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Biomedical subjects

M Morello

Publications and source records attributed to M Morello.

9 recordsLinked to original sources
PubMed1992

Late reoperations after repair of tetralogy of Fallot.

Twenty-two patients underwent 23 late reoperations after total correction of tetralogy of Fallot from 1965 to 1990. Indications for reoperation included: isolated ventricular septal defect (VSD) in 9 patients (41%), isolated right ventricular outflow tract (RVOT) obstruction in 3 patients (13.7%), VSD associated with a RVOT obstruction in 7 patients (31.8%), aneurysm of the pericardial RVOT patch in 1 patient (4.5%), aortic insufficiency with a residual VSD in 1 patient (4.5%), and tricuspid regurgitation in 1 patient (4.5%). The reoperation consisted of closure of a residual VSD in 17 patients, relief of a RVOT gradient in 11, insertion of a RVOT valve in 4, tricuspid valve replacement in 1 (reoperated twice), aortic valve replacement in 1, and excision of a RVOT aneurysm in 1. Two patients died in hospital (9%) but there were no early deaths in the 11 patients reoperated upon after 1978. Mean follow-up period was 135 months. There were 2 late deaths. The actuarial 20-year survival was 87%. Of the surviving patients, 16 (89%) were in New York Heart Association class I, 1 (5.5%) was in class II, and one (5.5%) was in class III. One patient required a second reoperation for tricuspid bioprosthesis degeneration and 1 patient had moderate recurrent RVOT gradient due to calcified pulmonary bioprosthesis. This study tends to support the policy of recommending reoperation in the presence of surgically significant residual defects. Reoperation is associated with a low early mortality and good long-term results.

Adolescent↗
PubMed1991

Coronary response to transient increases in transmural pressure.

Previous studies have shown that transient increases in aortic blood pressure obtained by occlusion of the descending thoracic aorta, in anesthetized dogs with beta-blockade and vagal section, did not affect coronary vascular resistance apart from a non-significant increase just after release of the constriction. The present study examined whether this response also occurred in the normally innervated heart. Experiments were carried out in six anesthetized dogs, in which pressure in the aortic root and in the left ventricle, as well as flow in the left circumflex coronary artery, were recorded. Coronary vascular resistance was calculated as the ratio of the difference between aortic pressure and left ventricular pressure to coronary circumflex flow during the slow inflow phase. Before occlusion coronary vascular resistance was significantly lower than during the same period in the previous studies using animals with beta-blockade and vagal section. During the occlusion, in contrast with the previous investigation, the increase in aortic pressure caused a significant increase in coronary vascular resistance 10 seconds after the beginning of the occlusion. Coronary vascular resistance was further increased immediately after release of the occlusion, concomitantly with the decrease in aortic pressure, which fell abruptly below the control level. The increase immediately after the release of the constriction was qualitatively similar, but greater in extent, to that observed in the animals with vagal section and beta-blockade. These differences are assumed to depend on a lower vasomotor tone in the normally innervated hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Coronary vascular resistance during transitory variations in aortic pressure].

The present study was aimed at studying the interaction between elastic properties and myogenic responses of the coronary wall in regulating coronary vascular resistance (CVR) during and after sudden changes in perfusion pressure. Whilst the effects of transient reductions and recoveries of the aortic blood pressure (ABP) were previously considered, in the present study attention was paid to the changes induced in CVR by the reverse procedure, i.e., by transient increases followed by abrupt decreases of ABP. The experiments were performed in 6 anesthetized dogs after section of the vagi nerves and beta-adrenergic receptor blockade. The increase of ABP was obtained by a 10 or 20 s constriction of the descending thoracic aorta. During the experimental maneuver, coronary flow increased without any significant change in CVR. Only in the late part of the 20 s constriction a reduction of CVR was observed as a likely consequence of increased myocardial metabolism. Immediately after the release of the constriction, the fall of ABP below the control was accompanied by a significant reduction of coronary flow without any significant increase in CVR. About 10 s later, a remarkable increase in flow occurred together with a significant fall of CVR, while ABP was recovering towards the control. In each animal the exact timing of these changes was independent of the duration of the constriction. When, about 20-30 s from the end of the constriction, ABP was back to the control, the hyperemia was completely over.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

[Anti-HCV in patients undergoing dialysis in Piedmont and in Valle d'Aosta].

Special questionnaires were distributed in order to assess the current incidence of anti-HCV antibodies in Dialysis Centres in Piedmont and the Aosta Valley. The analysis of findings showed an overall positivity of 23.9%, with higher values in those cases treated with extracorporal methods and lower values in those patients treated with peritoneal dialysis. The data also confirmed the correlations between anti-HCV antibodies and the number of transfusions performed, and suggested the possible influence of previous operations, high risk manual occupation, or more than one of these factors, in addition to environmental conditions. Lastly, the paper reports the prophylactic measures currently in use for patients and medical staff in the various centres in Piedmont and the Aosta Valley.

Comorbidity↗