Search PubMed⌕ Search

Biomedical subjects

G Thiene

Publications and source records attributed to G Thiene.

At least 109 records · Page 6Linked to original sources
PubMed1997

Sudden death in young people with apparently isolated mitral valve prolapse.

Ventricular electrical instability and sudden death in mitral valve prolapse (MVP) have been related to mitral valve regurgitation and left ventricular dysfunction, autonomic nervous system abnormalities, or underlying cardiomyopathy. The aim of the present study was to assess the frequency, nature and pathophysiologic significance of histologic myocardial abnormalities in young patients with apparently isolated MVP and sudden cardiac death. Among 163 cases of sudden cardiovascular death in young people, MVP was the only cardiac pathology found at postmortem gross examination in 17 (10%) (12 females and 5 males) aged 14 to 35 years, mean 24. In 12 cases sudden death occurred at rest (during pregnancy in 2). MVP was diagnosed during life in 8 patients, 6 of whom had experienced palpitations and/or syncope, and 3 had premature ventricular beats. In every case, postmortem gross examination revealed "floppy" mitral valve leaflets with marked myxoid degeneration, and no other cardiovascular pathology. Cardiomegaly with left chamber enlargement was observed in 5 cases (mild in 3 and moderate in 2). In 12 cases (70%), histopathologic study disclosed myocardial abnormalities which consisted of focal myocardial atrophy and fatty replacement of the right ventricular wall (mostly the outflow tract) in 9 cases, left ventricular myocardial disarray (without hypertrophy) in 2, and lymphocytic infiltrates in one. "Foetal" dispersion of specialized atrioventricular junction and fasciculoventricular Mahaim's fibers were found in 2 cases. In conclusion, apparently isolated MVP was found in nearly 10% of sudden cardiovascular fatalities in young people. Most young sudden death victims with MVP were asymptomatic females without significant mitral valve regurgitation. In more than two-thirds of the cases, histopathologic examination evidenced underlying silent but potentially arrhythmogenic myocardial substrates, mostly consisting of segmental right ventricular cardiomyopathic changes.

Adolescent↗
PubMed1997

Should right-sided fibroelastomas be operated upon?

There is general agreement that left-sided elastomas must be removed to avoid systemic complications. Right-sided localization is less risky and surgical treatment is not agreed upon. We report a case of surgical resected fibroelastoma of the tricuspid valve and discuss the indications to surgery by reviewing the literature on the few reported cases. We feel that, if surgery is timely, the tumor can be resected, thus preserving the native valve. This provides an opportunity to prevent possible right-sided complications due to increasing tumor size and embolization.

Adult↗
PubMed1996

Arrhythmogenic right ventricular cardiomyopathy. Dysplasia, dystrophy, or myocarditis?

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a frequent cause of sudden death in young individuals and athletes. Although familial occurrence has been documented and a gene defect was recently localized on chromosome 14q23-q24 the etiopathogenesis of the disease is still obscure. METHODS AND RESULTS: A pathological study was conducted in 30 hearts with ARVC (age range, 15 to 65 years; mean, 28 years). In the 27 autopsy cases, the mode of death was sudden in 24 and congestive heart failure in 3. ECG, available in 19 cases, showed inverted T waves in the right precordial leads in 15 cases (79%) and ventricular arrhythmias in 15 (79%). Right ventricular aneurysms were present in 15 hearts (50%) and located in the inferior wall in 12. Left ventricle and ventricular septum were involved in 14 (47%) and 6 (20%) cases, respectively. Scattered foci of lymphocytes with myocardial death were observed in 20 cases (67%). Electron microscopy studies, although confirming the myocardial death and lymphocyte infiltrates, did not show any specific ultrastructural substrate. Two pathological patterns, fatty (40%) and fibrofatty (60%), were identified. The fibrofatty pattern was associated with a thinner right ventricular wall (P < .0001) and a higher occurrence of focal myocarditis (P < .001). In sections of right ventricular free wall with maximal fatty infiltration, the mean percentage area of fatty tissue was 35.9 +/- 11.1% in control versus 80.4 +/- 9.6% in the ARVC, fatty variety (P < .00001). Involvement of the left ventricle and/or ventricular septum, right ventricular aneurysms, and inflammation were found almost exclusively in the fibrofatty variety. CONCLUSIONS: In the fibrofatty variety of ARVC, the myocardial atrophy appears to be the consequence of acquired injury (myocyte death) and repair (fibrofatty replacement), mediated by patchy myocarditis. Whether the inflammation is a primary event or a reaction to spontaneous cell death remains unclear.

Adolescent↗
PubMed1996

Fusion of valve cushions as a key factor in the formation of congenital bicuspid aortic valves in Syrian hamsters.

BACKGROUND: Bicuspid aortic valve is the most frequent congenital cardiac malformation in humans. However, the morphogenesis of the defect is still unknown. Previous work showed that, in the Syrian hamster, congenital bicuspid aortic valves with the aortic sinuses arranged in ventrodorsal orientation are expressions of a trait the variation of which takes the form of a continuous phenotypic spectrum, ranging from a tricuspid aortic valve with no fusion of the ventral commissure to a bicuspid aortic valve devoid of any raphe. The present study was designed to elucidate the mechanism involved in the formation of bicuspid aortic valves in Syrian hamsters as a possible starting point for further investigation of this process in humans. METHODS: The sample examined consisted of 80 embryos, aged between 10 days, 16 hours and 13 days, 1 hour postcoitum. Most (n = 59) of the embryos belonged to a laboratory-inbred family of Syrian hamsters with a high incidence of bicuspid aortic valves. The study was carried out using scanning electron microscopy and histological techniques for light microscopy. RESULTS: Twenty-three embryos showed a still undivided conotruncus. In all of these cases there were six mesenchymal semilunar valve primordia protruding into the lumen of the conotruncus. In a further 29 embryos, the conotruncus had just divided into the aortic and pulmonary channels; the embryos were at the beginning of the valvulogenesis. In 13 of these 29 embryos there were three well-defined aortic valve cushions, right, left, and dorsal, whereas in the other 16, the right and left valve cushions were more or less fused toward the lumen of the aorta; when they were completely fused, only two aortic valve cushions, a ventral and a dorsal, could be identified. In the remaining 28 embryos, the aortic valve cushions showed a marked degree of excavation. In 23 of these cases, the valve exhibited a basically tricuspid architecture, whereas it was unequivocally bicuspid in the other five. CONCLUSIONS: All variants of the aortic valve morphologic spectrum occurring in the Syrian hamster develop from three mesenchymal valve cushions, right, left, and dorsal, after normal septation of the conotruncus. The bicuspid condition of the aortic valve is not the consequence of improper development of the conotruncal ridges, conotruncal malseptation, valve cushion agenesis, or lesions acquired after a normal valvulogenesis. Fusion of the right and left valve cushions at the beginning of the valvulogenesis appears to be a key factor in the formation of bicuspid aortic valves. Each aortic valve acquires its specific morphology prior to the end of the valvulogenetic process.

Animals↗
PubMed1996

Familial cardiomyopathy underlies syndrome of right bundle branch block, ST segment elevation and sudden death.

OBJECTIVES: We sought to assess whether structural heart disease underlies the syndrome of right bundle branch block, persistent ST segment elevation and sudden death. BACKGROUND: Ventricular fibrillation and sudden death may occur in patients with a distinctive electrocardiographic (ECG) pattern of right bundle branch block and persistent ST segment elevation in the right precordial leads. METHODS: Sixteen members of a family affected by this syndrome underwent noninvasive cardiac evaluation, including electrocardiography, Holter ambulatory ECG monitoring, stress testing, echocardiography and signal-averaged electrocardiography; two patients had electrophysiologic and angiographic study. Endomyocardial biopsy was performed in one living patient, and postmortem examination, including study of the specialized conduction system, was performed in one victim of sudden death. RESULTS: Five years before a fatal cardiac arrest, the proband had been resuscitated from sudden cardiac arrest due to recorded ventricular fibrillation. Serial ECGs showed a prolonged PR interval, right bundle branch block, left-axis deviation and persistent ST segment elevation in the right precordial leads, in the absence of clinical heart disease. Postmortem investigation disclosed right ventricular dilation and myocardial atrophy with adipose replacement of the right ventricular free wall as well as sclerotic interruption of the right bundle branch. A variable degree of right bundle branch block and upsloping right precordial ST segment was observed in seven family members; four of the seven had structural right ventricular abnormalities on echocardiography and late potentials on signal-averaged electrocardiography. A sib of the proband also had a prolonged HV interval, inducible ventricular tachycardia and fibrofatty replacement on endomyocardial biopsy. CONCLUSIONS: An autosomal dominant familial cardiomyopathy, mainly involving the right ventricle and the conduction system, accounted for the ECG changes and the electrical instability of the syndrome.

Adolescent↗
PubMed1996

Spontaneous coronary artery dissection: a neglected cause of acute myocardial ischaemia and sudden death.

Spontaneous coronary artery dissection is a rare cause of acute myocardial ischaemia. Eight consecutive fatal cases which occurred in women aged 34-54 years (mean 43) are described. The dissection involved the left anterior descending coronary artery in four, the left main trunk in two, the right coronary artery in one, and both left anterior descending and circumflex arteries in one. The clinical presentation was sudden death in six cases, and acute myocardial infarction in two. Diagnosis was made at necropsy in every case but one, in which coronary dissection was diagnosed during life by selective coronary angiography. The only ascertained risk factor was hypertension in one patient; none of the women was in the puerperium, and Marfan syndrome was excluded in all. Histology showed a haematoma between the coronary tunica media and adventitia, that flattened and occluded the lumen; a coronary intimal tear was detected in only two cases. Unusual histological findings were cystic medial necrosis in one case, eosinophilic inflammatory infiltrates in four, and angiomatosis of the tunica adventitia in one. Patients dying of spontaneous coronary dissection are usually middle aged women, with no coronary atherosclerosis and apparently no risk factors. Spontaneous coronary artery dissection is unpredictable, and sudden death is the usual mode of clinical presentation. Prompt diagnosis and life saving treatment is far from being achieved.

Acute Disease↗
PubMed1996

Spin-echo nuclear magnetic resonance for tissue characterisation in arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVE: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a myocardial disorder characterised clinically by ventricular arrhythmias that can cause cardiac arrest and morphologically by fatty or fibro-fatty myocardial atrophy of the right ventricle. In vivo tissue characterisation without endomyocardial biopsy would be useful. The aim of this study was to investigate the diagnostic accuracy of spin-echo nuclear magnetic resonance (NMR) for tissue characterisation in ARVC. PATIENTS AND METHODS: Twenty three subjects (15 men and eight women, aged 18-49, mean 34) were studied with spin-echo T1-weighted NMR and multislice scan. Fifteen had a clinical diagnosis of ARVC and eight were controls (age and sex matched subjects). Data were independently evaluated by two expert observers. RESULTS: In the control group NMR was always negative (100% specificity). Ten of the 15 patients with ARVC had an abnormal NMR result (67% sensitivity), with areas that had a signal intensity close to that of pericardial or subcutaneous fat. In the remaining five cases the NMR signal was inadequate. Nine patients underwent both NMR and endomyocardial biopsy; biopsy was positive in eight (89%) and NMR was positive in five (56%). CONCLUSIONS: NMR is a useful non-invasive diagnostic tool in the evaluation of fatty replacement in ARVC. The technique can be used with other procedures in the initial diagnostic evaluation and is a useful alternative tool in the long term follow up of patients with ARVC.

Adolescent↗
PubMed1996

Evolution of focal moderate (International Society for Heart and Lung Transplantation grade 2) rejection of the cardiac allograft.

BACKGROUND: In the absence of clinical evidence of cardiac allograft rejection, it is still poorly defined whether the International Society for Heart and Lung Transplantation biopsy grade 2 (e.g., focal moderate rejection) should be treated. Aim of the present study was to retrospectively investigate the evolution of focal moderate rejection, diagnosed during the first postoperative year in patients who had undergone orthotopic heart transplantation. METHODS: A retrospective analysis was conducted on 256 International Society for Heart and Lung Transplantation grade 2 biopsies from 110 orthotopic heart transplantations; 125 episodes occurred within the first 3 months (group 1), 131 later (group 2). For each grade 2 diagnosis, two biopsies, one immediately before and one after, were analyzed and classified as follows: lower (grade 0 or 1), equal (grade 2), or higher (grade 3 or 4). RESULTS: Evolution of grade 2 rejection was to a lower grade in 66% of cases, an equal grade in 16.8%, and a higher grade in 17.2%, with differences between group 1 and 2 (higher: 25% versus 10%, respectively, p = 0.005). Episodes which progressed into higher grades occurred earlier compared with those which persisted or resolved (9.2 +/- 8.6 weeks versus 20.0 +/- 15.6, p < 0.001). Five-year actuarial survival and incidence of graft coronary disease were similar in patients whose conditions progressed and those whose conditions did not. However, left ventricular ejection fraction at 1 and 2 years was lower in patients whose conditions progressed compared with those whose conditions persisted or resolved (56% +/- 4% versus 66% +/- 2%, p = 0.004; 56% +/- 10% versus 64% +/- 8%, p = 0.02, respectively). CONCLUSIONS: Progression of grade 2 rejection occurred in a minority of cases and did not affect 5-year survival or incidence of coronary disease, but its relationship with long-term cardiac allograft dysfunction warrants further investigation.

Actuarial Analysis↗
PubMed1996

Low-profile porcine bioprosthesis (Liotta): pathologic findings and mode of failure in the long-term.

BACKGROUND AND AIMS OF THE STUDY: The Liotta low profile porcine bioprosthesis (LBP) was designed in order to minimize complications due to excessive protrusion of the stent prongs in the left ventricle. MATERIALS AND METHODS: From April 1984 to November 1993, 25 LBP surgical explants were available for pathology study, which included gross and X-ray evaluations. Reoperation was performed after a mean period of 95 +/- 25 months (range 46 to 143 months), in five males and 20 females (mean age at implantation 51.1 +/- 11.4 years). RESULTS: The cause of failure was stenosis due to cusp stiffness caused by dystrophic calcification in one and incompetence in 24 LBPs. In only one case was incompetence ascribable to endocarditis; in the remaining 23 the mechanism of regurgitation was due to commissural tearing (21 LBPs), commissural dehiscence (one LBP) and both tears and dehiscence (one LBP). Overall, 28 commissural tears were observed: 20 involved the right coronary cusp, eight the left coronary cusp, and none the non-coronary cusp. The anterior commissure was most frequently involved by tears (n = 17) followed by the right posterior (n = 9) and the left posterior (n = 2). Tears were calcium-related in all but two cases. Calcific deposits were observed in each explant, involving a total of 62 commissural attachments, 17 cusp bodies and five right muscular shelves. CONCLUSION: In conclusion, valve regurgitation is the usual mode of LBP failure in the mitral position; commissural tearing of the right coronary cusp was the most common cause of valve regurgitation, and occurred even in the presence of pin-point calcification. These pathologic findings seem to confirm that low profile design, which implies bulging of the right coronary cusp, entails the risk of increased stress at the commissures, accelerated calcification and tearing.

Adult↗
PubMed1996

Small aortic root in neonates.

Small aortic root in neonates and infants is usually associated with unicommissural aortic valve, namely the presence of only one leaflet with eccentrically located commissure. This condition implies aortic stenosis because of: (i) a small aortic ring diameter; (ii) an intrinsically stenotic unicommissural orifice; and (iii) a dysplastic leaflet with myxoid nodular excrescences. The frequent association with hypoplastic left ventricle, fibroelastosis, dysplastic mitral valve and aortic arch obstructions prohibits a biventricular repair.

Aortic Valve↗
PubMed1995

Extracorporeal photochemotherapy as adjuvant treatment of heart transplant recipients with recurrent rejection.

Recurrent rejection is an uncommon, severe complication after heart transplantation that is associated with a poor long-term prognosis. Photopheresis (ECP), a new form of extracorporeal photo-chemotherapy used for the treatment of cutaneous T cell lymphoma and several autoimmune diseases, has also been used for prevention and treatment of acute rejection in heart transplant recipients. It seems to induce specific suppression of both cellular and humoral rejection. In this study, we evaluated whether ECP added to standard therapies allowed better control of rejection and reduction of conventional immunosuppressive drugs in patients with repeated rejection episodes. Eight heart transplant recipients (6 men and 2 women, mean age 48 yr), with recurrent rejection were treated with ECP for 6 months. Endomyocardial biopsies (EMB) were performed monthly. As a result of treatment, 7 patients on ECP experienced a reduction of the number and severity of rejection episodes. The fraction of EMB negative for rejection increased from 13 to 41%, whereas the fraction of specimens with multifocal and/or diffuse moderate lymphocytes infiltration (grades 3A and 3B) decreased from 41 to 21%. ECP allowed reductions of daily immunosuppressive therapy: prednisone by 44% (16.9 vs. 9.4 mg), cyclosporine by 21% (366 vs. 291 mg), and azathioprine by 29% (137 vs. 97 mg). No major side effects were observed. We conclude that, although the number of patients is small, the use of ECP was safe and associated with improved control of recurrent rejection. This allowed tapering of immunosuppressive drugs, which was particularly useful in two patients with insulin-dependent diabetes and one with sternal wound osteomyelitis.

Adult↗
PubMed1995

Signal-averaged electrocardiography in familial form of arrhythmogenic right ventricular cardiomyopathy.

This study was performed to establish whether signal-averaged electrocardiography can aid in the diagnosis of the familial form of arrhythmogenic right ventricular cardiomyopathy in order to determine the severity of the disease and to predict ventricular arrhythmias. In arrhythmogenic right ventricular cardiomyopathy there is a fatty fibrous substitution of myocardium, which is the substrate for delayed myocardial activation; this is responsible for the abnormalities seen on the signal-averaged electrocardiogram (SAECG). Seventy-five members of 11 families, both healthy and with various forms of the disease, were studied using a signal-averaged electrocardiographic technique. Forty-seven members, 16 with a severe and 31 with a minor form of the disease, were found to be affected. Forty-three subjects had abnormal results on the SAECG; of these, 39 had the disease (100% in patients with widespread disease and 74.1% in patients with a minor form), whereas the other 4 had no sign of the disease. Only 44.1% of the subjects with an abnormal SAECG had ventricular arrhythmias, whereas 76% of the subjects with ventricular arrhythmias had an abnormal SAECG. In contrast, 90.6% of patients with an abnormal SAECG had the disease, and only subjects with arrhythmogenic right ventricular cardiomyopathy had ventricular arrhythmias. The abnormality on the SAECG appears to be correlated with the severity of the disease. Signal-averaged electrocardiography does not seem useful in diagnosing the minor forms of the disease and it does not give precise information about electrical instability in these patients.

Adolescent↗
PubMed1995

Arrhythmogenic right ventricular cardiomyopathy in young versus adult patients: similarities and differences.

OBJECTIVES: This study was designed to evaluate and compare the patterns of arrhythmogenic right ventricular cardiomyopathy in young people and adults. BACKGROUND: Few data are available on this cardiomyopathy in young people because clinical and morphologic findings considered pathognomonic are normally based on observations in adults. However, a familial occurrence with a probable genetic transmission led to the study of children and to early detection of this disease, in which sudden death has been reported even in young people. METHODS: Seventeen young patients with arrhythmogenic right ventricular cardiomyopathy diagnosed at a mean age +/- SD of 14.9 +/- 4.9 years were studied. Clinical, electrocardiographic, echocardiographic, cineangiographic and biopsy findings were compared with those of 19 adult patients whose condition was diagnosed at a mean age of 38.1 +/- 13.4 years. RESULTS: Syncope occurred in 23.5% of the young patients but in none of the adults (odds ratio of familial sudden death 5.54, p = 0.1). Ventricular couplets (odds ratio 16.0, p = 0.004) and subtricuspid bulging on echocardiography (odds ratio 5.95, p = 0.036) were prevalent in the young group. Cineangiographic data in the two groups were similar, except that more hypokinetic areas were found in adults (odds ratio 4.44, p = 0.05). Morphometric analysis of biopsy sections showed a greater amount of fibrous tissue in the young patients (p = 0.04) and a prevalence of fatty tissue in the adults (odds ratio 12, p = 0.005). During an equivalent follow-up time (mean 7 years), two young patients died suddenly, and two had ventricular fibrillation in the absence of antiarrhythmic therapy. CONCLUSIONS: The pathognomonic criteria for the diagnosis of arrhythmogenic right ventricular cardiomyopathy in adults are also valid for young people. Sudden or aborted death occurred frequently in young untreated patients.

Adolescent↗