Accelerated idioventricular rhythm of infundibular origin in patients with a concealed form of arrhythmogenic right ventricular dysplasia

Wide complex rhythm in a well neonate: Where are the P waves?

A neonate was seen for an evolving broad QRS complex rhythm initially captured at birth as intermittent escape beats on electrocardiogram. Continuous monitoring recorded features mimicking pre-excitation, but closer analysis revealed a regular broad QRS complex rhythm with isorhythmic atrioventricular dissociation, favouring a ventricular source. Treatment with flecainide and propranolol achieved successful control of the incessant arrhythmia with improvement in cardiac function on echocardiogram.

Accelerated Idioventricular Rhythm: A Rare Case of Wide-Complex Dysrhythmia in a Teenager

BACKGROUND

Accelerated idioventricular rhythm (AIVR) is an uncommon and typically benign dysrhythmia with similarities to more malignant forms of ventricular tachycardia (VT). It is often seen in adults after myocardial infarctions, although it also arises in the newborn period, as well as in children with and without congenital heart disease.

CASE REPORT

We describe a presentation of AIVR in an otherwise healthy 13-year-old girl, discovered on arrival to the pediatric emergency department in the setting of post-tonsillectomy bleeding. The case reviews the diagnostic criteria of AIVR, associated symptoms, the pathophysiologic origin of AIVR, and potential treatment strategies. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Given its morphologic similarities to life-threatening forms of VT, AIVR can be misdiagnosed in the emergency department or primary care settings. With an understanding of the dysrhythmia's unique features, emergency physicians can avoid unnecessary interventions and provide the correct diagnosis, workup, and management of AIVR for pediatric patients.

Management of cardiac conduction abnormalities and arrhythmia in aircrew

Cardiovascular diseasesⁱ are the most common cause of loss of flying licence globally, and cardiac arrhythmia is the main disqualifier in a substantial proportion of aircrew. Aircrewⁱⁱ often operate within a demanding physiological environment, that potentially includes exposure to sustained acceleration (usually resulting in a positive gravitational force, from head to feet (+Gz)) in high performance aircraft. Aeromedical assessment is complicated further when trying to discriminate between benign and potentially significant rhythm abnormalities in aircrew, many of whom are young and fit, have a resultant high vagal tone, and among whom underlying cardiac disease has a low prevalence. In cases where a significant underlying aetiology is plausible, extensive investigation is often required and where appropriate should include review by an electrophysiologist. The decision regarding restriction of flying activity will be dependent on several factors including the underlying arrhythmia, associated pathology, risk of incapacitation and/or distraction, the type of aircraft operated, and the specific flight or mission criticality of the role performed by the individual aircrew.

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC/D): A Systematic Literature Review

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a genetic form of cardiomyopathy (CM) usually transmitted with an autosomal dominant pattern. It primary affects the right ventricle (RV), but may involve the left ventricle (LV) and culminate in biventricular heart failure (HF), life threatening ventricular arrhythmias and sudden cardiac death (SCD). It accounts for 11%-22% of cases of SCD in the young athlete population. Pathologically is characterized by myocardial atrophy, fibrofatty replacement and chamber dilation. Diagnosis is often difficult due to the nonspecific nature of the disease and the broad spectrum of phenotypic variations. Therefore consensus diagnostic criteria have been developed and combined electrocardiography, echocardiography, cardiac magnetic resonance imaging (CMRI) and myocardial biopsy. Early detection, family screening and risk stratification are the cornerstones in the diagnostic evaluation. Implantable cardioverter-defibrillator (ICD) implantation, ablative procedures and heart transplantation are currently the main therapeutic options.

Arrhythmogenic right ventricular cardiomyopathy a still underrecognized clinic entity

Arrhythmogenic right ventricular cardiomyopathy is a new morbid entity that was discovered thanks to the study of sudden death in the young. This heart muscle disease is characterized by myocardial atrophy, mostly of the right ventricle, with massive fibro-fatty infiltration, accounting for ventricular electrical instability at risk of severe arrhythmias and even cardiac arrest. The disease was found to be the major cause of sudden death in young people and athletes in the Veneto Region, Italy. A familial occurrence with autosomal dominant transmission was then discovered, and the prevalence was estimated to be higher than 1 in 5000. The disease is genetically heterogeneous: Linkage analysis, carried out in a large family with recurrence of sudden deaths, led to map the gene to chromosome 14q23-q24. Linkage analysis in a second family allowed mapping of another gene to chromosome 1q42-q43. Clinical diagnosis can be achieved through electrocardiography, echocardiography, angiocardiography, magnetic resonance imaging, and endomyocardial biopsy. Diagnostic criteria have been put forward by a committee of the International Society and Federation of Cardiology. The disease was recently included among the cardiomyopathies in the revised World Health Organization (WHO) classification. Study of the natural history allowed us to distinguish (a) a covert phase in apparently normal subjects who have a risk of abrupt electrical instability and sudden death, (b) an overt arrhythmic phase with palpitations and impending cardiac arrest, (c) congestive heart failure with pump depression, sometimes so severe as to require heart transplantation. Both the etiology and pathogenesis of the disease are unknown. In particular, the mechanisms leading to progressive loss of myocardium and fibro-fatty replacement are still speculative. Apoptosis in the right ventricle occurring not only in infancy, as in the normal heart, but also in childhood and adulthood might account for the progressive disappearance of myocardial tissue. (Trends Cardiovasc Med 1997;7:84-90). © 1997, Elsevier Science Inc.

Accelerated idioventricular rhythm: history and chronology of the main discoveries

Accelerated Idioventricular Rhythm (AIVR) is a ventricular rhythm consisting of three or more consecutive monomorphic beats, with gradual onset and gradual termination. It can rarely manifest in patients with completely normal hearts or with structural heart disease. It is usually seen during acute myocardial infarction reperfusion. This manuscript aims to review the history of the main discoveries that lead to the identification and comprehension of this fascinating arrhythmia.

Accelerated idioventricular rhythm in newborns: a worrisome but benign entity with or without congenital heart disease

Broad QRS rhythms (fast and slow) are worrisome findings in newborns. We present five cases with varied clinical presentations found to have broad QRS tachycardias, consistent with idioventricular rhythms. Each patient had an excellent prognosis because the tachycardias resolved, and eventually the patients were in sinus rhythm. None were symptomatic from their arrhythmia. It is important to establish the diagnosis when it occurs to differentiate this benign phenomenon from dangerous ventricular tachycardia.

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.

Significance of morphological abnormalities detected by MRI in patients undergoing successful ablation of right ventricular outflow tract tachycardia

BACKGROUND

MRI can demonstrate subtle morphological changes of the right ventricle in patients with idiopathic right ventricular outflow tract tachycardia (RVOT). The present study examines the incidence and significance of right ventricular (RV) abnormalities detected by MRI with respect to the site of successful radiofrequency catheter ablation of the clinical tachycardia.

METHODS AND RESULTS

The study population comprised 20 patients (mean age, 40+/-12 years) undergoing elimination of recurrent RVOT by radiofrequency catheter ablation. MRI studies were performed before ablation to assess RV volumes and function, as well as structural abnormalities of the RV myocardium. Ten healthy age- and sex-matched subjects served as control subjects. The successful ablation sites, as documented by radiographs of the catheter position, were compared with MRI findings. Patients with RVOT showed no difference in respect to RV volumes and ejection fractions compared with control subjects. Whereas RV abnormalities were limited to prominent fatty deposits of the right atrioventricular groove extending into the inlet portion of the RV wall in 2 of 10 control subjects, MRI studies demonstrated morphological changes of the RV free wall in 13 (65%) of 20 patients with RVOT, including presence of fatty tissue (n=5), wall thinning (n=9), and dyskinetic wall segments (n=4). Eight of these patients had additional fat deposits, thinning, or a saccular aneurysm in the RV outflow tract, corresponding with the ablation site in 6 patients.

CONCLUSIONS

In RVOT, structural abnormalities of the right ventricle can be detected in a substantial number of patients despite normal RV volumes and global function. MRI abnormalities within the RV outflow tract are significantly associated with the origin of tachycardia.

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

OBJECTIVES

This study was designed to evaluate and compare the patterns of arrhythmogenic right ventricular cardiomyopathy in young people and adults.

BACKGROUND

Few data are available on this cardiomyopathy in young people because clinical and morphologic findings considered pathognomonic are normally based on observations in adults. However, a familial occurrence with a probable genetic transmission led to the study of children and to early detection of this disease, in which sudden death has been reported even in young people.

METHODS

Seventeen young patients with arrhythmogenic right ventricular cardiomyopathy diagnosed at a mean age +/- SD of 14.9 +/- 4.9 years were studied. Clinical, electrocardiographic, echocardiographic, cineangiographic and biopsy findings were compared with those of 19 adult patients whose condition was diagnosed at a mean age of 38.1 +/- 13.4 years.

RESULTS

Syncope occurred in 23.5% of the young patients but in none of the adults (odds ratio of familial sudden death 5.54, p = 0.1). Ventricular couplets (odds ratio 16.0, p = 0.004) and subtricuspid bulging on echocardiography (odds ratio 5.95, p = 0.036) were prevalent in the young group. Cineangiographic data in the two groups were similar, except that more hypokinetic areas were found in adults (odds ratio 4.44, p = 0.05). Morphometric analysis of biopsy sections showed a greater amount of fibrous tissue in the young patients (p = 0.04) and a prevalence of fatty tissue in the adults (odds ratio 12, p = 0.005). During an equivalent follow-up time (mean 7 years), two young patients died suddenly, and two had ventricular fibrillation in the absence of antiarrhythmic therapy.

CONCLUSIONS

The pathognomonic criteria for the diagnosis of arrhythmogenic right ventricular cardiomyopathy in adults are also valid for young people. Sudden or aborted death occurred frequently in young untreated patients.

Role of myocarditis in athletes with minor arrhythmias and/or echocardiographic abnormalities

We report the clinical and instrumental data, including the endomyocardial biopsy findings, of six young athletes presenting with minor arrhythmias and/or echocardiographic abnormalities. In one of them, a left ventricular dilation with moderate depression of the systolic function had been attributed to an athlete's heart. A diagnosis of arrhythmogenic right ventricular dysplasia had been made in three others, one with right ventricular dilation and apical hypokinesia, and two with ventricular arrhythmias with QRS morphology of left bundle branch block. A myocarditis could be unequivocally established in four athletes (two with and two without fibrosis). In the remaining two, with a clinical history strongly suggesting a previously acute myocarditis, the endomyocardial biopsy specimen revealed a nonspecific fibrosis compatible but not definitely pathognomonic of a healed myocarditis. Our report suggests that a myocarditis may be a cause of minor rhythm disturbances and/or echocardiographic abnormalities in athletes. A prevalent localization of the inflammatory process in the right ventricle with or without the occurrence of ventricular arrhythmias with left bundle branch block morphology can mimic an arrhythmogenic right ventricular dysplasia. An early diagnosis of myocarditis in athletes is useful to avoid the risk of fatal arrhythmias, also considering that rest still keeps on being one of the most effective strategies in myocarditis management.

Regional myocardial sympathetic dysinnervation in arrhythmogenic right ventricular cardiomyopathy. An analysis using 123I-meta-iodobenzylguanidine scintigraphy

BACKGROUND

In patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), the frequent provocation of ventricular tachycardia during exercise, the sensitivity toward catecholamines, and the response toward antiarrhythmic drug regimen with antiadrenergic properties suggest an involvement of the sympathetic nervous system in arrhythmogenesis.

METHODS AND RESULTS

To analyze the presence, extent, and location of impaired myocardial sympathetic innervation in ARVC, 123I-meta-iodobenzylguanidine (123I-MIBG) scintigraphy was performed in 48 patients with ARVC. For comparison, 9 patients with idiopathic ventricular tachycardia and a control group of 7 patients without heart disease were investigated. In patients with ARVC, the clinical sustained (n = 25; 52%) or nonsustained (n = 23; 48%) ventricular tachycardia originated in the right ventricular outflow tract in 38 patients (79%), whereas in the remaining 10 patients (21%), the site of origin was the apical (n = 5) or inferior (n = 5) right ventricle. In 33 patients (69%), nonsustained or sustained ventricular tachycardia was provocable by exercise (n = 28 of 48; 58%) and/or by isoproterenol infusion (n = 16 of 37; 43%), whereas programmed ventricular stimulation induced sustained or nonsustained ventricular tachycardia in 16 patients each (33% each). With 123I-MIBG scintigraphy, the right ventricle was not visible in any patient. No areas of intense 123I-MIBG uptake ("hot spots") were observed. All patients of the control group and 7 of 9 patients (78%) with idiopathic ventricular tachycardia showed a uniform tracer uptake in the left ventricle. In contrast, only 8 of 48 ARVC patients (17%) showed a homogeneous distribution of 123I-MIBG uptake, whereas 40 patients (83%) demonstrated regional reductions or defects of tracer uptake. In 3 of 48 patients (6%), the defect area was < 15%; in 21 patients (44%), it was 15% to 30%; and in 16 patients (33%), it was > 30% of the polar map area of the left ventricle (mean, 23 +/- 15%; range, 0% to 57%). In 38 of 40 patients (95%) with an abnormal 123I-MIBG scan, reduced tracer uptake was located in the basal posteroseptal left ventricle, involving the adjacent lateral wall in 10, the anterior wall in 2, and the apex in 12 patients. Only 2 patients demonstrated isolated defects of the anterior or lateral wall; one involved the apex. Perfusion abnormalities in the areas of 123I-MIBG defects were excluded by stress/redistribution 201T1 single-photon emission computed tomography scintigraphy and by normal coronary angiograms in all patients. Abnormalities in 123I-MIBG scintigraphy in patients with ARVC correlated with the site of origin of ventricular tachycardia, demonstrating a regionally reduced tracer uptake in 36 of 38 patients (95%) with right ventricular outflow tract tachycardia compared with only 4 of 10 patients (40%) with other right ventricular origins of tachycardia. There was no correlation between the results of 123I-MIBG scintigraphy and the extent of right ventricular contraction abnormalities, right ventricular ejection fraction, biopsy results, coronary anatomy, or left ventricular involvement in ARVC.

CONCLUSIONS

In patients with ARVC, regional abnormalities of sympathetic innervation are frequent and can be demonstrated by 123I-MIBG scintigraphy. Sympathetic denervation appears to be the underlying mechanism of reduced 123I-MIBG uptake and may be related to frequent provocation of ventricular arrhythmias by exercise or catecholamine exposure in ARVC. Therefore, in patients with ARVC, the noninvasive detection of localized sympathetic denervation by 123I-MIBG imaging may have implications for the early diagnosis and for the choice of antiarrhythmic drugs in the treatment of arrhythmias.

Treatment of presumed arrhythmogenic right ventricular dysplasia in an adolescent

Familial arrhythmogenic right ventricular dysplasia is a rare cardiomyopathy that is usually diagnosed on postmortem examination or on presentation with progressive congestive heart failure. We present a patient in whom an automatic implantable cardioverter-defibrillator was inserted prophylactically. A review of the condition and possible therapies is included.

Risk assessment in nonischemic ventricular arrhythmia by left and right ventriculography

Ventricular fibrillation and sudden death are rare phenomena in nonischemic ventricular arrhythmia, particularly in arrhythmogenic right ventricular cardiomyopathy. In most instances electrophysiologic studies help to assess the risk of sudden death, but sometimes programmed ventricular stimulation is unsuccessful. Among 48 patients with ventricular fibrillation (n = 9) and sustained (n = 25) and nonsustained (n = 19) ventricular tachycardia, invasive and noninvasive diagnostic tests (coronary angiography, biventricular angiography, programmed ventricular stimulation, and echocardiography) were performed to obtain more information about the underlying heart disease. In 43 patients (90%) arrhythmogenic right ventricular cardiomyopathy was diagnosed with segmental hypokinesia (n = 31) and diffuse hypokinesia (n = 12) of the right ventricle. In patients with documented ventricular fibrillation, the right ventricular ejection fraction was lower (30.8% vs 47.8% and 45.9%, respectively) and multisegmental contraction impairment of the right ventricle was significantly more frequent (p less than 0.001). Additional left ventricular abnormalities and right ventricular dilatation were not significant parameters for identifying high-risk patients. In addition to programmed ventricular stimulation, quantitative analysis of the results of right and left ventricular angiography contributes to risk assessment in patients with nonischemic ventricular arrhythmia.

Efficacy of antiarrhythmic drugs in patients with arrhythmogenic right ventricular disease. Results in patients with inducible and noninducible ventricular tachycardia

BACKGROUND

Ventricular tachyarrhythmias are the major clinical manifestation of arrhythmogenic right ventricular disease. Although antiarrhythmic therapy has been widely advocated, there is only limited information available on the efficacy of antiarrhythmic drugs in these patients.

METHODS AND RESULTS

The short- and long-term efficacies of various antiarrhythmic agents were retrospectively and prospectively analyzed in 81 patients (mean age, 39 +/- 14 years; range, 16-68 years; 61.7% males) with arrhythmogenic right ventricular disease. In 42 patients with inducible ventricular tachycardia during programmed ventricular stimulation, the following efficacy rates were obtained: class Ia and Ib drugs (n = 18), 5.6%; class Ic drugs (n = 25), 12%; beta-blockers (n = 8), 0%; sotalol (n = 38), 68.4%; amiodarone (n = 13), 15.4%; verapamil (n = 5), 0%; and drug combinations (n = 26), 15.4%. Only one of the 10 patients not responding to sotalol was treated effectively by amiodarone, whereas the remaining nine patients proved to be drug refractory toward all other drugs tested (3.8 +/- 2.3 drugs, including amiodarone in five cases) and underwent nonpharmacological therapy. During a follow-up of 34 +/- 25 months, three of the 31 patients (9.7%) discharged on pharmacological therapy had nonfatal recurrences of ventricular tachycardia after 0.5, 51, and 63 months, respectively. In 39 patients with noninducible ventricular tachycardia during programmed ventricular stimulation, the following efficacy rates were observed: class Ia and Ib drugs (n = 16), 0%; class Ic agents (n = 23), 17.4%; beta-blockers (n = 7), 28.6%; sotalol (n = 35), 82.8%; amiodarone (n = 4), 25%; verapamil (n = 24), 50%; and drug combinations (n = 11), 9.1%. During a follow-up of 14 +/- 13 months, four of 33 patients (12.1%) discharged on antiarrhythmic drugs had nonfatal relapses of their clinical ventricular arrhythmia.

CONCLUSIONS

Thus, in arrhythmogenic right ventricular disease, sotalol proved to be highly effective in patients with inducible as well as noninducible ventricular tachycardia. Patients with inducible ventricular tachycardia not responding to sotalol are likely to not respond to other antiarrhythmic drugs and should be considered for nonpharmacological therapy without further drug testing. Amiodarone did not prove to be more effective than sotalol and may not be an alternative because of frequent side effects during long-term therapy, especially in young patients. Verapamil and beta-blockers were effective in a considerable number of patients with noninducible ventricular tachycardia and may be a therapeutic alternative in this subgroup. Class I agents appear to be rarely effective in the treatment of both inducible and noninducible ventricular tachycardia in arrhythmogenic right ventricular disease.

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 case of arrhythmogenic right ventricular dysplasia associated with FANA positiveness--a case report

This is the case report of a forty-five-year-old woman who manifested clinical findings characteristic of arrhythmogenic right ventricular dysplasia (ARVD) except for fluorescent antinuclear antibody (FANA) positiveness. To the authors' knowledge, this is the first report of FANA positiveness associated with ARVD.

Sudden death in young competitive athletes: clinicopathologic correlations in 22 cases

PURPOSE

To investigate the pathologic substrates of sudden death in young competitive athletes.

PATIENTS AND METHODS

Twenty-two cases of sudden death in young competitive athletes occurring in the Veneto region (northern Italy) in the period January 1979 to December 1989 were studied by postmortem examination. The athletes included 19 males and three females, ranging in age from 11 to 35 years (mean, 23 years).

RESULTS

In 18 cases, sudden death occurred during (16 cases) or immediately after (two cases) a competitive sport activity. In 10 subjects, sudden death was apparently the first sign of disease. Postmortem examination disclosed that this fatality was due to arrhythmic cardiac arrest in 17 cases; among these, right ventricular cardiomyopathy, also known as "right ventricular dysplasia," was the most frequently encountered cardiovascular disease (six cases), followed by atherosclerotic coronary artery disease (four cases), conduction system pathology (three cases), anomalous origin of right coronary artery from the wrong aortic sinus (two cases), and mitral valve prolapse (two cases). In two athletes, the abrupt lethal complication was "mechanical" and consisted of pulmonary embolism and rupture of the aorta; in three athletes, death was due to a cerebral cause. All athletes with right ventricular cardiomyopathy died during effort, and most had a history of palpitations and/or syncope. Whenever available, electrocardiographic (ECG) tracings showed inverted T waves in precordial leads and/or left bundle branch block ventricular arrhythmias.

CONCLUSIONS

Clinicopathologic correlations indicate that in the Veneto region of Italy, right ventricular cardiomyopathy is not so rare among the cardiovascular diseases associated with the risk of arrhythmic cardiac arrest, and seems to account for the majority of cases of sudden death in young athletes; this disorder can be suspected during life on the basis of prodromal symptoms and ECG signs.

Diagnostic accuracy of right ventriculography in arrhythmogenic right ventricular cardiomyopathy

Diagnostic sensitivity and specificity of cineangiography were evaluated by multivariate logistic discriminant analysis in 32 patients with arrhythmogenic right ventricular (RV) cardiomyopathy, 27 patients with biventricular dilated cardiomyopathy, 28 patients with atrial septal defect and 18 normal subjects. In patients with arrhythmogenic RV cardiomyopathy and biventricular dilated cardiomyopathy, the diagnosis was confirmed by endomyocardial biopsy. All RV values overlapped for the diagnosis of atrial septal defect and arrhythmogenic RV cardiomyopathy; overlapping extended to dilated cardiomyopathy for end-diastolic volume and infundibular dimensions. RV ejection fraction appeared reduced in all the diseases; in particular, mean values in dilated cardiomyopathy and arrhythmogenic RV cardiomyopathy were 38 and 53%, respectively (p less than 0.05). Left ventricular quantitative studies showed a significant difference between dilated and arrhythmogenic RV cardiomyopathy, both in terms of pumping indexes (mean end-diastolic volumes 180 vs 91 ml/m2 and mean ejection fraction 33 vs 60%), and indexes of contractility (stress/end-diastolic volume 3.7 vs 6.7). Multivariate analysis disclosed that transversally arranged hypertrophic trabeculae, separated by deep fissures, were associated with the highest probability of arrhythmogenic RV cardiomyopathy (p less than 0.001). Posterior subtricuspid and anterior infundibular wall bulgings were the only other independently significant variables. Coexistence of these signs was associated with 96% specificity and 87.5% sensitivity. Thus, arrhythmogenic RV cardiomyopathy presents quantitative volumetric and hemodynamic as well as qualitative features that clearly distinguish it from dilated cardiomyopathy and confirm its nosographic autonomy among the primary diseases of the myocardium.

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.

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.

Right ventricular tachycardia with left bundle branch block and inferior axis morphology: clinical and arrhythmological characteristics in 15 patients

Fifteen patients (mean age 30) presenting with right ventricular tachycardia (VT) of the outflow tract type (left bundle branch block with inferior axis morphology), in the absence of obvious organic heart disease, were studied. Seven patients had palpitations, one presyncope and seven were asymptomatic. The echo and/or angiographic findings were normal in 11 patients (73%), suggesting arrhythmogenic right ventricular dysplasia (ARVD) in three (20%) and dubious in one (7%). The VT was sustained in three patients (20%), nonsustained (11 +/- 6 beats) in twelve (80%), inducible during exercise in two out of 15 patients (13%) and with ventricular stimulation in one out of eight (12.5%). Four patients were treated with sotalol, three with Class IC drugs and one with amiodarone. At follow-up of 36 +/- 30 months, only three patients had VT recurrences due to drug withdrawal.

IN CONCLUSION

(1) abnormal echo and/or angiographic findings suggested that ARVD was observed in a minority of the patients (22%); (2) the low inducibility of VT and the good response to sotalol suggested a possible mechanism of abnormal automaticity; and (3) at a 3-year follow-up the prognosis appeared to be good in both patients with or without echo-angiographic signs suggestive of right ventricular dysplasia.

Familial occurrence of right ventricular dysplasia: a study involving nine families

Right ventricular pathologic involvement, with autopsy evidence of fibrous and fatty infiltration of the right ventricle, was investigated in members of families in which cases of juvenile sudden death had occurred. Seventy-two subjects from nine families were studied. Sixteen died at a young age and 56 are living. Postmortem investigation in 11 cases (mean age at death 24 years) revealed massive replacement of the right ventricular free wall by fat or fibrous tissue. In the 56 living patients clinical examination included an electrocardiogram (ECG) at rest, ambulatory ECG recording, posteroanterior and lateral chest roentgenograms, M-mode and two-dimensional echocardiograms and exercise stress tests. In 14 patients, hemodynamic, angiographic and electrophysiologic studies were also carried out; right ventricular endomyocardial biopsy was performed in four. Structural and dynamic right ventricular impairment was detected in 30 living patients (mean age 25 years), and concomitant mild left ventricular abnormalities were present in 4. In eight of the nine families studied at least two members were affected. Ventricular arrhythmias (Lown grade greater than or equal to 4a) were recorded in more than half of the cases. The data reveal that right ventricular dysplasia shows a familial clustering and causes electrical instability that may place affected subjects at risk of sudden death. The mean age of these subjects suggests that the disease is manifested at a young age with a polymorphic clinical and arrhythmic profile. Finally, because this disease is a primary disorder of the ventricular myocardium, it should be included among the cardiomyopathies.