Value of MRI in patients with a clinical suspicion of acute myocarditis

MRI Findings in Desmoplakin-related Arrhythmogenic Left Ventricular Cardiomyopathy in a Pediatric Patient: A Case Report

Arrhythmogenic cardiomyopathy (ACM) is a heart muscle disorder that cannot be explained by ischemic, hypertensive, or valvular heart disease and often results in sudden cardiac death. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is the best-characterized ACM and can be diagnosed using the revised task force criteria. In contrast, there are no accepted clinical diagnostic criteria for arrhythmogenic left ventricular cardiomyopathy (ALVC), another subtype of ACM. Cardiac MRI aids in ARVC diagnosis by delineating biventricular structural and functional abnormalities and can be instrumental in diagnosing ALVC. This report presents a pediatric case of desmoplakin cardiomyopathy, a distinct subtype of ALVC, with findings overlapping myocarditis and LV noncompaction. Keywords: Pediatrics, Heart, Cardiomyopathies Supplemental material is available for this article. © RSNA, 2023.

Diagnostic evaluation of unexplained ventricular tachyarrhythmias in younger adults

BACKGROUND

The diagnostic work-up for cardiac arrest from ventricular tachyarrhythmias occurring in younger adults and structurally normal hearts is variable and often incomplete.

METHODS

We reviewed records for all recipients of a secondary prevention implantable cardiac defibrillator (ICD) younger than 60 years at a single quaternary referral hospital from 2010 to 2021. Patients with unexplained ventricular arrhythmias (UVA) were identified as those with no structural heart disease on echocardiogram, no obstructive coronary disease, and no clear diagnostic features on ECG. We specifically evaluated the adoption rate of five modalities of "second-line" cardiac investigations: cardiac magnetic resonance imaging (CMR), exercise ECG, flecainide challenge, electrophysiology study (EPS), and genetic testing. We also evaluated patterns of antiarrhythmic drug therapy and device-detected arrhythmias and compared them with secondary prevention ICD recipients with a clear etiology found on initial assessment.

RESULTS

One hundred and two recipients of a secondary prevention ICD under the age of 60 were analyzed. Thirty-nine patients (38.2%) were identified with UVA and were compared with the remaining 63 patients with VA of clear etiology (61.8%). UVA patients were younger (35.6 ± 13.0 vs. 46.0 ± 8.6 years, p < .001) and were more often female (48.7% vs. 28.6%, p = .04). CMR was performed in 32 patients with UVA (82.1%), whereas flecainide challenge, stress ECG, genetic testing, and EPS were only performed in a minority of patients. Overall, the use of a second-line investigation suggested an etiology in 17 patients with UVA (43.5%). Compared to patients with VA of clear etiology, UVA patients had lower rates of antiarrhythmic drug prescription (64.1% vs. 88.9%, p = .003) and had a higher rate of device-delivered tachy-therapies (30.8% vs. 14.3%, p = .045).

CONCLUSION

In this real-world analysis of patients with UVA, the diagnostic work-up is often incomplete. While CMR was increasingly utilized at our institution, investigations for channelopathies and genetic causes appear to be underutilized. Implementation of a systematic protocol for work-up of these patients requires further study.

Perimyocarditis With Acute Heart Failure as the First Manifestation of Systemic Lupus Erythematosus

Cardiac abnormalities are common in patients with systemic lupus erythematosus (SLE). However, many of them tend to be mild or asymptomatic and can be recognized by non-invasive studies such as transthoracic echocardiography and cardiac magnetic resonance imaging (CMR). However, heart failure secondary to perimyocarditis as the initial manifestation of SLE remains an extremely rare form of presentation. Below, we present the case of an adult female patient who initially consulted due to symptoms of acute dyspnea, atypical chest pain, and edema of the lower limbs, who underwent a chest X-ray as part of the initial studies, which described an increase in the cardiac silhouette associated with diffuse opacities in both lung fields. The admission electrocardiogram only showed sinus tachycardia and nonspecific alterations of the T wave, with an initial report of frankly elevated cardiac biomarkers compatible with acute myocardial injury together with the positivity of specific antibodies for SLE.

Tuberculosis of the Heart: A Diagnostic Challenge

Tuberculosis of the heart is relatively rare and presents a significant diagnostic difficulty for physicians. It is the leading cause of death from infectious illness. It is one of the top 10 leading causes of death worldwide, with a disproportionate impact in low- and middle-income nations. The radiologist plays a pivotal role as CMR is a non-invasive radiological method that can aid in identifying potential overlap and differential diagnosis between tuberculosis, mass lesions, pericarditis, and myocarditis. Regardless of similarities or overlap in observations, the combination of clinical and certain particular radiological features, which are also detected by comparison to earlier and follow-up CMR scans, may aid in the differential diagnosis. CMR offers a significant advantage over echocardiography for detecting, characterizing, and assessing cardiovascular abnormalities. In conjunction with clinical presentation, knowledge of LGE, feature tracking, and parametric imaging in CMR may help in the early detection of tuberculous myopericarditis and serve as a surrogate for endomyocardial biopsy resulting in a quicker diagnosis and therapy. This article aims to explain the current state of cardiac tuberculosis, the diagnostic utility of CMR in tuberculosis (TB) patients, and offer an overview of the various imaging and laboratory procedures used to detect cardiac tuberculosis.

Non-invasive assessment of early and acute myocarditis in a rat model using cardiac magnetic resonance tissue tracking analysis of myocardial strain

Background

Myocardial strain analysis can provide diagnostic and prognostic information for myocarditis. The aim of the present study was to assess early and acute myocarditis in a rat model using cardiac magnetic resonance tissue tracking (CMR-TT) for myocardial strain analysis. We compared the strain's findings with the histological and immunohistochemical results.

Methods

Experimental autoimmune myocarditis (EAM) was induced by footpad injections of porcine cardiac myosin. The rats were examined by 7.0T preclinical CMR at day 14 (n=15) and day 21 (n=16) after EAM induction and the two control groups (each n=15) were also examined at day 14 and day 21, respectively. Using CMR-TT, we found a global peak systolic radial strain (Err_SAX) and a circumferential strain (Ecc_SAX) from the short-axis cine views and a radial strain (Err_LAX) and a longitudinal strain (Ell_LAX) from the long-axis cine views, which were calculated by dedicated TT software. Subsequently, histological and immunohistochemical evaluations were performed.

Results

Ell_LAX significantly decreased in early myocarditis compared with the control (-23.40%±1.48% vs. -22.02%±0.81%, P<0.05). Err_SAX, Ecc_SAX, Err_LAX, and Ell_LAX values significantly reduced in acute myocarditis compared with the controls (Err_SAX: 34.27%±9.80% vs. 49.76%±4.97%, Ecc_SAX: -18.98%±3.69% vs. -24.13±1.23, Err_LAX: 33.21%±10.24% vs. 49.59%±5.69%, and Ell_LAX: -17.75%±3.58% vs. -23.39%±1.48%; P<0.001, respectively). The receiver operating characteristic curve showed that myocardial strain analysis had a good diagnostic performance in early and acute myocarditis. The pathological evaluation revealed that inflammatory lesions began to appear in early myocarditis and peaked in acute myocarditis.

Conclusions

The CMR-TT strain analysis allowed accurate and reliable evaluation of early and acute myocarditis in a rat model, and has the potential to serve as a diagnostic indicator for the assessment of myocardial dysfunction in myocarditis.

Pneumococcal Pneumonia Resembling Acute Myocardial Infarction in an Adolescent Male

Myocarditis is commonly associated with viruses. However, we present a novel case of a teenager with pneumococcal pneumonia and bacteremia complicated by myocarditis and rhabdomyolysis, presenting with features of acute ST-elevation myocardial infarction and cardiogenic shock. Physicians should be aware that Streptococcus pneumoniae infection, like Group A Streptococcus, can mimic acute myocardial infarction in young males without cardiovascular risk factors.

Diagnostic and prognostic value of cardiac magnetic resonance in acute myocarditis: a systematic review and meta-analysis

While diagnostic criteria were elaborated for acute myocarditis using cardiac magnetic resonance (CMR) in 2009, studies have since examined the yield of traditional and novel CMR parameters to achieve greater accuracy and to predict clinical outcomes. The purpose of this systematic review and meta-analysis was to determine the diagnostic and prognostic value of CMR parameters for acute myocarditis. MEDLINE and EMBASE were systematically searched for original studies that reported CMR parameters in adult patients suspected of acute myocarditis. Each CMR parameter's binary prevalence, mean value and standard deviation were extracted. Parameters were meta-analyzed using a random-effects model to generate standardized mean differences. After screening 1492 abstracts, 53 studies were included encompassing 2823 myocarditis patients and 803 controls. Pooled standardized mean differences between myocarditis patients and controls were: T2 mapping time 2.26 (95% CI 1.50-3.02), extracellular volume 1.64 (95% CI 0.87-2.42), LGE percentage 1.30 (95% CI 0.95-1.64), T1 mapping time 1.18 (95% CI 0.35-2.01), T2 ratio 1.17 (95% CI 0.80-1.54), and EGE ratio 0.93 (95% CI 0.66-1.19). Prolonged T1 mapping time had the highest sensitivity (82%), pericardial effusion had the highest specificity (99%). Baseline LV dysfunction and the presence of LGE were predictive of major adverse cardiac events. The results support integration of parametric mapping criteria in the diagnostic criteria for myocarditis. The presence of baseline LV dysfunction and LGE predict patients at higher risk of adverse events.

Evaluation of Early Gadolinium Enhancement (EGE) and Cardiac Functional Parameters in Cine-Magnetic Resonance Imaging (MRI) on Artificial Intelligence in Patients with Acute Myocarditis: A Case-Controlled Observational Study

<strong>BACKGROUND</strong> The diagnosis of myocarditis is challenging, and the treatment is generally delayed due to misdiagnosis or missed diagnosis. Endomyocardial biopsy (EMB) is not a specific or sensitive method. A case-controlled observational study was conducted to evaluate early gadolinium enhancement (EGE) and left ventricular functional parameters on Artificial Intelligence in cine-MRI in patients with acute myocarditis. <strong>MATERIAL AND METHODS</strong> We selected 21 patients with pathologically proven acute myocarditis. We analyzed the EGE findings (total/serial number and location of positive-segments using the 17-segment model according to the American Heart Association) and clinical characteristics (symptoms, arrhythmias in ECG, coronary angiography, and EMB). All patients were divided into positive EGE and negative EGE groups to analyze left ventricular functional parameters (LVEF, FS, LVEDD, LVEDV, LVESV, LVMM, LVSV, CO, and CI) on Artificial Intelligence. <strong>RESULTS</strong> We enrolled 21 patients (11 males) with a mean age of 32.6±9.8 years (range, 16 to 51 years). Abnormalities on EGE were found in 2/3 of patients, involving 41 segments among multiple locations on the myocardium. The differences in LVEF (40.2±10.2% <i>vs.</i> 51.3±3.6%), LVESV (69.0±16.1ml <i>vs.</i> 52.5±10.6ml) and LVSV (42.6±11.4 <i>vs.</i> 52.8±2.8 ml) on Artificial Intelligence was statistically significant between the positive EGE and negative EGE groups (p<0.05). <strong>CONCLUSIONS</strong> Our results suggest a significant role of EGE on the basis of Lake Louise criteria in evaluating patients with clinical suspicion of acute myocarditis. Parameters, including LVEF, LVESV, and LVSV, on Artificial Intelligence, may be useful independent predictors for capillary leakage and microcirculatory disturbance in myocarditis.

Natural History of Myocardial Injury and Chamber Remodeling in Acute Myocarditis

Background:

Cardiovascular magnetic resonance (CMR) imaging is commonly used to diagnose acute myocarditis. However, the natural history of CMR-based tissue markers and their association with left ventricular recovery is poorly explored. We prospectively investigated the natural history of CMR-based myocardial injury and chamber remodeling over 12 months in patients with suspected acute myocarditis.

Methods:

One hundred patients with suspected acute myocarditis were enrolled. All underwent CMR evaluations at baseline and 12 months, inclusive of T2 and late gadolinium enhancement. Blinded quantitative analyses compared left ventricular chamber volumes, function, myocardial edema, and necrosis at each time point using predefined criteria. The predefined primary outcomes were improvement in left ventricular ejection fraction ≥10% and improvement in the indexed left ventricular end diastolic volume ≥10% at 12 months.

Results:

The mean age was 39.9±14.5 years (82 male) with baseline left ventricular ejection fraction of 57.1±11.2%. A total of 72 patients (72%) showed late gadolinium enhancement at baseline with 57 (57%) having any T2 signal elevation. Left ventricular volumes and EF improved significantly at 12 months. Global late gadolinium enhancement extent dropped from 8.5±9.2% of left ventricular mass to 3.0±5.2% ( P =0.0001) with prevalence of any late gadolinium enhancement dropping to 48%. Reductions in global T2 signal ratio occurred at 12 months (1.85±0.3 to 1.56±0.2; P =0.0001) with prevalence of T2 ratio ≥2.0 dropping to 7%. Neither marker provided associations with the primary outcomes.

Conclusions:

In clinically suspected acute myocarditis, significant reductions in tissue injury markers occur during the first 12 months of convalescence. Neither the presence nor extent of the investigated CMR-based tissue injury markers were predictive of our pre-defined function or remodeling outcomes at 12 months in this referral population.

Assessment of acute myocarditis by cardiac magnetic resonance imaging: Comparison of qualitative and quantitative analysis methods

BACKGROUND

To compare cardiac magnetic resonance (CMR) qualitative and quantitative analysis methods for the noninvasive assessment of myocardial inflammation in patients with suspected acute myocarditis (AM).

METHODS

A total of 61 patients with suspected AM underwent coronary angiography and CMR. Qualitative analysis was performed applying Lake-Louise Criteria (LLC), followed by quantitative analysis based on the evaluation of edema ratio (ER) and global relative enhancement (RE). Diagnostic performance was assessed for each method by measuring the area under the curves (AUC) of the receiver operating characteristic analyses. The final diagnosis of AM was based on symptoms and signs suggestive of cardiac disease, evidence of myocardial injury as defined by electrocardiogram changes, elevated troponin I, exclusion of coronary artery disease by coronary angiography, and clinical and echocardiographic follow-up at 3 months after admission to the chest pain unit.

RESULTS

In all patients, coronary angiography did not show significant coronary artery stenosis. Troponin I levels and creatine kinase were higher in patients with AM compared to those without (both P < .001). There were no significant differences among LLC, T2-weighted short inversion time inversion recovery (STIR) sequences, early (EGE), and late (LGE) gadolinium-enhancement sequences for diagnosis of AM. The AUC for qualitative (T2-weighted STIR 0.92, EGE 0.87 and LGE 0.88) and quantitative (ER 0.89 and global RE 0.80) analyses were also similar.

CONCLUSIONS

Qualitative and quantitative CMR analysis methods show similar diagnostic accuracy for the diagnosis of AM. These findings suggest that a simplified approach using a shortened CMR protocol including only T2-weighted STIR sequences might be useful to rule out AM in patients with acute coronary syndrome and normal coronary angiography.

A multi-band double-inversion radial fast spin-echo technique for T2 cardiovascular magnetic resonance mapping of the heart

BACKGROUND

Double inversion recovery (DIR) fast spin-echo (FSE) cardiovascular magnetic resonance (CMR) sequences are used clinically for black-blood T2-weighted imaging. However, these sequences suffer from slice inefficiency due to the non-selective inversion pulses. We propose a multi-band (MB) encoded DIR radial FSE (MB-DIR-RADFSE) technique to simultaneously excite two slices. This sequence has improved signal-to-noise ratio per unit time compared to a single slice excitation. It is also motion robust and enables the reconstruction of high-resolution black-blood T2-weighted images and T2 maps for the excited slices.

METHODS

Hadamard encoded MB pulses were used in MB-DIR-RADFSE to simultaneously excite two slices. A principal component based iterative reconstruction was used to jointly reconstruct black-blood T2-weighted images and T2 maps. Phantom and in vivo experiments were performed to evaluate T2 mapping performance and results were compared to a T2-prepared balanced steady state free precession (bSSFP) method. The inter-segment variability of the T2 maps were assessed using data acquired on healthy subjects. A reproducibility study was performed to evaluate reproducibility of the proposed technique.

RESULTS

Phantom experiments show that the T2 values estimated from MB-DIR-RADFSE are comparable to the spin-echo based reference, while T2-prepared bSSFP over-estimated T2 values. The relative contrast of the black-blood images from the multi-band scheme was comparable to those from a single slice acquisition. The myocardial segment analysis on 8 healthy subjects indicated a significant difference (p-value < 0.01) in the T2 estimates from the apical slice when compared to the mid-ventricular slice. The mean T2 estimate from 12 subjects obtained using T2-prepared bSSFP was significantly higher (p-value = 0.012) compared to MB-DIR-RADFSE, consistent with the phantom results. The Bland-Altman analysis showed excellent reproducibility between the MB-DIR-RADFSE measurements, with a mean T2 difference of 0.12 ms and coefficient of reproducibility of 2.07 in 15 clinical subjects. The utility of this technique is demonstrated in two subjects where the T2 maps show elevated values in regions of pathology.

CONCLUSIONS

The use of multi-band pulses for excitation improves the slice efficiency of the double inversion fast spin-echo pulse sequence. The use of a radial trajectory and a joint reconstruction framework allows reconstruction of TE images and T2 maps for the excited slices.

Speckle tracking imaging in inflammatory heart diseases

Accurate diagnosis of acute myocarditis is important for the prognosis and risk stratification of these patients. Cardiac magnetic resonance (CMR) has become a major modality for diagnosis of myocarditis, but not widely available. In this study, we tried to evaluate regional and global longitudinal strain by speckle tracking echocardiography in patients with acute inflammatory myocardial diseases in correlation with CMR. Patients with suspected acute myocarditis were recruited prospectively. Clinical diagnosis was established based on clinical, electrocardiographic, laboratory and conventional echocardiographic data. All patients underwent CMR and repeat echocardiographic examination within 24 h of CMR. Echocardiographic examinations were analyzed offline with speckle tracking imaging software. Thirty-two patients with acute perimyocarditis and myopericarditis were included. Mean age was 29 ± 8, 30 males. All patients presented with chest pain and an abnormal electrocardiogram, in 28 ST elevation was found. Troponin was elevated in 30 and was 0.7 ± 0.5 ng/ml. Creatine kinase was 487 ± 319 U. LVEF was 56 ± 5%. Wall motion abnormalities were present in postero-lateral (53%), and inferior wall (21%). Delayed enhancement on CMR was found in 29 patients. Echocardiographic EF based on speckle tracking imaging correlated with CMR calculated EF. There was a positive correlation between the amplitude of regional strain and delayed enhancement, r = 0.52. Sensitivity and specificity of regional strain for prediction of delayed enhancement was 85 and 73% respectively. Speckle tracking imaging can help in the diagnosis of acute myocarditis when CMR is not readily available. Speckle tracking imaging based EF correlates with CMR calculated LVEF and with global strain.

Performance of Cardiac Magnetic Resonance Imaging for Diagnosis of Myocarditis Compared with Endomyocardial Biopsy: A Meta-Analysis

Background

Cardiac magnetic resonance imaging (CMRI) is considered to be useful for the diagnosis of myocarditis, and the Lake Louise Criteria (LLC) has been proved to be of significance as the standard of diagnosis. However, the diagnostic performance of LLC-based CMRI for myocarditis compared with endomyocardial biopsy (EMB) has not been quantitatively evaluated in a meta-analysis.

Material/Methods

The databases PubMed, Cochrane’s Library, and EMBASE were searched to identify studies on LLC and its individual components for the diagnosis of myocarditis. EMB was the control reference. The sensitivity, specificity, and positive and negative diagnostic likelihood ratios were calculated with a random-effects model. The area under the receiver operating characteristic curve (AUC) was estimated to show overall effectiveness.

Results

We included 9 cohorts (614 patients) of patients with suspected MC. The combined sensitivities, specificities, and AUCs for T1-weighed global relative enhancement were 0.66, 0.73, and 0.71; for T2-weighed edema ratio they were 0.52, 0.73, and 0.72; for the late gadolinium enhancement, they were 0.70, 0.57, and 0.67; and for LLC-based CMRI they were 0.70, 0.56, and 0.70, respectively. Subgroup analysis indicated that the sensitivities, specificities, and diagnostic accuracies of LLC and its individual component-based CMRI seemed to be similar in patients with acute or chronic myocarditis. Results of the Deeks’ funnel plot asymmetry test showed no significant publication bias among the studies.

Conclusions

CMRI based on LLC or its individual components seems to have moderate accuracy in diagnosis of acute or chronic myocarditis.

Clinical applications of multi-parametric CMR in myocarditis and systemic inflammatory diseases

Cardiac magnetic resonance (CMR) has changed the management of suspected viral myocarditis by providing a ‘positive’ diagnostic test and has lead to new insights into myocardial involvement in systemic inflammatory conditions. In this review we analyse the use of CMR tissue characterisation techniques across the available studies including T2 weighted imaging, early gadolinium enhancement, late gadolinium enhancement, Lake Louise Criteria, T2 mapping, T1 mapping and extracellular volume assessment. We also discuss the use of multiparametric CMR in acute cardiac transplant rejection and a variety of inflammatory conditions such as sarcoidosis, systemic lupus erythrematous, rheumatoid arthritis and systemic sclerosis.

Is Endomyocardial Biopsy a Safe and Useful Procedure in Children with Suspected Cardiomyopathy?

Endomyocardial biopsy (EMB) is a common procedure used to aid in the diagnosis, prognosis and treatment of suspected pediatric cardiomyopathy. In suspected cardiomyopathy, no multicenter experience has previously reported on the safety and utility of EMBs. Retrospectively, adverse event (AE) and patient and procedural characteristics were obtained at seven institutions participating in the Congenital Cardiac Catheterization Outcomes Project for both a cardiomyopathy (n = 158) and a post-transplant surveillance (n = 2665) cohort. Descriptive information regarding biopsy indication, pathology and clinical management based on EMB findings were retrospectively obtained. High-severity AEs were more common in the cardiomyopathy cohort when compared to the post-transplant surveillance cohort. The cardiomyopathy cohort was younger, more hemodynamically vulnerable and required more cardiorespiratory support during the procedure. The eight high-severity AEs in the cardiomyopathy group included one myocardial perforation, two ECMO cannulations and three deaths following the EMB. Factors associated with high-severity AEs included performing another catheter-based intervention during the EMB and longer fluoroscopy time. Notably, an increased number of biopsy attempts did not increase the risk of an AE. Suspected myocarditis was the most common indication. Diagnostic EMB pathology and thus alteration to clinical management based on pathology occurred more frequently in patients with suspected myocarditis. In conclusion, there is an increased incidence of high-severity AEs in patients undergoing EMB for suspected cardiomyopathy. EMB may be more clinically useful in the management of suspected myocarditis. The increased risk of high-severity AEs when additional interventions are performed highlights the hemodynamic vulnerability in patients with suspected cardiomyopathy.

Myocarditis

Viral myocarditis remains a prominent infectious-inflammatory disease for patients throughout the lifespan. The condition presents several challenges including varied modes of clinical presentation, a range of timepoints when patients come to attention, a diversity of approaches to diagnosis, a spectrum of clinical courses, and unsettled perspectives on therapeutics in different patient settings and in the face of different viral pathogens. In this review, we examine current knowledge about viral heart disease and especially provide information on evolving understanding of mechanisms of disease and efforts by investigators to identify and evaluate potential therapeutic avenues for intervention.

Myocardial T1 maps reflect histological findings in acute and chronic stages of myocarditis in a rat model

BACKGROUND

Cardiovascular magnetic resonance offers both diagnostic and prognostic information in myocarditis. Using an established animal model of myocarditis, the aim of this study was to measure myocardial T1 before the onset, in the acute and in the chronic phases of the disease and to compare its course with histological and immunohistochemistry findings.

METHODS

Male young Lewis rats were immunized with 0.25 mg porcine myocardial myosin into the rear footpads on day 0. Native and contrast-enhanced ECG-triggered cardiac MRI examinations were performed before immunization on day 0 and on days 14, 21 and 35. Left ventricular function, pre- and post- contrast T1 parameters and LGE images were assessed using Small animal look-locker inversion recovery (SALLI). For each of the indicated time points a minimum of 4 rats were randomly sacrificed for pathological investigations including conventional histology (HE and Sirius-Red staining) and immunohistochemistry (CD 68) investigations.

RESULTS

All immunized rats developed myocarditis (morbidity 100%). Histologically we observed increased wall thickness with biventricular macrophage-rich mixed inflammatory infiltrates. All rats with a histologically severe myocarditis showed increased native T1 and decreased post-contrast T1 of the myocardium.

CONCLUSIONS

The assessment of native T1 and post-contrast T1 allows accurate differentiation between healthy myocardium and myocardium with inflammation and also between the acute and chronic phases of the disease.

Patients with exercise-associated ventricular ectopy present evidence of myocarditis

BACKGROUND

The origin and clinical relevance of exercise-induced premature ventricular beats (PVBs) in patients without coronary heart disease or cardiomyopathies is unknown. Cardiovascular magnetic resonance enables us to non-invasively assess myocardial scarring and oedema. The purpose of our study was to discover any evidence of myocardial anomalies in patients with exercise-induced ventricular premature beats.

METHODS

We examined 162 consecutive patients presenting palpitations and documented exercise-induced premature ventricular beats (PVBs) but no history or evidence of structural heart disease. Results were compared with 70 controls matched for gender and age. ECG-triggered, T2-weighted, fast spin echo triple inversion recovery sequences and late gadolinium enhancement were obtained as well as LV function and dimensions.

RESULTS

Structural anomalies in the myocardium and/or pericardium were present in 85 % of patients with exercise-induced PVBs. We observed a significant difference between patients with PVBs and controls in late gadolinium enhancement, that is 68 % presented subepicardial or midmyocardial lesions upon enhancement, whereas only 9 % of the controls did so (p < 0.0001). More patients presented pericardial enhancement (35 %) or pericardial thickening (27 %) compared to controls (21 % and 13 %, p < 0.0001). Myocardial oedema was present in 37 % of the patients and in only one control, p < 0.0001. Left ventricular ejection fraction did not differ between patients and controls (63.1 ± 7.9 vs. 64.7 ± 7.0, p = 0.13).

CONCLUSIONS

The majority of patients with exercise-associated premature ventricular beats present evidence of myocardial disease consistent with acute or previous myocarditis or myopericarditis.

Myocardial oedema in acute myocarditis detected by echocardiographic 2D myocardial deformation analysis

AIMS

The clinical diagnosis of acute myocarditis is based on symptoms, electrocardiography, elevated myocardial necrosis biomarkers, and echocardiography. Often, conventional echocardiography reveals no obvious changes in global cardiac function and therefore has limited diagnostic value. Myocardial deformation imaging by echocardiography is an evolving method used to characterize quantitatively longitudinal systolic function, which may be affected in acute myocarditis. The aim of our study was to assess the utility of echocardiographic deformation imaging of the left ventricle in patients with diagnosed acute myocarditis in whom cardiovascular magnetic resonance (CMR) evaluation was performed.

METHODS AND RESULTS

We included 28 consecutive patients (mean age 32 ± 13 years) with CMR-verified diagnosis of acute myocarditis according to the Lake Louise criteria. Cardiac function was evaluated by a comprehensive assessment of left ventricular (LV) function, including 2D speckle-tracking echocardiography. We found no significant correlation between the peak values of cardiac enzymes and the amount of myocardial oedema assessed by CMR (troponin: r= 0.3; P = 0.05 and CK-MB: r = 0.1; P = 0.3). We found a larger amount of myocardial oedema in the basal part of the left ventricle [American Heart Association (AHA) segments 1-6] in inferolateral and inferior segments, compared with the anterior, anterolateral, anteroseptal, and inferoseptal segments. In the mid LV segments (AHA segments 7-12), this was more pronounced in the anterior, anterolateral, and inferolateral segments. Among conventional echocardiographic parameters, LV function was not found to correlate with the amount of myocardial oedema of the left ventricle. In contrast, we found the wall motion score index to be significantly correlated with the amount of myocardial oedema, but this correlation was only present in patients with an extensive amount of oedema (>11% of the total left ventricle). Global longitudinal systolic myocardial strain correlated significantly with the amount of oedema (r = 0.65; P < 0.001). We found that both the epicardial longitudinal and the endocardial longitudinal systolic strains were significantly correlated with oedema (r = 0.55; P = 0.003 and r = 0.54; P < 0.001).

CONCLUSION

In patients with acute myocarditis, 2D speckle-tracking echocardiography was a useful tool in the diagnostic process of acute myocarditis. Global longitudinal strain adds important information that can support clinical and conventional echocardiographic evaluation, especially in patients with preserved LV ejection fraction in relation to the diagnosis and degree of myocardial dysfunction.

T2 mapping of the heart with a double-inversion radial fast spin-echo method with indirect echo compensation

BACKGROUND

The abnormal signal intensity in cardiac T2-weighted images is associated with various pathologies including myocardial edema. However, the assessment of pathologies based on signal intensity is affected by the acquisition parameters and the sensitivities of the receiver coils. T2 mapping has been proposed to overcome limitations of T2-weighted imaging, but most methods are limited in spatial and/or temporal resolution. Here we present and evaluate a double inversion recovery radial fast spin-echo (DIR-RADFSE) technique that yields data with high spatiotemporal resolution for cardiac T2 mapping.

METHODS

DIR-RADFSE data were collected at 1.5 T on phantoms and subjects with echo train length (ETL) = 16, receiver bandwidth (BW) = ±32 kHz, TR = 1RR, matrix size = 256 × 256. Since only 16 views per echo time (TE) are collected, two algorithms designed to reconstruct highly undersampled radial data were used to generate images for 16 time points: the Echo-Sharing (ES) and the CUrve Reconstruction via pca-based Linearization with Indirect Echo compensation (CURLIE) algorithm. T2 maps were generated via least-squares fitting or the Slice-resolved Extended Phase Graph (SEPG) model fitting. The CURLIE-SEPG algorithm accounts for the effect of indirect echoes. The algorithms were compared based on reproducibility, using Bland-Altman analysis on data from 7 healthy volunteers, and T2 accuracy (against a single-echo spin-echo technique) using phantoms.

RESULTS

Both reconstruction algorithms generated in vivo images with high spatiotemporal resolution and showed good reproducibility. Mean T2 difference between repeated measures and the coefficient of repeatability were 0.58 ms and 2.97 for ES and 0.09 ms and 4.85 for CURLIE-SEPG. In vivo T2 estimates from ES were higher than those from CURLIE-SEPG. In phantoms, CURLIE-SEPG yielded more accurate T2s compared to reference values (error was 7.5-13.9% for ES and 0.6-2.1% for CURLIE-SEPG), consistent with the fact that CURLIE-SEPG compensates for the effects of indirect echoes. The potential of T2 mapping with CURLIE-SEPG is demonstrated in two subjects with known heart disease. Elevated T2 values were observed in areas of suspected pathology.

CONCLUSIONS

DIR-RADFSE yielded TE images with high spatiotemporal resolution. Two algorithms for generating T2 maps from highly undersampled data were evaluated in terms of accuracy and reproducibility. Results showed that CURLIE-SEPG yields T2 estimates that are reproducible and more accurate than ES.

Distribution of late gadolinium enhancement in various types of cardiomyopathies: Significance in differential diagnosis, clinical features and prognosis

The recent development of cardiac magnetic resonance (CMR) techniques has allowed detailed analyses of cardiac function and tissue characterization with high spatial resolution. We review characteristic CMR features in ischemic and non-ischemic cardiomyopathies (ICM and NICM), especially in terms of the location and distribution of late gadolinium enhancement (LGE). CMR in ICM shows segmental wall motion abnormalities or wall thinning in a particular coronary arterial territory, and the subendocardial or transmural LGE. LGE in NICM generally does not correspond to any particular coronary artery distribution and is located mostly in the mid-wall to subepicardial layer. The analysis of LGE distribution is valuable to differentiate NICM with diffusely impaired systolic function, including dilated cardiomyopathy, end-stage hypertrophic cardiomyopathy (HCM), cardiac sarcoidosis, and myocarditis, and those with diffuse left ventricular (LV) hypertrophy including HCM, cardiac amyloidosis and Anderson-Fabry disease. A transient low signal intensity LGE in regions of severe LV dysfunction is a particular feature of stress cardiomyopathy. In arrhythmogenic right ventricular cardiomyopathy/dysplasia, an enhancement of right ventricular (RV) wall with functional and morphological changes of RV becomes apparent. Finally, the analyses of LGE distribution have potentials to predict cardiac outcomes and response to treatments.

Myopericarditis and severe myocardial dysfunction as the initial manifestation of systemic lupus erythematosus

Pericarditis is the most frequent cardiac manifestation of systemic lupus erythematosus (SLE). However, a large pericardial effusion as the initial manifestation of the disease is infrequent, especially when it is associated with myocardial damage. We describe an unusual case of a young female with pleuropericarditis and severe myocardial dysfunction as the initial manifestation of SLE.

Contrast-enhancement cardiac magnetic resonance imaging beyond the scope of viability

The clinical applications of cardiovascular magnetic resonance imaging with contrast enhancement are expanding. Besides the direct visualisation of viable and non-viable myocardium, this technique is increasingly used in a variety of cardiac disorders to determine the exact aetiology, guide proper treatment, and predict outcome and prognosis. In this review, we discuss the value of cardiovascular magnetic resonance imaging with contrast enhancement in a range of cardiac disorders, in which this technique may provide insights beyond the scope of myocardial viability.

Pericardial disease: value of CT and MR imaging

The pericardium represents an important focus of morbidity and mortality in patients with cardiovascular disease. Fortunately, in recent years knowledge regarding this enigmatic part of the heart and the diagnosis of related diseases has substantially advanced. To a large extent, this can be attributed to the availability of several noninvasive cardiac imaging modalities. Transthoracic echocardiography, which combines structural and physiologic assessment, is the first-line technique for examination of patients suspected of having or known to have pericardial disease; however, cardiac computed tomography (CT) and magnetic resonance (MR) imaging are becoming increasingly popular for the study of this part of the heart. Modern multidetector CT scanners merge acquisition speed and high spatial and contrast resolution, with volumetric scanning to provide excellent anatomic detail of the pericardium. Multidetector CT is by far the modality of choice for depiction of pericardial calcifications. MR imaging is probably the best imaging modality for the acquisition of a comprehensive view of the pericardial abnormalities. MR imaging combines cardiac and pericardial anatomic assessment with tissue characterization and appraisal of the effects of pericardial abnormalities on cardiac performance. This review aims to elucidate the role of the pericardium and its interaction with the remainder of the heart in normal and pathologic conditions. It focuses on the rapidly evolving insights regarding pericardial disease provided by modern imaging modalities, not infrequently necessitating reconsideration of evidence that has thus far been taken for granted.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121059/-/DC1.

Clinically suspected acute myopericarditis with cardiac tamponade associated with peripheral blood eosinophilia presenting in early pregnancy: a case report

Introduction

The clinical presentation of eosinophilic myocarditis may vary from asymptomatic to the manifestation of severe symptoms, including cardiac tamponade and arrhythmias. In pregnant patients with this condition, drugs must be used cautiously up to approximately the 4th month of pregnancy because drug use should be limited during the period of fetal organogenesis.

Case presentation

A 30-year-old Asian woman at 14 weeks of pregnancy with progressive malaise was hospitalized. The electrocardiogram revealed ST elevation and low QRS voltage. Echocardiography revealed massive pericardial effusion and myocardial swelling. A laboratory examination revealed an increase in her white blood cell count, with a predominance of neutrophils. Pericardial drainage was performed for relief of the cardiac tamponade. The pericardial effusion revealed an abundance of eosinophils. Subsequently, the peripheral blood eosinophil count began to rise, and the patient was clinically diagnosed with eosinophilic myopericarditis. The patient’s condition improved rapidly following the initiation of prednisolone treatment, and she finally delivered a full-term normal infant.

Conclusions

A patient with clinically suspected myopericarditis in the early stage of pregnancy who improved rapidly with pericardial drainage and prednisolone therapy, and successfully delivered a normal full-term infant; the diagnosis was made in the early stage of the disease, based on the detection of an abundance of eosinophils in the pericardial effusion preceding the subsequent development of peripheral blood eosinophilia.

[Clinical indications for the use of cardiac MRI. By the SIRM Study Group on Cardiac Imaging]

Cardiac magnetic resonance (CMR) is considered an useful method in the evaluation of many cardiac disorders. Based on our experience and available literature, we wrote a document as a guiding tool in the clinical use of CMR. Synthetically we describe different cardiac disorders and express for each one a classification, I to IV, depending on the significance of diagnostic information expected.

Left ventricular function in acute inflammatory peri-myocardial diseases - new insights and long-term follow-up

Background

Until recently acute inflammatory peri-myocardial syndromes have been associated with global rather regional left ventricular (LV) dysfunction. Recent advances in cardiac imaging with echocardiographic techniques and magnetic resonance imaging (MRI) permit comprehensive evaluation of global and regional LV function. Our study was aimed to assess regional LV function in 100 patients with acute perimyocarditis, and correlate these findings with the clinical presentation.

Methods

We report on 100 patients with acute perimyocarditis admitted during 2008–2011, in whom LV function was assessed by semi-quantitative wall motion score analysis on conventional echo. Long-term mortality and recurrent hospitalization were also assessed.

Results

Wall motion score in 100 patients with acute perimyocarditis demonstrated a significant predominance of regional wall motion abnormalities in the infero-postero-lateral LV wall. These data correspond well with speckle tracking results of a subgroup of these patients published earlier. Recent MRI data show frequent late enhancement of contrast in the infero-lateral region of the LV in patients with perimyocarditis. These observations were useful in re-classification of our patients into one of the following groups: pure or predominant pericarditis, and pure or predominant myocarditis. Over a mean period of 37 months, there was no mortality. Though recurrent hospitalizations were rather frequent, no significant differences were observed among groups.

Conclusions

Regional wall motion abnormalities in the infero-postero-lateral segments of the LV are frequent in patients with acute perimyocarditis. Detailed echocardiographic examination early in the course of the disease should become a major factor in the clinical differentiation among the various clinical presentations of acute inflammatory peri-myocardial syndromes. The long-term outcome of these patients appears to be benign, though recurrent hospitalizations are not infrequent.

[Myocarditis: magnetic resonance imaging diagnosis and follow-up]

Myocarditis, inflammation of the myocardium, is usually due to viral infection. Diagnostic confirmation in ordinary clinical practice is difficult because the findings on the clinical history, physical examination, electrocardiogram, and laboratory tests offer scant diagnostic accuracy, and the differential diagnosis is often done with acute myocardial infarction. Cardiac magnetic resonance imaging (CMR) has become the method of choice for the diagnosis of myocarditis. In this article, we describe the CMR findings at diagnosis and during the follow-up of patients with myocarditis, the differential diagnosis with other acute processes like myocardial infarction, and the prognostic factors studied with CMR.

Pericardial delayed hyperenhancement with CMR imaging in patients with constrictive pericarditis undergoing surgical pericardiectomy: a case series with histopathological correlation

OBJECTIVES

The purpose of this study was to examine the prevalence and histopathologic correlates of pericardial delayed hyperenhancement (DHE) seen with cardiac magnetic resonance imaging (CMR) among patients with constrictive pericarditis (CP) undergoing pericardiectomy.

BACKGROUND

Constrictive pericarditis patients studied by CMR will occasionally demonstrate pericardial DHE following gadolinium contrast administration.

METHODS

We identified 25 CP patients who underwent pericardiectomy following CMR-gadolinium study. We also assessed 10 control subjects with no evidence of pericardial disease referred for cardiac viability imaging. A novel 14-segment pericardial model was used to determine pericardial DHE score and thickness score. Histopathology of pericardial specimens was reviewed and evaluated semiquantitatively on a 4-point scale for the extent of calcification, fibrosis, inflammation, and neovascularization.

RESULTS

DHE was present in 12 (48%) CP patients (DHE+ group), and absent in 13 CP patients (DHE- group) and all control patients. The DHE+ group had greater fibroblastic proliferation and neovascularization, as well as more prominent chronic inflammation and granulation tissue. Fibroblastic proliferation and chronic inflammation correlated with DHE presence quantitated by DHE score (Spearman r = 0.578, p < 0.002, and r = 0.590, p < 0.002, respectively), but not with pericardial thickness. Segmental analysis demonstrated no significant difference in the percentage of patients with different pericardial segmental thickness; however, overall, in each segment, the DHE+ group tended to have greater pericardial thickness.

CONCLUSIONS

The presence of pericardial DHE on CMR is common in patients with CP, and its presence is associated with histological features of organizing pericarditis, which may be a target for future focused pharmacological interventions. Patients with CP without pericardial DHE had more pericardial fibrosis and calcification, as well as lesser degrees of pericardial thickening.

The role of cardiac magnetic resonance imaging in the assessment of non-ischemic cardiomyopathy

Cardiovascular magnetic resonance imaging (CMR) plays an increasing role in the assessment of patients with various cardiovascular disorders. Given its enhanced spatial resolution, improved tissue characterization, and lack of ionizing radiation, it has become the test of choice in the evaluation of patients with new-onset cardiomyopathy of unknown etiology. In this paper, we will review the role of CMR in the evaluation of patients with various types of non-ischemic cardiomyopathy.

The role of cardiac magnetic resonance in the evaluation of patients presenting with suspected or confirmed acute coronary syndrome

Cardiac magnetic resonance imaging (CMR) has an important emerging role in the evaluation and management of patients who present with symptoms concerning for acute coronary syndrome (ACS). This paper discusses the role of CMR in the emergency department setting, where CMR can aid in the early and accurate diagnosis of non-ST elevation ACS in low and intermediate risk patients. For those with confirmed myocardial infarction (MI), CMR provides comprehensive prognostic information and can readily diagnose structural complications related to MI. Furthermore, the pattern of late gadolinium enhancement (LGE) seen on CMR can help determine the etiology of cardiac injury in the subset of patients presenting with ACS who do not have obstructive coronary artery disease by angiography.

Diagnostic contributions of cardiac magnetic resonance imaging in patients presenting with elevated troponin, acute chest pain syndrome and unobstructed coronary arteries

AIMS

Myocardial infarction with unobstructed coronary artery disease represents a serious diagnostic challenge. The role of cardiac magnetic resonance in the management of cardiomyopathies is increasing. We examined the diagnostic contributions of cardiac magnetic resonance in patients presenting with acute chest pain syndrome, elevated serum cardiac troponin concentrations and no significant coronary artery stenoses.

METHODS

Over a 3-year period, 107 consecutive patients (mean age 43.5 years; 62% men) presented to our institution with acute onset of chest pain, elevated serum troponin concentration and unobstructed coronary arteries, and underwent 3-tesla cardiac magnetic resonance at a mean delay of 6.9 days. A diagnosis was made based on: wall motion abnormalities and pericardial effusion on cine mode; myocardial oedema on T2-weighted imaging; abnormalities on first-pass perfusion imaging; and late gadolinium enhancement on T1-weighted imaging.

RESULTS

Cardiac magnetic resonance was normal in 10.3% of patients and contributed a diagnosis in 89.7%, including myocarditis in 59.9%, stress cardiomyopathy (takotsubo syndrome) in 14% and myocardial infarction in 15.8%. Patients with normal cardiac magnetic resonance had a significantly lower mean peak troponin concentration (2.6ng/mL) than patients with diagnostic cardiac magnetic resonance (9.7ng/mL; P=0.01).

CONCLUSION

Cardiac magnetic resonance contributed a diagnosis in nearly 90% of patients presenting with acute chest pain, elevated serum troponin and unobstructed coronary arteries.

Utility of T2-weighted short-tau inversion recovery (STIR) sequences in cardiac MRI: an overview of clinical applications in ischaemic and non-ischaemic heart disease

T2-weighted short-tau inversion recovery (T2w-STIR) imaging is the best approach for oedema-weighted cardiac magnetic resonance imaging (MRI), as it suppresses the signal from flowing blood and from fat and enhances sensitivity to tissue fluid. The purpose of this pictorial review is to illustrate the clinical use and application of this technique in various ischaemic and non-ischaemic conditions. In ischaemic heart disease, T2w-STIR represents the technique of choice for detecting oedema in patients with acute myocardial infarction (MI), allowing discrimination of acute and chronic injuries. Myocardial haemorrhage may also be depicted as a region of signal abnormality characterised by a central hypointense core with a peripheral hyperintense rim, presumably reflecting the presence of intracellular methaemoglobin within the necrotic area. In the acute setting, elevated T2 relaxation times in association with regional contractile dysfunction but no signs of delayed enhancement may also signify a reversible ischaemic injury without necrosis. In acute myocarditis, the distribution pattern of T2w hyperintensity may be focal in approximately 30% of patients or diffuse in the remaining 70%, and myocardial oedema may be the only marker of disease. Tissue oedema may also be observed in various other conditions, such as primary cardiomyopathies (CMP), storage disease, pulmonary hypertension and cardiac transplant rejection. T2w-STIR represents an appealing and versatile technique that can be applied in a wide variety of ischaemic and non-ischaemic conditions, allowing detection of segmental or global increase of myocardial free water content, reflecting an acute myocardial injury.