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

Case 305: Loeffler Endocarditis

HISTORY

A 27-year-old man was admitted to the emergency department with fever and thoracic pain. In the previous 6 months, the patient lost a substantial amount of weight (12 kg). His family history was negative for cardiac disease. Electrocardiography revealed sinus rhythm and diffuse T-wave inversion. Two-dimensional echocardiography was performed and revealed normal left systolic function (ejection fraction, 60%). Laboratory tests showed elevated levels of high-sensitivity cardiac troponin (1.07 ng/mL; normal value, <0.015 ng/mL), high levels of C-reactive protein (16 mg/dL; normal range, 0-5 mg/dL), and leukocytosis with an eosinophilia level of 8710/μL (normal level, <400/μL). Parasitic and infectious diseases (Toxocara canis, strongyloides, filariasis, cysticercosis, fasciola, trichinella, echinococcosis) were excluded based on blood and fecal test results. Corticosteroid therapy was started, and the patient was dismissed. A few days later, he was readmitted to the emergency department with a headache and suddenly blurred vision. Neurologic and ophthalmologic findings were normal, and MRI of the brain was performed. Cardiac MRI was performed 2 days later and revealed the following quantitative results: (a) left ventricular end-diastolic volume (LVDV) of 165 mL (LVDV/body surface area [BSA], 89 mL/m²; normal range, 64-100 mL/m²), left ventricular end-systolic volume (LVSV) of 80 mL (LVSV/BSA, 43 mL/m²; normal range, 17-39 mL/m²), stroke volume (SV) of 85 mL (SV/BSA, 46 mL/m²; normal range, 43-67 mL/m²), and ejection fraction of 52% and (b) right ventricular end-diastolic volume (RVDV) of 163 mL (RVDV/BSA, 88 mL/m²; normal range, 63-111 mL/m²), right ventricular end-systolic volume (RVSV) of 81 mL (RVSV/BSA, 44 mL/m²; normal range, 32-92 mL/m²), stroke volume (SV) of 82 mL (SV/BSA, 44 mL/m²; normal range, 39-71 mL/m²), and ejection fraction of 50%.

Baicalin relieves hypoxia-aroused H9c2 cell apoptosis by activating Nrf2/HO-1-mediated HIF1α/BNIP3 pathway

Background: Myocardial ischemia is the main reason for ischemic heart disease. Baicalin is a plant-derived flavonoid with cardio-protective activity. Herein, we tested the influences of baicalin on cardiomyocytes H9c2 apoptosis aroused by hypoxia stimulation. Methods: Firstly, H9c2 cells were subjected to hypoxia and/or baicalin exposure. Cell viability and apoptosis, along with hypoxia-inducible factor 1α (HIF1α) and Bcl-2/adenovirus E1B 19-KDa interacting protein 3 (BNIP3) expressions were tested respectively. Then, si-HIF1α was transfected into H9c2 cells to probe whether up-regulation of HIF1α attended to the influences of baicalin on hypoxia-stimulated H9c2 cells. Finally, the regulatory effect of nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway on HIF1α expression was analyzed. Results: Hypoxia exposure aroused H9c2 cell viability reduction and apoptosis. Baicalin mitigated H9c2 cell viability reduction and apoptosis aroused by hypoxia. Moreover, HIF1α/BNIP3 pathway was further activated by baicalin in hypoxia-exposed H9c2 cells. Silencing HIF1α lowered the functions of baicalin on hypoxia-exposed H9c2 cells. Besides, baicalin enhanced hypoxia-caused activation of Nrf2/HO-1 pathway. Activation of Nrf2/HO-1 pathway was associated with the up-regulation of HIF1α and protective functions of baicalin on hypoxia-exposed H9c2 cells. Conclusion: Baicalin relieved cardiomyocytes H9c2 apoptosis aroused by hypoxia might be achieved through activating Nrf2/HO-1-mediated HIF1α/BNIP3 pathway. Highlights Baicalin mitigates H9c2 cell viability loss and apoptosis aroused by hypoxia; Baicalin activates HIF1a/BNIP3 pathway in hypoxia-exposed H9c2 cells; Silencing HIF1α weakens the influences of baicalin on hypoxia-exposed H9c2 cells; Baicalin promotes Nrf2/HO-1 pathway in hypoxia-exposed H9c2 cells; Promotion of Nrf2/HO-1 pathway is related to the up-regulation of HIF1α.

Utilization of Emergency and Hospitalization Care after Coronary Artery Bypass Surgery for Patients with Ischemic Heart Disease

This retrospective follow-up study explored the status of patients with myocardial infarction with regard to the likelihood of being readmitted to the hospital within 30 days after undergoing coronary artery bypass surgery (CABG) and their survival status within one year of the procedure.The rate of readmission within 30 days was 10.7% (167/1,575), primarily due to surgical wound infection (11.3% of readmission cases), ischemic heart disease (10.3%), and heart failure (8.7%). The readmission group consisted mainly of older males with a high comorbidity index. No significant differences existed between the two groups with regard to case distribution, hospital level, tenure of physicians, or teaching status of the hospitals. Most subsequent emergency department visits one month after surgery involved older male patients with a high comorbidity index. Compared to patients in the non-emergency group, those in the emergency group had longer hospital stays but lower mortality rates. Males constituted a higher proportion of survivors at one year post CABG, with age and comorbidity index being the primary variables affecting the risk of death.The National Health Insurance may adopt the policy of increasing payments for medical institutions that avoid readmission within 30 days post CABG in order to encourage better patient care and avoid the costs associated with readmission.

Overlapping Phenotypes and Degree of Ventricular Dilatation Are Associated with Severity of Systolic Impairment and Late Gadolinium Enhancement in Non-Ischemic Cardiomyopathies

Background

Dilatation and other infrastructural rearrangements of the left ventricle are connected with poor prognosis. The aim of our study was to analyze the overlapping phenotypes and dilatation of the ventricle on impairment of systolic function and existence of late gadolinium enhancement (LGE).

Material/Methods

Consecutive sample of cases with dilated left ventricle due to non-ischemic cardiomyopathy and healthy controls were included from our cardiac magnetic resonance imaging (CMR) database for a period of 3 years (n=1551 exams).

Results

The study included 127 patients; 30 (23.6%) with dilated cardiomyopathy (DCM); 30 (23.6%) with left ventricular non-compaction (LVNC); 13 (10.2%) with hypertrophic cardiomyopathy (HCM), and 50 (39.4%) controls. Overlapping phenotypes were found in 48 (37.8%) of the studied cases. Odds for impairment of systolic function in connection with overlapping phenotypes were estimated at 7.8 (95%-CI: 3.4–17.6), (p<0.001). There were significant differences in geometric parameters for patients with overlapping phenotypes vs. controls, as follows: left ventricle end-diastolic dimension(LVEDD)=6.6±0.8 vs. 5.6±1.0 cm (p<0.001); left ventricular ejection fraction (LVEF)=39.3±14.0 vs. 52.1±16.1 (p<0.001); and existence of LGE 36 (75.0%) vs. 21 (26.6%), (p<0.001), respectively. Overlapping phenotypes correlated with LVEDD (Spearman’s-Rho-CC)=0.521, p<0.001; LVEF (Rho-CC)=−0.447, p<0.001 and LGE (Rho-CC)=0.472, p<0.001.

Conclusions

This study found there are many patients with overlapping phenotypes among NICMPs with dilated left ventricles. Overlapping phenotype was associated with greater LVEDD, lesser systolic function, and commonly existing LGE, which all impose increased cardiovascular risk. Linear midventricular LGE stripe was the most powerfully connected with loss of systolic function.

Supplementary Diagnostic Landmarks of Left Ventricular Non-Compaction on Magnetic Resonance Imaging

PURPOSE

Diagnostic criteria for left ventricular non-compaction (LVNC) are still a matter of dispute. The aim of our present study was to test the diagnostic value of two novel diagnostic cardiac magnetic resonance (CMR) parameters: proof of non-compact (NC) myocardium blood flow using T2 sequences and changes in geometry of the left ventricle.

MATERIALS AND METHODS

The study included cases with LVNC and controls, from a data base formed in a period of 3.5 years (n=1890 exams), in which CMR protocol included T2 sequences. Measurement of perpendicular maximal and minimal end diastolic dimensions in the region with NC myocardium from short axis plane was recorded, and calculated as a ratio (MaxMinEDDR), while flow through trabecula was proven by intracavital T2-weighted hyperintensity (ICT2HI). LVNC diagnosis met the following three criteria: thickening of compact (C) layer, NC:C>2.3:1 and NC>20%LV.

RESULTS

The study included 200 patients; 71 with LVNC (35.5%; i.e., 3.76% of CMRs) and 129 (64.5%) controls. MaxMinEDDR in patients with LVNC was significantly different from that in controls (1.17±0.08 vs. 1.06±0.04, respectively; p<0.001). MaxMinEDDR >1.10 had sensitivity of 91.6% [95% confidence intervals (CI) 82.5-96.8], specificity of 85.3% (95% CI 78.0-90.0), and area under curve (AUC) 0.919 (95% CI 0.872-0.953; p<0.001) for LVNC. Existence of ICT2HI had sensitivity of 100.0% (95% CI 94.9-100.0), specificity of 91.5% (95% CI 85.3-95.7), and AUC 0.957 (95% CI 0.919-0.981; p<0.001) for LVNC.

CONCLUSION

Two additional diagnostic parameters for LVNC were identified in this study. ICT2HI and geometric eccentricity of the ventricle both had relatively high sensitivity and specificity for diagnosing LVNC.