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.

What is the Brugada syndrome?

In 1992, Brugada and Brugada reported a distinct subgroup of patients with episodes of "idiopathic"polymorphic ventricular tachycardia or ventricular fibrillation characterized by a unique electrocardiographic (ECG) pattern, which consisted of right bundle branch block and ST-segment elevation from V1 to V2-V3. As in patients with long QT syndrome, the ECG changes and the ventricular electrical instability could not be explained by structural heart disease, myocardial ischemia, or electrolyte disturbances. The syndrome can be inherited and predominantly affects males. Clinical presentation includes cardiac arrest or syncope caused by rapid ventricular tachycardia or fibrillation characteristically occurring at rest or during sleep. The clinical outcome of affected patients is poor unless they receive an implantable cardioverter defibrillator. The ECG pattern and the electrical ventricular instability have been explained by the dispersion of repolarization between the right ventricular epicardium and endocardium, which predisposes to local reexcitation of myocytes with different action potential durations. A disease-causing missense mutation in the cardiac sodium channel gene SCN5A has been recently reported in patients with Brugada syndrome. It is mandatory for the clinician to carefully rule out any organic heart disease before suggesting a diagnosis of Brugada syndrome, because the typical ECG pattern with the risk of sudden arrhythmic death is also observed in patients with structural heart diseases in the setting of arrhythmogenic right ventricular cardiomyopathy.

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.

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.

[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.

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.

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.

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.

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.

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.

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.

Inflammatory cytokines in the tears of patients with ocular rosacea

OBJECTIVE

The purpose of the study is to compare tear fluid concentrations of interleukin-1alpha (IL-1alpha), tumor necrosis factor-alpha (TNF-alpha), and epidermal growth factor (EGF) in ocular rosacea with those in control subjects and to examine the relation between tear functions, such as production and clearance rate, and the concentrations of cytokines in tear fluid.

PARTICIPANTS AND INTERVENTION

Fourteen patients with severe meibomian gland disease, facial rosacea, and symptoms of ocular irritation were examined for ocular surface disease, tear production, and tear clearance rate (TCR). Twelve control subjects, frequency-matched for age, and 15 ideal normal subjects with no ocular symptoms and normal tear function were assessed using the same parameters. Minimally stimulated tear samples (20 microl) were drawn from each subject and analyzed using a sandwich enzyme-linked immunosorbent assay to detect IL-1alpha, TNF-alpha, and EGF.

RESULTS

Tear IL-1alpha concentration was significantly higher in patients with rosacea than in age-matched (P = 0.003) and ideal control subjects (P < 0.001). Tumor necrosis factor-alpha was not detected in patients or control subjects, indicating levels of less than 10 pg/ml. Epidermal growth factor was not significantly higher in patients with rosacea than in age-matched control subjects. Tear turnover LN(TCR) was lower in patients with rosacea than in both age-matched (P = 0.048) and ideal control subjects (P = 0.002). Schirmer I scores were statistically lower in patients with rosacea than in ideal control subjects (P = 0.013), but not age-matched control subjects. Interleukin-1alpha was correlated inversely with LN(TCR) (r= -0.58, P < 0.0001) and Schirmer I (r = -0.39, P = 0.012).

CONCLUSIONS

Concentrations of IL-1alpha are present in normal tears but are elevated in ocular rosacea, whereas TNF-alpha is not present in either case. The reduced tear turnover, LN(TCR), its inverse correlation with IL-1alpha, and the absence of TNF-alpha in the tears of these patients suggest that the increased concentration of IL-1alpha observed may be largely because of clearance failure of cytokine normally produced at the ocular surface.

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.

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.

On the correct determination of reference values for serum antibodies against pigeon serum antigen using a group of healthy blood donors

An enzymatic immunoassay was developed in order to evaluate the statistical distribution of IgG serum antibodies against pooled pigeon sera antigen in 102 healthy blood donors (HBD). A non-normal distribution was obtained as demonstrated by abnormal values of skewness (2.02) and kurtosis (6.50). A cut-off point (0.120) was determined from the mean plus 2 standard deviations of the optical density values obtained in the HBD group. This value was able to segregate 94% of subjects. However, when calculation of the mean less 2 SD was performed to delimit 95% of the samples, an aberrant negative value was obtained. In contrast, when the nonparametric method of percentile calculation was applied, an optical density value of 0.130 discriminated 97.5% of samples. In addition, the interval between p97.5 and p2.5 delimited 95% of samples. We conclude that when reference values and cut-off point are determined from an enzymatic immunoassay, careful analysis of the statistical distribution of reference values is necessary in order to avoid the inappropriate application of parametric procedures as demonstrated in this study for antibodies against pigeon serum antigens.

The effects of age, gender, and fluid dynamics on the concentration of tear film epidermal growth factor

PURPOSE

To identify the relationship between epidermal growth factor (EGF) concentration in human tears and clinical tear-flow parameters and how these vary with age and gender.

METHODS

Tear samples were collected with minimal stimulation from 68 healthy and asymptomatic adults (33 men, 35 women), aged 21-88 years. EGF concentrations were determined by sandwich enzyme-linked immunosorbent assay (ELISA) in 65 cases. Schirmer tests were performed without anesthesia, and the clearance of fluorescein from the tear film assessed. The Tear Function Index (TFI) was calculated from these values.

RESULTS

There were approximately equal numbers of male and female subjects with a similar age distribution for each gender (48 +/- 3 and 51 +/- 3 years, mean +/- SEM, respectively). Ninety percent of tear EGF concentrations were between 0.75 and 7.1 ng/ml. Tear EGF level correlated significantly with Schirmer I value, but not with age. Schirmer I value correlated with tear clearance [LN(TCR)] but not with age. Tear EGF concentrations were significantly higher for men (3.4 +/- 0.3 ng/ml) than for women (2.4 +/- 0.3 ng/ml; p = 0.043).

CONCLUSIONS

EGF concentrations is tear samples from normal humans were found to correlate with gender and Schirmer I value but not with tear clearance.

Orthostatic sympathetic derangement in subjects with fibromyalgia

OBJECTIVE

To assess the sympathetic-parasympathetic balance in individuals with fibromyalgia (FM), and its response to orthostatic stress, by power spectral analysis of heart rate variability.

METHODS

We studied 19 women with FM and 19 age matched controls. A high resolution electrocardiogram was obtained in supine and standing postures after achieving a stable heart rate. Spectral analysis of R-R intervals was done by the fast Fourier transform algorithm.

RESULTS

Analyses of the different frequency components revealed significant difference between the 2 groups in the low frequency (0.050-0.150 Hz) band, which reflects modulation of the sympathetic nervous system. Controls displayed an increased power spectral density upon standing (+0.081 +/- 0.217 Hz); individuals with FM had a discordant response (-0.057 +/- 0.097 Hz) (p = 0.018).

CONCLUSION

In FM, there is a deranged sympathetic response to orthostatic stress. This abnormality may have implications regarding the pathogenesis of FM.

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.

Upright tilt test: correlation between results and patient clinical features

The aim of our study was to analyze how the clinical history and the main clinical characteristics of patients suffering from loss of consciousness may influence the results of the upright tilt test. A series of 745 patients (333 males, 412 females; mean age 44 +/- 18 years) with recurrent episodes of syncope or presyncope underwent complete clinical and noninvasive laboratory examination, including vagal maneuvers and upright tilt test (60 degrees for 45 min). Cardiological and neurological findings were normal in every case. Upright tilt test was positive in 462 patients (62%). Patients with presyncope showed a lower positivity compared to patients with syncope (70.2% vs 42.9%, P < 0.001). Younger patients (< 25 years) displayed highest upright tilt test positivity (68.5%), while familial occurrence of syncope or presyncope, results of vagal maneuvers, and different gender did not correlate with the results of the test. The time interval between the last syncopal episode and the day of upright tilt test negatively influenced the proportion of positive tests (> 30 days = 45.1% vs < 30 days = 77.2%; P < 0.001). Patients with more than three syncopal episodes in the 2 months preceding the test showed a higher upright tilt test positivity (83.9% vs 64.5%, P < 0.001). In conclusion, upright tilt test seems to be more sensitive in young patients with syncopal episodes during symptomatic periods. These findings suggest both an individual and temporal variability in autonomic nervous system activity, the implication of which are relevant to the indications for testing as well as the analysis of results.

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.