Population-based study of multisystem inflammatory syndrome associated with COVID-19 found that 36% of children had persistent symptoms.

AIM: Our aim was to describe the outcomes of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. METHODS: This national, population-based, longitudinal, multicentre study used Swedish data that were prospectively collected between 1 December 2020 and 31 May 2021. All patients met the World Health Organization criteria for MIS-C. The outcomes 2 and 8 weeks after diagnosis are presented, and follow-up protocols are suggested. RESULTS: We identified 152 cases, and 133 (87%) participated. When followed up 2 weeks after MIS-C was diagnosed, 43% of the 119 patients had abnormal results, including complete blood cell counts, platelet counts, albumin levels, electrocardiograms and echocardiograms. After 8 weeks, 36% of 89 had an abnormal patient history, but clinical findings were uncommon. Echocardiogram results were abnormal in 5% of 67, and the most common complaint was fatigue. Older children and those who received intensive care were more likely to report symptoms and have abnormal cardiac results. CONCLUSION: More than a third (36%) of the patients had persistent symptoms 8 weeks after MIS-C, and 5% had abnormal echocardiograms. Older age and higher levels of initial care appeared to be risk factors. Structured follow-up visits are important after MIS-C.

Delayed, Unprovoked, Hemodynamic Collapse with Following Asystole in a Pediatric Patient Following a High-Voltage Injury: A Case Report and Literature Review.

Electrical incidents are common and mostly uneventful, though can be severe and sometimes lethal. Aside from skin, muscle and soft tissue damage, electrical injuries can cause cardiac arrhythmias, the most common cardiac complication. The case of a 14-year-old girl who sustained 48.5% TBSA burns following a high-voltage electrical injury is described. She suffered five episodes of asystole 78 h following the injury, requiring extracorporeal membrane oxygenation. The cause of the delayed asystole was investigated and a PubMed literature search was conducted to explore late presenting cardiac sequelae following electrical injuries. This yielded fifteen studies, identified as relevant, of high quality and in the English language. These studies included a total of 1411 patients of whom only 3 were found to have had late potentially lethal arrhythmias, all manifesting within the first 24 h after the injury. Of these patients, 32 suffered cardiac arrests shortly after the electrical injury, 11 of which were documented as asystolic arrests though these were all from a single study with the rural locale and prolonged delay in arrival to the hospital setting contributing to this finding. To our knowledge, this is the only pediatric cardiac arrest developing in a stable patient over 72 h following the initial electrical injury. No other patient has suffered any significant cardiac complications first presenting outside the initial 24-h period following the electrical injury. Guidelines and recommendations on post electrical injury observation of patient vary and further research into this field is required to allow for guidance unification.

Current T1 and T2 mapping techniques applied with simple thresholds cannot discriminate acute from chronic myocadial infarction on an individual patient basis: a pilot study.

BACKGROUND: Studying T1- and T2-mapping for discrimination of acute from chronic myocardial infarction (AMI, CMI). METHODS: Eight patients with AMI underwent CMR at 3 T acutely and after >3 months. Imaging techniques included: T2-weighted imaging, late enhancement (LGE), T2-mapping, native and post-contrast T1-mapping. Myocardial T2- and T1-relaxation times were determined for every voxel. Abnormal voxels as defined by having T2- and T1-values beyond a predefined threshold (T2 > 50 ms, native T1 > 1250 ms and post-contrast T1 < 350 ms) were highlighted and compared with LGE as the reference. RESULTS: Abnormal T2-relaxation times were present in the voxels with AMI (=> delete acute infarction; unfortunately this is not possible in your web interface) acute infarction only in half of the subjects. Abnormal T2-values were also present in subjects with CMI, thereby matching the chronically infarcted territory in some. Abnormal native T1 times were present in voxels with AMI in 5/8 subjects, but also remote from the infarcted territory in four. In CMI, abnormal native T1 values corresponded with infarcted voxels, but were also abnormal remote from the infarcted territory. Voxels with abnormal post-contrast T1-relaxation times agreed well with LGE in AMI and CMI. CONCLUSIONS: In this pilot-study, T2- and T1-mapping with simple thresholds did not facilitate the discrimination of AMI and CMI.

Prospective, randomized comparison of gadopentetate and gadobutrol to assess chronic myocardial infarction applying cardiovascular magnetic resonance.

BACKGROUND: We hypothesized that the contrast medium gadobutrol is not inferior compared to Gd-DTPA in identifying and quantifying ischemic late gadolinium enhancement (LGE), even by using a lower dose. METHODS: We prospectively enrolled 30 patients with chronic myocardial infarction as visualized by LGE during clinical routine scan at 1.5 T with 0.20 mmol/kg Gd-DTPA. Participants were randomized to either 0.15 mmol/kg gadobutrol (group A) or 0.10 mmol/kg gadobutrol (group B). CMR protocol was identical in both exams. LGE was quantified using a semiautomatic approach. Signal intensities of scar, remote myocardium, blood and air were measured. Signal to noise (SNR) and contrast to noise ratios (CNR) were calculated. RESULTS: Signal intensities were not different between Gd-DTPA and gadobutrol in group A, whereas significant differences were detected in group B. SNR of injured myocardium (53.5+/-21.4 vs. 30.1+/-10.4, p = 0.0001) and CNR between injured and remote myocardium (50.3+/-20.3 vs. 27.3+/-9.3, p < 0.0001) were lower in gadobutrol. Infarct size was lower in both gadobutrol groups compared to Gd-DTPA (group A: 16.8+/-10.2 g vs. 12.8+/-6.8 g, p = 0.03; group B: 18.6+/-12.0 g vs. 14.0+/-9.9 g, p = 0.0016). CONCLUSIONS: Taking application of 0.2 mmol/kg Gd-DTPA as the reference, the delineation of infarct scar was similar with 0.15 mmol/kg gadobutrol, whereas the use 0.10 mmol/kg gadobutrol led to reduced tissue contrast. TRIAL REGISTRATION: The study had been registered under EudraCT Number: 2010-020775-22. Registration date: 2010.08.10.

Assessment of nonischemic fibrosis in hypertrophic cardiomyopathy: comparison of gadopentetate dimeglumine and gadobenate dimeglumine for enhanced cardiovascular magnetic resonance imaging.

PURPOSE: To compare whether the higher relaxivity contrast agent gadobenate is superior for the identification of nonischemic late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) compared to standard relaxivity agents such as gadopentetate. MATERIALS AND METHODS: Fifteen patients with HCM and positive LGE based on routine cardiac magnetic resonance (CMR) with 0.2 mmol/kg gadopentetate were enrolled. Each patient thereafter underwent a second enhanced CMR exam with 0.2 mmol/kg gadobenate using the same CMR protocol. LGE was assessed in a short axis stack acquired after contrast administration using an inversion recovery gradient echo sequence. Two independent blinded readers quantified LGE by manual planimetry. The signal intensities of injured myocardium, remote myocardium, left ventricular cavity, and air were measured in identical locations using anatomical landmarks and dedicated software. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. RESULTS: No adverse events related to contrast administration occurred. Gadobenate dimeglumine showed a higher SNR of injured myocardium (45.4 ± 24.0 vs. 31.1 ± 16.6, P = 0.002) and a higher CNR between remote and injured myocardium (37.6 ± 25.0 vs. 26.5 ± 17.6, P = 0.006) compared to gadopentetate dimeglumine. The amount of LGE (based on the same postprocessing criteria and definitions) was higher with gadobenate dimeglumine (12.7 ± 8.5 g vs. 9.4 ± 5.6 g, P = 0.005). There was no difference in intra- and interobserver variability between gadopentetate dimeglumine and gadobenate dimeglumine. CONCLUSION: CMR with the high relaxivity contrast agent gadobenate dimeglumine reveals significantly more tissue with LGE in patients with HCM.

Contractures and hypertrophic cardiomyopathy in a novel FHL1 mutation.

We investigated a large German family (n = 37) with male members who had contractures, rigid spine syndrome, and hypertrophic cardiomyopathy. Muscle weakness or atrophy was not prominent in affected individuals. Muscle biopsy disclosed a myopathic pattern with cytoplasmic bodies. We used microsatellite markers and found linkage to a locus at Xq26-28, a region harboring the FHL1 gene. We sequenced FHL1 and identified a new missense mutation within the third LIM domain that replaces a highly conserved cysteine by an arginine (c.625T>C; p.C209R). Our finding expands the phenotypic spectrum of the recently identified FHL1-associated myopathies and widens the differential diagnosis of Emery-Dreifuss-like syndromes.

Assessment of mitral bioprostheses using cardiovascular magnetic resonance.

BACKGROUND: The orifice area of mitral bioprostheses provides important information regarding their hemodynamic performance. It is usually calculated by transthoracic echocardiography (TTE), however, accurate and reproducible determination may be challenging. Cardiovascular magnetic resonance (CMR) has been proven as an accurate alternative for assessing aortic bioprostheses. However, whether CMR can be similarly applied for bioprostheses in the mitral position, particularly in the presence of frequently coincident arrhythmias, is unclear. The aim of the study is to test the feasibility of CMR to evaluate the orifice area of mitral bioprostheses. METHODS: CMR planimetry was performed in 18 consecutive patients with mitral bioprostheses (n = 13 Hancock(R), n = 4 Labcore(R), n = 1 Perimount(R); mean time since implantation 4.5 +/- 3.9 years) in an imaging plane perpendicular to the transprosthetic flow using steady-state free-precession cine imaging under breath-hold conditions on a 1.5T MR system. CMR results were compared with pressure half-time derived orifice areas obtained by TTE. RESULTS: Six subjects were in sinus rhythm, 11 in atrial fibrillation, and 1 exhibited frequent ventricular extrasystoles. CMR image quality was rated as good in 10, moderate in 6, and significantly impaired in 2 subjects. In one prosthetic type (Perimount(R)), strong stent artifacts occurred. Orifice areas by CMR (mean 2.1 +/- 0.3 cm2) and TTE (mean 2.1 +/- 0.3 cm2) correlated significantly (r = 0.94; p < 0.001). Bland-Altman analysis showed a 95% confidence interval from -0.16 to 0.28 cm2 (mean difference 0.06 +/- 0.11 cm2; range -0.1 to 0.3 cm2). Intra- and inter-observer variabilities of CMR planimetry were 4.5 +/- 2.9% and 7.9 +/- 5.2%. CONCLUSIONS: The assessment of mitral bioprostheses using CMR is feasible even in those with arrhythmias, providing orifice areas with close agreement to echocardiography and low observer dependency. Larger samples with a greater variety of prosthetic types and more cases of prosthetic dysfunction are required to confirm these preliminary results.

Aortic dilatation in patients with prosthetic aortic valve: comparison of MRI and echocardiography.

BACKGROUND AND AIM OF THE STUDY: Patients with prosthetic aortic valve have an increased risk for aortic dissection, which rises further with growing aortic diameters. Thus, accurate aortic monitoring is required. As transthoracic echocardiography (TTE), the current clinical standard, is frequently restricted to the proximal ascending aorta, the use of two-dimensional cardiovascular magnetic resonance (2D-CMR) in transverse orientation was investigated as a screening tool to assess ascending aortic dimensions. METHODS: Fast, non-contrast-enhanced, non-breath-hold, steady-state free-precession (SSFP) sequences (1.5 Tesla, slice thickness 7 mm, gap 1.8 mm, scan time 10-15 s) were applied to image the thorax in transverse planes. To test the accuracy of aortic dimensions obtained in this way, comparison was made to contrast-enhanced three-dimensional MR angiography (3D-MRA) as the 'gold standard' in 30 patients with aortic or aortic valve disease. After validation, transverse 2D-CMR was used to assess ascending aortic dimensions in 65 patients with aortic bioprostheses, and the results were compared to those acquired with TTE. RESULTS: Data acquired with both 2D-CMR and 3D-MRA agreed well when assessing ascending aortic diameters (r = 0.99; p < 0.001; mean difference 0.1 +/- 0.1 cm). In patients with bioprostheses, the image quality was diagnostic in 100% of cases for 2D-CMR, and in 93.4% for TTE. The ascending aortic diameter by 2D-CMR (mean 3.8 +/- 0.5 cm; range: 2.6-5.0 cm) was larger (p < 0.001) than by TTE (3.3 +/- 0.6 cm; range: 2.3-4.9 cm). Aortic dilatation (diameter, indexed by body surface area, > 2.1 cm/m2) was present in 38.5% of 2D-CMR cases and in 11.5% of TTE cases. The intra- and inter-observer variabilities to assess aortic dimensions by 2D-CMR were 2.1 +/- 1.9% and 4.3 +/- 3.7%, respectively. CONCLUSION: Imaging of the complete thorax in transverse orientation using fast, non-contrast-enhanced SSFP images provided an accurate and reliable approach to screen for aortic dilatation. In patients with aortic bioprostheses, 2D-CMR revealed a high prevalence of aortic dilatation, which was considerably underestimated by TTE.

An open-source software tool for the generation of relaxation time maps in magnetic resonance imaging.

BACKGROUND: In magnetic resonance (MR) imaging, T1, T2 and T2* relaxation times represent characteristic tissue properties that can be quantified with the help of specific imaging strategies. While there are basic software tools for specific pulse sequences, until now there is no universal software program available to automate pixel-wise mapping of relaxation times from various types of images or MR systems. Such a software program would allow researchers to test and compare new imaging strategies and thus would significantly facilitate research in the area of quantitative tissue characterization. RESULTS: After defining requirements for a universal MR mapping tool, a software program named MRmap was created using a high-level graphics language. Additional features include a manual registration tool for source images with motion artifacts and a tabular DICOM viewer to examine pulse sequence parameters. MRmap was successfully tested on three different computer platforms with image data from three different MR system manufacturers and five different sorts of pulse sequences: multi-image inversion recovery T1; Look-Locker/TOMROP T1; modified Look-Locker (MOLLI) T1; single-echo T2/T2*; and multi-echo T2/T2*. Computing times varied between 2 and 113 seconds. Estimates of relaxation times compared favorably to those obtained from non-automated curve fitting. Completed maps were exported in DICOM format and could be read in standard software packages used for analysis of clinical and research MR data. CONCLUSIONS: MRmap is a flexible cross-platform research tool that enables accurate mapping of relaxation times from various pulse sequences. The software allows researchers to optimize quantitative MR strategies in a manufacturer-independent fashion. The program and its source code were made available as open-source software on the internet.

Heritability of left ventricular and papillary muscle heart size: a twin study with cardiac magnetic resonance imaging.

AIMS: Earlier studies in monozygotic (MZ) and dizygotic (DZ) twins showed genetic variance on echocardiographically determined heart size. However, cardiovascular magnetic resonance (CMR) is more precise and reproducible. We performed a twin study relying on CMR, focusing on left ventricular (LV) mass and papillary muscle, since there are no genetic reports on this structure. METHODS AND RESULTS: We measured left heart dimensions of 25 healthy twin pairs with a 1.5T MR scanner, analysed with the mass, Medis Software. We performed heritability analysis and tests for genetic influences shared between cardiac structures. We found that CMR-based heritability estimates (h(2) = 84%) substantially exceeded estimates based on echocardiography. We also found significant genetic influence on papillary muscle mass (h(2) = 82%). Bivariate analysis of papillary and LV muscle mass revealed significant genetic influences shared by both phenotypes (genetic correlation 0.59) and suggested an additional genetic component specific to papillary muscle. We observed correlations between body mass index, surface area, and systolic blood pressure with cardiac dimensions, even in this small study. Environmental influences were relevant as well, indicating reciprocal influences on papillary vs. LV muscle mass. CONCLUSION: Cardiovascular magnetic resonance, even with few subjects, allows a genetic assessment of cardiac structures that cannot be attained with echocardiography. Hitherto fore unappreciated relationships can be uncovered by this method.

Gender-specific differences in left ventricular remodelling and fibrosis in hypertrophic cardiomyopathy: insights from cardiovascular magnetic resonance.

BACKGROUND: Gender is an independent risk factor for heart failure mortality in hypertrophic cardiomyopathy (HCM). AIMS: To explore the interaction between gender, myocardial fibrosis and remodelling in HCM. METHODS: We studied 64 HCM patients (28 females, aged 51+/-16 years) categorized as non-obstructive (HNCM, n=31) or obstructive (HOCM, n=33) and 60 healthy subjects (31 females, aged 43+/-14 years). Cine imaging was performed to assess left ventricular volumes and mass. LV remodelling index (LVRI) was calculated. Extension of late gadolinium enhancement (LGE) was quantified. RESULTS: Females in the control group and in the HNCM group had a lower LVRI than males (control: 0.7+/-0.1 vs. 0.9+/-0.2 g/ml, p<0.002; HNCM: 1.1+/-0.2 vs. 1.5+/-0.5 g/ml, p<0.001). In contrast, HOCM females had a similar LVRI compared to males (1.8+/-0.5 vs. 1.7+/-0.4 g/ml, p=ns). Thus the increase in LVRI was more pronounced in females compared to males. LGE was noted in 70% of the patients. No relation was found between the presence or the quantity of myocardial fibrosis and gender in any of the patient subgroups. CONCLUSION: Our data suggest a disproportionate degree of remodelling in different forms of HCM depending on gender. Gender does not appear to influence the quantity of fibrosis as defined by LGE.

Relation between myocardial edema and myocardial mass during the acute and convalescent phase of myocarditis--a CMR study.

BACKGROUND: Myocardial edema is a substantial feature of the inflammatory response in human myocarditis. The relation between myocardial edema and myocardial mass in the course of healing myocarditis has not been systematically investigated. We hypothesised that the resolution of myocardial edema as visualised by T2-weighted cardiovascular magnetic resonance (CMR) is associated with a decrease of myocardial mass in steady state free precession (SSFP)-cine imaging. METHODS: 21 patients with acute myocarditis underwent CMR shortly after onset of symptoms and 1 year later. For visualization of edema, a T2-weighted breath-hold black-blood triple-inversion fast spin echo technique was applied and the ratio of signal intensity of myocardium/skeletal muscle was assessed. Left ventricular (LV) mass, volumes and function were quantified from biplane cine steady state free precession images. 11 healthy volunteers served as a control group for interstudy reproducibility of LV mass. RESULTS: In patients with myocarditis, a significant decrease in LV mass was observed during follow-up compared to the acute phase (156.7 +/- 30.6 g vs. 140.3 +/- 28.3 g, p < 0.0001). The reduction of LV mass paralleled the normalization of initially increased myocardial signal intensity on T2-weighted images (2.4 +/- 0.4 vs. 1.68 +/- 0.3, p < 0.0001). In controls, the interstudy difference of LV mass was lower than in patients (5.1 +/- 2.9 g vs. 16.3 +/- 14.2 g, p = 0.02) resulting in a lower coefficient of variability (2.1 vs 8.9%, p = 0.04). CONCLUSION: Reversible abnormalities in T2-weighted CMR are paralleled by a transient increase in left ventricular mass during the course of myocarditis. Myocardial edema may be a common pathway explaining these findings.

Detection and Monitoring of Acute Myocarditis Applying Quantitative Cardiovascular Magnetic Resonance.

BACKGROUND: Cardiovascular magnetic resonance based on the Lake Louise Criteria is used to make the diagnosis of acute myocarditis. Novel quantitative parametric mapping techniques promise to overcome some of its limitations. We aimed to evaluate quantitative cardiovascular magnetic resonance to detect and monitor acute myocarditis. METHODS AND RESULTS: Eighteen patients with clinical diagnosis of acute myocarditis (25 years [23-38 years]; 78% males) were prospectively enrolled and repeatedly underwent cardiovascular magnetic resonance at 1.5 T seven days (5-10 days) after symptom onset (FU0), after 5 weeks (FU1), and after 6 months (FU2). Eighteen age- and sex-matched healthy subjects served as controls. Cardiovascular magnetic resonance included imaging of edema, hyperemia, necrosis, and fibrosis using semiquantitative T2-weighted spin echo, T2 mapping, and T1 mapping before and 3 and 10 minutes after gadobutrol administration. Extracellular volume for diffuse and late gadolinium enhancement for focal fibrosis were assessed. Compared with controls, patients had significantly higher global T2 times at FU0 (55.1 ms [53.3-57.2 ms] versus 50.2 ms [49.2-52.0 ms]; P<0.001) and at FU1 (52.0 ms [52.0-53.2 ms]; P=0.007), which normalized at FU2 (50.9 ms [49.6-53.3 ms]; P=0.323). Global native T1 times in patients were elevated acutely (1004 ms [988-1048 ms] versus 975 ms [957-1004 ms]; P=0.002) and remained elevated throughout the follow-up (FU1: 998 ms [990-1027 ms]; P=0.014; FU2: 1000 ms [972-1027 ms]; P=0.044). Global extracellular volume fraction was statistically not different between patients and controls (P=0.057). 77.8% (14/18) of patients had focal late gadolinium enhancement. T2 ratio was significantly elevated in patients with myocarditis at FU0 (2.2 [2.0-2.3] versus 1.6 [1.5-1.7]; P<0.001). The difference decreased during follow-up (FU1: 1.9 [1.7-1.9]; P=0.001 and FU2: 1.7 [1.7-1.8]; P=0.053). The diagnostic accuracy to discriminate between patients with acute myocarditis and healthy controls was 86% for T2>52 ms, 78% for native T1>981 ms, 74% for extracellular volume fraction >0.24, and 100% for T2 ratio >1.9. CONCLUSIONS: Although both T2 and T1 mapping reliably detected acute myocarditis, only T2 mapping discriminated between acute and healed stages, underlining the incremental value of T2 mapping.

Influence of acute and chronic myocardial loading conditions, function, structural changes and extracardiac factors on NT-proBNP in asymptomatic patients with preserved ejection fraction.

BACKGROUND: We compared the effect of different loading conditions, parameters of structural heart disease and extracardiac confounders on NT-proBNP to validate the application of NT-proBNP for a characterisation of loading conditions and clinical course of patients with chronic heart diseases. METHODS: NT-proBNP was measured in 15 controls and 34 patients with preserved ejection fraction and chronic pressure (by aortic stenosis) or volume overload (by aortic or mitral regurgitation) before and after physical as well as dobutamine stress. Myocardial fibrosis was evaluated by contrast-enhanced cardiovascular magnetic resonance. RESULTS: In patients with elevated NT-proBNP due to chronic pressure or volume overloaded ventricles, physical and dobutamine stress were associated with only marginal nonsignificant additional NT-proBNP responses. Univariate analyses showed that myocardial fibrosis has the greatest effect on NT-proBNP (P < 0.01). Forward regression analyses revealed left ventricular filling, systolic function, the presence of valvular heart disease, serum creatinine and responses to dobutamine stress as independent determinants of NT-proBNP (P < 0.05 each). CONCLUSION: NT-proBNP cannot be used simply to characterise intensity of ventricular load. Character and duration of loading conditions, cardiac structure and function, as well as confounders should be considered when NT-proBNP is used for clinical follow-up assessment.

Noninvasive detection of fibrosis applying contrast-enhanced cardiac magnetic resonance in different forms of left ventricular hypertrophy relation to remodeling.

OBJECTIVES: We aimed to evaluate the incidence and patterns of late gadolinium enhancement (LGE) in different forms of left ventricular hypertrophy (LVH) and to determine their relation to severity of left ventricular (LV) remodeling. BACKGROUND: Left ventricular hypertrophy is an independent predictor of cardiac mortality. The relationship between LVH and myocardial fibrosis as defined by LGE cardiovascular magnetic resonance (CMR) is not well understood. METHODS: A total of 440 patients with aortic stenosis (AS), arterial hypertension (AH), or hypertrophic cardiomyopathy (HCM) fulfilling echo criteria of LVH underwent CMR with assessment of LV size, weight, function, and LGE. Patients with increased left ventricular mass index (LVMI) resulting in global LVH in CMR were included in the study. RESULTS: Criteria were fulfilled by 83 patients (56 men, age 57 +/- 14 years; AS, n = 21; AH, n = 26; HCM, n = 36). Late gadolinium enhancement was present in all forms of LVH (AS: 62%, AH: 50%; HCM: 72%, p = NS) and was correlated with LVMI (r = 0.237, p = 0.045). There was no significant relationship between morphological obstruction and LGE. The AS subjects with LGE showed higher LV end-diastolic volumes than those without (1.0 +/- 0.2 ml/cm vs. 0.8 +/- 0.2 ml/cm, p < 0.015). Typical patterns of LGE were observed in HCM but not in AS and AH. CONCLUSIONS: Fibrosis as detected by CMR is a frequent feature of LVH, regardless of its cause, and depends on the severity of LV remodeling. As LGE emerges as a useful tool for risk stratification also in nonischemic heart diseases, our findings have the potential to individualize treatment strategies.

Cardiac magnetic resonance monitors reversible and irreversible myocardial injury in myocarditis.

OBJECTIVES: We sought to assess the value of cardiac magnetic resonance (CMR) to monitor the spectrum of myocarditis-related injuries over the course of the disease. BACKGROUND: Myocarditis is associated with a wide range of myocardial tissue injuries, both reversible and irreversible. Differentiating these types of injuries is a clinical demand. METHODS: We studied 36 patients (31 males, age 33 +/- 14 years) hospitalized with myocarditis during the acute phase and 18 +/- 10 months thereafter. CMR was performed on 2 1.5T scanners and included the following techniques: steady-state free precession (to assess left ventricular function and volumes), T2-weighted (myocardial edema), early (global relative enhancement [gRE], reflecting increased capillary leakage) and late T1-weighted after gadolinium-DTPA injection (late gadolinium enhancement [LGE], reflecting irreversible injury). RESULTS: In the acute phase, T2 ratio was elevated in 86%, gRE in 80%, and LGE was present in 63%. At follow-up, ejection fraction increased from 56 +/- 8% to 62 +/- 7% (p < 0.0001) while both T2 ratio (2.4 +/- 0.5 to 1.9 +/- 0.2; p < 0.0001) and gRE (7.6 +/- 8 to 4.4 +/- 4; p = 0.018) significantly decreased. LGE persisted in all but 1 patient in whom LGE completely resolved. No patient had simultaneous elevation of T2 and gRE during the convalescent phase, resulting in a negative predictive value of 100% to differentiate the 2 phases of the disease. The acute phase T2 ratio correlated significantly with the change of end-diastolic volume over time (beta = 0.47; p = 0.008). This relation remained significant in a stepwise regression analysis model including T2 ratio, gRE, LGE extent, baseline ejection fraction, age, and creatine kinase, in which only T2 emerged as an independent predictor of the change in end-diastolic volume. CONCLUSIONS: A comprehensive CMR approach is a useful tool to monitor the reversible and irreversible myocardial tissue injuries over the course of myocarditis and to differentiate acute from healed myocarditis in patients with still-preserved ejection fraction.

Feasibility of cardiovascular magnetic resonance to assess the orifice area of aortic bioprostheses.

BACKGROUND: Prosthetic orifice area, usually calculated by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE), provides important information regarding the hemodynamic performance of aortic bioprostheses. However, both TTE and TEE have limitations; therefore accurate and reproducible determination of the orifice area often remains a challenge. The present study aimed to investigate the feasibility of cardiovascular magnetic resonance (CMR) to assess the orifice areas of aortic bioprostheses. METHODS AND RESULTS: CMR planimetry of the orifice area was performed in 65 patients (43/22 stented/stentless prostheses; mean time since implantation, 3.1+/-2.8 years; mean orifice area [TTE], 1.70+/-0.43 cm(2); 62 normally functioning prostheses, 2 severe stenoses, and 1 severe regurgitation) in an imaging plane perpendicular to the transprosthetic flow using steady-state free-precession cine imaging under breath-hold conditions on a 1.5-T MR system. CMR results were compared with TTE (continuity equation, n=65) and TEE (planimetry, n=31). CMR planimetry was readily feasible in 80.0%; feasible with limitation in 15.4% because of stent, flow, and sternal wire artifacts; and impossible in 4.6% because of flow artifacts. Correlations of the orifice areas by CMR with TTE (r=0.82) and CMR with TEE (r=0.92) were significant. The average difference between the methods was -0.02+/-0.24 cm(2) (TTE) and 0.05+/-0.15 cm(2) (TEE). Agreement was present for stented and stentless devices and independent of orifice size. Intraobserver and interobserver variabilities of CMR planimetry were 6.7+/-5.4% and 11.5+/-7.8%. CONCLUSIONS: The assessment of aortic bioprostheses with normal orifice areas by CMR is technically feasible and provides orifice areas with a close correlation to echocardiography and low observer dependency.

Delayed enhancement cardiac magnetic resonance imaging reveals typical patterns of myocardial injury in patients with various forms of non-ischemic heart disease.

BACKGROUND: Late gadolinium-hyperenhancement (LHE) on cardiac magnetic resonance imaging (CMR) has been linked to cardiovascular risk in ischemic and non-ischemic heart disease. We aimed to systematically categorize LHE-patterns in a variety of non-ischemic heart diseases (NIHD) and to explore their relationship with left ventricular (LV) function. METHODS: In a retrospective database search, 156 patients with NIHD who exhibited LHE on CMR were identified. All images were re-analyzed stepwise. LHE was correlated to LV functional parameters. Cardiac magnetic resonance (CMR) was conducted on 1.5 T scanners. RESULTS: Typically, LHE spared the subendocardium. Consistent LHE-patterns were observed in myocarditis, hypertrophic and dilated cardiomyopathy and systemic vasculitis. No conclusive LHE-patterns were observed in patients with aortic stenosis, arterial hypertension, lupus erythematosus, sarcoidosis, ventricular arrhythmia and in a mixed subgroup of rare NIHDs. There was no significant relationship between LHE and ejection fraction. There was no correlation between enddiastolic volume and LHE in either myocarditis (P = 0.13) or dilated cardiomyopathy (P = 0.62). LHE was unrelated to LV-mass in aortic stenosis (P = 0.13) and hypertrophic cardiomyopathy (P = 0.38). CONCLUSIONS: Distinct LHE patterns exist in various NIHDs and their visualization may ultimately aid diagnosis. Unlike in ischemic heart disease, the structure-function relationship does not appear to be strong.