricular tachycardia and the non-ventricular tachycardia group, or between the late ventricular potentials and the non-late ventricular potential groups. Negative data were also obtained when we tried to find a correlation between the ejection fraction and late ventricular potential length and/or voltage. Good results were observed with regard to sensitivity (100%), specificity (87%) and predictive accuracy (81%) but follow-up data did not specify a definite prognostic value for late ventricular potentials. The Authors conclude that late ventricular potentials are markers of patients with idiopathic dilated cardiomyopathy who are prone to ventricular tachycardia. However, the role of late ventricular potentials in sudden cardiac death is still uncertain.

Adolescent↗

Heart transplant rejection detected by signal averaged QRS analysis. Preliminary results.

Detailed QRS wave analysis from the limb leads of the surface high resolution electrocardiograms recorded in five cyclosporine-treated heart transplant recipients gave good correlation with the corresponding results of endomyocardial biopsy. That is when the result of the biopsies has identified the presence of rejection, a concomitant (p = 0.001) variation in some parameters of the QRS has been observed. The reproducibility of such parameters (established by means of the correlation coefficient r) gave r values ranging from 0.6 up to 0.93. The correlation regarded parameters analyzed both in time and frequency domain. Biopsy results were divided into two classes on the basis of the presence or absence of rejection. The most significant parameters obtained from high-frequency (25-300 Hz) ECGs within a few hours of each biopsy were: a) the total high-frequency voltage amplitude Vt of the QRS and the voltage amplitude of its initial Vi and middle thirds Vm; b) the peak voltage amplitude Vp of the QRS; c) the QRS duration L; d) the integrated voltage time product I of the QRS; e) three mean voltage amplitudes V5, V6, V7, of the power spectral density constructed on the basis of the 512-point fast Fourier transform applied on each recording. The above mentioned parameters appear to be useful in predicting the biopsy result in terms of the presence or absence of rejection.

Adolescent↗

Analysis of high-resolution atrial activation: report on 403 cases.

The findings of a study carried out on a sample of 403 P waves, selected over the 50 to 300 Hz frequency range, by a portable microcomputer system capable of averaging 512 P waves, are reported. Detailed analysis of P waves was attempted in healthy subjects and in patients affected by pathologic processes where atrial involvement had been observed. An attempt was made to individualize P wave parameters which may be associated with these pathologic conditions. On each atrial signal a 512-point fast Fourier transform was used. The original sample was divided into 18 classes, and the mean values of some parameters of each class were computed. The results of fast Fourier transform computing and of the mean values of parameters for both patients and healthy subjects show two different behaviors with respect to the amplitude-frequency relationships and mean peak-to-peak amplitude, respectively. The present results indicate that this technique may be useful for further detailed analysis of P waves.

Adult↗

High resolution atrial depolarization of MZ twins detected by surface signal averaging technique.

High resolution tracings of atrial depolarization can be obtained by surface signal averaging technique. A study was conducted on 4 male and 4 female healthy MZ twin pairs aged 10.4 +/- 1.3 yrs. Each subject underwent 3 or more recordings, at 10-days intervals. The essential reproducibility could be confirmed, with personal characteristics, as well as the reliability of the technique and the electrophysiological value of the spikes complex. In 3/8 pairs the cotwins showed a significant likeness of the atriogram, while in 5/8 pairs the tracings were not quite resembling between the twins and that is attributed to variations in the chronogenetic characteristics of MZ twins.

Atrial Function↗

High resolution recordings of atrial flutter.

We present high resolution tracings of atrial flutter which, to our knowledge, have not been previously described. Two patients have been studied; in both cases atrial activity was made by waves similar to each other, differing only in voltage. We discuss the nature of these waves, which are probably related to continuous atrial activity, with a segregation into small and large waveform activity. It is concluded that high resolution recordings may be valid support for the interpretation of atrial flutter activity.

Atrial Flutter↗

[Recording of His bundle potentials by means of non-invasive computerized and high-resolution electrocardiographic technique (author's transl)].

Recording of His bundle potentials by means of non invasive technique was first obtained in 1973. The Authors used a computerized, high resolution cardiograph to study 26 patients, 17 males and 9 females, mean age 57.15 +/- 21.79 years. H wave could be identified and therefore H-V interval could be calculated in 19 patients (73%). H wave identification is based on its morphological differentiation from other bioelectrical signals present in P-Q interval and on its repeated presence in all, or at least in the largest number of the six available leads. This technique, based on averaging process, is very useful in depistage of acute and chronic A-V conduction troubles.

Adolescent↗