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A Nava

Publications and source records attributed to A Nava.

At least 37 records · Page 2Linked to original sources
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

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

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

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

Strong association of autoantibodies to human nuclear lamin B1 with lupus anticoagulant antibodies in systemic lupus erythematosus.

OBJECTIVE: To determine the frequency and clinical significance of high titers of IgG autoantibodies to nuclear lamin B1 in a large number of unselected and well-characterized systemic lupus erythematosus (SLE) patients, disease controls, and normal healthy controls. METHODS: A cross-sectional study of anti-lamin B1 autoantibodies, as measured by enzyme-linked immunosorbent assay using human recombinant lamin B1 autoantigen, was performed on serum samples obtained at first evaluation of 238 consecutive French Canadian adults: 61 healthy control subjects, 20 patients with osteoarthritis, 22 with ankylosing spondylitis, 11 with autoimmune hepatitis, 30 with rheumatoid arthritis, and 94 with SLE. SLE patients were studied for 57 disease manifestations. A case-control study was performed to analyze the relationship between anti-lamin B1 status and thrombotic manifestations between SLE onset and last followup. RESULTS: High titers of anti-lamin B1 were strikingly restricted to a subset of 8 SLE patients (8.5%). The mean anti-lamin B1 titer was higher in this subset than in the other SLE patients or any control group (P<0.001). By univariate analysis and stepwise multiple logistic regression, the most striking association of anti-lamin B1 was with lupus anticoagulant (LAC) antibodies (P = 0.00001). Although LAC were significantly associated with thrombosis in our SLE patients, anti-lamin B1 was not. The frequency of thrombosis in SLE patients expressing both LAC and anti-lamin B1 was similar to that in patients without LAC (P = 1.0). However, patients expressing LAC without anti-lamin B1 had a greater frequency of thrombosis (P = 0.018). CONCLUSION: High titers of IgG anti-lamin B1 autoantibodies are highly specific for a subset of SLE patients whose clinical characteristics include the presence of LAC and other laboratory manifestations of the antiphospholipid syndrome. The presence of LAC without anti-lamin B1 may define a subset of SLE patients at greater risk for thrombosis.

Adult↗
PubMed1999

Fine mapping and genomic structure of ACTN2, the human gene coding for the sarcomeric isoform of alpha-actinin-2, expressed in skeletal and cardiac muscle.

The present paper reports on the fine mapping of the ACTN2 gene and on the reconstruction of its genomic structure. By radiation hybrid mapping, the gene was located about 912 cR from the 1p-telomere. ACTN2 was placed between the marker WI-9317 (alias D1S2421) and the marker AFMA045ZC5, within the chromosomal band 1q43. The gene was detected in YAC 955 c 12. This YAC was used as template DNA for long-distance and Alu-PCR, using a set of putative exonic primers, designed on the cDNA sequence of alpha-actinin-2, in order to characterize the ACTN2 intron-exon boundaries. The entire genomic structure of the gene was reconstructed. The ACTN2 gene contained 21 exons, in a segment spanning about 40 kb of genomic DNA. Only the proximal part of the gene shows a high conservation through evolution, whereas in the remaining part a divergence from the genomic organization of C. elegans and D. melanogaster was noticed. A series of intronic primers was specifically designed and produced, to amplify all the exons of ACTN2, directly from genomic DNA. This will enable mutation screening in patients affected with hereditary diseases linked to the marker CA4F/R, a polymorphism in the last intron of the alpha-actinin-2 gene.

Actinin↗
PubMed1999

Accuracy of electrocardiographic and echocardiographic indices in predicting life threatening ventricular arrhythmias in patients operated for tetralogy of Fallot.

OBJECTIVE: To validate the accuracy of the prognostic significance of non-invasive clinical diagnostic indices as predictors of sustained ventricular tachycardia (sVT) or fibrillation (VF) in patients undergoing repair for tetralogy of Fallot. METHODS: One way analysis of variance and pairwise comparison of the values with the Bonferroni correction, logistic multivariate analysis, and ordinal logistic analysis were used to study quantitative electrocardiographic and echocardiographic variables in 66 patients who had undergone surgery for tetralogy of Fallot by ventriculotomy at a mean (SD) age of 11.8 (9.5) years. The mean (SD) period of follow up was 16.1 (5.7) years after surgery. RESULTS: Four groups of patients were identified by ECG and 24 hour Holter monitoring: 19 (28.7%) without ventricular arrhythmias, 34 (51.5%) with minor ventricular arrhythmias, seven (10.6%) with non-sustained ventricular tachycardia (nsVT), and six (9.0%) with sVT or VF. One way analysis indicated significant differences in QT dispersion (QTd) and end diastolic volume of the right ventricle (EDVRV) among the groups. Univariate logistic analysis showed EDVRV, QTd, and QRS duration to be significantly associated with sVT or VF. Stepwise multivariate analysis and ordinal logistic analysis showed QTd to be preferable to QRS duration as an indicator, because it was unrelated to EDVRV, and was capable of separating different probability curves for nsVT as opposed to sVT or VF. CONCLUSIONS: Stratification of patients undergoing corrective surgery for tetralogy of Fallot and at risk of life threatening arrhythmias is possible by simple and inexpensive means, which provide sensitive and specific indices.

Adolescent↗
PubMed1999

[Cloacal exstrophy, ultrasonic diagnosis].

This study aims to underline the importance of transvaginal ultrasonography in the first three months of pregnancy. The authors report a case which was referred to their attention for preliminary tests performed prior to amniocentesis, recommended by the general physician because of the mother's age. The primapara woman and father of the fetus were healthy and the family history excluded hereditary diseases or congenital pathologies. Transvaginal ultrasonography permitted the diagnosis at the start of the fourth month of pregnancy of a polymalformed fetus with cloacal exstrophy, sacral myelomeningocele, clubfoot, single umbilical artery. In this case, the mother decided to undergo eugenic abortion in view of the severity of the pathology.

Cloaca↗
PubMed1998

Cytokines and tear function in ocular surface disease.

In summary, tear EGF levels correlate most strongly with tear production in normals, and it is likely that some form of homeostatic mechanism exists to provide a constant supply to the ocular surface. Commercial ELISA kits appear to measure EGF in tears with good consistency and may be useful in the future to improve comparability of data from different studies. In addition, in ocular rosacea, which mimics keratoconjunctivitis sicca in a number of respects, there is a differential increase in the level of the inflammatory cytokine IL-1 alpha in the tear fluid. Much of this elevation appears to be the result of reduced tear turnover, which may form an important positive feedback mechanism encouraging tear stagnation and the perpetuation of ocular surface inflammation.

Adult↗
PubMed1998

Tolerate, engage or withdraw: a study of the structure of families coping with alcohol and drug problems in south west England and Mexico City.

AIMS: To explore the structure underlying individual differences in the ways family members cope with drinking or drug problems. DESIGN: Cross-sectional interview and questionnaire study of a series of family members in two contrasting socio-cultural groups. SETTING: Mexico City and South West England. PARTICIPANTS: Two hundred and seven family members from separate families, three-quarters women, one-quarter men, mostly partners or parents. DATA: Long semi-structured interviews; the Coping Questionnaire (CQ). FINDINGS: Factor and subscale analyses of the CQ data and textual analysis of the interview reports were used to test the hypothesis that the underlying structure to coping could be described in terms of eight or nine coherent and distinct ways of coping. Neither form of analysis gave strong support to this hypothesis. CONCLUSIONS: It is concluded that the structure of coping can best be described in terms of three broad coping positions: tolerating, engaging and withdrawing. These conclusions challenge some previous assumptions about functional and dysfunctional ways of coping with excessive appetitive behaviour in the family.

Adaptation, Psychological↗
PubMed1998

Incidence of atrial fibrillation in patients with different mode of pacing. Long-term follow-up.

We evaluated the incidence of atrial fibrillation in 189 patients (92 males, 97 females, mean age 75 +/- 12 yrs, range 41-100 yrs) with pacemaker, during a mean follow-up of 5.5 yrs (range 1-24 yrs). The indications for implant were: complete AV block (115 pts), second degree Möbitz 2 AV block (51 pts), bifascicular block (5 pts), sick sinus syndrome (14 pts), symptomatic bradycardia (4 pts). The mode of stimulation considered were VVI (105 pt), VVI rate responsive (21 pts), single lead VDD (43 pts), DDD (20 pts). The occurrence of retrograde VA conduction in patients with VVI or VVI rate responsive pacing was also evaluated. Atrial fibrillation occurred in 40 pts (21%). The highest incidence was evidenced in patients with sick sinus syndrome (9 pts, 64%), and in patients with VVI stimulation (28 pts, 27%). On the contrary, the lowest incidence was found in single lead VDD stimulation (4 pts, 9%). The patients with dual chamber pacing showed a relatively high incidence of the arrhythmia (5 pts, 25%). Atrial fibrillation occurred in 9 out of 32 patients with retrograde VA conduction, and in 22 out of 94 patients without retrograde conduction (28% versus 23%, p = NS). In conclusion, it is confirmed that patients with sick sinus syndrome are at high risk for atrial fibrillation. Single lead VDD stimulation seems to be the better mode of pacing in preventing atrial fibrillation, while dual chamber pacing showed minor efficacy. The presence of retrograde VA conduction could not predict the occurrence of the arrhythmia.

Aged↗
PubMed1998

Radiographic assessment of atrial dipole position in single pass lead VDD and DDD pacing. The Multicenter Study Group.

Atrial electrode position was determined by radiographic analysis in 160 patients paced in single-lead VDD for second- or third-degree A-V block, implanted > 1 year with Phymos single pass leads and Phymos 3D pacemakers. The packing lead features an atrial dipole with a 30-mm electrode interspace. In 44% of patients, the upper atrial electrode was positioned within a band of 20 mm centered at the level of the superior vena caval insertion (junctional area) and was in the inferior vena cava or in the atrium in 35% and 21% of cases, respectively. In spite of these different dipole locations, all patients had stable atrium-driven pacing at routine follow-up visits. With the electrode in the junctional area, unipolar stimulation of up to 5 V for 1 ms resulted in stable atrial capture in 63% and 59% of the patients in supine and upright positions, respectively. With the electrode in the atrium, corresponding success rates were 45% and 54%. In the atrium, however, the prevalence of diaphragmatic stimulation was significantly lower than at the junction (10% vs 42% in supine position; 21% vs 47% upright). Though atrial sensing function proved adequate in a wide range of positions, these results suggest that the Phymos lead atrial dipole should be positioned within the atrium, as close as possible to the atrial wall, to maximize the number of VDD patients who might benefit from single-lead DDD pacing.

Cardiac Pacing, Artificial↗
PubMed1998

In vivo evidence of apoptosis in arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary heart muscle disease characterized by progressive atrophy of the right ventricular myocardium with fibro-fatty replacement and the risk of electrical instability and sudden death. The disease is often familial and the aetiopathogenesis is still unknown. Recently apoptosis (genetically determined cell death) was postulated to account for progressive loss of myocardium. To establish whether apoptosis is present in ARVC, right ventricular endomyocardial biopsies from 20 patients with clinical and histological diagnosis of ARVC were examined by electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling method (TUNEL). Apoptotic index was calculated as the percentage of positive nuclei in sections stained by TUNEL. Cell proliferation activity was also assessed by argyrophilic staining of the nucleolar organizer region (AgNOR) and MIB-1 antibody analysis. Twenty biopsies taken from patients during monitoring of cardiac transplantation (grade 0 rejection) served as control. Occurrence of apoptosis was correlated with clinical history duration and the presence of acute symptoms and signs like angina, pyrexia, erythrocyte sedimentation rate and creatine phosphokinase elevation, as well as ST segment elevation on basal electrocardiogram. Electron microscopy and TUNEL revealed presence of apoptotic myocytes in seven cases (35%) with a mean apoptotic index of 24.4+/-9.8. The remaining 13 patients and all of the 20 controls were negative both at the electron microscopy and TUNEL. Presence of apoptosis appeared to be significantly related to clinical history duration of less than 6 months (P < 0.001) and presence of acute symptoms and signs (P = 0.007). AgNOR staining and MIB-1 antibody analysis ruled out cell proliferation activity. In conclusion, apoptosis is present in endomyocardial biopsies of patients with ARVC, especially in the early symptomatic phase of disease. Myocardial destruction with replacement by fat may be episodic rather than gradual and continuous.

Adult↗
PubMed1997

Spectrum of clinicopathologic manifestations of arrhythmogenic right ventricular cardiomyopathy/dysplasia: a multicenter study.

OBJECTIVES: The aim of the present investigation was to redefine the clinicopathologic profile of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC), with special reference to disease progression and left ventricular (LV) involvement. BACKGROUND: Long-term follow-up data from clinical studies indicate that ARVC is a progressive heart muscle disease that with time may lead to more diffuse right ventricular (RV) involvement and LV abnormalities and culminate in heart failure. METHODS: Forty-two patients (27 male, 15 female; 9 to 65 years old, mean [+/-SD] age 29.6 +/- 18) from six collaborative medical centers, with a pathologic diagnosis of ARVC at autopsy or heart transplantation, and with the whole heart available, were studied according to a specific clinicomorphologic protocol. RESULTS: Thirty-four patients died suddenly (16 during effort); 4 underwent heart transplantation; 2 died as a result of advanced heart failure; and 2 died of other causes. Sudden death was the first sign of disease in 12 patients; the other 30 had palpitations, with syncope in 11, heart failure in 8 and stroke in 3. Twenty-seven patients experienced ventricular arrhythmias (ventricular tachycardia in 17), and 5 received a pacemaker. Ten patients had isolated RV involvement (group A); the remaining 32 (76%) also had fibrofatty LV involvement that was observed histologically only in 15 (group B) and histologically and macroscopically in 17 (group C). Patients in group C were significantly older than those in groups A and B (39 +/- 15 years vs. 20 +/- 8.8 and 25 +/- 9.7 years, respectively), had significantly longer clinical follow-up (9.3 +/- 7.3 years vs. 1.2 +/- 2.1 and 3.4 +/- 2.2 years, respectively) and developed heart failure significantly more often (47% vs. 0 and 0, respectively). Patients in groups B and C had warning symptoms (80% and 87%, respectively, vs. 30%) and clinical ventricular arrhythmias (73% and 82%, respectively, vs. 20%) significantly more often than patients in group A. Hearts from patients in group C weighed significantly more than those from patients in groups A and B (500 +/- 150 g vs. 328 +/- 40 and 380 +/- 95 g, respectively), whereas hearts from both group B and C patients had severe RV thinning (87% and 71%, respectively, vs. 20%) and inflammatory infiltrates (73% and 88%, respectively, vs. 30%) significantly more often than those from group A patients. CONCLUSIONS: LV involvement was found in 76% of hearts with ARVC, was age dependent and was associated with clinical arrhythmic events, more severe cardiomegaly, inflammatory infiltrates and heart failure. ARVC can no longer be regarded as an isolated disease of the right ventricle.

Adolescent↗
PubMed1997

ARVD4, a new locus for arrhythmogenic right ventricular cardiomyopathy, maps to chromosome 2 long arm.

Autosomal dominant arrhythmogenic right ventricular dysplasia (ARVD; MIM 107970) is a genetically heterogeneous cardiomyopathy, which often causes sudden death in juveniles and athletes. Two disease loci were previously mapped respectively to 14q23-q24 (ARVD1) and to 1q42-q43 (ARVD2). A third possible locus was assigned to 14q12-q22. We report here on a linkage study performed on three independent families with recurrence of ARVD characterized by localized involvement of the left ventricle. In these families the disease appears to be transmitted with three polymorphic DNA markers of the chromosome 2 long arm, showing a maximum lod score of 3.46 at theta = 0 for the marker D2S152. The multipoint linkage analysis suggests that the novel ARVD locus, provisionally named ARVD4, maps to 2q32. 1-q32.3, within the chromosomal region including markers D2S152, D2S103, and D2S389.

Arrhythmogenic Right Ventricular Dysplasia↗