Multiparametric Rest and Dobutamine Stress Magnetic Resonance in Assessment of Myocardial Viability.

BACKGROUND: MR feature-tracking (FT) is a novel technique that quantitatively calculates myocardial strain and can assess myocardial viability. PURPOSE: To evaluate the feasibility of FT at rest and with low-dose dobutamine (LDD), visual assessment of contractility with LDD and left ventricle (LV) end-diastolic wall thickness (EDWT) in the assessment of viability in ischemic cardiomyopathy (ICM) patients compared to delayed gadolinium enhancement (DGE). STUDY TYPE: Prospective. SUBJECTS: Thirty ICM patients and 30 healthy volunteers. FIELD STRENGTH/SEQUENCES: A 1.5 T with balanced steady-state free precession (bSSFP) cine and phase-sensitive inversion prepared segmented gradient echo sequences. ASSESSMENT: LDD (5 µg/kg/min and 10 µg/kg/min) was administered in the patient group. LV was divided into 16 segments and MR-FT was derived from bSSFP cine images using dedicated software. Viable segments were defined as those with a dobutamine-induced increase in resting MR-FT values >20%, a dobutamine-induced increase in systolic wall thickening ≥2 mm by visual assessment, ≤50% fibrosis on DGE, and resting EDWT ≥5.5 mm. STATISTICAL TESTS: One-way analysis of variance (ANOVA), two-sampled t-test, paired samples t-test, and receiver operating characteristic (ROC) curve analysis. A P value < 0.05 was considered statistically significant. RESULTS: Resting peak global circumferential (Ecc) and radial (Err) strains were significantly impaired in patients compared to controls (-11.7 ± 7.9 vs. -20.1 ± 5.7 and 19.7 ± 13.9 vs. 32.7 ± 15.4, respectively). Segments with no DGE (n = 354) and ≤ 50% (n = 38) DGE showed significant improvement of both Ecc and Err with LDD while segments with >50% DGE (n = 88) showed no improvement. In comparison to viable and nonviable segments identified by reference-standard DGE, the sensitivity, specificity, and diagnostic accuracy of the four methods were: 74%, 92%, and 89%, respectively, for Ecc; 70%, 89%, and 86%, respectively, for Err; 67%, 88%, and 84% for visual assessment; and 39%, 90%, and 80% for EDWT. DATA CONCLUSION: Quantitative assessment of MR-FT, along with EDWT and qualitative visual assessment of myocardial contractility with LDD, are feasible alternative methods for the assessment of myocardial viability with moderate sensitivity and high specificity. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage: 2.

Reproducibility and accuracy of late gadolinium enhancement cardiac magnetic resonance measurements for the detection of left atrial fibrosis in patients undergoing atrial fibrillation ablation procedures.

AIMS: Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) may define left atrial (LA) anatomy and structural remodelling, and facilitate atrial fibrillation (AF) ablation. We aimed to assess the intra- and inter-observer reproducibility and agreement of LGE-CMR parameters with direct application to AF ablation techniques. METHODS AND RESULTS: One experienced and one non-experienced observer performed complete LGE-CMR data analysis twice, on different days, in 40 randomly selected LGE-CMR examinations [20 performed before ablation (pre-ablation) and 20 performed 3 months after ablation (post-ablation)]. Four additional observers (two experienced and two non-experienced) performed complete LGE-CMR data analysis in a subgroup of 30 patients (15 pre-ablation and 15 post-ablation). All LGE-CMR were performed in sinus rhythm. Intra- and inter-observer reproducibility of LA volume, LA area, and sphericity index (SI) was high: coefficient of variation <10% and intraclass correlation coefficient >0.71. Geometric congruency of repeated reconstruction of LA shape was high: maximal error <5 mm for intra-observer and <8 mm for inter-observer. The precision of scar location increased with extent of scar, and was high (Dice coefficient >0.75) when the scar area was >5 cm2 for a single observer and >15 cm2 for multiple observers. Non-experienced observers performed equally well to experienced observers. CONCLUSION: Late gadolinium enhancement cardiac magnetic resonance measurements of LA area, volume, and SI were reproducible, and geometric congruency of LA shape was high. Location of scar was precise for scar areas >5 cm2 for single observers and >15 cm2 for multiple observers, regardless of the observers' experience. These results may serve as a reference for future studies on the role for substrate-based AF ablation procedures.

Right Heart Involvement in Patients with Sarcoidosis.

The left ventricle (LV) is affected in 20-25% of patients with sarcoidosis and its involvement is associated with morbidity and mortality. However, effects of sarcoidosis on the right ventricle (RV) are not well documented. Our aims were to investigate the prevalence of RV dysfunction in patients with sarcoidosis and determine whether it is predominantly associated with direct cardiac involvement, severity of lung disease, or pulmonary hypertension (PH). We identified 50 patients with biopsy-proven extra-cardiac sarcoidosis and preserved LV function, who underwent echocardiography, pulmonary function (PF) testing, and cardiovascular magnetic resonance. RV function was quantified by free wall longitudinal strain. Tricuspid valve Doppler and estimated right atrial pressure were used to estimate systolic pulmonary artery pressure. Myocardial late gadolinium enhancement was considered diagnostic for cardiac sarcoidosis and assumed to involve both ventricles. Of the 50 patients, 28 (56%) had RV dysfunction, 4 with poorly defined PF status. Of the remaining 24 patients, 16 (67%) had lung disease, 8 (33%) had PH, and 10 (42%) had LV involvement. Ten patients had greater than one of these findings, and 4 had all 3. In contrast, in 4/24 patients (17%), RV dysfunction could not be explained by these mechanisms, despite severely reduced RV strain. In conclusion, RV dysfunction is common in patients with sarcoidosis and is usually associated with either direct LV involvement, lung disease, or PH, but may occur in the absence of these mechanisms, suggesting the possibility of isolated RV involvement and underscoring the need for imaging protocols that would include RV strain analysis.

Potentially simple score of late gadolinium enhancement cardiac MR in acute myocarditis outcome.

PURPOSE: To determine the value of cardiac MRI for the monitoring and the prognosis of patients with acute myocarditis. Cardiac MRI plays an increasingly important role in the diagnosis of acute myocarditis. However, it is less established as a prognostic tool, which requires specific postprocessing of images. MATERIALS AND METHODS: In a prospective pilot study, we assessed the prognostic value of the evolution in a simplified visual quantitative score (SQS) of late gadolinium enhancement (LGE) between initial hospitalization and 3 months later. The prognostic value was assessed at 1 year using a combination of death, heart transplant, and confirmed recurrence as main outcome. RESULTS: Twenty-eight patients were included in this study. A significant correlation was found between LGE measured by SQS and planimetry (r = 0.95, P < 0.001). Intraobserver and interobserver reproducibilities were good for SQS (ICC = 0.95 [95% CI: 0.86 to 0.98], and 0.94 [95% CI: 0.84 to 0.98], respectively). At initial hospitalization, patient characteristics between the two groups were similar. Patients with stable or increased SQS suffered more frequently from clinical outcome events than patients with a decrease in SQS (P = 0.02). CONCLUSION: Monitoring of the evolution of LGE using a simple visual score is of interest to identify patients at risk of pejorative prognosis after acute myocarditis.

Coexistence of acute poststreptococcal glomerulonephritis and acute rheumatic fever in a Japanese girl with primary Sjögren's syndrome.

Although acute poststreptococcal glomerulonephritis (APSGN) and acute rheumatic fever (ARF) are well-known complications of group A streptococcus infection, concomitant occurrence of both diseases is rare. We report an 11-year-old Japanese girl with primary Sjögren's syndrome complicated by acute renal failure about 2 weeks after the onset of pharyngitis. Although histopathological findings of the kidney were not confirmative, APSGN was suggested by the spontaneous recovery of her renal function, typical latent period with high levels of antistreptolysin O and low serum levels of C3 but not of C4. In addition, cardiac hypomotility and regurgitation of the 4 valves progressed in the convalescent phase of APSGN, which was accompanied by elevation of serum C-reactive protein and plasma brain natriuretic peptide (BNP) levels. Myocarditis was suggested by delayed gadolinium-enhancement of cardiac walls on cardiac magnetic resonance imaging. She was diagnosed with APSGN and ARF and was treated with a combination of short course prednisolone and prophylactic penicillin G. There is no relapse of renal or cardiac symptoms during 6 years follow-up. Unexpected elevation of plasma BNP in a convalescent stage of APSGN suggests the development of ARF. Underlying Sjögren's syndrome (SS) may modify the histopathological findings and make it difficult to differentiate APSGN from CTD-associated nephritis such as lupus nephritis (LN) even by renal biopsy.

Proximal culprit lesion and coronary artery occlusion independently predict the risk of microvascular obstruction in acute myocardial infarction.

Microvascular obstruction (MO) and coronary flow have been independently described to have a high prognostic impact after acute myocardial infarction (AMI). Their interdependence has not been precisely elucidated, so far. Aim of this study was to investigate the impact of coronary flow on the occurrence of MO in patients with AMI. 336 patients with revascularized AMI were examined by cardiac magnetic resonance imaging. Patients were categorised into two groups based on the presence of MO. Procedural characteristics and marker of infarct size were analyzed. MO was present in 110 (33 %) and absent in 226 (67 %) patients. Both groups differed significantly regarding pre- and post-interventional thrombolysis in myocardial infarction (TIMI) flow. After multivariable regression analysis pre-interventional TIMI-flow 0, proximal culprit lesion, post-interventional TIMI-flow

Magnetic Resonance Imaging of Non-ischemic Cardiomyopathies: A Pictorial Essay.

Non-ischemic cardiomyopathies are defined as either primary or secondary diseases of the myocardium resulting in cardiac dysfunction. While primary cardiomyopathies are confined to the heart and can be genetic or acquired, secondary cardiomyopathies show involvement of the heart as a manifestation of an underlying systemic disease including metabolic, inflammatory, granulomatous, infectious, or autoimmune entities. Non-ischemic cardiomyopathies are currently classified as hypertrophic, dilated, restrictive, or unclassifiable, including left ventricular non-compaction. Cardiovascular Magnetic Resonance Imaging (CMRI) not only has the capability to assess cardiac morphology and function, but also the ability to detect edema, hemorrhage, fibrosis, and intramyocardial deposits, providing a valuable imaging tool in the characterization of non-ischemic cardiomyopathies. This pictorial essay shows some of the most important non-ischemic cardiomyopathies with an emphasis on magnetic resonance imaging features.

Assessment of Ischemic Cardiomyopathy Using Cardiovascular Magnetic Resonance Imaging: A Pictorial Review.

Ischemic heart disease is the leading cause of death worldwide. In the last two decades, cardiovascular magnetic resonance imaging (CMRI) has emerged as the primary imaging tool in the detection and prognostic assessment of ischemic heart disease. In a single study, CMRI allows evaluation of not only myocardial wall perfusion, but also the presence, acuity, and extent of myocardial ischemia and infarction complications. Also, rest and stress perfusion imaging can accurately depict inducible ischemia secondary to significant coronary artery stenosis. We present a pictorial review of the assessment of ischemic cardiomyopathy with an emphasis on CMRI features.

Cardiac imaging and stress testing asymptomatic athletes to identify those at risk of sudden cardiac death.

Sudden cardiac death in young athletes is rare but tragic. The cardiology community is faced with the challenge of providing a sensible strategy for the prevention of SCD while simultaneously reaffirming that the benefits of regular exercise far outweigh potential risks. At present, there is a broad range of screening recommendations dependent upon country, sporting discipline, and competition level. While much recent debate has focused on the efficacy of screening with electrocardiography, a number of sporting bodies also mandate the inclusion of exercise testing and echocardiography in screening protocols. Cardiac magnetic resonance imaging, coronary calcium scoring and computed tomography coronary angiography have also been promoted as potentially valuable screening tools for competitive athletes. This review will examine the controversial topic of utilizing cardiac imaging for athlete pre-participation screening. Specifically, the limitations of screening for relatively rare disorders using imaging tools with uncertain or imperfect accuracy will be addressed. Current evidence suggests that the accuracy of all cardiac imaging modalities is insufficient to justify their use as primary screening modalities in athletes. Atypical findings such as marked cardiac dilation, reduced deformation, or small patches of delayed gadolinium enhancement may be commonly encountered in well-trained athletes, but, at present, the prognostic significance of such findings is unknown. Resulting uncertainty for the clinician and athlete has the potential for psychological stress, further testing, and unnecessary exclusions from competition. However, these concerns must not be confused with the extremely useful applications of cardiac imaging for the assessment of athletes with symptoms, an abnormal electrocardiogram or a positive family history. As modern imaging further enhances our understanding of the spectrum of athlete's heart, its role may expand from the assessment of athletes with suspected disease to being part of comprehensive pre-participation screening in apparently healthy athletes.