Adipose replacement and wall motion abnormalities in right ventricle arrhythmias: evaluation by MR imaging. Retrospective evaluation on 124 patients

Favorable electrocardiographic changes after substantial weight loss in patients with morbid obesity : Results of a prospective study

BACKGROUND

Obese patients have an increased risk of arrhythmias and sudden death, even in the absence of structural heart disease and cardiac dysfunction. This study aimed to determine whether weight loss by bariatric surgery has an effect on arrhythmia-related electrocardiographic (ECG) variables in morbidly obese patients.

METHODS

In this prospective study, the data of 48 patients were analyzed. All ECG variables that have the potential to predict ventricular arrhythmia were evaluated before surgery, and were compared with the 1‑month and 6‑month follow-up results.

RESULTS

The mean body mass index was 45.74 ± 5.60 kg/m² before surgery. There was a statistically significant decline in body mass index in the first and sixth month after surgery (39.26 ± 5.00 kg/m² and 31.71 ± 4.49 kg/m², respectively; p < 0.001). Furthermore, notable reduction was found in terms of heart rate measurements-QTc‑d, JTc, JTc‑d, Tp‑e, TP-e/QT, TP-e/QTc-in the first month and sixth month compared with baseline (p < 0.001 for all comparisons). Several ECG variables, such as heart rate (r = 0.369, p = 0.001), QTc‑d (r = 0.449, p = 0.001), JTc‑d (r = 0.324, p = 0.002), Tp‑e (r = 0.592, p = 0.001), Tp-e/QTc (r = 0.543, p = 0.001), Tp-e/JTc (r = 0.515, p = 0.001), exhibited a positive and significant correlation with weigh loss. Moreover, a negative and weakly significant correlation was found between the index of cardiac electrophysiological balance (r = -0.239, p = 0.004) and body mass index.

CONCLUSION

Substantial weight loss following laparoscopic sleeve gastrectomy in obese patients is accompanied by a significant improvement in ventricular repolarization. Therefore, this effect may lead to a decrease in the incidence of lethal ventricular arrhythmia and sudden cardiac death.

Severe Myocardial Steatosis: Incidental Finding or a Significant Anatomic Substrate for Sudden Cardiac Arrest?

Myocardial steatosis, also known as lipomatosis cordis, is characterized by adipose tissue within the myocardium without significant fibrosis. Evidence suggests that accumulation of fat can disturb the normal electromechanical physiology of the myocardium. Herein, we discuss the case of a 60-year-old woman with a history of chronic obstructive pulmonary disease who died because of anoxic encephalopathy after a sudden cardiac arrest (SCA). An electrocardiogram showed QRS fragmentation noted as notched R in inferior leads. The autopsy revealed a very small thromboembolus in a distal subsegmental branch of the pulmonary artery, which could not explain the SCA. There was an extensive intramyocardial accumulation of adipose tissue involving the right ventricle and interventricular septum, which split the myocardium into discrete bundles. Arrhythmogenic right ventricular cardiomyopathy was ruled out based on the absence of typical fibrofatty changes. The mechanism of fat replacement was likely secondary to redistribution of visceral fat in the setting of Cushing syndrome. We propose that severe myocardial steatosis can create an anatomic substrate to facilitate the development of SCA. Myocardial steatosis should be reported to identify patients who are at risk for developing cardiovascular events secondary to extreme cardiac adiposity.

Assessment of Atrial Fibrillation and Ventricular Arrhythmia Risk after Bariatric Surgery by P Wave/QT Interval Dispersion

BACKGROUND

The association of obesity with atrial fibrillation (AF) and with ventricular arrhythmias is well documented.

OBJECTIVE

The aim of this study was to investigate whether weight reduction by a laparoscopic sleeve gastrectomy has any effect on P wave dispersion (PWD), a predictor of AF, and corrected QT interval dispersion (CQTD), a marker of ventricular arrhythmias, in obese individuals.

METHODS

In a prospective study, a total of 114 patients (79 females, 35 males) who underwent laparoscopic sleeve gastrectomy were examined. The patients were followed 1 year. PWD and CQTD values before and 3rd, 6th, and 12th months after the surgery were calculated and compared.

RESULTS

There was a statistically significant decline in body mass index (BMI), PWD, and CQTD values among baseline, 3rd, 6th, and 12th months (p < 0.001 for all comparisons). Correlation analysis showed a statistically significant correlation between ΔPWD and ΔBMI (r = 0.719, p < 0.001), ΔPWD and Δleft ventricular end-diastolic diameter (LVEDD) (r = 0.291, p = 0.002), ΔPWD and Δleft atrial diameter (LAD) (r = 0.65, p < 0.001), ΔCQTD and ΔBMI (r = 0.266, p = 0.004), ΔCQTD and ΔLVEDD (r = 0.35, p < 0.001), ΔCQTD and ΔLAD (r = 0.289, p = 0.002). In multiple linear regression analysis, there was a statistically significant relationship between ΔPWD and ΔBMI (β = 0.713, p < 0.001), ΔPWD and ΔLVEDD (β = 0.174, p = 0.016), ΔPWD and ΔLAD (β = 0.619, p < 0.001), ΔCQTD and ΔBMI (β = 0.247, p = 0.011), ΔCQTD and ΔLVEDD (β = 0.304, p < 0.001), ΔCQTD and ΔLAD (β = 0.235, p = 0.009).

CONCLUSION

PWD and CQTD values of patients were shown to be attenuated after bariatric surgery. These results indirectly offer that there may be a reduction in risk of AF, ventricular arrhythmia, and sudden cardiac death after obesity surgery.

Epicardial Fat Distribution Assessed with Cardiac CT in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

Purpose To compare epicardial fat in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) with that in healthy subjects. Materials and Methods In this retrospective study, cardiac CT scans in 44 patients with ARVD/C (mean age, 39 years ± 12; 23 men) were compared with those in 45 control group participants between January 2008 and July 2015. Volumes of intrathoracic adipose tissue, mediastinal adipose tissue (MAT), and total epicardial adipose tissue (EAT) were quantified. EAT was subdivided into three regions-right ventricular (RV) EAT, left ventricular (LV) EAT, and peri-atrial EAT (atrial EAT)-and normalized to MAT for all regions. Logistic regression and receiver operating characteristic analysis were performed to evaluate the association between epicardial fat with the diagnosis of ARVD/C. Results Total EAT volume was higher in patients with ARVD/C than in healthy control group participants (median, 98 mL vs 76 mL, respectively; P = .04). Regionally, LV and RV EAT volumes were higher in patients with ARVD/C than in control group participants, most notably when indexed to MAT (median LV EAT index: 0.49 vs 0.15, respectively; median RV EAT index: 0.91 vs 0.52; P ˂ .0005 for both). The optimal cutoff for diagnosis of ARVD/C was an LV EAT index of 0.24, with a sensitivity and specificity of 91% and 71%, respectively. Atrial EAT volume and total intrathoracic adipose tissue volume were not different between groups. RV diameter showed a positive correlation with total EAT index and LV EAT index (r = 0.21, P = .05 and r = 0.33, P = .002, respectively). Conclusion Higher amounts of right ventricular and left ventricular epicardial fat are found in hearts with arrhythmogenic right ventricular dysplasia/cardiomyopathy, particularly adjacent to the left ventricle, which correlates with disease severity and helps differentiate patients from healthy subjects. © RSNA, 2018 Online supplemental material is available for this article.

QRS fragmentation and sudden cardiac death in the obese and overweight

Background

Obesity has been associated with significantly greater risk of sudden cardiac death (SCD); however, identifying the obese patient at highest risk remains a challenge. We evaluated the association between QRS fragmentation on the 12‐lead electrocardiogram and SCD, in obese/overweight subjects.

Methods and Results

In the ongoing prospective, community‐based Oregon Sudden Unexpected Death Study (population approximately 1 million), we performed a case‐control analysis, comparing obese/overweight SCD victims with obese/overweight controls from the same geographic region. Archived ECGs prior and unrelated to the SCD event were used for cases and all ECG measurements were assessed in blinded fashion. Fragmentation was defined as the presence of RSR’ patterns and/or notching of the R/S wave in at least 2 contiguous leads. Analysis was limited to ECGs with QRS duration <120 ms. Overall prevalence of fragmentation was higher in cases (n=185; 64.9±13.8 years; 67.0% male) compared with controls (n=405; 64.9±11.0 years; 64.7% male) (34.6% versus 26.9%, P=0.06). Lateral fragmentation was significantly more frequent in cases (8.1% versus 2.5%; P<0. 01), with non‐significant differences in anterior and inferior territories. Fragmentation in multiple territories (≥2) was also more likely to be observed in cases (9.7% versus 4.9%, P=0.02). In multivariable analysis with consideration of established SCD risk factors, lateral fragmentation was significantly associated with SCD (OR 2.84; 95% CI 1.01 to 8.02; P=0.05).

Conclusion

QRS fragmentation, especially in the lateral territory is a potential risk marker for SCD independent of the ejection fraction, among obese/overweight subjects in the general population.

Which Is The Appropriate Arrhythmia Burden To Offer RF Ablation For RVOT Tachycardias?

Premature ventricular complexes (PVCs) and ventricular tachycardia (VT) in patients with structurally normal hearts originate from the right ventricular outflow tract (RVOT) in the majority of cases. In the last few decades catheter ablation of these arrhythmias has been proven to be effective. RVOT VT/PVCs may cause disabling symptoms or arrhythmia induced cardiomyopathy. However, the PVC burden at which catheter ablation should be recommended is still controversial. What adds to the controversy is why some patients with only a low number of PVCs can be highly symptomatic and may even develop arrhythmia induced cardiomyopathy, whilst others may have a higher PVC/VT burden and remain asymptomatic and do not develop cardiomyopathy for a long period of time. Therefore, although catheter ablation of RVOT PVCs has high success and low complication rates, the time point of when ablation should be recommended is currently still under debate. This review discusses the treatment strategies and prognosis for RVOT tachycardias and focuses on the question of which arrhythmia burden is appropriate to offer RF ablation.

Reappraisal of cardiac magnetic resonance imaging in idiopathic outflow tract arrhythmias

INTRODUCTION

Because of prognostic and therapeutic implications, the distinction between idiopathic right ventricular (RV) outflow tract (iRVOT) and arrhythmogenic RV cardiomyopathy (ARVC) is clinically important. Over the last 2 decades multiple reports have identified RV abnormalities using CMR in patients with idiopathic VT, suggesting a link between these arrhythmias and ARVC. The purpose of this study was to assess for structural abnormalities in patients with iRVOT tachycardia using contemporary cardiac magnetic resonance (CMR) imaging.

METHODS AND RESULTS

CMR was performed in 46 patients with iRVOT tachycardia and 16 normal controls, with quantitative evaluation of RV and left ventricular volumes and function, as well as assessment of myocardial fat and scar. iRVOT patients were similar to controls with respect to RV end-diastolic volumes (81 ± 19 mL/m(2) vs. 79 ± 18 mL/m(2) , P = 0.77) and RV ejection fraction (57 ± 8% vs. 59 ± 7%, P = 0.31). The prevalence of RV chamber dilation, defined using ARVC major task force criteria, was uncommon among iRVOT patients (9%) and controls (7%; P = 1.0). Regional RV wall motion abnormalities were present in 2 iRVOT patients who had concomitant RV dilation or dysfunction. CMR tissue characterization demonstrated absence of both myocardial scar and fat infiltration in all patients and controls.

CONCLUSIONS

In patients with the clinical diagnosis of iRVOT tachycardia, CMR reveals RV structure, function, and myocardial tissue characteristics similar to normal controls. These findings suggest that the vast majority of patients with RVOT arrhythmias have a primary electrical disorder that is not a forme-fruste of ARVC.

Clinico-radiological profile of arrhythmogenic right ventricular dysplasia at a tertiary care center: Two year experience

BACKGROUND

Arrythmogenic right ventricular dysplasia (ARVD/C) refers to fibro fatty infiltration replacement of ventricular myocardium especially that of right ventricle. The clinical presentation varies from asymptomatic state to ventricular tachycardia, heart failure and even sudden death. Diagnosis is established using modified ARVD/C taskforce criteria. Among all the various modalities of diagnosis, magnetic resonance imaging (MRI) gives most comprehensive evaluation of both morphological and functional abnormalities in this disease. MRI may not only obviate need for myocardial biopsy but also give insights into the nature of disease like presence of left ventricular myocardial involvement. We present our 2 years experience of ARVD/C patents who were admitted in our center and in whom diagnosis of ARVD/C was supported by excellent MR imaging.

MATERIALS AND METHODS

This study was conducted by Department of Radiology and Cardiology SKIMS, a tertiary care center for a period of 2 years. Patients with suspected ARVD/C based on clinical, electrophysiological and echocardiographic findings were subjected to MR imaging. Patients were excluded if they had history metallic implants, claustrophobia or were uncooperative. In this study stress was laid on diagnostic role of MRI in ARVD/C.

RESULTS

The median age at presentation was 31 years (range 21-43 years). 80% of patients were males. Most common clinical presentation was palpatations (40%). Syncope was present in 27% and heart failure in 13%. EKG suggestive of ARVD was seen in 87%. Echocardiographic features suggestive of ARVD/C was seen in all 15 patients. Family history of premature sudden death less than 35 years old was present in one patient only. MRI evidence classical for ARVD/C was seen in 80%.

CONCLUSION

Demographic features and mode of presentation of our patients is consistent with what has been rest of the world. We performed MRI in all patients to increase the specificity of our diagnosis. MR imaging allows a three-dimensional evaluation of the right ventricle and provides the most important anatomic, functional, and morphologic criteria for diagnosis of ARVD/C within one single study. MR imaging appears to be the optimal imaging technique for detection and follow-up of clinically suspected ARVD/C.

Cardiac imaging techniques for physicians: late enhancement

Late enhancement imaging is used to diagnose and characterize a wide range of ischemic and nonischemic cardiomyopathies, and its use has become ubiquitous in the cardiac MR exam. As the use of late enhancement imaging has matured and the span of applications has widened, the demands on image quality have grown. The characterization of subendocardial MI now includes the accurate quantification of scar size, shape, and characterization of borders which have been shown to have prognostic significance. More diverse patterns of late enhancement including patchy, mid-wall, subepicardial, or diffuse enhancement are of interest in diagnosing nonischemic cardiomyopathies. As clinicians are examining late enhancement images for more subtle indication of fibrosis, the demand for lower artifacts has increased. A range of new techniques have emerged to improve the speed and quality of late enhancement imaging including: methods for acquisition during free breathing, and fat water separated imaging for characterizing fibrofatty infiltration and reduction of artifacts related to the presence of fat. Methods for quantification of T1 and extracellular volume fraction are emerging to tackle the issue of discriminating globally diffuse fibrosis from normal healthy tissue which is challenging using conventional late enhancement methods. The aim of this review will be to describe the current state of the art and to provide a guide to various clinical protocols that are commonly used.

Cardiac MRI evaluation of nonischemic cardiomyopathies

The purpose of this manuscript is to review the major MRI findings in patients with nonischemic cardiomyopathies. Cardiac MRI has become an integral part in the diagnosis and management of patients with nonischemic cardiomyopathies. Findings on cardiac MRI studies can help distinguish between different types of cardiomyopathies and can provide valuable diagnostic and prognostic information.

Myocardial Fat Imaging

The presence of intramyocardial fat may form a substrate for arrhythmias, and fibrofatty infiltration of the myocardium has been shown to be associated with sudden death. Therefore, noninvasive detection could have high prognostic value. Fat-water–separated imaging in the heart by MRI is a sensitive means of detecting intramyocardial fat and characterizing fibrofatty infiltration. It is also useful in characterizing fatty tumors and delineating epicardial and/or pericardial fat. Multi-echo methods for fat and water separation provide a sensitive means of detecting small concentrations of fat with positive contrast and have a number of advantages over conventional chemical-shift fat suppression. Furthermore, fat and water–separated imaging is useful in resolving artifacts that may arise due to the presence of fat. Examples of fat-water–separated imaging of the heart are presented for patients with ischemic and nonischemic cardiomyopathies, as well as general tissue classification.

N-terminal prohormone brain natriuretic peptide-proBNP levels in ventricular arrhythmias in children

BACKGROUND

Ventricular arrhythmias are the most common consequences of structural and functional heart diseases, but cases with no evident pathology are also observed. A parameter indicating asymptomatic circulatory failure could support decisions related to possible treatment of ventricular arrhythmias.

HYPOTHESIS

The study objective was the evaluation of N-terminal prohormone brain natriuretic peptide (NT-proBNP) levels in children with ventricular arrhythmias and an attempt to determine if this parameter may be used for diagnosis and prognosis of ventricular arrhythmias.

MATERIAL AND METHODS

The study population was comprised of 36 children age 5 to 17.5 years old with idiopathic ventricular arrhythmias (Group B) graded mild or potentially malignant; 29 patients with mild ventricular arrhythmias were included into Group B1; and 7 patients with potentially malignant cases into Group B2. In all the patients, NT-proBNP assays were performed.

RESULTS

The NT-proBNP levels in Groups B, B1, B2 and the control group (Group K) were as follows: 41.5 +/- 15.1 pg/mL, 35.5 +/- 18.5 pg/mL, 66.3 +/- 24.9 pg/mL and 31.5 +/- 15.1 pg/mL, respectively. Between the groups with and without arrhythmias (Group B vs Group K), no statistically significant differences in NT-proBNP levels were found. However, markedly higher NT-proBNP levels were shown in the children with potentially malignant arrhythmias (Group B2) compared to the patients with mild arrhythmias (B1) and the control group (Group K).

CONCLUSIONS

The level of NT-proBNP increases with the severity of ventricular arrhythmia. NT-proBNP assays can be helpful for diagnosing and grading the severity of ventricular arrhythmias.

[The utility of magnetic resonance imaging in the evaluation of arrhythmogenic right ventricular cardiomyopathy]

OBJECTIVE

To discuss the utility of magnetic resonance imaging in the evaluation of arrhythmogenic right ventricular cardiomyopathy.

METHODS

16 patients with suspicious ARVC joined this study from January 2005 to May 2008. CMR was performed on a 1.5 Tesla GE signa scanner. Short axis view, four-chamber view and long axis view of tow ventricle were acquired by white blood technique (Fast cine sequence). Short axis view and long axis view of right ventricle were acquired by black blood techniques (Double IRFSE and Triple IRFSE). The ARVC was diagnosed by MRI and golden criteria respectively.

RESULTS

Of the 16 patients, 11 were diagnosed ARVC by MRI, 9 were by golden criteria. 9 ARVC patients were manifested by thinning of RV wall, dilatation of the RV (8 cases) trabecular hypertrophy and disarray (6 cases), fat signal intensity of right ventricular(RV)wall in DIRFSE,irregular insular pieces or continuity breaking of myocardium in TIRFSE (3 cases) dilatation of the LV (2cases), a bit thickening of ventricular septum (1case), enlargement of the outflow of the right ventricular(RV) (2 cases) and ventricular aneurysm formation (2 cases).And the positions including apex of the right ventricle (4 cases), facies diaphragmatica (6 cases), anterior ventricle (4 cases), infundibulum (4 cases) and the papillary muscle of the RV (1case) were involved.

CONCLUSION

CMR is a specific and sensitive examination technique in diagnosing of ARVC, which could present structural, functional changes and the quality, degree, range of the disease. We should take this examination as the routine method if suspect ARVC in clinical.

The utility of magnetic resonance imaging in the evaluation of arrhythmogenic right ventricular cardiomyopathy

PURPOSE OF REVIEW

Perceptions of the utility of cardiovascular magnetic resonance in the evaluation of arrhythmogenic right ventricular cardiomyopathy have changed considerably in the past decade. This review offers an up-to-date perspective on the diagnostic role of cardiovascular magnetic resonance in the genetics era.

RECENT FINDINGS

Originally hailed as a putative gold standard in arrhythmogenic cardiomyopathy, cardiovascular magnetic resonance has received a more guarded reception lately owing to interobserver variability and lack of standardized protocols. Recent studies have nonetheless affirmed its value as an integral component of the diagnostic work-up. Quantitative volume analysis is relatively robust, but visualization of myocardial fat by spin-echo imaging is less reliable. Interpretation of wall motion abnormalities appears reproducible among expert readers. Emerging data suggest a key role for late gadolinium enhancement in detection of left ventricular involvement.

SUMMARY

Cardiovascular magnetic resonance in arrhythmogenic cardiomyopathy is facilitated by appropriate patient selection and preparation, experienced readers and operators, and a dedicated, comprehensive protocol. Indications for magnetic resonance assessment include proven arrhythmogenic cardiomyopathy in the family, unexplained ventricular arrhythmia, inverted T-waves in the right precordial or lateral leads, and/or family history of sudden cardiac death. Arrhythmia suppression is essential for optimal electrocardiographic triggering and image acquisition.

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.

Marked lipomatous infiltration of the right ventricle: MRI findings in relation to arrhythmogenic right ventricular dysplasia

OBJECTIVE

The purpose of this study was to describe the structure and function of the heart in the presence of marked lipomatous infiltration of the right ventricular wall in 13 patients referred for second opinions about fatty infiltration of the right ventricular wall and suspected arrhythmogenic right ventricular dysplasia.

CONCLUSION

Lipomatous infiltration with right ventricular thickness > or = 6 mm on MRI but without regional or global functional abnormalities of the right ventricle appears to be distinct from fatty right ventricle associated with arrhythmogenic right ventricular dysplasia. The finding of right ventricular fat must be interpreted cautiously to avoid the pharmacologic and defibrillator intervention associated with management of arrhythmogenic right ventricular dysplasia.

Magnetic Resonance Imaging Abnormalities in Right Ventricular Outflow Tract Tachycardia and the Prediction of Radiofrequency Ablation Outcome

BACKGROUND

Recent reports have shown abnormalities on cardiac magnetic resonance imaging (MRI) in patients with right ventricular outflow tract (RVOT) tachycardia.

OBJECTIVES

OBJECTIVES of this study were to demonstrate abnormalities on MRI and signal-averaged ECG (SAECG) in patients with RVOT tachycardia and their correlation with the outcome of radiofrequency (RF) ablation.

METHODS

We studied 41 patients with symptomatic RVOT tachycardia and 15 controls. SAECG and cardiac MRI were performed on every subject. An evaluation of structural abnormality, chamber size, function, and wall motion abnormality of the left and right ventricle was performed by MRI. Focal wall thinning was evaluated by the black blood technique and fatty infiltration was evaluated by the T1 image with and without fat suppression.

RESULTS

MRI abnormalities were demonstrated in 24 (58.5%) patients with RVOT tachycardia. The abnormalities included localized wall bulging in 22 (53.7%), focal wall thinning in 10 (24.4%), and fatty replacement in 9 (22%) patients. MRI abnormality was found in only one patient in the control group (P < 0.001). Late potentials from SAECG were demonstrated in six (10.7%) patients but none in the controls (P = 0.117). Among 29 patients who underwent RF ablation, 3 patients had a failed procedure and 3 having arrhythmia recurrence needed repeated ablation. MRI abnormalities and late potentials were associated with an unfavorable outcome of RF ablation.

CONCLUSIONS

MRI abnormalities were frequently found in patients with RVOT tachycardia. MRI abnormalities and late potentials can predict outcomes of RF ablation.

Electrocardiographic predictors of long-term outcomes after radiofrequency ablation in patients with right-ventricular outflow tract tachycardia

AIMS

The objectives of this study were to identify electrocardiographic (ECG) predictors of long-term outcomes after radiofrequency (RF) ablation in patients with right-ventricular outflow tract (RVOT) tachycardia.

METHODS AND RESULTS

We correlated ECG characteristics with RF ablation outcomes in 144 patients with RVOT tachycardia who underwent RF ablation for >1 year. Unfavourable RF ablation outcomes were predefined as unsuccessful RF ablation or recurrence of tachycardia requiring repeated ablation. RF ablation was not successful in 11 (7.6%) patients and 16 (12%) patients had arrhythmia recurrence requiring repeated ablation. Average follow-up time was 72.2+/-28.4 months. Selected parameters from univariate analysis included number of RF applications, pacemapping, application of bonus burn, procedure time, monophasic R-wave in lead I, QS pattern in leads I and aVL, QRS duration in leads II and V(2), and right axis deviation, in ventricular tachycardia. From logistic regression analysis, only monophasic R-wave in lead I remained in the final equation (P=0.004, odds ratio 12.9).

CONCLUSION

Monophasic R-wave in lead I during RVOT tachycardia is associated with unfavourable outcomes after RF ablation. This finding may help clinicians in the selection of patients for RF ablation and for the prediction of RF ablation outcome.

Serial Reevaluation for ARVD/C Is Indicated in Patients Presenting with Left Bundle Branch Block Ventricular Tachycardia and Minor ECG Abnormalities

INTRODUCTION

Diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is based on a set of criteria proposed by the International Task Force (TF) for Cardiomyopathies in 1994. To fulfill these criteria, presence of both electrocardiographic and anatomical abnormalities must be assessed with ECG and imaging techniques, respectively. This may be difficult in patients with early/mild forms of the disease as detectable structural abnormalities may still be absent. We evaluated in which patients presenting with right ventricular tachycardia (VT) serial reevaluation for ARVD/C is indicated.

METHODS AND RESULTS

Sixty consecutive patients (41 men, mean age 40+/-15 years) were evaluated by the TF criteria for possible ARVD/C because of presentation with a left bundle branch block (LBBB) VT, representing 1 minor criterion. The presence on the ECG of a T-wave inversion beyond lead V2 (1 minor), right precordial QRS prolongation (1 major), or an epsilon wave (1 major) was assessed together with the visualization of severe regional/global right ventricle dysfunction (1 major) or mild segmental dilatation/regional hypokinesia (1 minor) by standard imaging techniques. Initially, 22 (37%) patients were diagnosed as having ARVD/C. After 47+/-39 (range 6-146) months, 23 initially TF-negative patients were reevaluated because of recurrent symptoms, with 12 (52%) additional patients now meeting the TF criteria. Eleven of these 12 (92%) patients presented initially with ECG abnormalities only, but developed structural abnormalities on imaging at follow-up.

CONCLUSION

ECG abnormalities may precede structural abnormalities warranting serial reevaluation for ARVD/C in initially TF-negative patients presenting with LBBB VT with only ECG abnormalities.

Evaluation and course of an unusual case of arrhythmogenic right ventricular dysplasia

We report a case of a 42-year-old Caucasian man who presented with isolated right ventricular failure and atrial fibrillation without ventricular arrhythmia. In this report, we describe accurate evaluation by MR imaging confirmed by histopathologic findings as well as imaging progression of this unusual case of arrhythmogenic right ventricular dysplasia.

Left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy - a scintigraphic and echocardiographic study

BACKGROUND

Left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy (ARVC) is a common finding in autopsy studies. In clinical studies using myocardial scintigraphy, MRI and echocardiography, contradictory results have been reported. In this study, we therefore investigated a group of 15 patients with ARVC using thallium-201 (Tl) single-photon emission tomography (SPECT) and echocardiography including assessment of mitral annular motion with M-mode and pulsed tissue Doppler.

METHODS

Exercise and rest Tl-201 SPECT were performed in 15 patients with ARVC. The time from diagnosis of the disease varied from less than 1-16 years. All patients fulfilled the established diagnostic criteria for ARVC. An echocardiographic examination, including assessment of left and right ventricular motion and measurements of the mitral annulus motion with M-mode and pulsed tissue Doppler was performed in the patients and in 25 normal subjects.

RESULTS

Tl-201 uptake defects in the left ventricular myocardium were present in all except one patient (93%). The uptake defects were predominantly located to the anteroseptal and basal posterior segments. Wall motion abnormalities were seen in the same segments, and in addition to this, in the septal area. In line with this, the total amplitude and the peak systolic velocity of mitral annular motion at the septal point were significantly decreased in the patients compared with the control group.

CONCLUSIONS

Our data show that left ventricular involvement is common in ARVC. Tl-201 SPECT and echocardiographic abnormalities were seen not only in patients with long-lasting symptoms but also in asymptomatic patients and in those with short duration of symptoms.

Regional differences in systolic and diastolic function in arrhythmogenic right ventricular dysplasia/cardiomyopathy using magnetic resonance imaging

Global and regional biventricular functions were analyzed in 14 patients diagnosed with arrhythmogenic right ventricular dysplasia/cardiomyopathy using cine magnetic resonance imaging and compared with similar data from 18 age-matched controls. In this study, we report results of quantitative evaluation of biventricular global and regional function using peak ejection rate and peak filling rate as measures of systolic and diastolic function, respectively (volumetric method).

Myocardial late enhancement in contrast-enhanced cardiac MRI: distinction between infarction scar and non-infarction-related disease

OBJECTIVE

Our objective was to assess and compare the patterns of late enhancement (LE) in contrast-enhanced cardiac MRI caused by myocardial infarction and different myocardial diseases that are not related to ischemic infarction.

MATERIALS AND METHODS

A total of 811 consecutive contrast-enhanced cardiac MRI studies performed for different indications were reviewed for left ventricular myocardial LE after gadopentetate dimeglumine administration. MRI studies were performed on a 1.5-T scanner using an inversion recovery turbo FLASH sequence (TR/TE, 8/4 msec; flip angle, 25 degrees). The LE pattern of ischemic infarction scar was compared with that in nonischemic myocardial disease.

RESULTS

LE was found in 421 (52%) patients. In all patients with myocardial infarction, LE included the subendocardial layer. Nineteen patients without history of myocardial infarction and angiographically excluded coronary artery disease showed different patterns of LE caused by myocarditis, sarcoidosis, arrhythmogenic right ventricular dysplasia, cardiomyopathy, endomyocardial fibrosis, and iatrogenic scars after biopsy, ablation of septal hypertrophy, and myocardial laser revascularization.

CONCLUSION

LE in contrast-enhanced cardiac MRI is not specific for ischemic infarction. LE in ischemic infarction always involves the subendocardial layer, whereas it does not necessarily do so in other myocardial diseases. Therefore, if LE omit the subendocardial layer, different nonischemic myocardial diseases have to be considered. The pattern of LE might be helpful for the differential diagnosis of myocardial disease and in distinguishing it from ischemic disease.

The impact of implantable cardioverter-defibrillator therapy on survival in autosomal-dominant arrhythmogenic right ventricular cardiomyopathy (ARVD5)

OBJECTIVES

We sought to determine the impact of implantable cardioverter-defibrillator (ICD) therapy in patients with familial arrhythmogenic right ventricular cardiomyopathy (ARVC).

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy is a cause of sudden cardiac death, which may be prevented by ICD.

METHODS

We studied 11 families in which a 3p25 deoxyribonucleic acid (DNA) haplotype at locus ARVD5 segregated with disease and compared mortality in subjects who received an ICD with that in control subjects who were matched for age, gender, ARVC status, and family. Subjects (n = 367) at 50% a priori risk of inheriting ARVC were classified as high risk (HR) (n = 197), low risk (n = 92), or unknown (n = 78) on the basis of clinical events, DNA haplotyping, and/or pedigree position. Forty-eight HR subjects (30 males, [median age 32 years] and 18 females [median age 41 years]) were followed after ICD (secondary to ventricular tachycardia [VT] in 27%). Survival was compared with 58 HR control subjects who were alive at the same age to-the-day at which the ICD subject received the device.

RESULTS

In the HR group, 50% of males were dead by 39 years and females by 71 years: relative risk of death was 5.1 (95% confidence interval 3 to 8.5) for males. The five-year mortality rate after ICD in males was zero compared with 28% in control subjects (p = 0.009). Within five years, the ICD fired for VT in 70% and for VT >240 beats/min in 30%, with no difference in discharge rate when analyzed by ICD indication.

CONCLUSIONS

The unknown mutation at the ARVD5 locus causing ARVC results in high mortality. Risk stratification using genetic haplotyping and ICD therapy produced improved survival for males.

Misdiagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy

INTRODUCTION

Diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) has major implications for the management of patients and their first-degree relatives. Diagnosis is based on a set of criteria proposed by the International Task Force for Cardiomyopathies. We report our experience in providing a re-evaluation for patients who previously have been diagnosed with ARVD/C.

METHODS AND RESULTS

We studied 89 patients who requested a re-evaluation for diagnosis of ARVD/C at our center. Each of these patients had been diagnosed with ARVD/C at their initial evaluation. Each patient was re-evaluated with clinical history, physical examination, and noninvasive testing at our center. Invasive testing, which included electrophysiologic testing, right ventricular angiography, and endomyocardial biopsy, was performed when clinically indicated. Sixty (92%) of the 65 patients who had undergone magnetic resonance imaging (MRI) at an outside institution were reported to have an abnormal MRI consistent with ARVD/C. Among these patients, the only abnormality identified was the qualitative finding of intramyocardial fat/wall thinning in 46 patients. On re-evaluation, these qualitative findings were not confirmed. None of these 46 patients ultimately were diagnosed with ARVD/C. Among the entire patient group, only 24 (27%) of the 89 patients met the Task Force criteria for ARVD/C.

CONCLUSION

This study demonstrates that the high frequency of "misdiagnosis" of ARVD/C is due to over-reliance on the presence of intramyocardial fat/wall thinning on MRI, incomplete diagnostic testing, and lack of awareness of the Task Force criteria. Diagnosis of ARVD/C cannot rely solely upon qualitative features on MRI.

MR evaluation of arrhythmogenic right ventricular cardiomyopathy in pediatric patients

OBJECTIVE

The aim of our study was to correlate the findings of three MR imaging sequences with the clinical findings of possible arrhythmogenic right ventricular cardiomyopathy in pediatric patients.

MATERIALS AND METHODS

Twenty-six consecutive pediatric patients underwent MR imaging with ECG-gated non-breath-hold spin-echo T1-weighted non-fat-suppressed and fat-suppressed sequences. The MR images were evaluated for thinning or fat signal in the right ventricular wall and for enlargement or increased trabeculation of the right ventricle or right ventricular outflow tract. Cine MR imaging was used to assess wall motion abnormalities. Cardiac biopsy was performed in 17 patients. Biopsy results and other clinical findings suggesting arrhythmogenic right ventricular cardiomyopathy were tabulated.

RESULTS

Two MR imaging studies were of poor quality as a result of arrhythmias, and one study was incomplete. In the 23 remaining patients, there were (mean +/- SD) 1.5 +/- 1.0 and 0.8 +/- 1.0 findings of possible arrhythmogenic right ventricular cardiomyopathy in the non-fat-suppressed and the fat-suppressed sequences, respectively. Fat-compatible signal in the myocardium was detected in 16 (70%) of 23 non-fat-suppressed studies and in five (22%) of 23 fat-suppressed studies (p = 0.003). The non-fat-suppressed sequence had a higher sensitivity (75% vs 43%) and a lower specificity (38% vs 75%) for fatty infiltration than did the fat-suppressed sequence when correlated with the biopsies. The linear correlation between all MR findings and all clinical diagnostic criteria, including biopsy, was better for the combination of cine and both T1 sequences (r = 0.58) than for the non-fat-suppressed (r = 0.53) or fat-suppressed (r = 0.46) T1 sequences alone.

CONCLUSION

MR imaging showed moderate correlation with the clinical criteria in the diagnosis of arrhythmogenic right ventricular cardiomyopathy.

Long-term follow-up of right ventricular monomorphic extrasystoles

OBJECTIVES

The purpose of this study was to verify in a long-term follow-up whether frequent monomorphic right ventricle extrasystoles may progress to arrhythmogenic right ventricular dysplasia (ARVD).

BACKGROUND

Frequent monomorphic right ventricle extrasystoles are generally considered benign. However, in patients with this pattern, cardiac magnetic resonance (MR) has recently shown anatomical and functional abnormalities of the right ventricle.

METHODS

Sixty-one patients who had been classified by noninvasive examinations as having frequent idiopathic right ventricle ectopy were contacted after 15 +/- 2 years (12 to 20) and submitted to clinical examination, electrocardiogram (ECG), Holter monitoring, stress test, signal averaged ECG, echocardiography and, in 11 patients, cardiac MR. The primary end point was to ascertain the presence of cases of sudden death or progression to ARVD.

RESULTS

At the end of the follow-up, 55 patients were alive; six died, none of sudden death; eight stated to be well but refused further examinations. The 47 patients examined had normal ECG; in 24 patients (51%), extrasystoles were no longer present at Holter monitoring; late potentials were present in up to 15% of the patients; the right ventricle was normal at echocardiography. In 8 of 11 patients (73%), cardiac MR showed focal fatty replacement and other abnormalities of the right ventricle.

CONCLUSIONS

In this long-term follow-up study, no patient died of sudden death nor developed ARVD; two-thirds of the patients were asymptomatic, and, in half of the patients, ectopy had disappeared. Focal fatty replacement in the right ventricle was present in most.