Automatic segmentation of the great arteries for computational hemodynamic assessment.

BACKGROUND: Computational fluid dynamics (CFD) is increasingly used for the assessment of blood flow conditions in patients with congenital heart disease (CHD). This requires patient-specific anatomy, typically obtained from segmented 3D cardiovascular magnetic resonance (CMR) images. However, segmentation is time-consuming and requires expert input. This study aims to develop and validate a machine learning (ML) method for segmentation of the aorta and pulmonary arteries for CFD studies. METHODS: 90 CHD patients were retrospectively selected for this study. 3D CMR images were manually segmented to obtain ground-truth (GT) background, aorta and pulmonary artery labels. These were used to train and optimize a U-Net model, using a 70-10-10 train-validation-test split. Segmentation performance was primarily evaluated using Dice score. CFD simulations were set up from GT and ML segmentations using a semi-automatic meshing and simulation pipeline. Mean pressure and velocity fields across 99 planes along the vessel centrelines were extracted, and a mean average percentage error (MAPE) was calculated for each vessel pair (ML vs GT). A second observer (SO) segmented the test dataset for assessment of inter-observer variability. Friedman tests were used to compare ML vs GT, SO vs GT and ML vs SO metrics, and pressure/velocity field errors. RESULTS: The network's Dice score (ML vs GT) was 0.945 (interquartile range: 0.929-0.955) for the aorta and 0.885 (0.851-0.899) for the pulmonary arteries. Differences with the inter-observer Dice score (SO vs GT) and ML vs SO Dice scores were not statistically significant for either aorta or pulmonary arteries (p = 0.741, p = 0.061). The ML vs GT MAPEs for pressure and velocity in the aorta were 10.1% (8.5-15.7%) and 4.1% (3.1-6.9%), respectively, and for the pulmonary arteries 14.6% (11.5-23.2%) and 6.3% (4.3-7.9%), respectively. Inter-observer (SO vs GT) and ML vs SO pressure and velocity MAPEs were of a similar magnitude to ML vs GT (p > 0.2). CONCLUSIONS: ML can successfully segment the great vessels for CFD, with errors similar to inter-observer variability. This fast, automatic method reduces the time and effort needed for CFD analysis, making it more attractive for routine clinical use.

Analysis of athlete QT intervals by age: Fridericia and Hodges heart rate corrections outperform Bazett for athlete ECG screening.

BACKGROUND: Cardiac screening of elite athletes including a 12­lead electrocardiogram (ECG) is recommended by numerous international bodies. Current athlete ECG interpretation guidelines recommend the Bazett method to correct the QT interval (QTc). OBJECTIVE: This study sought to investigate normative QTc changes by age using athlete screening ECGs and different QT correction methods in a population of elite cricketers. METHODS: Initial cardiac screening ECGs from an existing database of elite Australian cricketers aged 14-35 years were examined. Average QT interval, QTcB (corrected QT-Bazett), QTcF (Fridericia), QTcH (Hodges), and heart rate (HR) were analyzed by age and sex. RESULTS: A total of 1310 athletes (66% male, 34% female) were included with mean age 19.1 years and mean heart rate 66.9 bpm (range 38-121 bpm). With increasing age, HR decreased and absolute QT increased. The pattern of QTc change with age differed depending on the method of correction: Bazett correction (QTcB) demonstrated a "dish-shaped" or broad U-shaped appearance; while Fridericia and Hodges corrections showed a linear increase in QTc from young to older age. The Bazett method had a stronger correlation of HR with QTc (R2 = 0.32) than either Fridericia (R2 = 0.0007) or Hodges (R2 = 0.009) methods. CONCLUSIONS: The Bazett method is not the most accurate QT correction in athletes, especially during adolescence. In elite cricketers, QTcB revealed a drop in QTc from adolescence to early adulthood due to mis-correction of the QT interval. The Fridericia method has the smoothest correction of HR and least QT variation by age and may be preferred for athlete screening.

Comparison between a 6­lead smartphone ECG and 12­lead ECG in athletes.

Athletes sometimes experience transient arrhythmias during intense exercise, which may be difficult to capture with traditional Holter monitors. New and highly portable technology, such as smartphone electrocardiogram (ECG) devices, may be useful in documenting and contribute to diagnosis of exercise-induced arrhythmias. There are little data available regarding the new Kardia 6 lead device (6L) and no data regarding its use in athletic populations. In this short communication, we present pilot data from 30 healthy athletes who underwent a 12­lead ECG and subsequent 6L reading. Our pilot data show relatively high levels of agreement for QTc and PR interval and QRS duration, with the 6L readings slightly but significantly shorter on average.

A systematic review and meta-analysis of the prevalence of left ventricular non-compaction in adults.

AIMS: To assess the reported prevalence of left ventricular non-compaction (LVNC) in different adult cohorts, taking in to consideration the role of diagnostic criteria and imaging modalities used. METHODS AND RESULTS: A systematic review and meta-analysis of studies reporting LVNC prevalence in adults. Studies were sourced from Pre-Medline, Medline, and Embase and assessed for eligibility according to inclusion criteria. Eligible studies provided a prevalence of LVNC in adult populations (≥12 years). Studies were assessed, and data extracted by two independent reviewers. Fifty-nine eligible studies documenting LVNC in 67 unique cohorts were included. The majority of studies were assessed as moderate or high risk of bias. The pooled prevalence estimates for LVNC were consistently higher amongst cohorts diagnosed on cardiac magnetic resonance (CMR) imaging (14.79%, n = 26; I2 = 99.45%) compared with echocardiogram (1.28%, n = 36; I2 = 98.17%). This finding was unchanged when analysis was restricted to studies at low or moderate risk of bias. The prevalence of LVNC varied between disease and population representative cohorts. Athletic cohorts demonstrated high pooled prevalence estimates on echocardiogram (3.16%, n = 5; I2 = 97.37%) and CMR imaging (27.29%, n = 2). CONCLUSION: Left ventricular non-compaction in adult populations is a poorly defined entity which likely encompasses both physiological adaptation and pathological disease. There is a higher prevalence with the introduction of newer imaging technologies, specifically CMR imaging, which identify LVNC changes more readily. The clinical significance of these findings remains unclear; however, there is significant potential for overdiagnosis, overtreatment, and unnecessary follow-up.

LV non-compaction in patients with coarctation of the aorta: prevalence and effects on cardiac function.

BACKGROUND: Left ventricular non-compaction has been associated with heart failure, arrhythmia, thromboembolism and sudden death. The prevalence of non-compaction in patients with coarctation of the aorta and its clinical significance remains unknown, although obstructive left heart disease is common in patients with non-compaction. We sought to evaluate the prevalence of left ventricular non-compaction in patients with repaired aortic coarctation as well as its effect on left ventricular size and systolic function. METHODS AND RESULTS: In total, 268 patients (Mean age 26 (inter-quartile range 21-37) years, 63% male) undergoing cardiac magnetic resonance imaging for clinical follow-up were included from three tertiary centres for adult congenital heart disease. Clinical data was obtained from medical records and correlated with ventricular volumes and function. Left ventricular non-compaction was defined as a diastolic non-compacted:compacted dimension ratio >2.3 in the worst affected segment on a long-axis view. Left ventricular non-compaction was present in 8.2% of patients with repaired coarctation. Left ventricular end-diastolic volumes and stroke volumes were significantly higher in patients with non-compaction compared to those without. There were no significant differences in ventricular mass or ejection fraction in these two groups. CONCLUSIONS: Left ventricular non-compaction is relatively common in patients with repaired coarctation of the aorta and correlates with increased left ventricular end-diastolic volumes.

Comparison of conventional autopsy with post-mortem magnetic resonance, computed tomography in determining the cause of unexplained death.

Conventional autopsy is the gold standard for identifying unexplained death but due to declines in referrals, there is an emerging role for post-mortem imaging. We evaluated whether post-mortem magnetic resonance (PMMR) and computed tomography (PMCT) are inferior to conventional autopsy. Deceased individuals ≥ 2 years old with unexplained death referred for coronial investigation between October 2014 to December 2016 underwent PMCT and PMMR prior to conventional autopsy. Images were reported separately and then compared to the autopsy findings by independent and blinded investigators. Outcomes included the accuracy of imaging modalities to identify an organ system cause of death and other significant abnormalities. Sixty-nine individuals underwent post-mortem scanning and autopsy (50 males; 73%) with a median age of 61 years (IQR 50-73) and median time from death to imaging of 2 days (IQR 2-3). With autopsy, 48 (70%) had an organ system cause of death and were included in assessing primary outcome while the remaining 21 (30%) were only included in assessing secondary outcome; 12 (17%) had a non-structural cause and 9 (13%) had no identifiable cause. PMMR and PMCT identified the cause of death in 58% (28/48) of cases; 50% (24/48) for PMMR and 35% (17/48) for PMCT. The sensitivity and specificity were 57% and 57% for PMMR and 38% and 73% for PMCT. Both PMMR and PMCT identified 61% (57/94) of other significant abnormalities. Post-mortem imaging is inferior to autopsy but when reported by experienced clinicians, PMMR provides important information for cardiac and neurological deaths while PMCT is beneficial for neurological, traumatic and gastrointestinal deaths.

Predictors of Change in Left-Ventricular Structure and Function in a Trial of Extended Hours Hemodialysis.

BACKGROUND: Myocardial pathology is common in patients undergoing hemodialysis. To explore the effects of differing aspects of dialysis treatment on its evolution, we examined the impact of change in markers of volume status, hemodynamics and solute clearance on left ventricular (LV) parameters in a randomized trial of extended hours dialysis. METHODS AND RESULTS: A Clinical Trial of IntensiVE (ACTIVE) Dialysis randomized 200 patients undergoing hemodialysis to extended dialysis hours (≥ 24 hours/week) or standard hours (12-18 hours/week) for 12 months. In a prespecified substudy, 95 participants underwent cardiac magnetic resonance imaging (CMR) at baseline and at the study's end. Generalized linear regression was used to model the relationship between changes in LV parameters and markers of volume status (normalized ultrafiltration rate and total weekly interdialytic weight gain), hemodynamic changes (systolic and diastolic blood pressure) and solute control (urea clearance, dialysis hours and phosphate). Randomization to extended hours dialysis was not associated with change in any CMR parameter. Reduction in ultrafiltration rate was associated with reduction in LV mass index (P = 0.049) and improved ejection fraction (P = 0.024); reduction in systolic blood pressure was also associated with improvement in ejection fraction (P = 0.045); reduction in interdialytic weight gain was associated with reduced stroke volume (P = 0.038). There were no associations between change in urea clearance, phosphate or total hours per week and CMR parameters. CONCLUSIONS: Reduction in ultrafiltration rate and blood pressure are associated with improved myocardial parameters in hemodialysis recipients independently of solute clearance or dialysis time. These findings underscore the importance of fluid status and related parameters as potential treatment targets in this population.

Left ventricular non-compaction in patients with single ventricle heart disease.

OBJECTIVE: Left ventricular non-compaction is an architectural abnormality of the myocardium, associated with heart failure, systemic thromboembolism, and arrhythmia. We sought to assess the prevalence of left ventricular non-compaction in patients with single ventricle heart disease and its effects on ventricular function. METHODS: Cardiac MRI of 93 patients with single ventricle heart disease (mean age 24 ± 8 years; 55% male) from three tertiary congenital centres was retrospectively reviewed; 65 of these had left ventricular morphology and are the subject of this report. The presence of left ventricular non-compaction was defined as having a non-compacted:compacted (NC:C) myocardial thickness ratio >2.3:1. The distribution of left ventricular non-compaction, ventricular volumes, and function was correlated with clinical data. RESULTS: The prevalence of left ventricular non-compaction was 37% (24 of 65 patients) with a mean of 4 ± 2 affected segments. The distribution was apical in 100%, mid-ventricular in 29%, and basal in 17% of patients. Patients with left ventricular non-compaction had significantly higher end-diastolic (128 ± 44 versus 104 ± 46 mL/m2, p = 0.047) and end-systolic left ventricular volumes (74 ± 35 versus 56 ± 35 mL/m2, p = 0.039) with lower left ventricular ejection fraction (44 ± 11 versus 50 ± 9%, p = 0.039) compared to those with normal compaction. The number of segments involved did not correlate with ventricular function (p = 0.71). CONCLUSIONS: Left ventricular non-compaction is frequently observed in patients with left ventricle-type univentricular hearts, with predominantly apical and mid-ventricular involvement. The presence of non-compaction is associated with increased indexed end-diastolic volumes and impaired systolic function.

Cardiovascular Magnetic Resonance Imaging of Inherited Heart Conditions.

Imaging modalities are central to diagnosis and prognostication of confirmed or suspected inherited cardiomyopathies. The availability and use of cardiovascular magnetic resonance imaging (CMR) to supplement traditional modalities has increased substantially and has several advantages over traditional imaging techniques. CMR is unique in its ability to easily acquire images in any plane. Moreover, advances in CMR sequences have begun to enable characterisation of the myocardium without the need for invasive biopsy and has provided a major step forward in the understanding of inherited heart disease pathology and genotype-phenotype interactions. This review summarises the current role of CMR in inherited cardiomyopathies depending on their genotype and phenotype status, using arrhythmogenic right ventricular dysplasia/cardiomyopathy and hypertrophic cardiomyopathy as prototypical examples.

Left Ventricular Non-Compaction: Review of the Current Diagnostic Challenges and Consequences in Athletes.

Left ventricular non-compaction (LVNC) is a complex clinical condition with no diagnostic gold standard. At present, there is trepidation about the accuracy of the diagnosis, the correlation to clinical outcomes and the long-term medical management. This article reviews the current imaging criteria, the limitations of echocardiography and cardiac magnetic resonance and the consequences of LV hypertrabeculation in athletes.

A Prospective Study of Sudden Cardiac Death among Children and Young Adults.

BACKGROUND: Sudden cardiac death among children and young adults is a devastating event. We performed a prospective, population-based, clinical and genetic study of sudden cardiac death among children and young adults. METHODS: We prospectively collected clinical, demographic, and autopsy information on all cases of sudden cardiac death among children and young adults 1 to 35 years of age in Australia and New Zealand from 2010 through 2012. In cases that had no cause identified after a comprehensive autopsy that included toxicologic and histologic studies (unexplained sudden cardiac death), at least 59 cardiac genes were analyzed for a clinically relevant cardiac gene mutation. RESULTS: A total of 490 cases of sudden cardiac death were identified. The annual incidence was 1.3 cases per 100,000 persons 1 to 35 years of age; 72% of the cases involved boys or young men. Persons 31 to 35 years of age had the highest incidence of sudden cardiac death (3.2 cases per 100,000 persons per year), and persons 16 to 20 years of age had the highest incidence of unexplained sudden cardiac death (0.8 cases per 100,000 persons per year). The most common explained causes of sudden cardiac death were coronary artery disease (24% of cases) and inherited cardiomyopathies (16% of cases). Unexplained sudden cardiac death (40% of cases) was the predominant finding among persons in all age groups, except for those 31 to 35 years of age, for whom coronary artery disease was the most common finding. Younger age and death at night were independently associated with unexplained sudden cardiac death as compared with explained sudden cardiac death. A clinically relevant cardiac gene mutation was identified in 31 of 113 cases (27%) of unexplained sudden cardiac death in which genetic testing was performed. During follow-up, a clinical diagnosis of an inherited cardiovascular disease was identified in 13% of the families in which an unexplained sudden cardiac death occurred. CONCLUSIONS: The addition of genetic testing to autopsy investigation substantially increased the identification of a possible cause of sudden cardiac death among children and young adults. (Funded by the National Health and Medical Research Council of Australia and others.).

Long term CMR follow up of patients with right ventricular abnormality and clinically suspected arrhythmogenic right ventricular cardiomyopathy (ARVC).

BACKGROUND: The Task Force Criteria (TFC) for arrhythmogenic right ventricular cardiomyopathy (ARVC) was updated in 2010 to improve specificity. There was concern however that the revised cardiovascular magnetic resonance (CMR) criteria was too restrictive and not sensitive enough to detect early forms of the condition. We previously described patients with clinically suspected ARVC who satisfied criteria from non-imaging TFC categories and fulfilled parameters from the original but not the revised CMR criteria; as a result, these patients were not confirmed as definite ARVC but may represent an early phenotype. METHODS: Patients scanned between 2008 and 2015 who had either right ventricular (RV) dilatation or regional dyskinesia satisfying at least minor imaging parameters from the original criteria and without contra-indication underwent serial CMR scanning using a 1.5 T scanner. The aims were to assess the risk of progressive RV abnormalities, evaluate the accuracy of the revised CMR criteria and the need for guideline directed CMR surveillance in at-risk individuals. RESULTS: Overall, 48 patients were re-scanned; 24 had a first-degree relative diagnosed with ARVC using the revised TFC or a first-degree relative with premature sudden death from suspected ARVC and 24 patients had either left bundle branch morphology ventricular tachycardia or > 500 ventricular extra-systoles in 24-h. Mean follow up was 69+/- 25 months. The indexed RV end-diastolic, end-systolic volumes and ejection fraction were calculated for both scans. There was significant reduction in RV volumes and improvement in RV ejection fraction (EF) irrespective of changes to body surface area; - 11.7+/- 15.2 mls/m2, - 6.4+/- 10.5 mls/m2 and + 3.3 +/- 7.9% (p = 0.01, 0.01 and 0.04). Applying the RV parameters to the revised CMR criteria, two patients from the family history group (one with confirmed ARVC and one with a premature death) had progressive RV abnormalities satisfying major criteria. The remaining patients (n = 46) did not satisfy the criteria and either had normal RV parameters with regression of structural abnormalities (27,56.3%) or stable abnormalities (19,43.7%). CONCLUSION: The revised CMR criteria represents a robust tool in the evaluation of patients with clinical suspicion of ARVC, especially for those with ventricular arrhythmias without a family history for ARVC. For patients with RV abnormalities that do not fulfill the revised criteria but have a family history of ARVC or an ARVC associated gene mutation, a surveillance CMR scan should be considered as part of the clinical follow up protocol.

Left arm structure and function late after subclavian flap repair of aortic coarctation in childhood.

OBJECTIVES: Concerns exist over the long-term consequences of subclavian artery ligation in subclavian flap repair for coarctation of the aorta. We sought to analyse upper limb structural and functional performance in adults who have had surgery in childhood for coarctation of the aorta, using either subclavian flap repair or end to end aortic anastomosis. METHODS: Two-group observational design using anatomical and upper limb functional performance measures. Purposive sampling from our specialist adult congenital heart disease database of patients who received subclavian flap repair or end to end anastomosis for coarctation of the aorta as children. Upper limb measurements were completed using MRI and blood flow velocity with ultrasound imaging. Bilateral standardised upper limb functional testing of assessment of strength, dexterity and a standardised self-report of upper limb disability was completed. RESULTS: Eighteen right-handed patients, 9 with subclavian repair, (38 ± 12 years, 78% males) were studied. Age at repair was 4.7 ± 5.9 years; mean time from initial repair 32 ± 9 years. The subclavian group had a larger difference between right and left when compared the end to end anastomosis group in: lower arm muscle mass (94.5 ± 42.3 mls versus 37.8 ± 94.5 mls, p = 0.008), lower arm maximal cross-sectional area, (5.9 ± 2.8 cm2 versus 2.9 ± 2.6 cm2, p = 0.038) and grip strength (14.7 ± 8.3 lbs versus 5.9 ± 5.3 lbs, p = 0.016) There were no significant functional differences between groups. CONCLUSIONS: In adults with repaired coarctation of the aorta, those with subclavian flap repair had a greater right to left arm muscle mass and grip strength differential when compared to those with end to end anastomosis repair.

Post-Mortem Imaging Adjudicated Sudden Death: Causes and Controversies.

Sudden cardiac death (SCD) is a catastrophic complication of many cardiac conditions often occurring without warning. In these cases, a post-mortem examination is required to elucidate the cause of death and is regarded as the 'gold standard'. However, in circumstances of certain religious/cultural beliefs and advanced body decomposition an alternative non-invasive approach would be preferred. Although a developing field, post-mortem imaging using computed tomography (pmCT) or magnetic resonance imaging (pmMR) provides a non-invasive and accurate alternative to traditional post-mortem in specific circumstances. In particular, pmMR has an important role in younger decedents while pmCT is more suited to examination of adults with SCD. Despite encouraging results from several preliminary studies, more research is needed to determine the most appropriate role for post-mortem imaging in the clinical algorhythm for investigation of SCD.

A Trial of Extending Hemodialysis Hours and Quality of Life.

The relationship between increased hemodialysis hours and patient outcomes remains unclear. We randomized (1:1) 200 adult recipients of standard maintenance hemodialysis from in-center and home-based hemodialysis programs to extended weekly (≥24 hours) or standard (target 12-15 hours, maximum 18 hours) hemodialysis hours for 12 months. The primary outcome was change in quality of life from baseline assessed by the EuroQol 5 dimension instrument (3 level) (EQ-5D). Secondary outcomes included medication usage, clinical laboratory values, vascular access events, and change in left ventricular mass index. At 12 months, median weekly hemodialysis hours were 24.0 (interquartile range, 23.6-24.0) and 12.0 (interquartile range, 12.0-16.0) in the extended and standard groups, respectively. Change in EQ-5D score at study end did not differ between groups (mean difference, 0.04 [95% confidence interval, -0.03 to 0.11]; P=0.29). Extended hours were associated with lower phosphate and potassium levels and higher hemoglobin levels. Blood pressure (BP) did not differ between groups at study end. Extended hours were associated with fewer BP-lowering agents and phosphate-binding medications, but were not associated with erythropoietin dosing. In a substudy with 95 patients, we detected no difference between groups in left ventricular mass index (mean difference, -6.0 [95% confidence interval, -14.8 to 2.7] g/m2; P=0.18). Five deaths occurred in the extended group and two in the standard group (P=0.44); two participants in each group withdrew consent. Similar numbers of patients experienced vascular access events in the two groups. Thus, extending weekly hemodialysis hours did not alter overall EQ-5D quality of life score, but was associated with improvement in some laboratory parameters and reductions in medication burden. (Clinicaltrials.gov identifier: NCT00649298).

Reproducibility of Cardiac Magnetic Resonance Imaging (CMRI)-Derived Right Ventricular Parameters in Repaired Tetralogy of Fallot (ToF).

BACKGROUND: Quantification of right ventricular (RV) volumes is challenging owing to variable reproducibility and is especially so in congenital heart disease. Cardiac magnetic resonance (CMR) has the ability to more comprehensively survey the entire right ventricle and is currently considered the gold standard. AIMS: We aimed to determine the inter-observer reproducibility of CMR-derived RV volumes generated by two independent and experienced (SCMR Level III) observers in Tetralogy of Fallot (ToF) patients with varying degrees of RV dilatation. METHODS: We performed a retrospective analysis of 120 consecutive patients with repaired ToF who underwent CMR. Two blinded observers calculated RV volumes in each oblique short axis slice independently. Bland-Altman analysis and inter-observer correlation coefficients (ICC) were assessed. RESULTS: The coefficients of variation for RV parameters were: 2.9%, 8% and 3.4% for right ventricular end diastolic volume (RVEDV), right ventricular end systolic volume (RVESV) and right ventricular ejection fraction (RVEF) respectively. For RVEDV the interobserver correlation was 0.992 demonstrating excellent volumetric correlation between observers. The mean difference between the observers for right ventricular end diastolic volume index (RVEDVi) was 2.5ml/m2 (95% limits of agreement -7.3 to 12.2ml/m2). For patients with mild-moderate RV dilatation (RVEDVi <150ml/m2) the mean difference of RVEDVi was 1.8ml/m2 (95% limits of agreement -5.7 to 9.3ml/m2). For patients with severe RV dilatation (RVEDVi≥150ml/m2) the mean difference was -3.4ml/m2 (95% limits of agreement -8.6 to 15.4ml/m2). CONCLUSIONS: In patients with repaired ToF and variable degrees of RV dilatation, CMR assessment of RV volumes and function has high inter-observer reproducibility. This allows for optimal timing of pulmonary valve replacement, based on progression of RV dilatation over time.

Diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy: Progress and Pitfalls.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy that predominantly affects the right ventricle. With a prevalence in the range of 1:5000 to 1:2000 persons, ARVC is one of the leading causes of sudden cardiac death in young people and in athletes. Although early detection and treatment is important, the diagnosis of ARVC remains challenging. There is no single pathognomonic diagnostic finding in ARVC; rather, current international task force criteria specify diagnostic major and minor criteria in six categories: right ventricular imaging (including echocardiography and cardiac magnetic resonance imaging (MRI)), histology, repolarisation abnormalities, depolarisation and conduction abnormalities, arrhythmias and family history (including genetic testing). Combining findings from differing diagnostic modalities can establish a "definite", "borderline" or "possible" diagnosis of ARVC. However, there are limitations inherent in the current task force criteria, including the lack of specificity for ARVC; future iterations may be improved, for example, by enhanced imaging protocols able to detect subtle changes in the structure and function of the right ventricle, incorporation of electro-anatomical data, response to adrenergic challenge, and validated criteria for interpreting genetic variants.

The Utility of Cardiac Magnetic Resonance Imaging in the Diagnosis of Cardiac Sarcoidosis.

BACKGROUND: Autopsy reports suggest that cardiac sarcoidosis occurs in 20 to 25% of patients with pulmonary sarcoidosis, yet the clinical ante-mortem diagnosis is made in only 5% of cases. Current diagnostic algorithms are complex and lack sensitivity. Cardiac Magnetic Resonance imaging (CMR) provides an opportunity to detect myocardial involvement in sarcoidosis. The aim of this study is to determine the prevalence and clinical significance of late gadolinium enhancement (LGE) on CMR in patients with sarcoidosis. METHODS: Consecutive patients with biopsy-proven sarcoidosis undergoing CMR were retrospectively evaluated for cardiac sarcoidosis. Medical records were correlated with CMR. RESULTS: Forty-six patients were evaluated. Late gadolinium enhancement was present in 22%, indicating myocardial involvement, and 70% had corresponding hyper-intense T2 signal indicating active inflammation. Late gadolinium enhancement was 18%+/-9.7% of overall left ventricular (LV) mass and most commonly located in the basal to mid septum. There was no association between LGE and cardiovascular symptoms or pulmonary stage. Eighty per cent of patients with LGE did not fulfill conventional diagnostic criteria for cardiac sarcoidosis. However, LGE was associated with clinically significant arrhythmia (p<0.01) and a lower LVEF (p=0.04). CONCLUSIONS: Using CMR, we identified a higher prevalence of cardiac sarcoidosis than previously reported clinical studies, a prevalence which is more consistent with autopsy data. The presence of LGE was highly correlated with clinically significant arrhythmias and lower LVEF.