Dihydrotestosterone prevents glucocorticoid-negative effects on fetal rat metatarsal bone in vitro

The effects of dihydrotestosterone (DHT) on glucocorticoid-pretreated fetal rat long bone were studied in an in vitro culture system. First, dose-response curves of corticosterone, hydrocortisone, and dexamethasone were studied at several concentrations. Then, hydrocortisone (H) at 10(-5) M was selected for the second part of the study, as it slackened rudiment mineralization (104 +/- 16% of the initial dark zone vs. 141 +/- 9% in control bones), as well as its lengthening (140 +/- 4% of the harvesting day length vs. 160 +/- 1% in control bones), by both inhibition of cell proliferation and stimulation of resorption. On the contrary, in H-pretreated metatarsal bones, DHT (10(-7) M) partly limited slackening of mineralization (124 +/- 5%) and lengthening (153 +/- 2%). Moreover, a control-like cell proliferation was re-established and resorption holes were filled in. Thus, in this study, DHT partly limited hydrocortisone-induced impairment of fetal rat metatarsal bone development.

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.

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.

Sudden death in mitral valve prolapse with Holter monitoring-documented ventricular fibrillation: evidence of coexisting arrhythmogenic right ventricular cardiomyopathy

We report the case of a 42-year-old female, affected by mitral valve prolapse and ventricular arrhythmias, who died suddenly from ventricular fibrillation recorded during Holter monitoring. The lethal arrhythmia initiated with late diastolic couplets followed by a ventricular tachycardia that eventually degenerated into ventricular fibrillation. The patient had experienced four orthostatic and stress-related syncopal episodes, associated with nausea and diaphoresis, and a positive tilt test. Holter monitoring documented ventricular arrhythmias, consisting of both isolated monomorphic and sporadic repetitive beats. Her standard ECG and exercise test were normal, but signal-averaged study findings were significantly positive. QT prolongation in the absence of arrhythmias was observed during the Valsalva manoeuvre and isoproterenol infusion. 2D echo showed a remarkable mitral valve prolapse without regurgitation and localized structural abnormalities of the right ventricle. Postmortem study confirmed mitral valve prolapse, and also disclosed pulmonary infundibulum dilatation, massive adipose infiltration of the right ventricular free wall, patchy fibrosis and scattered myocardial inflammatory infiltrates in the left ventricle; these features are all consistent with arrhythmogenic right ventricular cardiomyopathy.

[Ventricular tachycardia secondary to myocardial contusion in an athlete: a clinical case report]

A 22-year-old athlete complained of palpitations shortly after a chest trauma during a basket competition. His electrocardiogram showed a ventricular tachycardia of 250 beats per minute, reverted to sinus rhythm with a chest thump. Standard electrocardiogram was normal. The following days he had an enzymatic pattern consistent with acute myocardial infarction, and the echocardiogram evidentiated an apical hypokinesia with a mural thrombosis. The patient recovered completely; and 15 days after the acute event, a coronary arteriography and ventriculography did not revealed any abnormality.

Prolonged cardiac arrest and complete AV block during upright tilt test in young patients with syncope of unknown origin--prognostic and therapeutic implications

The purpose of this study was to define the history and prognosis of 12 patients (8 males, 4 females) with syncope of unknown origin (5 to 15 episodes), who developed prolonged asystole or complete AV block during the upright tilt test (UTT). The mean age (+/- SD) of the patients was 29 +/- 7.4 years, and all had normal neurological and cardiological findings on evaluation. These patients were selected from a larger group of 92 cases with positive UTT out of a total of 136 subjects who were referred for recurrence of syncope. Neither clinical nor autonomic nervous system evaluation distinguished these 12 patients from those with positive UTT. Following UTT, therapy was initiated and consisted of transdermal scopolamine in four, disopyramide in two, and beta-blockers in four patients. During follow-up (mean, 17 +/- 5.4 months), four patients had recurrences but none experienced episodes of life-threatening syncope. These patients do not show an enhanced risk of sudden death, and drug therapy seems to improve their clinical course. Only long-term follow-up would correctly identify a subgroup at higher risk.

Clinical profile of concealed form of arrhythmogenic right ventricular cardiomyopathy presenting with apparently idiopathic ventricular arrhythmias

In 24 subjects presenting with apparently idiopathic ventricular arrhythmias, a final diagnosis of arrhythmogenic right ventricular cardiomyopathy was formulated following global evaluation of the clinical, cross-sectional echocardiography and angiographic findings, and the observation of myocardial atrophy with fibrous-fatty substitution in right ventricular endomyocardial biopsy. All patients had good effort tolerance, and a normal cardiac silhouette. Ventricular arrhythmias with a left bundle branch block pattern were present in 23 cases (sustained ventricular tachycardia, nonsustained ventricular tachycardia, ventricular couplets, and ventricular premature complexes); 1 patient experienced an episode of ventricular fibrillation. A nearly constant electrocardiographic feature was T wave negativity in the right precordial leads. Cross-sectional echocardiography and hemodynamic studies showed that right ventricular impairment consisted only of localized structural and dynamic abnormalities; in a few cases the left ventricle was segmentally involved. Familial occurrence was present in 29% of the cases. No case of sudden death was observed during follow-up. These findings confirm that the concealed form of arrhythmogenic right ventricular cardiomyopathy is a cause of so-called "idiopathic" ventricular arrhythmias in subjects with apparently "normal hearts". Echocardiographic and angiographic investigations may lead to the correct diagnosis.

A casual spontaneous mutation as possible cause of the familial form of arrhythmogenic right ventricular cardiomyopathy (arrhythmogenic right ventricular dysplasia)

In a family affected by arrhythmogenic right ventricular cardiomyopathy (ARVC) the familial occurrence was investigated. All 14 members of two generations were investigated carefully, and only 2 (father and one son) members were affected. Both subjects had a massive form of the disease with relevant ventricular arrhythmias. Apart from the limitations of having investigated few subjects, this behavior suggests a genetic mutation appearing in the father and transmitted via an autosomal dominant trait.

Cultures of human retinal pigment epithelium. Modulation of extracellular matrix

The extracellular matrix of retinal pigment epithelial (RPE) cells is an important component of the fibroelastic membranes formed in proliferative vitreoretinopathy (PVR). These membranes consist of cells intermingled with fibrillar proteins, such as elastin and collagen. Because RPE cells may be exposed to vitreous and serum-derived factors in conditions that lead to PVR, the effects of vitreous and serum on the deposition of fibrillar proteins by RPE cells were studied using radioactive labeling and indirect immunofluorescence techniques. The RPE cells, modulated by combined vitreous and serum into a fibrocytic-like appearance, deposited less fibroelastic proteins per cell. However, as a result of simultaneous cell proliferation, the total deposition of fibroelastic proteins per culture was increased. Indirect immunofluorescence studies suggest that it is type I collagen that is altered in the matrix of these modulated cell cultures. This information is important in pathologic conditions characterized by intraocular cell proliferation and fibroelastic membrane formation; these phenomena are seen in many vitreoproliferative disorders.

Arrhythmia development in a young subject with right ventricular cardiomyopathy (right ventricular dysplasia)

In right ventricular cardiomyopathy the relationship between the progression of structural abnormalities and arrhythmia development is not yet well known. This report describes a case in which severe ventricular arrhythmias appeared 3 years after the demonstration of right ventricular (RV) structural and dynamic abnormalities. In this interval of time structural changes were not detectable with the commonly used diagnostic methods, but endocavitary RV late fractionated QRS potentials appeared suggesting the development of an arrhythmic component of the disease.

Synthesis of extracellular matrix by macrophage-modulated retinal pigment epithelium

In proliferative vitreoretinopathy, macrophages and retinal pigment epithelial cells are associated with microfibrillar matrix proteins in the vitreous cavity, but the contribution of this extracellular matrix to the pathophysiology is not known. We used radiolabeling techniques on cultured human retinal pigment epithelial cells to correlate the secretion of extracellular matrix proteins with macrophage-induced modulation of cell proliferation and morphologic features. Retinal pigment epithelial cells incubated in a macrophage-conditioned medium assumed fibrocytelike morphologic characteristics, grew faster, and exhibited a decreased cellular release of fibrillar and nonfibrillar matrix components. However, due to a simultaneous greater increase in cell numbers in these modulated cultures, the total production of fibrillar and nonfibrillar matrix components by the culture population was increased.

Coexistence of kent accessory pathway, enhanced AV node conduction, and various conduction disturbances in a young athlete with tricuspid valve dysplasia

An asymptomatic 19-year-old top-level athlete had electrocardiographic evidence of intermittent cardiac preexcitation and intermittent left bundle branch block. The electrophysiologic study demonstrated the presence of a direct accessory pathway and enhanced atrioventricular node conduction that resulted in infrahisian and intraventricular conduction disturbances. The echocardiogram disclosed tricuspid valve dysplasia.

[Unusual manifestations of Ebstein's disease in a 53 year old adult. Ebstein's disease in an adult]

B.P., asymptomatic until her fifties, was admitted to hospital because of precordial pain. Her ECG and chest X rays were normal. When 52 she was again admitted, because of congestive heart failure. ECG showed repolarization abnormalities and chest X rays showed marked cardiomegaly. 2d echocardiogram was consistent with right atrial dilatation, dislodged posterior leaflet of the tricuspid valve and marked tricuspid regurgitation; these features were consistent with Ebstein anomaly. The patient was successfully treated by digitalis and diuretics. This case shows that in very rare cases this congenital heart disease can produce its clinical manifestations only late in lifetime.

[Electro-vectorcardiographic study of ventricular extrasystole in arrhythmogenic dysplasia of the right ventricle]

The morphology of ventricular extrasystole (VES) in 46 cases of arrhythmogenic dysplasia of the right ventricle (ADRV) was correlated with the point of origin located by intracavitary mapping. The cases concerned 41 of left bundle-branch block (LBB) with various axes on the frontal plane (FP), 4 of right bundle-branch block (RBB), and 5 of atypical morphology (frontal plane shifted inferiorly and increased R from V1 to V6; on the horizontal plane, clockwise rotation of the loop oriented anteriorly and leftward). There is a good correlation with the site of origin: VESs which were LBB in appearance originated in the right ventricle (apex, septum, infundibulum); VESs which were RBB in appearance originated in the apex of the left ventricle, while the atypical VESs started in the upper posterior septum. A study of morphology may therefore also give an indication of the location of the disease.

Monomorphic repetitive rhythms originating from the outflow tract in patients with minor forms of right ventricular cardiomyopathy

We studied in detail 17 patients presenting with monomorphic repetitive ventricular rhythms having left bundle branch block morphology and right axis deviation. All had an apparently normal heart at physical examination. At chest radiography, three patients had mild cardiomegaly, and at electrocardiography, five patients had inverted T waves beyond V2. Five patients had syncope or near syncope. In seven patients the tachycardia occurred on effort. One patient died suddenly. The patients were extensively investigated, using cross-sectional echocardiography, complete haemodynamic and angiographic studies, electrophysiology and histology, to search for any structural basis of the arrhythmias. Tachycardia was sustained in 8 patients, nonsustained in 3, and consistent with accelerated idioventricular rhythm and repetitive paroxysmal ventricular tachycardia in 5 and 1 patients, respectively. Despite the differences in clinical and arrhythmologic features, similar abnormalities of right ventricular structure and/or wall motion were detected in all patients, consistent with localized forms of right ventricular cardiomyopathy. Different antiarrhythmic drugs were successfully used in twelve patients (the four patients with accelerated idioventricular rhythm were not treated). The patient who died suddenly had previously had a sustained ventricular tachycardia and was being treated by beta-blockade. Postmortem study revealed massive fibro-adipose substitution of the right ventricular free wall and pulmonary infundibulum.

Giant P wave in a patient with right ventricular cardiomyopathy

A P wave of 7.5 mm in lead I and 12.5 in V1 was detected in a 28-year-old man, with a progressive cardiomegaly since the age of 14 years. At last admission he had minor symptoms, and a systolic murmur consistent with tricuspid regurgitation. The electrocardiogram showed an extremely tall P wave and a QRS of a very low amplitude; T waves were inverted on the precordial leads. These ECG features, and subsequent investigations, were consistent with right ventricular cardiomyopathy with massive tricuspid regurgitation, and right atrial abnormality.

[Arrhythmogenic myocardiopathy of the left ventricle: dynamic ECG. Morphologic data and age of the patient in the prediction of the onset of arrhythmic events]

In 57 patients with arrhythmogenic right ventricular cardiomyopathy, 34 males 23 females, aged 5 to 60 average 27.93 years, arrhythmias recorded during the whole clinical history have been compared with the 24 hours ECG ambulatory monitoring data, age and anatomic extension of the disease. In 77.77% of patients with history of sustained ventricular tachycardia Holter monitoring showed Lown class less than or equal to 3 arrhythmias, in 75% of patients with ventricular fibrillation Holter monitoring showed no arrhythmias. 55.88% of patients whose Holter monitoring documented Lown class less than or equal to 3 arrhythmias had more severe arrhythmias in their history. There is not a close relation between Holter data and arrhythmias that occurred during the whole history; however, Holter monitoring is a useful tool in evaluating risk when it shows complex arrhythmias.

Ventricular fibrillation without apparent heart disease: description of six cases

Since 1977, six patients (five males and one female), aged 14 to 35 years, resuscitated from ventricular fibrillation, were referred to our department for detailed evaluation, after exclusion of major cardiac pathologic conditions. Four patients had a family history of heart disease. Basic ECGs showed sinus rhythm in all of them. PR interval was prolonged in one. Two patients had complete and one had incomplete right bundle branch block. One patient had inverted t waves in V1-3 and late potentials. Three had an upsloping ST-T segment elevation in V1-2. The cardiothoracic index was less than 0.5 in five and 0.50 in one. In one of the five patients studied, the clinical episode of ventricular fibrillation was reproduced by stimulation of the right ventricular outflow tract during electrophysiologic study. Results of cross-sectional echocardiography and angiography showed predominantly structural and wall motion abnormalities of the right ventricle in five patients and slight wall motion abnormalities of the left ventricle in two. Two patients also had mitral and tricuspid valve prolapse. Coronary arteries were normal in all five patients examined. Results of endomyocardial biopsy showed no abnormalities in one patient, fibrosis in two, and fibrolipomatosis in one. Two patients died during follow-up: autopsy was performed in one and results showed right ventricular cardiomyopathy. Thus in five of these selected patients with apparent idiopathic ventricular fibrillation, some abnormalities, predominantly of the right ventricle, were documented only after detailed investigation; however, clinical history and some nonspecific ECG abnormalities were factors in the diagnostic procedure.