Electroanatomic mapping of arrhythmogenic right ventricular dysplasia

OBJECTIVES: We tested the hypothesis that spatial association of low-amplitude intracardiac electrograms can identify the presence, location and extent of dysplastic regions in arrhythmogenic right ventricular dysplasia (ARVD). BACKGROUND: Arrhythmogenic right ventricular dysplasia is a right ventricular (RV) cardiomyopathy characterized pathologically by fibrofatty infiltration and clinically by a spectrum of arrhythmias, sudden cardiac death and RV failure. Diagnosis of ARVD still remains a clinical challenge. METHODS: A three-dimensional electroanatomic mapping technique was used to map the RV of two groups of patients: 1) those with ARVD presenting with typical clinical, electrocardiographic and echocardiographic or magnetic resonance imaging (MRI) findings; and 2) those with structurally normal ventricles. RESULTS: The dysfunctional RV area could be identified only in the first group and was characterized by the presence of discrete areas of abnormally low-amplitude electrograms. Hence, the normal voltage values observed in the control group (unipolar: 11.9 +/- 0.3 mV; bipolar: 4.6 +/- 0.2 mV [mean +/- SEM]) and in the nonaffected zones in the ARVD group (unipolar: 10.4 +/- 0.2 mV; bipolar: 4.6 +/- 0.2 mV) were reduced significantly (p < 0.05) in the dysplastic areas (unipolar: 3.3 +/- 0.1 mV; bipolar: 0.5 +/- 0.1 mV). The pathologic process mainly involved the RV anterolateral free wall, apex and inflow and outflow tracts and ranged from patchy areas to uniform and extensive involvement. Concordance between electroanatomic findings and MRI or echocardiographic findings was noted in all patients. CONCLUSIONS: The pathologic substrate in ARVD can be identified by spatial association of low-amplitude endocardial electrograms, reflecting replaced myocardial tissue. The ability to accurately identify the presence, location and extent of the pathologic substrate may have important diagnostic, prognostic and therapeutic implications.     

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.     

Magnetic resonance imaging findings in patients meeting task force criteria for arrhythmogenic right ventricular dysplasia

INTRODUCTION: Magnet resonance imaging (MRI) findings in patients meeting Task Force criteria for the diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) have not been systematically described. We report qualitative and quantitative MRI findings in ARVD using state-of-the-art MRI. METHODS AND RESULTS: MRI was performed on 12 patients with ARVD who were prospectively diagnosed using the Task Force criteria. The imaging protocol included breath-hold double inversion recovery spin-echo and gradient-echo images. Ventricular volumes and dimensions were compared to 10 age- and sex-matched normal volunteers. High intramyocardial T1 signal similar to fat signal was observed in 9 (75%) of the 12 patients and in none of the controls. Right ventricular (RV) hypertrophy was seen in 5 (42%) patients, trabecular disarray in 7 (59%), and wall thinning in 3 (25%). Both the RV end-diastolic diameter and the outflow tract area were significantly higher in ARVD patients compared to controls (51.2 vs 43.2 mm, P < 0.01; and 14.5 vs 9.3 cm2, P < 0.01, respectively). ARVD patients had a higher RV end-diastolic volume index and lower RV ejection fraction compared with controls (127.4 vs 87.5, P < 0.01; and 41.6% vs 57%, P < 0.01, respectively). CONCLUSION: High intramyocardial T1 signal indicative of fat is seen in a high percentage (75%) of patients who meet the Task Force criteria for ARVD. Trabecular disarray is seen more frequently than wall thinning and aneurysms. RV dimensions and volumes differ significantly in ARVD compared to controls, indicating a role for quantitative evaluation in the diagnosis of ARVD.     

Histologic findings in patients with clinical and instrumental diagnosis of sporadic arrhythmogenic right ventricular dysplasia

OBJECTIVES: We sought to analyze the histologic findings of 30 patients with a diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) based on established clinical and instrumental criteria, who did not have a family history of ARVD. BACKGROUND: The diagnostic role of endomyocardial biopsy (EMB) in patients with a clinical profile of ARVD is still debated. METHODS: Thirty patients (19 male, 11 female, mean age 27 +/- 10 years) with left bundle branch block morphology ventricular tachyarrhythmias and echocardiographic, angiographic, and magnetic resonance imaging (MRI) findings diagnostic of ARVD were studied. All patients, besides diagnostic, noninvasive, and invasive cardiac studies, underwent EMB in the apex, anterior free wall, inferior wall of the right ventricle (RV) and in the septal-apical region of the left ventricle. RESULTS: Diagnostic histologic features of ARVD were found only in 9 (30%) patients and a myocarditis, according to the Dallas criteria, in the remaining 21 (70%) patients. Morphometric evaluation of RV samples showed significant differences in fatty tissue and myocyte percent area between ARVD and myocarditis (p < 0.001). Conversely, no difference was found between the two groups in arrhythmic patterns and structural and functional echocardiographic, angiographic, and MRI RV alterations. Magnetic resonance imaging showed hyperintense signals in 67% of ARVD and in 62% of myocarditis group (p = NS). During follow-up (mean, 23 +/- 14 months), all patients with myocarditis remained stable on antiarrhythmic therapy while five patients with ARVD required implantation of an implantable cardioverter defibrillator. CONCLUSIONS: A myocarditis involving the RV can mimic ARVD. An EMB appears the most reliable diagnostic technique, with significant prognostic and therapeutic implications.     

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.     

Angiographic right and left ventricular function in arrhythmogenic right ventricular dysplasia

We prospectively documented right ventricular (RV) and left ventricular (LV) volumes and ejection fractions in a large series of patients with arrhythmogenic RV dysplasia/cardiomyopathy (ARVD/C). Eighty-five patients with ARVD/C and 11 controls underwent 2 successive orthogonal right and left monoplane x-ray-digitized cineangiographies. Volumes were calculated using the hemielliptical RV and ellipsoidal LV models. All controls and 58 of 85 patients (ARVD/C-I) had a RV ejection fraction > or =35% and 27 patients had a RV ejection fraction <35% (ARVD/C-II). Tricuspid annulus plane systolic excursion (TAPSE) was lower in ARVD/C-II than in ARVD/C-I patients (6 +/- 3 vs 14 +/- 3 mm) and controls (16 +/- 2 mm) (each p <0.001). In patients with ARVD/C, TAPSE was positively related to RV ejection fraction (r = 0.79) and to crista supraventricularis shortening (r = 0.81) (each p <0.001). Sensitivity and specificity of TAPSE <12 mm in identifying patients with RV ejection fraction <35% were 96% and 78%, respectively. LV ejection fraction was > or =50% in 68 patients, 40% to 49% in 10, and <40% in 7. Diffuse RV outflow tract aneurysm was observed in 9 patients, all belonging to ARVD/C-II, and this sign identified patients with LV ejection fraction <40% with 86% sensitivity and 96% specificity. In conclusion, 68% of ARVD/C patients had normal RV ejection fraction and RV volumes, and 80% of ARVD/C patients had normal LV ejection fraction. Decreased TAPSE <12 mm and a diffuse RV outflow tract aneurysm were sensitive and specific indicators of RV ejection fraction <35% and LV ejection fraction <40%, respectively.     

Noninvasive detection of myocardial fibrosis in arrhythmogenic right ventricular cardiomyopathy using delayed-enhancement magnetic resonance imaging

OBJECTIVES: We evaluated the role of myocardial delayed-enhancement (MDE) magnetic resonance imaging (MRI) for noninvasive detection of fibrosis in Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). BACKGROUND: Arrhythmogenic right ventricular dysplasia/cardiomyopathy is characterized by fibro-fatty replacement of the right ventricle (RV) leading to arrhythmias and RV failure. Endomyocardial biopsy can demonstrate fibro-fatty replacement of the RV myocardium; however, the test is invasive and carries a risk of perforation. METHODS: Thirty consecutive patients were prospectively evaluated for ARVD/C. Magnetic resonance imaging was performed on a 1.5-T scanner. Ten minutes after intravenous administration of 0.2 mmol/kg of gadodiamide, MDE-MRI was obtained. Diagnosis of ARVD/C was based upon the Task Force criteria and did not include MRI findings. RESULTS: Twelve (40%) of 30 patients met the Task Force criteria for ARVD/C. Eight (67%) of the 12 ARVD/C patients demonstrated increased signal on MDE-MRI in the RV compared with none (0%) of the 18 patients without ARVD/C (p <0.001). Endomyocardial biopsy was performed in 9 of the 12 ARVD/C patients. Of the nine patients, four had fibro-fatty changes consistent with the diagnosis of ARVD/C. Each of these patients had increased RV signal on MDE-MRI. None of the patients without ARVD/C had any abnormalities either on histopathology or on MDE-MRI. Electrophysiologic testing revealed inducible sustained ventricular tachycardia (VT) in six of the eight ARVD/C patients with delayed enhancement, compared with none of the ARVD/C patients without delayed enhancement (p=0.01). CONCLUSIONS: Noninvasive detection of RV myocardial fibro-fatty changes in ARVD/C is possible by MDE-MRI. Magnetic resonance imaging findings had an excellent correlation with histopathology and predicted inducible VT on programmed electrical stimulation, suggesting a possible role in evaluation and diagnosis of patients with suspected ARVD/C.     

Feasibility and variability of three dimensional echocardiography in arrhythmogenic right ventricular dysplasia/cardiomyopathy

Arrhythmogenic right ventricular dysplasia (ARVD/C) is a genetic cardiomyopathy characterized by fibrous fatty replacement of the right ventricular (RV) myocardium, leading to progressive RV failure and ventricular arrhythmias in young athletes. This study evaluated whether transthoracic, real-time, 3-dimensional echocardiography (3DE) can adequately assess RV morphology and function in ARVD/C by comparing 3DE with cardiac magnetic resonance (CMR), the current reference standard. Three-dimensional echocardiography was prospectively performed in 58 patients (23 with ARVD/C, 20 first-degree relatives with no ARVD/C, 8 with idiopathic ventricular tachycardia with no ARVD/C, and 7 healthy volunteers). All patients, except 15 patients with ARVD/C with implanted defibrillators, also underwent CMR. Three-dimensional echocardiography and CMR-derived RV volumes and ejection fractions were obtained by offline data analysis by blinded, independent observers. The mean age of the study group was 37 +/- 11 years (30 men). The feasibility of 3DE was high, and analyzable images were obtained in all subjects. Three-dimensional echocardiography revealed a wide variety of RV morphologic abnormalities in ARVD/C. There was a good correlation between 3DE and CMR for RV end-systolic volume (r = 0.72, p = 0.0001), RV end-diastolic volume (r = 0.50, p = 0.0001), and the RV ejection fraction (r = 0.88, p = 0.001). We found high intraobserver and moderate interobserver correlations for 3DE estimations of volumes and ejection fractions. In conclusion, 3DE measurements of RV volumes and ejection fractions closely correlate with CMR values and may be useful in the follow-up of patients with ARVD/C.     

Prospective Study of Cardiac Sarcoid Mimicking Arrhythmogenic Right Ventricular Dysplasia

Introduction: Case studies indicate that cardiac sarcoid may mimic the clinical presentation of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C); however, the incidence and clinical predictors to diagnose cardiac sarcoid in patients who meet International Task Force criteria for ARVD/C are unknown.
Methods and Results: Patients referred for evaluation of left bundle branch block (LBBB)-type ventricular arrhythmia and suspected ARVD/C were prospectively evaluated by a standardized protocol including right ventricle (RV) cineangiography-guided myocardial biopsy. Sixteen patients had definite ARVD/C and four had probable ARVD/C. Three patients were found to have noncaseating granulomas on biopsy consistent with sarcoid. Age, systemic symptoms, findings on chest X-ray or magnetic resonance imaging (MRI), type of ventricular arrhythmia, RV function, ECG abnormalities, and the presence or duration of late potentials did not discriminate between sarcoid and ARVD/C. Left ventricular dysfunction (ejection fraction <50%) was present in 3/3 patients with cardiac sarcoid, but only 2/17 remaining patients with definite or probable ARVD/C (P = 0.01).
Conclusions: In this prospective study of consecutive patients with suspected ARVD/C evaluated by a standard protocol including biopsy, the incidence of cardiac sarcoid was surprisingly high (15%). Clinical features, with the exception of left ventricular dysfunction and histological findings, did not discriminate between the two entities.     

The impact of hypertension and hypertension-related left ventricle hypertrophy on right ventricle function

AIM: The aim of our study is to determine the effect of hypertension and hypertension-related left ventricle hypertrophy on right ventricle (RV) morphology and function by using RV standard Doppler echocardiographic indices, myocardial Doppler imaging, and strain/strain rate imaging indices. METHODS: We studied 35 patients with arterial hypertension and 30 age- and sex-adjusted control subjects who had no other pathological conditions. Standard transthoracic Doppler echocardiographical measurements, pulsed-wave tissue Doppler from tricuspid anulus (Peak systolic-st, peak early diastolic-et, peak late diastolic velocity-at), reconstructed spectral pulsed-wave tissue Doppler velocities (peak systolic-S, peak early-E, peak late diastolic velocity-A), and strain/strain rate imaging of RV free wall mid region (peak systolic strain-in, peak systolic strain rate-SR) were obtained. RESULTS: Age, body surface area, blood pressure, and heart rate were comparable between two groups. Hypertensive subjects had significantly increased LV end-diastolic septal and posterior wall thickness, left atrial diameter, LV mass, LV mass index, and relative wall thickness during diastole. At the level of right ventricular lateral tricuspid annulus without systolic changes, the majority of diastolic measurements were altered in hypertensives (early diastolic velocity et; 13 +/- 2 vs. 18 +/- 4 m/sec, P < 0.0001, late diastolic velocity at; 20 +/- 4 vs. 14 +/- 3 m/sec, P < 0.0001, early to late diastolic velocity ratio; 0.69 +/- 0.14 vs. 1.32 +/- 0.38, P < 0.0001). The velocity data from two-dimensional color myocardial imaging at the level of RV free wall mid region again showed altered diastolic measurements in hypertensives (E; 8.01 +/- 2.6 vs. 10.4 +/- 3.14 m/sec, P < 0.001, A; 11.5 +/- 2.6 vs. 9.12 +/- 3.7 m/sec, P < 0.0001, E/A ratio; 0.75 +/- 0.41 vs. 1.87 +/- 0.48, P < 0.00). The peak systolic strain of RV free wall mid region was significantly lower in hypertensive individuals than controls (25.666 +/- 5.64 vs. 30.03 +/- 6.78%, P < 0.05). No significant differences were found in other parameters of RV function between hypertensive and control subjects. CONCLUSIONS: The present study demonstrates that besides the manifest morphologic LV adaptations, significant RV functional alterations can be determined by TDI and strain/strain rate imaging in patients arterial hypertension. Both tissue velocities by TDI and strain imaging may be new tools to define and quantitate subtle change in systolic and diastolic function of right ventricular function in arterial hypertension that cannot be determined in standard echocardiographic parameters.     

Evolving role of multidetector computed tomography in evaluation of arrhythmogenic right ventricular dysplasia/cardiomyopathy

The purpose of this study was to report 1 center's experience with multidetector computed tomography (MDCT) in the evaluation of patients suspected to have arrhythmogenic right ventricular (RV) dysplasia/cardiomyopathy (ARVD/C). RV dilatation/dysfunction is 1 of the most important criteria for establishing the diagnosis of ARVD/C. Cardiac magnetic resonance imaging (MRI) is the most preferred imaging modality for the diagnosis of ARVD/C. However, many patients with suspected ARVD/C have implantable cardioverter-defibrillators, prohibiting the use of MRI. Thirty-one patients (19 men; mean age 41 +/- 12 years) referred for evaluation of known or suspected ARVD/C had a complete reevaluation including contrast-enhanced cardiac MDCT at the center. Two patients underwent both cardiac MRI and MDCT. Seventeen of 31 patients met Task Force criteria for ARVD/C and were confirmed to have ARVD/C. Multidetector computed tomographic images were analyzed for qualitative and quantitative characteristic findings of ARVD/C. Increased RV trabeculation (p <0.001), RV intramyocardial fat (p <0.001), and scalloping (p <0.001) were significantly associated with the final diagnosis of ARVD/C. RV volumes, RV inlet dimensions, and RV outflow tract surface area were increased in patients with ARVD/C compared with patients who did not meet the criteria. RV and left ventricular functional analysis was performed in 2 patients. In conclusion, cardiac MDCT has a strong potential to detect many qualitative and quantitative abnormalities of the right ventricle in patients with ARVD/C. Limitations include implantable cardioverter-defibrillators and motion artifacts, along with well-known radiation and contrast-induced reaction.     

Two autopsied cases of arrhythmogenic right ventricular dysplasia

Autopsy studies of arrhythmogenic right ventricular dysplasia (ARVD) have rarely been reported, and its etiology remains unknown. The present report describes a detailed histopathological study of two autopsied cases of ARVD. Case 1: This 21-year-old man experienced palpitation accompanied by syncope. He died after ventricular tachycardia of right ventricular origin. The heart weighed 365 g and the right ventricular cavity was markedly dilated. The distribution of fatty tissue was roughly limited to the middle layer of the free wall, replacing the myocardium with fatty degeneration. Medial hyperplasia of the small arteries within the fatty tissue was also observed. Fibroelastosis was observed in the left ventricular endocardium. In the conduction system, fatty tissue was found in the sinus node. In addition, medial hypoplasia was observed in the pulmonary arteries. Case 2: This 32-year-old man who had had an arrhythmia for 10 years died of ventricular tachycardia of right ventricular origin. His older brother also died of heart disease. His heart weighed 515 g and both the right and left ventricles were dilated. Fatty tissue, unlike that in Case 1, was shown to markedly infiltrate from the epicardium into both the right and left ventricular walls. In the right ventricular wall, muscle layers disappeared in some portions. In the conduction system, fatty tissue was observed in the sinus node. Although ARVD may be considered a syndromic entity, individual cases are different in terms of pathological morphology, with possible variations in the etiology and pathogenesis.     

Magnetic resonance imaging of arrhythmogenic right ventricular dysplasia: sensitivity, specificity, and observer variability of fat detection versus functional analysis of the right ventricle.

OBJECTIVES: The purpose of this study was to determine interobserver agreement for interpretation of magnetic resonance imaging (MRI) examinations of arrhythmogenic right ventricular dysplasia (ARVD) and to determine sensitivity and specificity of fat detection versus functional parameters measured by MRI. BACKGROUND: The interobserver variability of MRI and the relative importance of different MRI parameters (fat detection, regional and global right ventricular [RV] function) for ARVD diagnosis is unknown. METHODS: Two experienced observers blinded to the clinical history independently analyzed MRI datasets obtained from 40 patients evaluated for ARVD. Twenty normal subjects underwent MRI and served as control subjects. The MRI scans were performed according to a standard protocol on a 1.5-T scanner. The observers reported on fat infiltration, global and regional RV function, myocardial thinning, and chamber dilatation qualitatively. The RV volumes were measured on the cine sequences. RESULTS: Interobserver kappa scores for fat infiltration, global and regional RV function, wall thinning, and RV outflow dilatation were 0.74, 0.94, 0.89, 0.93, and 0.93, respectively. Correlation coefficients between observers for RV end-diastolic volume, end-systolic volume, and ejection fraction were 0.93, 0.94, and 0.95, respectively (p < 0.001). Fifteen patients were diagnosed with ARVD using Task Force criteria. Sensitivity of fat infiltration, RV enlargement, and regional RV dysfunction for diagnosing ARVD was 84%, 68%, and 78%, and specificity was 79%, 96%, and 94%, respectively. CONCLUSIONS: Qualitative assessment of RV structure and function is highly reproducible for experienced observers. Among the qualitative parameters, fat infiltration is less reproducible and lacks specificity compared with RV kinetic abnormalities.     

Blockade of the renin‐angiotensin‐aldosterone system in patients with arrhythmogenic right ventricular dysplasia: A double‐blind,multicenter, prospective,randomized, genotype‐driven study (BRAVE study)

Arrhythmogenic right ventricular dysplasia (ARVD) is a rare cardiomyopathy characterized by the progressive replacement of cardiomyocytes by fatty and fibrous tissue in the right ventricle (RV). These infiltrations lead to cardiac electrical instability and ventricular arrhythmia. Current treatment for ARVD is empirical and essentially based on treatment of arrhythmia. Thus, there is no validated treatment that will prevent the deterioration of RV function in patients with ARVD. The aim of the BRAVE study is to evaluate the effect of ramipril, an angiotensin‐converting enzyme inhibitor, on ventricular myocardial remodeling and arrhythmia burden in patients with ARVD. Despite the fact that myocardial fibrosis is one of the structural hallmarks of ARVD, no study has tested an antifibrotic drug in ARVD patients. The trial is a double‐blind, parallel, multicenter, prospective, randomized, phase 4 drug study. Patients will be randomized into 2 groups, ramipril or placebo. The 120 patients (60 per group) will be enrolled by 26 centers in France. Patients will be followed up every 6 months for 3 years. The 2 co–primary endpoints are defined as the difference of telediastolic RV volume measured by magnetic resonance imaging between baseline and 3 years of follow‐up, and the change in arrhythmia burden during the 3 years of follow‐up. A decrease in RV and/or left ventricular deterioration and in arrhythmia burden are expected in ARVD patients treated with ramipril. This reduction will improve quality of life of patients and will reduce the number of hospitalizations and the risk of terminal heart failure.     

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.     

Thromboembolic complications in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy.

AIMS: Incidence and clinical presentation of thromboembolic complications in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) were analysed. In reports on ARVD/C, thromboembolism is rarely mentioned. The possible risk factors are: right ventricle (RV) dilatation, aneurysms, and wall motion abnormalities. METHODS AND RESULTS: A group of 126 patients (89 male, 37 female, aged 43.6+/-14.3) with ARVD/C was retrospectively analysed for the presence of thromboembolic complications. The mean follow-up period was 99+/-64 months. Thromboembolic complications, i.e. pulmonary embolism (n=2), RV outflow tract thrombosis with severe RV failure (n=1), and cerebrovascular accident associated with atrial fibrillation (n=2) were observed in 4% of the patients. Spontaneous echogenic contrast was observed in seven patients with severe damage to RV. In four of them supraventricular arrhythmias resulting in heart failure were reported. Annual incidence of thromboembolic complications was 0.5/100 patients. CONCLUSIONS: (i) ARVD/C may be complicated by thrombosis. Annual incidence of such complications is significantly lower than reported for left ventricle failure. (ii) Anticoagulation should be used in ARVD/C patients with large, hypokinetic RV and slow blood flow. (iii) Patients with severe forms of ARVD/C, thrombus formation in the RV and/or spontaneous echocardiographic contrast are at higher risk of a poor outcome.     

Right ventricular strain and strain rate properties in patients with right ventricular myocardial infarction

BACKGROUND: This study was planned to assess strain and strain rate properties of right ventricle in patients with RV myocardial infarction. MATERIAL AND METHOD: Thirty patients with acute inferior myocardial infarction were included in this study. The presence of right ventricular infarction in association with an inferior myocardial infarction was defined by an ST-segment elevation 0.1 mV in lead V4 R. According to this definition, 15 patients had electrocardiographic signs of inferior myocardial infarction without right ventricular infarction (group I), and 15 patients had electrocardiographic signs of inferior myocardial infarction with right ventricular infarction (group II). Echocardiography was performed using a Vivid 5 System (GE Ultrasound; Horten, Norway) and a 2.5-MHz transducer. 2-dimensional color doppler myocardial imaging (CDMI) data for longitudinal function were recorded from the RV free wall using standard apical view. Offline analysis of the myocardial color Doppler data for regional velocity (V), strain rate (Sr), and strain (S) curves was performed using a special software program (EchoPac 6.4 Vingmed, Horten, Norway). They were assessed in basal, middle and apical segments of the RV. The differences between different groups were assessed with the Mann-Whitney U-test. A value of P < 0.05 was considered statistically significant. RESULTS: Systolic tissue velocity, strain, strain rate of basal (4.8 +/- 0.8 cm/s vs 6.5 +/- 1.2 cm/s, -12 +/- 3% vs -24 +/- 5%, 1.28 +/- 0.3/s vs -1.9 +/- 0.4/s; P < 0.001, <0.001, <0.001, respectively) and mid (4.2 +/- 0.5 cm/s vs 5.4 +/- 0.5 cm/s, -16 +/-3% vs -26 +/- 4%, -1.2 +/- 0.3/s vs -2.1 +/- 0.3/s; P < 0.001, <0.001, <0.001, respectively) segments of right ventricle were significantly lower in patients with RV infarction than in patients without RV infarction. There were no differences between groups for apical strain, strain rate, and systolic tissue velocity. CONCLUSION: This study demonstrates that right ventricular strain and strain rate were lower in patients with left ventricular inferior wall myocardial infarction with, compared to without, right ventricular infarction.     

组织多普勒联合Tei指数评价右室梗死患者右心功能

目的探讨应用多普勒组织成像(DTI)技术及Tei指数评价右室梗死患者的右心功能。方法急性下壁心肌梗死51例,于心尖四腔观切面以DTI速度模式录取三尖瓣游离壁侧瓣环、室间隔侧瓣环和游离壁中段收缩期、舒张早、晚期峰值运动速度(Sm、Em、Am)及Em/Am;以脉冲多普勒记录三尖瓣关闭至再次开放间期,并于胸骨旁短轴切面记录射血时间,计算右心Tei指数。结果右室心肌梗死组于三尖瓣游离壁侧瓣环及右室游离壁中部Sm、Em较无右室心肌梗死及正常对照组明显减低[游离壁侧瓣环Sm(70±20)cm/s比(87±19)cm/s和(106±21)cm/s,P<001;游离壁侧瓣环Em(63±19)cm/s比(79±18)cm/s和(96±19)cm/s;P<001;游离壁中段Sm(64±19)cm/s比(80±19)cm/s和(94±20)cm/s,P<005;游离壁中段Em(61±20)cm/s比(76±20)cm/s和(92±23)cm/s;P<005];右心Tei指数亦较其他两组普遍增高(065±019比040±015和026±010;P<001)。结论DTI技术检测三尖瓣游离壁侧瓣环及右室游离壁中段运动速度及右心Tei指数可无创、迅速评价右室心肌梗死患者右心室功能。     

Ventricular myocardial fat: CT findings and clinical correlates

OBJECTIVES: Replacement of the myocardium by fat is a feature of arrythmogenic right ventricular dysplasia (ARVD). Pathology literature describes ventricular myocardial fat to be present not only in ARVD, but much more frequently related to aging, prior myocardial infarction (MI), and chronic ischemia. We noted focal ventricular myocardial fat in a group of patients who underwent chest computed tomography (CT) for varied indications. The aim of this study is to describe the noncontrast CT findings and clinical correlates of ventricular myocardial fat in this population. MATERIALS AND METHODS: We prospectively identified 26 patients whose noncontrast chest CT (5/03 to 6/04) demonstrated ventricular myocardial fat and whose clinical charts were available. There were 14 men and 12 women with a mean age of 70 years. Twenty-three percent (6/26) had prior CTs. Each CT was reviewed by 3 radiologists in consensus. The site of the ventricular fat was noted. Each patient was categorized based on the location of the fat as follows: group 1-right ventricle (RV) only, group 2-left ventricle (LV) only, group 3-biventricular. Results of cardiac history, laboratory tests, and cardiac imaging were noted. RESULTS: The distribution of ventricular myocardial fat was: group 1 RV-27% (7/26), group 2 LV-46% (12/26), and group 3 biventricular-27% (7/26). Echocardiographic, nuclear cardiology, or electrocardiographic data localizing a prior MI to a specific site were available in 35% (9/26) of patients: 14% (1/7) of group 1, 50% (6/12) of group 2, and 29% (2/7) of group 3. Myocardial fat corresponded to the site of MI in 89% (8/9). The presence and distribution of ventricular fat on CT was unchanged from prior CT in 100% (6/6). When comparing group 1 and group 2, group 1 was older (77 vs. 64 y, P=0.005), more often female (57% vs. 17%, P=0.13) and had fewer prior MI (14% vs. 50%, P=0.17) than group 2. Only 1 patient in this series had ARVD. He was in group 3. CONCLUSIONS: The significance of ventricular myocardial fat varies by location. Fat in the RV is most often related to aging. Prior RV MI and ARVD are less common etiologies. Fat in the LV is frequently related to prior MI. Recognition of myocardial fat on a noncontrast chest CT may be the first opportunity to diagnose a silent MI.     

致心律失常性右室发育不良或心肌病15例的临床特点及疗效

目的 探讨致心律失常性右室发育不良或心肌病(ARVD/C)的临床特点及分析疗效。方法 分析2000～2007年诊断为ARVD/C 15例入院病例资料,对其临床特点作统计分析,并探讨治疗方法及疗效。结果 在ARVD/C 15例病例中(7男),年龄为13～61(31±12)岁,首发症状年龄为10～51(28±11)岁;3例有家族史;6例(40%)有晕厥发作史;5例(33%)患者仅有心悸症状;1例常规心电图检查中发现Epsilon波,见于右侧胸导联V2～3,伴有T波倒置;13例(87%)超声心动图结果异常,主要为RV扩大;4例行心脏磁共振（MRI）检查:见右室壁脂肪信号2例,右室壁变薄3例,右心室扩大3例;有症状的室性心律失常患者接受胺碘酮、β阻滞剂或采用其他抗心律失常药物治疗,但47%的患者(7/15)应用抗心律失常药物治疗无效,3例患者接受射频消融治疗,其中有1例患者出现室性心动过速复发。4例患者植入植入式心脏自动复律除颤器 (ICD),其中1例因多次自动除颤,电池耗竭,而更换ICD。结论 ARVD/C以室性心律失常为主要表现,诊断依靠家族史、晕厥发作史、ECG、超声心动图、MRI。抗心律失常药物的疗效较差,射频消融或植入ICD可治疗致命性心律失常,减少猝死的发生。