Search PubMed⌕ Search

Biomedical subjects

G Thiene

Publications and source records attributed to G Thiene.

At least 55 records · Page 3Linked to original sources
PubMed2000

Clinical profile of congenital coronary artery anomalies with origin from the wrong aortic sinus leading to sudden death in young competitive athletes.

OBJECTIVES: The purpose of this study is to characterize the clinical profile and identify clinical markers that would enable the detection during life of anomalous coronary artery origin from the wrong aortic sinus (with course between the aorta and pulmonary trunk) in young competitive athletes. BACKGROUND: Congenital coronary artery anomalies are not uncommonly associated with sudden death in young athletes, the catastrophic event probably provoked by myocardial ischemia. Such coronary anomalies are rarely identified during life, often because of insufficient clinical suspicion. However, since anomalous coronary artery origin is amenable to surgical treatment, timely clinical identification is crucial. METHODS: Because of the paucity of available data characterizing the clinical profile of wrong sinus coronary artery malformations, we reviewed two large registries comprised of young competitive athletes who died suddenly, assembled consecutively in the U.S. and Italy. RESULTS: We reported 27 sudden deaths in young athletes, identified solely at autopsy and due to either left main coronary artery from the right aortic sinus (n = 23) or right coronary artery from the left sinus (n = 4). Each athlete died either during (n = 25) or immediately after (n = 2) intense exertion on the athletic field. Fifteen athletes (55%) had no clinical cardiovascular manifestations or testing during life. However, in the remaining 12 athletes (45%) aged 16 +/- 7, certain clinical data were available. Premonitory symptoms had occurred in 10, including syncope in four (exertional in three and recurrent in two, 3 to 24 months before death) and chest pain in five (exertional in three, all single episodes, < or =24 months before death). All cardiovascular tests were within normal limits, including 12-lead electrocardiogram (ECG) pattern (in 9/9), stress ECG with maximal exercise (in 6/6) and left ventricular wall motion and cardiac dimensions by two-dimensional echocardiography (in 2/2). CONCLUSIONS: With regard to congenital coronary artery anomalies of wrong aortic sinus origin in young competitive athletes, 1) standard testing with ECG under resting or exercise conditions is unlikely to provide clinical evidence of myocardial ischemia and would not be reliable as screening tests in large athletic populations, 2) premonitory cardiac symptoms not uncommonly occurred shortly before sudden death (typically associated with anomalous left main coronary artery), suggesting that a history of exertional syncope or chest pain requires exclusion of this anomaly. These observations have important implications for the preparticipation screening of competitive athletes.

Adolescent↗
PubMed2000

Clinical profile and long-term follow-up of 37 families with arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVES: We sought to define the clinical picture and natural history of familial arrhythmogenic right ventricular cardiomyopathy (ARVC). BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy is a myocardial disease, often familial, clinically characterized by the impending risk of ventricular arrhythmias and sudden death. METHODS: Thirty-seven ARVC families of northeast Italy were studied. Probands had a histologic diagnosis of ARVC, either at autopsy (19 families) or endomyocardial biopsy (18 families). Protocol of the investigation included basal electrocardiogram (ECG), 24-hour ECG, signal-averaged ECG, stress test and two-dimensional Doppler echocardiography. Invasive evaluation was performed when deemed necessary. RESULTS: Of the 365 subjects, 151 (41%) were affected, 157 (43%) were unaffected, 17 (5%) were healthy carriers, and 40 (11%) were uncertain. Mean age at diagnosis was 31+/-13 years. By echocardiography, 64% had mild, 30% had moderate, and 6% had severe form. Forty percent had ventricular arrhythmias, 49 were treated with antiarrhythmic drugs, and two were treated with implantable cardioverter defibrillators. Sport activity was restricted in all. Of the 28 families who underwent linkage analysis, 6 mapped to chromosome 14q23-q24, 4 to 1q42-q43, and 4 to 2q32.1-q32.3. No linkage with known loci was found in four families and 10 had uninformative results. During a follow-up of 8.5+/-4.6 years, one patient died (0.08 patient/year mortality), and 15 developed an overt form of ARVC. CONCLUSIONS: Arrhythmogenic right ventricular cardiomyopathy is a progressive disease appearing during adolescence and early adulthood. Systematic evaluation of family members leads to early identification of ARVC, characterized by a broad clinical spectrum with a favorable outcome. In the setting of positive family history, even minor ECG and echocardiographic abnormalities are diagnostic.

Adult↗
PubMed2000

Local photodynamic therapy with Zn(II)-phthalocyanine in an experimental model of intimal hyperplasia.

Photodynamic therapy (PDT) appears to be a novel promising modality to prevent intimal hyperplasia (IH) and restenosis after angioplasty. Local PDT, that consists of local delivery of photosensitizing agents followed by intraluminal local irradiation, represents a recent advancement. This methodology requires optimization in order to achieve the best prompt outcome especially in terms of pharmacokinetics of the photosensitizing agent. We studied the pharmacokinetic properties by using the photosensitizing agent Zn(II)-phthalocyanine (ZnPc), locally released by a channeled balloon. The efficacy of local PDT in reducing IH was evaluated in an experimental rabbit model of arterial injury. The maximum accumulation of ZnPc was found at 30 min: the injured portion of the artery gave a ZnPc recovery of 1.18 micromol/mg, as compared with undetectable amounts of ZnPc in the non injured arteries; within 90 min after the local delivery, clearance of the agent was almost complete. Local PDT produced an effective reduction of IH in our vascular injury model: at 7, 14, 21 and 28 days IH and intima/media ratio (IMR) was significantly reduced as compared with balloon injured arteries. The local delivery of ZnPc showed favourable pharmacokinetic properties, that allow the performance of PDT immediately after the vascular injury. Local PDT performed in these conditions represents a promising approach to prevent IH after balloon injury. Further studies are needed to better clarify the biological response of the injured arterial wall to local PDT.

Animals↗
PubMed2000

Signal-averaged electrocardiogram in patients with arrhythmogenic right ventricular cardiomyopathy and ventricular arrhythmias.

OBJECTIVE: The aim of the study was to assess the prevalence, sensitivity, specificity and predictive value of the signal-averaged ECG in patients with arrhythmogenic right ventricular cardiomyopathy and different forms of ventricular arrhythmias. METHODS: The signal averaged ECG in 138 patients and 146 healthy subjects (control group), using a three bandpass filter system (25-250, 40-250, 80-250 Hz), was considered abnormal when at least two parameters were abnormal at each filter setting. Patients were divided into three groups according to the extent of the right ventricular enlargement (mild, moderate, extensive), and into five groups according to the type of ventricular arrhythmia. RESULTS: The signal averaged ECG was abnormal in 57% of the patients and in 4% of the healthy subjects. The sensitivity was 57%, specificity 95% and positive predictive value 92%. The signal averaged ECG was abnormal in 94.4% of patients with the extensive form of the disease, in 77.7% of patients with the moderate form and in 31.8% of patients with the minor form, demonstrating good correlation with the extent of the disease. According to the type of ventricular arrhythmia, a higher correlation was found between signal averaged ECG abnormality and sustained ventricular tachycardia with superior axis (94.4%, P<0. 02); the correlation for the other arrhythmias varied from 16.6% to 55.8%. CONCLUSION: There is a closer correlation between the signal averaged ECG and extent of disease than with the presence of ventricular arrhythmias. The signal averaged ECG is not helpful in diagnosing minor forms of the disease, but since it is a non-invasive method, it may be useful in evaluating progression of the disease.

Adult↗
PubMed2000

Hypertrophic cardiomyopathy and sudden death in the young: pathologic evidence of myocardial ischemia.

The mechanism underlying cardiac arrest in patients with hypertrophic cardiomyopathy (HC) is intriguing. In the clinical setting, myocardial ischemia has long been incriminated, particularly in the young. Among 274 cardiovascular sudden deaths in the young (< or = 35 years), 19 (7.0%), 14 males and 5 females, median age 23 years, had HC. Familial occurrence of HC was ascertained in 3 (16%). SD occurred on effort in 6 (31%). Previous syncope occurred in 5 and palpitations in 3. Basal electrocardiogram (ECG) was abnormal in 7 of 8 available cases. Hypertrophy was septal asymmetric in 14. Gross examination showed large isolated or multiple septal scars in 11 (58%); at histomorphometry, the mean percent area of fibrosis of the septal myocardium was 18.6 +/- 6. Four showed a deep intramyocardial course of the left anterior descending coronary artery. At histology, myocardial disarray involved 30 +/- 16% of the septal myocardium; evidence of acute-subacute myocardial necrosis was present in 14 (74%), 1 of them with a regional acute myocardial infarction. By comparing hearts with (n = 11) and without (n = 8) areas of scar-type fibrosis, we found a statistically significant difference in terms of age (25.5 +/- 5.4 v 15.5 +/- 12.4 years, P = .04), septal thickness (25.4 +/- 5.4 v 15.4 +/- 4.9 mm, P < .001), percent increase of septal thickness versus normal value for age and sex (46.2 +/- 15 v 25.2 +/- 13.6%, P < .01) and mean score of small vessel disease (1.7 +/- 0.4 v 1.2 +/- 0.4, P = .04). Linear regression analysis showed a positive correlation of percent area of replacement fibrosis with septal thickness (P = .01) and with mean score of small vessel disease (P < .01). In conclusion, our pathologic findings of ischemic damage, either acute-subacute or in the form of fibrotic scars, support the clinical evidence that ischemia occurs in the natural history of HC and may contribute to life-threatening electrical instability.

Adolescent↗
PubMed2000

Clinical diagnosis and management strategies in arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a myocardial disease, often familial, that is characterized by fibro-fatty replacement of the right ventricular (RV) myocardium. The most common clinical manifestations of ARVC consists of ventricular arrhythmias of RV origin, which may lead to sudden death mostly in young people and athletes, electrocardiograph depolarization/repolarization changes mostly localized to right precordial leads, and global and/or regional dysfunction and structural alterations of the RV. The diagnosis of ARVC may be difficult due to several problems with the specificity of the electrocardiograph abnormalities, the different potential etiologies of ventricular arrhythmias with a left bundle branch morphology, the assessment of the RV structure and function, and the interpretation of endomyocardial biopsy findings. Therefore, standardized diagnostic criteria have been proposed by the Study Group on ARVC of the European Society of Cardiology. According to these guidelines, the diagnosis of ARVC is based on the presence of major and minor criteria encompassing electrocardiograph, arrhythmic, morphofunctional, histopathologic, and genetic factors. Because the assessment of sudden death risk in patients with ARVC is still not well established, there are no precise guidelines to determine which are the patients who need to be treated and which is the best management approach. The therapeutic options include beta blockers, antiarrhythmic drugs, catheter ablation, and implantable cardioverter defibrillator. The implantable defibrillator is the most effective safe-guard against arrhythmic sudden death. However, its precise role in changing natural history of ARVC by preventing sudden and nonsudden death needs to be evaluated by a prospective study of a large series of patients. In patients in whom ARVC has progressed to severe RV or biventricular systolic dysfunction with risk of thromboembolic complications, treatment consists of current therapy for heart failure including anticoagulant therapy. In case of refractory congestive heart failure, the patients may become candidates for heart transplantation.

Anti-Arrhythmia Agents↗
PubMed2000

Morphological aspects of Ebstein's anomaly in adults.

The essence of the Ebstein's malformation is that the tricuspid valve leaflets do not attach normally to the valve annulus, and the effective orifice is displaced downward into the right ventricular cavity at the junction of the inlet and trabecular components of the right ventricle. Only the septal and posterior leaflets are displaced and divide the right ventricle into two portions. The inlet portion is usually integrated functionally with the right atrium ("atrialized portion"), while the other, including the trabecular and outlet portions, constitutes the functional right ventricle. The proximal atrialized right ventricle often has a wall thinner than the distal functional right ventricle, due to partial congenital absence of myocardium. An atrial septal defect is present in more than one-third of hearts, and the majority of the remainder has a patent foramen ovale resulting in a right-to-left shunt. The downward displacement of the septal tricuspid valve leaflet is associated with discontinuity of the central fibrous body and septal atrioventricular ring, thus creating a potential substrate for accessory atrioventricular connections and ventricular pre-excitation making the patient at risk of sudden death. Angiography has demonstrated that a significant number of patients with Ebstein's anomaly also have morphofunctional abnormalities of the left ventricle, which may be explained by increased fibrosis in the left ventricular wall and ventricular septum as demonstrated by histological studies. Regarding embryology, the leaflets and tensile apparatus of the tricuspid valve are believed to be formed mostly by a process of delamination of the inner layers of the inlet zone of the right ventricle. The downward displacement of the leaflets in Ebstein's anomaly suggests that delamination from the inlet portion failed to occur.

Adult↗
PubMed2000

Arrhythmogenic right ventricular dysplasia/cardiomyopathy: need for an international registry. European Society of Cardiology and the Scientific Council on Cardiomyopathies of the World Heart Federation.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a heart muscle disease characterized by peculiar right ventricular involvement and electrical instability that precipitates ventricular arrhythmias and sudden death. The purpose of the present consensus report of the Study Group of the European Society of Cardiology and the Scientific Council on Cardiomyopathies of the World Heart Federation is to review the considerable progress in our understanding of the etiopathogenesis, morbid anatomy, and clinical presentation of ARVD/C since its first description in 1977. This article will focus on the important but still unanswered issues, mostly regarding risk stratification, clinical outcome, and management of affected patients. Because ARVD/C is relatively uncommon and any one center may have experience with only a few patients, an international registry is being established to accumulate information and enhance the numbers of patients that can be analyzed to answer the pending questions. The registry also will facilitate pathologic, molecular, and genetics research on the etiology and pathogenesis of the disease. Furthermore, availability of an international database will enhance awareness of this largely unrecognized condition among the medical community. Physicians are encouraged to enroll patients in the International Registry of ARVD/C.

Arrhythmias, Cardiac↗
PubMed2000

Myocarditis mimicking acute myocardial infarction: role of endomyocardial biopsy in the differential diagnosis.

OBJECTIVE: To test the hypothesis, using endomyocardial biopsies, that unexplained cases of apparent acute myocardial infarction were caused by myocarditis. MATERIAL: Between 1992 and 1998, 12 patients were admitted to the coronary care unit with severe chest pain, ST segment elevation, increased serum creatine kinase and MB isoenzyme, and with wall motion abnormalities on echocardiogram highly suggestive of acute myocardial infarction. These patients were further investigated by endomyocardial biopsy, as their coronary angiograms were normal. A diagnosis of myocarditis was made according to the Dallas criteria. A panel of antibodies was used for immunohistochemical characterisation of inflammatory cell infiltrate. Polymerase chain reaction (PCR) was used to detect viral genomes in seven cases. RESULTS: Haematoxylin and eosin staining of the endomyocardial biopsy showed active myocarditis in six patients and borderline myocarditis in one. Immunohistochemistry was positive for inflammatory cell infiltrates in 11 patients, including all the seven who were positive on haematoxylin and eosin staining according to the Dallas criteria. Only one patient had no evidence of inflammation. PCR was positive in two patients, both for Epstein-Barr virus. Follow up showed complete resolution of echocardiographic abnormalities in all patients except one. CONCLUSIONS: Myocarditis can mimic acute myocardial infarction in patients with angiographically normal coronary arteries, leading to errors of treatment. In patients with apparent myocardial infarction and a normal coronary angiogram, endomyocardial biopsy may help in the diagnosis of myocarditis. The sensitivity of endomyocardial biopsy was enhanced by using immunohistochemical and molecular biological techniques.

Adult↗
PubMed2000

No detection of enteroviral genome in the myocardium of patients with arrhythmogenic right ventricular cardiomyopathy.

AIMS: Despite the evidence of familial occurrence, chromosomal gene mapping, and apoptosis as a mechanism of myocyte death, the aetiopathogenesis of arrhythmogenic right ventricular cardiomyopathy (ARVC) remains speculative. Because of the frequent histological finding of focal inflammatory infiltrates, the hypothesis of an infective myocarditis aetiology has been put forward. The aim of this investigation was to test this hypothesis. The presence of enteroviruses was investigated by a highly sensitive and specific molecular technique. METHODS: Endomyocardial tissue samples from 20 patients with ARVC (11 male, nine female; mean age, 40 years; SD, 16) and 20 control subjects with other cardiac diseases were analysed using reverse transcription and nested polymerase chain reaction (PCR). Myocardial samples obtained from four patients with enteroviral myocarditis and coxsackie B3 virus infected cells were used as positive controls. RESULTS: Endomyocardial biopsy was diagnostic for ARVC in all patients: myocardial atrophy was seen, with less than 45% residual myocytes. Foci of inflammatory infiltrates were seen in four biopsies, and the cells were identified by immunohistochemistry as mainly T cells. All samples, from both patients with ARVC and subjects with other cardiac diseases, were negative for enteroviral genome by means of nested PCR. CONCLUSION: These findings indicate that enteroviruses are not involved in the aetio-pathogenesis of ARVC. Future molecular studies should investigate the presence of other infective agents, as well as their possible role in triggering apoptosis.

Adult↗
PubMed1999

Histologic findings in the conduction system after cardiac transplantation and correlation with electrocardiographic findings.

The study of the sinus node and the specialized atrioventricular junction by serial sections in cardiac transplantation revealed that acute rejection involving the conduction system was equally severe as the working myocardium, with the exception of the His bundle. During acute rejection, the sudden appearance of a first-degree atrioventricular block may suggest severe involvement of the conduction system with impending cardiac arrest.

Adult↗
PubMed1999

Living anatomy of the atrioventricular junctions. A guide to electrophysiologic mapping. A Consensus Statement from the Cardiac Nomenclature Study Group, Working Group of Arrhythmias, European Society of Cardiology, and the Task Force on Cardiac Nomenclature from NASPE.

Current nomenclature for the atrioventricular (AV) junctions derives from a surgically distorted view, placing the valvar rings and the triangle of Koch in a single plane with antero-posterior and right-left lateral coordinates. Within this convention, the aorta is considered to occupy an anterior position, although the mouth of the coronary sinus is shown as being posterior. Although this nomenclature has served its purpose for the description and treatment of arrhythmias dependent on accessory pathways and atrioventricular nodal reentry, it is less than satisfactory for the description of atrial and ventricular mapping. To correct these deficiencies, a consensus document has been prepared by experts from the Working Group of Arrhythmias of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. It proposes a new anatomically sound nomenclature that will be applicable to all chambers of the heart. In this report, we discuss its value for description of the AV junctions, establishing the principles of this new nomenclature.

Atrioventricular Node↗
PubMed1999

Late potentials and ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy.

We studied 38 patients (mean age 32 +/- 14 years) with arrhythmogenic right ventricular cardiomyopathy (ARVC) to evaluate the clinical significance of histologic features on endomyocardial biopsy specimens as related to signal-averaged electrocardiography (SAECG), spontaneous ventricular arrhythmias, and hemodynamic features. Fifteen patients presented with ventricular tachycardia or fibrillation (sustained ventricular arrhythmias), 23 with other minor arrhythmias. SAECG variables and right ventricular ejection fraction (RVEF) were statistically correlated with the extent of myocardial fibrosis on biopsy in ARVC. An increased percentage of fibrous tissue (> or = 30%) was a significant univariate predictor of late potentials (p = 0.004) and reduced RVEF (p = 0.02). The 18 patients with late potentials had an increased percentage of fibrous tissue (p = 0.01), a reduced RVEF (p = 0.0004), and a higher risk for sustained ventricular arrhythmias (p = 0.05) than the 20 patients without late potentials. RVEF was the most powerful predictor of late potentials (p = 0.004) at multivariate analysis. Moreover, RVEF < or = 50% was associated with an increased risk for development of sustained ventricular arrhythmias (p = 0.02). A SAECG parameter, namely the root-mean-square voltage of the terminal 40 ms at 25 Hz, was an independent predictive factor for the occurrence of sustained ventricular arrhythmias (p = 0.02). Although fibrous tissue may contribute to delayed myocardial activation in ARVC, a reduced RVEF plays an essential role for spontaneous manifestation of sustained ventricular arrhythmias.

Adolescent↗
PubMed1999

Reoperations for acute prosthetic thrombosis and pannus: an assessment of rates, relationship and risk.

OBJECTIVE: Mechanical valvular prostheses have the advantage of longevity but carry a risk of thrombosis which is dependant on valve design, materials and host-related interface. While pannus is common to both biologic and mechanical valves, acute prosthetic thrombosis is mostly a complication of mechanical valves; therefore we investigated to find rates and risk of these obstructive complications. METHODS: Between 1/1/70 and 31/12/97, 2680 patients received at least one mechanical prosthesis in the aortic or mitral or tricuspid position and a total of 3014 operations were performed. Follow-up included 18523 years and was 98% complete. Incidence rates, Kaplan-Meier estimates, modeling of the hazard and multivariate analysis in the hazard domain were used in the analysis. RESULTS: Overall survival was 76%, 64%, 51%, 38.5% and 29% at 5, 10, 15, 20 and 25 years, respectively. It was significantly better in aortic than in mitral than in double prosthesis. 290 patients received a single reoperation, 37 a second, six a third and one a fourth reoperation. Two-hundred and fifty-one of these reoperations were exclusively due to malfunction of mechanical prosthesis, nine to malfunction of both mechanic and biologic prostheses. Most frequent reoperative indications was dehiscence (133), pannus (48) and thrombosis (29). The linearized rate of reoperations for pannus was 0.24%/patient per year, for valvular thrombosis 0.15%/patient per year. The shape of the thrombotic hazard was constant (at random) and the relative risk 12 times higher for tricuspid prosthesis, seven times higher for mitral prosthesis. Multivariate analysis controlling for prosthetic position, age, sex and prosthetic size, showed a 67% risk reduction with larger prosthesis (>27 mm), a 69% risk reduction with the Sorin tilting disk prosthesis and an 83% risk reduction with the bileaflet prosthesis. Pannus hazard shows a delayed exponential rise and was two times higher in tricuspid and three times higher in mitral position. Multivariate analysis showed a 50% risk reduction with larger prosthesis, an 11 times higher hazard of old (caged-disk, caged ball) prosthesis and a three times higher hazard of Lillehei-Kaster prosthesis. Reoperation for thrombosis has a 62% perioperative (30 days) survival compared to 92% survival of pannus reoperation. CONCLUSIONS: Mechanical valves have a low incidence of reoperation, mostly for prosthetic dehiscence. Pannus development is the next frequent complication increasing with time since implant, therefore in this series it was related to old valvular models and tilting disk prosthesis, with longer follow-up. Acute thrombosis occurs significantly earlier than pannus formation. Despite shorter follow-up we are therefore confident that bileaflet prostheses are less prone to this complication and pannus is a rare early etiologic factor. Thrombosis has very high operative risk as compared to pannus, justifying the present trend to thrombolysate selected cases.

Acute Disease↗
PubMed1999

Living anatomy of the atrioventricular junctions. A guide to electrophysiological mapping. A Consensus Statement from the Cardiac Nomenclature Study Group, Working Group of Arrythmias, European Society of Cardiology, and the Task Force on Cardiac Nomenclature from NASPE. North American Society of Pacing and Electrophysiology.

Current nomenclature for atrioventricular junctions derives from a surgically distorted view, placing the valvar rings and the triangle of Koch in a single plane with antero-posterior and right-left lateral coordinates. Within this convention, the aorta is considered to occupy an anterior position, while the mouth of the coronary sinus is shown as being posterior. While this nomenclature has served its purpose for the description and treatment of arrhythmias dependent on accessory pathways and atrioventricular nodal re-entry, it is less than satisfactory for the description of atrial and ventricular mapping. To correct these deficiencies, a consensus document has been prepared by experts from the Working Group of Arrhythmias of the European Society of Cardiology, and the North American Society of Pacing and Electrophysiology. It proposes a new, anatomically sound, nomenclature that will be applicable to all chambers of the heart. In this report, we discuss its value as regards the description of the atrioventricular junctions, establishing the principles of this new nomenclature.

Atrioventricular Node↗