Background While catheter ablation therapy for atrial fibrillation (AF) is becoming more common, results vary widely and patient selection criteria remain poorly defined. We hypothesized that late gadolinium enhancement magnetic resonance imaging (LGE-MRI) can identify left atrial (LA) wall structural remodeling (SRM) and stratify patients who are likely or not to benefit from ablation therapy. Methods and Results LGE-MRI was performed on 426 consecutive AF patients without contraindications to MRI and before undergoing their first ablation procedure and on 21 non-AF control subjects. Patients were categorized by SRM stage (I–IV) based on percentage of LA wall enhancement for correlation with procedure outcomes. Histological validation of SRM was performed comparing LGE-MRI to surgical biopsy. A total of 386 patients (91%) with adequate LGE-MRI scans were included in the study. Post-ablation, 123 (31.9%) experienced recurrent atrial arrhythmias over one-year follow-up. Recurrent arrhythmias (failed ablations) occurred at higher SRM stages with 28/133 (21.0%) stage I, 40/140 (29.3%) stage II, 24/71 (33.8%) stage III, and 30/42 (71.4%) stage IV. In multi-variate analysis, ablation outcome was best predicted by advanced SRM stage (hazard ratio (HR) 4.89; p<0.0001) and diabetes (HR 1.64; p=0.036) while increased LA volume and persistent AF were not significant predictors. LA wall enhancement was significantly greater in AF patients vs. non-AF controls (16.6±11.2% vs. 3.1±1.9%, p<0.0001). Histological evidence of remodeling from surgical biopsy specimens correlated with SRM on LGE-MRI. Conclusions Atrial SRM is identified on LGE-MRI and extensive LGE (≥30% LA wall enhancement) predicts poor response to catheter ablation therapy for AF.

For patients with impaired breath-hold capacity and/or arrhythmias, real-time cine MRI may be more clinically useful than breath-hold cine MRI. However, commercially available real-time cine MRI methods using parallel imaging typically yield relatively poor spatio-temporal resolution due to their low image acquisition speed. We sought to achieve relatively high spatial resolution (~2.5mm × 2.5mm) and temporal resolution (~40ms), to produce high-quality real-time cine MR images that could be applied clinically for wall motion assessment and measurement of left ventricular (LV) function. In this work, we present an 8-fold accelerated real-time cardiac cine MRI pulse sequence using a combination of compressed sensing and parallel imaging (k-t SPARSE-SENSE). Compared with reference, breath-hold cine MRI, our 8-fold accelerated real-time cine MRI produced significantly worse qualitative grades (1–5 scale), but its image quality and temporal fidelity scores were above 3.0 (adequate) and artifacts and noise scores were below 3.0 (moderate), suggesting that acceptable diagnostic image quality can be achieved. Additionally, both 8-fold accelerated real-time cine and breath-hold cine MRI yielded comparable LV function measurements, with coefficient of variation < 10% for LV volumes. Our proposed 8-fold accelerated real-time cine MRI with k-t SPARSE-SENSE is a promising modality for rapid imaging of myocardial function.

Characterization of chemokine expression patterns in virus-infected epithelial cells provides important clues to the pathophysiology of such infections. The aim of this study was to determine the chemokine response pattern of respiratory epithelium when infected with respiratory syncytial virus (RSV). Macrophage inflammatory protein-1-alpha (MIP-1-alpha), interleukin-8 (IL-8), and RANTES concentrations were measured from RSV-infected HEp-2, MRC-5, and WI-38 cell culture supernatants daily following infection. Additionally, MIP-1-alpha, IL-8, and RANTES concentrations were measured from lower respiratory secretions obtained from 10 intubated infants (0-24 mo) with RSV bronchiolitis, and from 10 control subjects. Our results indicate that respiratory epithelial cells respond to RSV infection by producing MIP-1-alpha, IL-8, and RANTES. Production of MIP-1-alpha required ongoing viral replication, whereas RANTES and IL-8 could be elicited by inactivated forms of the virus. MIP-1-alpha, RANTES, and IL-8 were also present in lower airway secretions obtained from patients with RSV bronchiolitis. Eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN), the eosinophil secretory ribonucleases, were detected in lower airway secretions from RSV-infected patients; ECP concentrations correlated with MIP-1-alpha concentrations (r = 0.93). We conclude that MIP-1-alpha is present in the lower airways during severe RSV disease. The correlation between MIP-1-alpha and ECP concentrations suggests a role for eosinophil degranulation products in the pathogenesis of RSV bronchiolitis.

The objective of this study was to identify the incidence of feeding difficulties in infants with hypoplastic left heart syndrome (HLHS) and d-transposition of the great arteries (d-TGA). Congenital heart disease is a risk factor for growth failure. The etiologies include poor caloric intake, inability to utilize calories effectively, and increased metabolic demands. The goals of our study were to (1) identify feeding difficulties in infants with HLHS and d-TGA and (2) assess their growth in the first year of life. We performed a chart review of 27 consecutive infants with HLHS and 26 with d-TGA. Descriptive statistics were generated for demographic and clinical variables within each group and are presented as means +/- standard deviations. HLHS and d-TGA groups were compared on time to achieving nutritional goals using the log rank test, on complication rate using the chi-square test, and on weight using the t-test. A significance level of 0.05 was used for all tests. Birth weight was similar for both the HLHS and d-TGA groups (3.19 +/- 0.69 vs 3.35 +/- 0.65 kg, respectively; p = 0.38). Infants with HLHS weighed less than those with d-TGA at l month (3.29 +/- 0.58 vs 3.70 +/- 0.60 kg, respectively; p = 0.021), 6 months (6.27 +/- 1.06 vs 7.31 +/- 1.02 kg, p = 0.003), and 12 months of age (8.40 +/- 1.11 vs 9.49 +/- 1.01 kg, p = 0.006). Time to achieving full caloric intake (at least 100 kcal/kg/day) for the HLHS group (24 +/- 11.9 days) was significantly longer than for the d-TGA group (12.0 +/- 11.2 days, p < 0.001). In addition, infants with HLHS had a higher incidence of feeding-related complications that those with d-TGA (48 vs 4%, respectively; p = 0.001). Compared to the d-TGA group, infants with HLHS weighed less at follow-up, took longer to reach nutritional goals, and had a much higher incidence of feeding-related complications.

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Early extubation is possible in many very young children undergoing congenital heart surgery, with a low rate of failed extubation. The model would be improved by prospective validation with larger numbers at multiple institutions.

Prolonged high-dose suppressive therapy (HDST) is a mainstay in the management of refractory status epilepticus (RSE), albeit with high morbidity and mortality. The authors studied 10 patients who were carefully selected for epilepsy surgery after failing prolonged (>2 weeks) HDST. Status epilepticus was stopped acutely in all of them with no mortality and no substantial morbidity. At follow-up (median 7 months), 7 (70%) of 10 patients were seizure free, and 3 (30%) of 10 had significant improvement in their epilepsy.

The movement to CPOE affords real-time interaction between the laboratory and the physician through CDSTs that signal duplicate orders. These interactions save health care dollars and should also increase patient satisfaction and well-being.