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Biomedical subjects

G Scibilia

Publications and source records attributed to G Scibilia.

At least 37 records · Page 2Linked to original sources
PubMed1993

Circadian rhythm of blood pressure and heart rate in cardiopathic patients before and after heart transplantation.

The aim of this study was to investigate the natural history of the circadian rhythm of blood pressure (BP) and heart rate (HR) in 10 patients with heart failure (class IV of the New York Heart Association), who underwent heart transplantation because of primary congestive cardiomyopathy. The control group was 10 age-matched clinically healthy subjects. The BP and HR monitorings were performed before and after transplantation. Preoperatively, analysis of variance and cosinor methods validated the occurrence of a statistically significant BP and HR circadian rhythm in cardiopathic patients. Over the 4 days after surgery, both the cosinor method and serial section analysis were unable to validate a 24-h periodicity for BP and HR in patients with heart transplants. Six months after surgery, the BP and HR circadian rhythm was not detected as well. One year after transplantation, the BP and HR circadian rhythm was statistically validated. The recovery of the BP and HR circadian rhythm 1 year after heart transplantation can be regarded as a clinical sign of a reacquired susceptibility to neurovegetative chronoregulation.

Adult↗
PubMed1993

[The acute and 24-hour modifications to the atrial natriuretic factor in patients who have undergone mitral valvuloplasty. The hemodynamic and echocardiographic correlations].

BACKGROUND: The recent introduction of percutaneous transvenous mitral valvuloplasty (PTMV) for the treatment of mitral stenosis (MS) has provided a unique human model for the study of short-term changes in ANF secretion before and after a reduction in left atrial pressure. This study was designed to investigate the effect of a short-term reduction in left atrial pressure and volume, as determined by echocardiographic study, on ANF and other neurohumoral factor plasma levels (renin and aldosterone). MATERIALS AND METHODS: 10 patients in III FC NYHA, with normal sinus rhythm and MS underwent PTMV. Hemodynamic parameters were measured immediately before and after (20-30 minutes) PTMV. Plasma levels of ANF, aldosterone and plasma renin activity (PRA) were obtained before (24 h) and after (2 h and 24 h) valvuloplasty; echocardiographic left atrial size before (24 h) and 24 h after PTMV. RESULTS: Immediately after PTMV mean left atrial (LA) pressure decreased from 22.3 +/- 6.8 mmHg to 10.0 +/- 2.4 mmHg (p < 0.01); mitral valve area (MVA) increased from 0.99 +/- 0.28 cm2 to 2.17 +/- 0.26 cm2 (p < 0.01). 24 hours after PTMV on echocardiography, LA systolic volume decreased from 59.5 +/- 16.9 cm3 to 42.3 +/- 8.3 cm3 (p < 0.01), LA diastolic volume from 82.6 +/- 15.8 cm3 to 66.5 +/- 12.6 cm3 (p < 0.01), and LA diameter from 48.1 +/- 7.5 mm to 39.2 +/- 4.4 mm (p < 0.01). ANF plasma levels before PTMV were 64.0 +/- 36.9 fmol/ml; 2 and 24 hours after PTMV they fell to 34.2 +/- 21.6 fmol/ml (p < 0.01) and to 20.3 +/- 21.0 fmol/ml (p < 0.01), respectively. PRA values were 15.7 +/- 13.2 ng/ml/h before PTMV; 2 and 24 hours after PTMV they increased to 17.5 +/- 23.2 ng/ml/h (NS) and to 22.3 +/- 16.8 ng/ml/h (p < 0.01). The aldosterone plasma levels were 43.2 +/- 27.9 ng/dl before PTMV and 47.3 +/- 35.8 ng/dl (NS) and 45.3 +/- 28.0 ng/dl (NS) 2 and 24 hours after PTMV. CONCLUSIONS: These results indicate that LA "de-stretching" due to the MVA increase and LA pressure decrease, leads to an abrupt reduction of ANF secretion. According to other studies, PRA increases immediately after PTMV, with a further increase 24 hours after PTMV.

Adult↗
PubMed1993

[The identification of vital myocardium with the dopamine stimulation test: an intraoperative echocardiographic study].

The aim of this study was to detect by dopamine echocardiography dysfunctioning but viable myocardial segments. We have studied 19 patients with 3-vessel disease and chronic, stable angina pectoris. Patients were studied by intraoperative transesophageal echocardiography during coronary artery bypass surgery. The analysis of regional systolic function was performed utilizing the transgastric short-axis view at papillary muscle level and dividing the left ventricle in 8 segments, according to the recommendations of the American Society of Echocardiography. A total of 152 myocardial segments were analyzed. Percent systolic wall thickening was calculated in each segment at baseline (early after pericardiectomy), during dopamine infusion (5 mcg/kg/min) and 30 min after separation from cardiopulmonary bypass (after protamine administration). The administration of vasodilatory or inotropic drugs was avoided. The echocardiographic images were recorded on videotape and analyzed off-line by 2 independent observers. Segments showing at baseline percent systolic wall thickening < 30% were considered dysfunctional (134/152 = 88%). Eighty-four (63%) of these segments, increasing during dopamine infusion percent systolic wall thickening > 10% (from 12.9 +/- 3.5 to 20.7 +/- 5.4%; p < 0.05) were considered responder. On the other hand, 50 segments (37%) showing during dopamine an increment in percent systolic wall thickening < 10%, were considered non-responder. After coronary surgery, responder segments showed a significant increase in percent systolic wall thickening in comparison with baseline values (from 12.9 +/- 3.5 to 22.1 +/- 4.3%; p < 0.05). Segments non-responding to dopamine showed no significant changes in percent systolic wall thickening after myocardial revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1992

Echocardiographic analysis of dysfunctional and normal myocardial segments before and immediately after coronary artery bypass graft surgery.

Echocardiography has revealed evidence of "subnormal" regional contraction patterns that result from myocardial ischemia and are often accompanied by nonadjacent "hyperkinetic" regions. Whether these regions of hyperkinetic wall motion persist unchanged or revert to normal after coronary artery bypass graft (CABG) surgery has not been studied in humans. Using echocardiography, we evaluated both dysfunctional and normal myocardial regions for changes in segmental wall motion and percent of systolic wall thickening that occurred immediately after CABG surgery in 32 patients. Segmental wall motion analysis before CABG surgery in these patients revealed that 170 (66%) of 256 myocardial segments were subnormal, of which 115 (67%) improved and 102 (60%) returned to normal immediately after CABG surgery. Eleven myocardial segments that were hyperkinetic before CABG surgery returned to normal after CABG surgery. Preoperatively, 162 (63%) of 256 myocardial segments had systolic wall thickening less than 30%, which increased from 11.8% +/- 8.9% to 24.3% +/- 14.3% (mean +/- SD) (P less than 0.01) postoperatively. Conversely, a reverse trend was found when systolic wall thickening was greater than 30% before CABG surgery: thickening decreased from 46.2% +/- 13.8% to 33.4% +/- 14.8% after CABG surgery (P less than 0.01). Thus, we conclude that immediately after CABG surgery, there is a recovery of function in some myocardial segments and a reduction in function in others. Furthermore, we conclude that the semiquantitative assessment of percent of systolic wall thickening is a more reliable (consistent) echocardiographic index of myocardial function compared with the qualitative assessment of segmental wall motion immediately after CABG surgery.

Adult↗
PubMed1992

Secondary aldosteronism documented by plasma renin and aldosterone circadian rhythm in subjects with kidney or heart transplantation.

The circadian rhythm (CR) of plasma renin activity (PRA), plasma aldosterone (PA), and plasma cortisol (PC) was investigated in 8 patients with kidney transplantation, and in 10 patients with heart transplantation. Ten clinically healthy subjects were studied as controls. The transplanted patients were all under cyclosporine treatment associated with prednisone (PDN). Time-qualified levels of PRA and PA were seen to be higher than normal in both groups of transplanted patients. The analysis of PRA and PA circadian rhythm provided evidence for a systematically higher level of within-day concentrations. The higher level of oscillation suggests the occurrence of a condition of hyperreninemic hyperaldosteronism. The higher levels of PRA and PA 24-h values show no periodicity. The finding suggests the abrogation of the rhythmic function for renin-aldosterone system. The disappearance of PRA-PA circadian rhythm seems to be attributable to a side effect of immunosuppressive therapy.

Adult↗
PubMed1992

[The circadian rhythm of plasma vasoactive intestinal peptide, atrial natriuretic peptide, renin activity, aldosterone and cortisol in heart transplantation. The effects of immunosuppressive therapy].

Vasoactive intestinal peptide (VIP) is released both by neural endings and lymphocytes. Aim of our investigation was to study the effects of immunosuppressive therapy on VIP plasma concentrations. The research has been performed on 10 heart transplanted patients assuming cyclosporine (CYCL) and prednisone (PRED). The circulating T lymphocyte subsets, atrial natriuretic peptide (ANP), plasma renin activity (PRA), plasma aldosterone (PA) and plasma cortisol (PC) have been also assayed. Blood pressure (BP) and heart rate (HR) have been monitored over a 24-hour period to detect whether circulating VIP in heart transplanted patients is influenced by pharmacologically-induced interactions. Seriate samplings along the 24-hour span have been performed. Mean values of ANP, PRA and PA were increased, while VIP, PC and T lymphocyte subsets were decreased in heart transplanted patients as compared to clinically healthy subjects. ANOVA and Cosinor analysis showed, respectively, a statistically significant 24-hour variability and circadian rhythm for all the investigated variables only in normal subjects. BP and HR circadian rhythm in heart transplanted patients suggest that the adrenergic activity regulating the cardiovascular system is restored. This finding argues that the reduction in VIP plasma concentrations is likely due to the decreased lymphocyte production secondary to immunosuppressive therapy, or can also be ascribed to the inhibiting action of high circulating levels of ANP.

Adult↗
PubMed1992

[Different behavior of phagocytes in young and old subjects].

Ageing is a dynamic phenomenon in which there is a physiological decay in all the functions of the individual. The consequence is an increased susceptibility to infections, autoimmune diseases and cancer. Phagocytic cells as polymorphonuclear leukocytes (PMNL) and monocytes (Mo) are of prime importance in the defence against invasive agents, PMNL and Mo seek out and destroy invading micro-organisms. Chemotaxis and phagocytosis are two mechanisms that are activated by these cells for this purpose. In this study, using "in vitro" techniques, we have verified if, at the level of such functions of cell defense, there could be variations in elderly subjects with respect to younger subjects. Our results show a chemotactic activity of PMNL in the elderly that is higher and a phagocytic activity that is lower. As regards Mo, there is a lower chemotactic activity in the elderly and only a slight difference in phagocytic activity with respect to the younger subjects. These results are in agreement with those found at the clinical level showing the elderly less protected from infection with respect to younger subjects.

Adolescent↗
PubMed1992

Herpes simplex pneumonia in a heart transplant recipient.

An unusual case of Herpes simplex virus (HSV) pneumonia in a heart transplant recipient receiving chronic immunosuppressive therapy is reported. This infection presented an indolent course manifested by a chronic left pulmonary infiltrate unresponsive to antibiotic therapy and mild hypoxemia. Death eventually occurred as a consequence of an other infectious complication of the postoperative period. The HSV etiology of the necrotizing pneumonia observed at autopsy was established on the basis of histologic findings.

Adult↗
PubMed1992

[The quantization of regional blood flow and volume with contrast echography: a mathematical model].

In this paper is described a new mathematical model for the study of regional blood flow in organs accessible to ultrasonic imaging. A prerequisite for the correct application of this model is the utilization of an echocontrast agent presenting with the same microrheology as red blood cells. This model is derived from an implementation of the indicator-dilution theory and is specifically designed to calculate relative changes in blood flow and volume in neighboring segments within the same organ. With this model is not required the acquisition of an input function, that is one of the major shortcomings affecting the classical theory. The applicability of quantitative contrast ultrasonography in humans may have a significant impact on our understanding of the pathophysiology of cardiovascular diseases.

Algorithms↗
PubMed1992

Reversal of left ventricular dysfunction early after coronary artery bypass grafting.

This study evaluated the early effect of coronary artery bypass grafting (CABG) on left ventricular systolic function. Intraoperative echocardiography was performed in 32 patients with coronary artery disease and chronic, stable angina pectoris. Left ventricular short-axis images at mid-papillary muscle level were videotaped at similar loading conditions shortly after pericardiotomy and 28 +/- 5 min after weaning from cardiopulmonary bypass. Inotropic or vasodilator administration was avoided or suspended at least 5 min before echocardiography. The left ventricle was divided off-line into 8 segments. The ejection fraction and percent systolic wall thickening (PSWT) were calculated pre- and post-CABG. A total of 256 myocardial segments were analyzed. Any segment showing a preoperative PSWT of less than 30% was considered dysfunctional, while segments with a PSWT of greater than 30% were considered normal. After surgery, the PSWT in 162 dysfunctional segments (63%) increased from 11.8 +/- 8.9 to 24.3 +/- 14.3% (p less than 0.001). Conversely, a reverse trend was found in the remaining 94 normal segments (37%) with a decreasing PSWT from 46.2 +/- 13.8 to 33.4 +/- 14.8% (p less than 0.001). Ejection fraction also increased from 47.2 +/- 3.5 to 58.5 +/- 18.9% (p less than 0.05). Thus, CABG is followed by an immediate recovery of systolic function in dysfunctional myocardial segments, while compensatory hyperfunction is reduced in normal segments. These results indicate that the post-CABG improvement in PSWT is due to redistribution of coronary blood flow, rather than to pharmacological or hormonal influences. Intraoperative echocardiography is a useful technique to monitor left ventricular function during surgery.

Adult↗
PubMed1991

Ventricular conduction defects and atrial fibrillation after coronary artery bypass grafting. Multivariate analysis of preoperative, intraoperative and postoperative variables.

Preoperative, intraoperative and postoperative variables, which might play a role in the development of ventricular conduction defects (VCD) and atrial fibrillation (AF) following coronary artery bypass grafting (CABG), were evaluated in 236 consecutive patients. VCD and AF developed postoperatively in 15.5% of patients: 4.5% had VCD (subgroup A), 11.0% had AF (subgroup B). In 84.5% of patients VCD and AF did not occur (subgroup C). Univariate analysis showed statistically significant differences between subgroups A and C with respect to: left main significant stenoses and number of diseased vessels. Bypass pump time and aortic cross-clamp time were significantly longer in subgroup B. Multivariate analysis showed a significantly greater incidence of left main disease and of right coronary artery occlusion associated with significant stenosis of the proximal left anterior descending artery in subgroup A. In subgroup B, the duration of aortic cross-clamp time was significantly higher. Ischaemic injury, with increasing duration of cardioplegic arrest, seems to play a key role in the development of AF. Nonhomogeneous cardioplegic delivery to critical areas of myocardium, and particularly to the specialized conducting system, may cause VCD after CABG.

Adult↗
PubMed1991

[The disappearance of the circadian rhythm of the heart rate in heart transplantation in the presence of acute rejection].

The present study is aimed to investigate the circadian rhythm (CR) of heart rate (HR) in acute rejecting and non-rejecting heart transplanted patients (HTP). The purpose is to provide evidence that an impairment in the HR CR may have a role in predicting episodes of acute rejection in HTP. The study was carried out on 32 Holter monitorings of 13 patients: 9 Holter monitorings were carried out during an episode of acute rejection documented by endomyocardial biopsy. Time data series were analyzed by Cosinor method in order to validate the occurrence of HR CR. The Cosinor analysis found a highly statistically significant HR CR in non-rejecting HTP. The occurrence of the HR CR was not statistically validated in acute rejecting HTP. These findings suggest that the lack of a periodic variability in the 24-hour HR pattern may be useful to diagnose acute heart rejection.

Acute Disease↗
PubMed1991

[Circadian rhythm of arterial blood pressure and heart rate in patients with heart transplantation: a longitudinal study before and after transplantation].

This investigation is designed to study the circadian rhythm (CR) of blood pressure (BP) and heart rate (HR) in heart transplanted patients (HTP). The research was performed on 10 heart failure patients (HFP), IV NYHA class, who underwent heart transplantation (HT) because of a primary congestive cardiomyopathy. The 24-h BP and HR monitorings were performed by means of a non-invasive method in pre-operative stage, over the 4 post-operative days, 6 and 12 months after surgery. ANOVA and Cosinor method validated the occurrence of a statistically significant CR in HFP. Over the 4 days after HT, the Serial Section Analysis did not show a 24-h periodicity of BP and HR: 6 months after HT, the BP and HR CR was not validated as well. One year after HT, the BP and HR CR was statistically detected. A significant difference between HTP and the clinically healthy subjects was validated only for the mean value of HR. In our opinion, the consolidation of the BP and HR CR 1 year after HT might be regarded as a clinical feature of a reacquired matching of cardiac function with vascular activity.

Adult↗
PubMed1991

[Circadian rhythm of the renin-angiotensin-aldosterone system in subjects with kidney and heart transplants].

The present investigation evaluates the circadian rhythm of renin-angiotensin-aldosterone system (RAAS) in subjects with kidney (KTS) or heart (HTS) transplantation undergoing conventional therapy with prednisone and cyclosporine. RAAS circadian rhythmicity has been compared with the circadian cycle of cortisol as a marker rhythm. The chronobiological exploration has been performed by measuring the circulating levels of plasma renin activity (PRA), plasma aldosterone (PA), and serum angiotensin-converting-enzyme (SACE) and plasma cortisol (PC) in serial samplings collected six times over a 24-h span. Time-qualified levels of plasma cyclosporine (CYCL) have been established. The control group consisted of 10 normal subjects matching in age and sex. Individual data series were analysed by the Cosinor method. The chronobiometric estimates demonstrate the lack of a circadian rhythmicity for PRA, PA and SACE in KTS and HTS. The PC circadian rhythm is demonstrable in KTS, but not in HTS. The abolition of the RAAS circadian rhythm in both KTS and HTS seems to be attributable to the effects exerted by CYCL. The disappearance of the PC circadian rhythm may be due to the prednisone therapy that is administered twice a day in HTS but not in KTS. The asynchronous effects of this drug lead us to suggest that antirejection therapy may be optimized by administering prednisone and cyclosporine according to a chronomodulated scheme.

Adult↗
PubMed1990

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↗