Comparison of two-dimensional echocardiographic and angiographic findings in arrhythmogenic right ventricular dysplasia

Analysis of statistical biases in studies used to formulate guidelines: the case of arrhythmogenic right ventricular cardiomyopathy (ARVC) the case of ARVC

RATIONALE AND OBJECTIVES

To analyze the statistical biases in the studies used to derive cardiac magnetic resonance-based major and minor criteria for the diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC).

MATERIALS AND METHODS

ARVC is a rare disorder of the heart that can lead to sudden death in young adults. Cardiac magnetic resonance imaging (CMR) plays a role in the diagnosis by contributing to the criteria set by experts. The original criteria emphasized qualitative analysis of CMR. The criteria were modified in 2010 to provide quantitative cutoffs.

RESULTS

We apply the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool for systematic review of diagnostic accuracy to the studies cited in the guidelines written in 1994 and revised in 2010. We use the signaling questions in QUADAS-2 to identify different types of statistical bias.

CONCLUSIONS

The studies have understandable biases that affect the sensitivity and specificity of CMR in the diagnosis of ARVC, as well as the truth of the disease state. There is potential to overdiagnose ARVC particularly in low prevalence populations.

Non-invasive recognition of arrhythmogenic right ventricular dysplasia

Arrhythmogenic right ventricular dysplasia causes ventricular arrhythmias and sometimes heart failure. The condition is easily overlooked, but once suspected, it may be diagnosed non-invasively. This is illustrated by the case reported. The clinical features of this syndrome are discussed, with special emphasis on the non-invasive findings.

Utility of tissue Doppler and strain echocardiography in arrhythmogenic right ventricular dysplasia/cardiomyopathy

Arrhythmogenic right ventricular dysplasia (ARVD) is a heritable cardiomyopathy characterized by the fibrofatty replacement of right ventricular (RV) myocardium leading to RV failure and arrhythmias. This study evaluated the potential utility of tissue Doppler echocardiography (TDE) and strain echocardiography (SE) to quantitatively assess RV function and their potential role in diagnosing ARVD. Images of 30 patients with ARVD (diagnosed by task force criteria) and 36 healthy controls were obtained. Peak systolic velocity, early diastolic velocity, displacement, strain rate, strain, outflow tract diameter, and fractional RV area change were measured in all subjects. Peak RV systolic velocity (6.4 +/- 2.2 vs 9 +/- 1.6 cm/s, p <0.0001), early diastolic velocity (-6.7 +/- 2.7 vs -9.4 +/- 2 cm/s, p <0.0001), displacement (13.7 +/- 5.8 vs 18.7 +/- 3.5 mm, p <0.0003), strain rate (-1 +/- 0.7 vs -2 +/- 1 s(-1), p = 0.002), and strain (-10 +/- 6% vs -28 +/- 11%, p = 0.001) were significantly lower in patients with ARVD compared with controls, respectively. Sensitivity and specificity, respectively, were 67% and 89% for systolic velocity, 77% and 71% for displacement, 73% and 87% for strain, 50% and 96% for strain rate, 53% and 93% for outflow tract diameter, and 47% and 83% for fractional area change. RV systolic velocity and displacement were significantly lower than in controls, even in the subset of patients with ARVD with apparently normal right ventricles by conventional echocardiography. Inter- and intraobserver agreement was high. In conclusion, TDE and SE enable the detection of ARVD via the quantification of RV function and may have potential clinical value in the assessment of patients with suspected ARVD. Peak RV systolic velocity <7.5 cm/s and peak RV strain <18% best identify patients with ARVD.

Echocardiographic findings in patients meeting task force criteria for arrhythmogenic right ventricular dysplasia: new insights from the multidisciplinary study of right ventricular dysplasia

OBJECTIVES

The purpose of this study was to quantify the echocardiographic abnormalities in probands who were newly diagnosed with arrhythmogenic right ventricular dysplasia (ARVD).

BACKGROUND

The diagnosis of ARVD remains challenging. The Multidisciplinary Study of Right Ventricular Dysplasia was initiated to characterize the cardiac structural, clinical, and genetic aspects of ARVD.

METHODS

Detailed echocardiograms were performed in 29 probands and compared with echoes from 29 normal control patients matched for age, gender, body size, and year of echo. Right atrial (RA) and right ventricular (RV) chamber dimensions, RV regional function, and the presence of morphologic abnormalities (hyper-reflective moderator band, trabecular derangement, and sacculations) were assessed. The RV systolic function was calculated as RV fractional area change (FAC).

RESULTS

The RV dimensions were significantly increased, and RV FAC was significantly decreased in probands versus control patients (27.2 +/- 16 mm vs. 41.0 +/- 7.1 mm, p = 0.0003). The right ventricular outflow tract (RVOT) was the most commonly enlarged dimension in ARVD probands (37.9 +/- 6.6 mm) versus control patients (26.2 +/- 4.9 mm, p < 0.00001). A RVOT long-axis diastolic dimension >30 mm occurred in 89% of probands and 14% of controls. The RV morphologic abnormalities were present in many probands (trabecular derangement in 54%, hyper-reflective moderator band in 34% and sacculations in 17%) but not in controls.

CONCLUSIONS

Probands with ARVD have significant RA and RV enlargement and decreased RV function, which can be easily assessed on standard echocardiographic imaging. These parameters should be measured when ARVD is suspected and compared with normal values.

Right ventricular exclusion surgery for arrhythmogenic right ventricular dysplasia with cardiomyopathy

IMPLICATIONS

The authors describe the management of a patient with arrhythmogenic right ventricular dysplasia treated with right ventricular exclusion surgery.

Arrhythmogenic right ventricular dysplasia. An illustrated review highlighting developments in the diagnosis and management of this potentially fatal condition

Arrhythmogenic right ventricular dysplasia is an inherited, progressive condition. Characterised by fatty infiltration of the right ventricle, it frequently results in life threatening cardiac arrhythmias, and is one of the important causes of sudden cardiac death in the young. There are characteristic electrocardiographic and echocardiographic features that all physicians need to be aware of if we are to reduce these occurrences of premature death. Diagnosis with magnetic resonance imaging is discussed along with current treatment options.

Exercise-induced ST elevation in patients with arrhythmogenic right ventricular dysplasia

To test the hypothesis that local or diffuse wall motion abnormalities in the right ventricle in patients with arrhythmogenic right ventricular dysplasia (ARVD) may induce the ST-segment elevation in response to exercise, we examined exercise electrocardiograms in patients with ARVD. In 17 patients with ARVD, who demonstrated right ventricular wall motion abnormalities without organic coronary lesions, we conducted a treadmill exercise test. Significant exercise-induced ST-segment elevation (ESTE) was defined as a 0.1 mV or more ST-segment elevation at J point. ESTE was observed in 11 patients (65%). It manifested most frequently in right-sided precordial leads. Severe right ventricular asynergy was seen in all but one (91%) among 11 with ESTE, whereas it was seen only in two (33%) among six without ESTE (P<.05). The maximal magnitude of ESTE inversely correlated with right ventricular ejection fraction (r = -0.58, P<.05). ESTE was seen in two thirds of ARVD patients, helping us noninvasively diagnose ARVD. The fact that ventricular wall motion abnormalities could cause ESTE in the absence of organic coronary lesions suggested the critical role of mechanical factors in the genesis of ESTE.

[Arrhythmogenic dysplasia of the right ventricle]

Arrhythmogenic right ventricular dysplasia is a disease of the cardiac muscle of unknown etiology. Landmarks of this disease are the presence of muscular atrophy and replacement of ventricular myocardium by adipous and fibroadipous tissue. This disease was originally described by Fontaine et al in 1977 during surgical ablation of drug refractory ventricular tachycardias in patients without evident structural heart disease. During surgery anomalies in contractility of the right ventricle and the presence of adipous tissue were documented. Some years later, Markus et al reported the first clinical series of patients with arrhythmogenic right ventricular dysplasia. Since then, this disease has been widely recognized and must be considered in the differential diagnosis of all patients with ventricular arrhythmias originating in the right ventricle.

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.

Arrhythmogenic right ventricular dysplasia

Right ventricular dysplasia is a primary disorder of the right ventricular myocardium characterised by a progressive replacement by adipose or fibrous tissue, proceeding from the epicardium towards the endocardium. Right ventricular dysplasia with the predominant clinical manifestation of an arrhythmia of right ventricular origin is defined as arrhythmogenic right ventricular dysplasia. There is, however, a wide spectrum of clinical presentation and physical findings owing to the polymorphism of the condition. The aetiology of right ventricular dysplasia remains unknown. Right ventricular angiography is currently regarded as the gold standard for the clinical diagnosis of right ventricular dysplasia Ventricular endomyocardial biopsy can be useful in confirming the diagnosis but a negative biopsy does not exclude the diagnosis of right ventricular dysplasia. There have been few electrophysiological studies and these, in general, have failed to help in risk stratification. Treatment is focused on the prevention of potentially lethal right ventricular electrical instability.

Value of the echocardiographic findings of arrhythmogenic right ventricular dysplasia with left ventricular involvement in a child

A 9-year-old girl was admitted because she had had palpitations for 2 years. Her electrocardiogram revealed multifocal ectopic beats with left bundle branch morphology, sinoatrial block, and first- and second-degree atrioventricular blocks. Cross-sectional echocardiography demonstrated an enlarged left ventricle and filling defects and sacculations of the posterior left ventricular wall, apex, and septum. The diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) was confirmed by endomyocardial biopsy and thallium 201 scintigraphy. We present this case because of the rarity of left ventricular involvement associated with ARVD. We also emphasize the value of echocardiography in the early diagnosis of ARVD.

Usefulness of Biplanar Transesophageal Echocardiography in Arrhythmogenic Right Ventricular Dysplasia: Clinical Experience with Seven Cases

This study evaluated the clinical usefulness of biplanar transesophageal echocardiography (TEE) in suspected arrhythmogenic right ventricular dysplasia (ARVD). Seven symptomatic subjects (3 male and 4 female: ages 18-64 years, mean 45) with clinical features of ARVD (typical ventricular arrhythmias) underwent comprehensive noninvasive assessment including transthoracic echocardiography (TTE), nuclear magnetic resonance (NMR), and TEE. Other systemic and cardiac diseases were reasonably excluded. TEE identified a significant right ventricular regional alteration in one subject with negative TTE and NMR, and nonsignificant abnormalities in two subjects with negative or no TTE and positive NMR. TEE confirmed the pathological findings detected by TTE in the four remaining patients and visualized several more abnormalities that approximately corresponded to NMR results. On the basis of these initial results, biplanar TEE appears to be comparable to NMR in the assessment of ARVD and a promising technique in identifying ARVD morphological alterations. (ECHOCARDIOGRAPHY, Volume 13, January 1996)

Ventricular tachycardias with left bundle branch block morphology

The differential diagnosis of VTs with LBBB morphology includes several well-defined syndromes. Although the majority of cases are attributable to acquired structural heart disease, including ischemia, prior infarction, or dilated cardiomyopathy, consideration of specific right ventricular processes is essential to proper evaluation and treatment. The approach to older patients or those with evidence for heart disease should begin with an evaluation for coronary artery disease and an assessment of biventricular function. Careful evaluation for bundle branch reentry should be performed during electrophysiological study, especially when there is underlying conduction system disease. Younger patients, those without overt heart disease, or those with isolated right ventricular disease, should receive a complete noninvasive evaluation of right and left ventricular size and function. An abnormal SAECG or identification of intracardiac late potentials suggest right ventricular dysplasia or cardiomyopathy, whereas responsiveness to adenosine and absence of detectable heart disease support the diagnosis of idiopathic right VT. Newer techniques, including MRI, show promise in identifying subtle right ventricular disease not otherwise detectable even in the setting of presumed idiopathic right VT. Following surgical repair of selected congenital heart defects, particularly tetralogy of Fallot, symptoms of recurrent palpitations, near syncope, syncope, or aborted sudden death may be attributable to recurrent VT, and diagnostic electrophysiological study should be considered for these patients. Finally, SVTs with LBBB morphology, particularly cases associated with right-sided or septal accessory pathways, should always be considered in this differential diagnosis.

Time- and frequency-domain analyses of the signal-averaged ECG in patients with arrhythmogenic right ventricular dysplasia

BACKGROUND

Arrhythmogenic right ventricular dysplasia (ARVD) is characterized by recurrent ventricular tachycardia of right ventricular origin and a cardiomyopathy with hypokinetic areas involving the free wall of the right ventricle. Subjects have a risk of sudden cardiac death, particularly during sports and strenuous exercise. Routine clinical examinations may be normal, but fragmented or delayed electrograms are usually recorded in the right ventricle of these patients. However, the frequency with which late potentials are detected by conventional time-domain analysis of the signal-averaged ECG (SAECG) is not high. This study evaluated the usefulness of the frequency-domain analysis of the SAECG in addition to the conventional time-domain analysis for a screening test to detect patients with ARVD.

METHODS AND RESULTS

SAECG was recorded by using a bipolar X, Y, and Z lead system in 28 patients with ARVD (mean age, 38 +/- 13 years) and 35 age-matched normal subjects (mean age, 35 +/- 11 years). The conventional time-domain analysis of the SAECG was performed at two different high-pass filter settings, 25 and 40 Hz, and the low-pass cutoff frequency was fixed at 250 Hz. The fast-Fourier transform analysis of SAECG was performed using a Blackman-Harris window. Area ratio 1 (area of 20 to 50 Hz)/(area of 0 to 20 Hz) and area ratio 2 (area of 40 to 100 Hz)/(area of 0 to 40 Hz) were calculated. In the conventional time-domain analysis, 20 (71%) and 18 (64%) patients had positive criteria at filter settings of 25 and 40 Hz, respectively. In the frequency-domain analysis, 18 (64%) and 20 (71%) patients had abnormal values in area ratios 1 and 2, respectively. Combining the time- and frequency-domain analyses, all patients were judged positive, with a sensitivity of 100% and a specificity of 94%.

CONCLUSIONS

Each result of the time- and frequency-domain analyses revealed that both methods had equivalent value. Combining the two domain analyses improved the sensitivity without reducing the specificity. These findings suggest that combining the time- and frequency-domain analyses of the SAECG may be useful as a screening test to detect patients with ARVD.

Diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy. Task Force of the Working Group Myocardial and Pericardial Disease of the European Society of Cardiology and of the Scientific Council on Cardiomyopathies of the International Society and Federation of Cardiology

Images

Spectrum of right heart involvement in patients with ventricular tachycardia unrelated to coronary artery disease or left ventricular dysfunction

We studied 41 patients with clinically symptomatic ventricular tachycardia in the absence of coronary artery disease or left ventricular dysfunction to define the extent of right and left heart derangement and their relation to electrophysiologic and clinical data. Individual echocardiographic measurements as well as global assessment scores of the right and left heart demonstrated a wide spectrum of right heart echocardiographic abnormalities. There was much less variation in the left heart, with the majority of patients being close to normal. There was an association between the right heart score, the clinical presentation of arrhythmia, the response to programmed electrical stimulation, and the recurrence of arrhythmia (p < 0.05). Thus echocardiographic findings demonstrate the whole spectrum of right heart involvement in patients with apparent idiopathic ventricular tachycardia and can give insight into clinical history, arrhythmia inducibility, and prognosis.

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.

Magnetic resonance imaging in right ventricular dysplasia

Fifteen patients with right ventricular dysplasia were investigated by T1-weighted spin- and gradient-echo pulse sequences, using a protocol that enabled both a subjective analysis of myocardial signal intensity and a quantitative/qualitative analysis of right and left ventricular function. In 8 patients, 3 investigators independently recognized abnormally hyperintense areas in the anatomic sites usually affected by the disease. In 7 of these patients, these areas showed an overlap with a-dyskinetic areas imaged by both magnetic resonance imaging (MRI) and echocardiography. In 1 patient who underwent a cardiac transplant, MRI of the explanted heart showed an excellent correlation between the distribution of the lesions and the in vivo/in vitro features. The data were compared with those from an equivalent sample of patients affected by dilated cardiomyopathy. In the latter patients, no focal hyperintensities were attributed to any anatomic sites in the right ventricule, and no focal a-dyskinetic foci were observed. Furthermore, the 2 groups of patients were significantly different in regard to dimensional and functional quantitative parameters. The results suggest that MRI is useful in integrating echocardiographic data and can be helpful in diagnosing this disease in late stages.

Frequency analysis of signal-averaged electrocardiogram in patients with right ventricular tachycardia

OBJECTIVES

The purpose of this study was to analyze the frequency content of signal-averaged electrocardiograms (ECGs) in patients with idiopathic ventricular tachycardia of right ventricular origin and in patients with arrhythmogenic right ventricular dysplasia.

BACKGROUND

The late potentials in the time domains are usually found in patients with arrhythmogenic right ventricular dysplasia. They are not usually found in patients with idiopathic ventricular tachycardia of right ventricular origin.

METHODS

Fast Fourier transform analysis of signal-averaged ECGs was performed with the use of a Blackman-Harris window in 43 subjects: 20 normal volunteers (group I), 12 patients with idiopathic ventricular tachycardia of right ventricular origin (group II) and 11 patients with arrhythmogenic right ventricular dysplasia (group III), and the frequency spectrum was displayed in a three-dimensional graph. Area ratio (ratio of the area under the spectral plot from 40 to 120 Hz to the area from 0 to 120 Hz) was calculated in all subjects.

RESULTS

Area ratio was significantly higher in group II than in group I (243 +/- 45 vs. 196 +/- 15, p < 0.01) and significantly higher in group III (396 +/- 51) than in group I or II (p < 0.001). The high frequency components in group II were confined within the QRS complex in the three-dimensional graph, whereas those in group III extended outside the QRS complex.

CONCLUSIONS

Frequency analysis of the signal-averaged ECG with fast Fourier transform analysis can detect the high frequency components in patients with right ventricular tachycardia, including idiopathic ventricular tachycardia and arrhythmogenic right ventricular dysplasia.

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.

Left ventricular involvement in right ventricular dysplasia

Right ventricular dysplasia, a heart muscle disease of unknown cause, anatomically characterized by variable replacement of myocardial muscle with adipose or fibroadipose tissue, is usually considered a selective disorder of the right ventricle. However, concomitant left ventricular involvement has been noted in a few cases. The aim of this study was to evaluate the prevalence and characteristics of left ventricular involvement in right ventricular dysplasia, as well as possible progression of the disease. Thirty-nine patients with right ventricular dysplasia were studied by M-mode and two-dimensional echocardiography; 28 of them also underwent cardiac catheterization, and in 25 endomyocardial biopsy was performed. On first examination the left ventricle was normal in 25 patients, whereas in the remaining 14 right ventricular abnormalities were associated with left ventricular involvement, characterized by asynergic areas (12 patients) or diffuse mild hypokinesis (two patients). During follow-up (27 patients, 84.1 +/- 66.1 months) 10 patients showed worsening of right ventricular function; in nine the appearance or worsening of left ventricular abnormalities was observed. Five patients died (four in congestive heart failure and one suddenly). Results of postmortem examination (available in two patients) showed atrophy of myocells and a massive fatty and fibrous infiltration of the right ventricular wall, associated with degenerative changes and fibrosis of the left ventricle. In conclusion, right ventricular dysplasia may be associated with left ventricular involvement and the disorder appears to be progressive in some instances.

Clinical and instrumental evaluation of the family of a patient with arrhythmogenic right ventricle dysplasia

The aim of the present study is a clinical and instrumental evaluation of the family of a patient with arrhythmogenic right ventricle dysplasia (ARVD), initially complicated by recurrent ventricular tachycardia and later by congestive cardiac failure. Because the probability of familial involvement is very high in those cases described in the literature, the authors evaluated the patient's 3 children: 2 daughters, twenty-four and twenty years old, respectively, and a twenty-one-year-old son; his niece, thirty-one years old; and her sons three and eight years old. The authors did not evaluate his fifty-six-year-old sister, because she was affected by rheumatic mitral valve disease. All in the study were asymptomatic, and clinical examination did not show any pathologic findings. Rest ECG was normal in all cases, and the exercise stress test (Bruce protocol) showed normal functional capacity. Holter recordings were normal without arrhythmias; chest x rays showed normal cardiothoracic ratio and cardiac morphologic volume. Two-dimensional echocardiography and pulsed and continuous wave Doppler demonstrated normal sizes of cardiac chambers and normal function and morphology of cardiac valves. Nevertheless, in 4 cases (66.5%) the right ventricles showed an apical bulging with normal systolic thickness, without hypokinetic or akinetic areas or diverticular outpouchings. The authors did not find those abnormalities in 5 control subjects who were studied in the same way.

CONCLUSIONS

In 4 family members (66.5%) of a patient with ARVD progressed to cardiac congestive failure, the authors found anomalies of right ventricle morphology: apical bulging, not revealed in a control group, and an absence of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Ventricular arrhythmias in children with an apparently normal heart

Ventricular ectopy occurs frequently in normal children. In the presence of a normal heart, these arrhythmias, including asymptomatic, nonsustained ventricular tachycardia, carry a benign prognosis and are not associated with sudden, unexpected death. However, complex ventricular arrhythmias frequently indicate the presence of underlying cardiac disease; patients with such arrhythmias must undergo an appropriately thorough evaluation before decisions regarding prognosis and the need for therapy can be made.

Nonischemic sustained ventricular tachycardia: clinical outcome in 12 patients with arrhythmogenic right ventricular dysplasia

The clinical course and long-term follow-up of 12 patients with arrhythmogenic right ventricular dysplasia causing ventricular tachycardia are presented. No patient had a history of congestive heart failure and the cardiothoracic ratio measured less than or equal to 0.5 in all patients. All 12 patients were symptomatic during ventricular tachycardia; syncope occurred in 4. Exercise-related symptoms were present in 8 (73%) of 11 patients. The mean right ventricular ejection fraction was 31% (range 20% to 54%), and the mean left ventricular ejection fraction was 68% (range 44% to 88%). Signal averaging of the rest electrocardiogram (ECG) revealed late potentials in five of eight patients. During programmed electrical stimulation, sustained or nonsustained ventricular tachycardia showing a left bundle branch block configuration was induced in all patients. One patient underwent right ventricular disconnection and died 1 week after operation of low cardiac output failure. The remaining 11 patients were all treated medically and are alive at a mean follow-up time of 7.9 years after the onset of symptoms. Recurrence of symptomatic and documented sustained monomorphic ventricular tachycardia occurred in eight patients and could not be predicted by results of long-term ECG monitoring, treadmill exercise testing or programmed stimulation. In conclusion, despite recurrence of ventricular tachycardia, patients with arrhythmogenic right ventricular dysplasia have a favorable outcome when treated medically. Noninvasive studies (imaging techniques, ambulatory ECG monitoring and exercise testing) provide data that may be sufficient in diagnosing arrhythmogenic right ventricular dysplasia.

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.

Juvenile sudden death and effort ventricular tachycardias in a family with right ventricular cardiomyopathy

A family with occurrence of juvenile sudden death and effort polymorphous ventricular tachycardias is reported. Nineteen members aged 9 to 63 years were investigated. Four of them died suddenly in their youth. Postmortem investigation performed in 2 deceased subjects disclosed an apparently normal heart at macroscopy but fibro-fatty substitution of the right ventricular free wall was noted at histologic examination. The 14 living members underwent physical examination, resting electrocardiography, chest X-radiography, Holter monitoring, exercise stress testing, and M-mode and cross-sectional echocardiography. Four patients underwent hemodynamic and electrophysiologic studies. All 14 subjects had normal physical examination as well as normal electrocardiographic and cardiothoracic indices. Localized right ventricular structural and dynamic abnormalities were noted at cross-sectional echocardiographic and angiographic investigation of 9 of the patients. The right ventricular volumes in these subjects were normal or slightly increased. In 7 of them, polymorphous ventricular tachycardias were induced by exercise stress testing. The arrhythmias which were responsive to beta-blockade, do not seem to depend on reentry. Enhanced automaticity appeared to be the more likely mechanism of their production. These data demonstrate that right ventricular cardiomyopathy may occur in an occult form with life-threatening electrical instability.

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.

Cardioangiographic findings in patients with arrhythmogenic right ventricular dysplasia

The dimension, contractility, and regional wall motion of the right and left ventricles were scored on the angiograms of 13 patients with arrhythmogenic right ventricular dysplasia. In 10 patients the right ventricle was enlarged, in eight the contractility of the right ventricle was reduced, and in all but one patient there were regional wall motion abnormalities of the right ventricle. The most common abnormality of regional wall motion was mild hypokinesia. There were bulging or dyskinetic areas in seven patients. Regional wall motion abnormalities of the left ventricle were found in five patients, two of whom also had bulging or dyskinetic areas. The reproducibility of right ventricular dimension, contractility, and regional wall motion scores was generally fair but varied unexpectedly both within and between two observers (Kendall's Tau 0.38-0.92). The score values of regional wall motion for some of the segments differed considerably within and between observers. One of the observers consistently gave higher scores than the other. These data suggest that a more objective approach is needed for evaluating angiographic changes in arrhythmogenic right ventricular dysplasia.

Critical analysis of cineangiographic criteria for diagnosis of arrhythmogenic right ventricular dysplasia

Biplane 30-degree RAO and 60-degree LAO RV selective cineangiography was performed in 21 patients with significant ventricular arrhythmias (ventricular tachycardia in 14, salvos in three, and complex PVCs in seven) and a high presumption of arrhythmogenic RV dysplasia (ARVD), and in a control group of 10 presumed normal individuals. Comparing the two series revealed the lack of specificity of some angiographic images usually reported as suggestive signs of ARVD, such as slow dye evacuation of RV during the levophase and deep fissuring in the anterior wall with a "pile of plates" image. Inversely, localized morphologic and contraction abnormalities in the RV free wall were more sensitive and specific signs for diagnosis of ARVD; these were localized akinetic or dyskinetic bulges sometimes giving a true image of aneurysm (90%), wide and deep fissuring of the apex or of the inferior wall (33%), and large areas of akinesia. By order of frequency, these abnormalities were found on the apex in 71%, on the inferior wall in 52%, on the anterior wall in 48%, in the subtricuspid area in 38%, and on the pulmonary infundibulum in 33%. These localized lesions can suffice for the diagnosis of RV dysplasia in the absence of associated pathologies, such as ischemic heart disease or congenital defects. Usually a global RV systolic dysfunction is associated in ARVD, as confirmed by greater RV volumes (134 +/- 26 vs 79 +/- 10 ml/m2 for RVEDV, p less than 0.001; 76 +/- 34 vs 32 +/- 6 ml/m2 for RVESV, p less than 0.001), and lower RV ejection fraction (58 +/- 18% vs 47 +/- 8%, p less than 0.001) in the ARVD group compared to controls. Nevertheless, normal RV volumes and ejection fraction can be observed in some localized forms with mono- or bisegmental lesions in which RV systolic dysfunction is absent or moderate, and extensive forms with multiple segmental lesions where RV systolic dysfunction is constant and often severe. Six out of 21 patients in the ARVD group exhibited obvious global or segmental LV dysfunction, indicating the possibility of biventricular forms, as previously reported in other publications.

Usefulness of noninvasive studies for diagnosis of right ventricular dysplasia

The value and limitations of echocardiography and cardiac scintigraphy in the diagnosis of right ventricular (RV) dysplasia were assessed. Criteria that defined RV dysfunction were developed first using data from 40 normal subjects. The sensitivity and specificity of these criteria to detect RV dysplasia were then determined in 44 patients suspected of having RV dysplasia. In these patients the presence (14 patients) or absence (30 patients) of RV dysplasia had been established using cardiac catheterization data, which included contrast RV cineangiograms. Mean RV end-diastolic and end-systolic diameters, and RV/left ventricular (LV) ratios of end-diastolic and end-systolic diameters and end-diastolic and end-systolic volumes were greater in patients with RV dysplasia (p less than 0.001). Using cardiac scintigraphy, all patients with RV dysplasia were identified by an RV/LV end-systolic volume greater than 1.8; exercise RV ejection fraction less than 50%; or exercise RV wall motion score more than 1. Using echocardiography, RV contraction abnormalities were seen in 80% of patients with RV dysplasia. The specificities, even in this selected population, were less than 100%. Thus, normal echocardiographic and scintigraphic results can be used instead of RV contrast cineangiography to exclude the diagnosis of RV dysplasia.