The Impact of High-Flow Nasal Cannula on Olfactory Function.

BACKGROUND: Oxygen therapy provided via high-flow nasal cannula (HFNC) improves gas exchange lung compliance and results in increased lung expiratory volumes. Previous data indicate that hyperbaric and humid states improve the olfactory thresholds compared to hypobaric and dry conditions. This prospective, observational study aimed to determine the impact of oxygen delivery through HFNC on olfactory function in subjects admitted to the ICU for acute respiratory failure (ARF). METHODS: 30 subjects who were admitted to the ICU for ARF underwent an olfactory sniff test before and after oxygen therapy with HFNC. Baseline olfactory function of subjects with ARF was also compared against 30 healthy controls. Odor threshold (OT), odor discrimination (OD), odor identification (OI) and global olfactory score (TDI) were recorded for all subjects. RESULTS: The OT, OD, OI, and TDI scores were significantly higher in the control group compared to the baseline scores of the subjects with ARF (P < .001 for all comparisons). In subjects with ARF, administration of oxygen with HFNC led to significant improvements in OT (P = .02), OD (P = .001), OI (P = .02), and TDI (25.5 ± 3.8 vs 27.1 ± 3.5, P < .001) scores. CONCLUSIONS: Our results indicate that subjects with ARF had relative olfactory dysfunction compared to healthy controls. These results also suggest that implementation of HFNC to relieve hypoxemia in subjects presenting with ARF can lead to a significant improvement in olfactory function.

Catheter ablation of supraventricular tachycardia after tricuspid valve surgery in patients with congenital heart disease: A multicenter comparative study.

BACKGROUND: Tricuspid valve (TV) surgery is often required for adult congenital heart disease (ACHD), but may hinder catheter ablation when an artificial material or imbricated tissue covers the tricuspid annulus. OBJECTIVE: The purpose of this study was to determine the outcomes of catheter ablation after TV surgery in a large ACHD cohort. METHODS: An international retrospective study involving 7 centers was conducted. Patients who did and did not undergo TV surgery were matched for age, lesion classification, and postsurgical duration. TV operations were classified as valve ring/replacement vs repair. RESULTS: One hundred thirty-six patients (42 ring/replacement, 39 repair, and 55 no TV surgery; median 32 years [IQR 20 - 46]) underwent 180 procedures targeting 239 tachycardias (cavotricuspid-isthmus dependent intraatrial reentrant tachycardia 36%, other intraatrial reentrant tachycardia 29%, focal atrial tachycardia 18%, and other supraventricular tachyarrhythmia 17%). Post-TV surgery, procedures were longer (4.3 hours vs 3.3 hours; P = .003) and required longer fluoroscopy time (31 minutes vs 18 minutes; P = .001). At least partial acute success was achieved in 81% of procedures in the TV ring/replacement group vs 94% in both TV repair and no TV surgery groups (P = .03). The difference was driven mainly by ablation of annular substrates, with acute success in 73% of TV ring/replacement, 92% of TV repair, and 94% of no TV surgery groups (P = .01). Over a median of 3.0 years, tachycardia recurred after 26% of procedures. TV ring/replacement predicted recurrence in the multivariable analysis (hazard ratio 2.4; 95% confidence interval 1.2-5.2; P = .009). CONCLUSION: After surgery for ACHD, catheter ablation success was lower and tachycardia recurrence was higher after TV valve ring/replacement surgery. The findings of this retrospective report support future larger multicenter series and prospective evaluation to determine the role of empirical annular substrate ablation.

Imaging of Atrioventricular Nodal Conduction Tissue in Porcine Hearts Using Optical Coherence Tomography.

Optical coherence tomography (OCT) employs near-infrared light to image the microstructure of different tissues. Clinically, it has been used to image the walls of coronary arteries. In research settings, one of the applications for OCT is visualizing endocardial and subendocardial structures. The present experiment sought to determine whether OCT can identify native conduction tissues in adult porcine hearts. During the study, the right atrial endocardial surfaces of excised adult porcine hearts were exposed. The triangle of Koch was imaged with the OCT system and the conduction tissue was identified. The area was then prepared for histologic examination with Masson's trichrome stain. The results of histologic preparations and OCT images were then compared. Ultimately, nine porcine hearts were examined using this methodology. OCT imaging successfully identified subendocardial structures presumed to be the compact atrioventricular node. Histologic images of the preparations delineated the different tissue types and conduction tissue was easily identified. The location of distinctive hyporeflective areas in the OCT images correlated with the location of conduction tissue in the histology images. In light of the findings of this study, it is suggested that atrioventricular nodal tissue can be identified by OCT in freshly dissected unfixed porcine hearts. OCT images distinguished the differentiated conduction tissue in close proximity with the endocardium, myofibers, and fibrous tissue, and the success of this was verified with histology. This technology may be useful for the direct visualization of the native conduction system during procedures in the operating room and electrophysiology laboratory. Further studies with perfused tissue samples and live animal experiments are needed to better assess the efficacy of this novel application.

Confirm RX™ Cardiac Monitor Placement in a Pediatric Patient.

We present the first known report of a pediatric implantation of the Bluetooth™-enabled Confirm RX™ insertable cardiac monitor (Abbott Laboratories, Chicago, IL, USA) in a 17-year-old patient with unexplained syncopal episodes. This case illustrates the ability to obtain immediate rhythm information from a patient using a Bluetooth™-enabled device following a minimally invasive procedure.

Is There a Relation between Reticular Formation and Storage Symptoms in Men.

OBJECTIVE: To reveal brainstem originated pathology in men with different types of lower urinary tract symptoms blink reflex latency times were assessed. METHODS: A total of 32 men, 16 with storage and 16 with voiding symptoms, were enrolled in the study. Blink reflex latency times were analyzed through electrical stimulation of the supraorbital nerve. Two responses in the orbicularis oculi muscle were recorded: the latency times for the early ipsilateral response, R1, and the late bilateral responses, R2. RESULTS: The mean ages of the patients with storage and voiding symptoms were 57.31 ± 6.87 and 58.06 ± 6.29 years, respectively. The R2 latency times were significantly longer in men with storage symptoms. However, the R1 latency times were similar for the two groups. CONCLUSION: Late blink latency times were long only in patients who had storage symptoms. An oligosynaptic path through the trigeminal nuclei, which includes one or two interneurons, is responsible for early response; however, late response is relayed through a polysynaptic path, including neurons in the reticular formation. It has also been shown that stimulation of the pontine reticular formation inhibits the micturition contraction. In some patients, storage symptoms may result from pathology that originates with the reticular formation and this pathology may lead to increases in late blink latency times. Additional studies are needed on other reflexes that are mediated through reticular formation, in order to show the possible dysfunction of the reticular formation in men with storage symptoms.

Association Between Prostate Volume and Red Cell Distribution Width.

OBJECTIVES: To evaluate relation between red cell distribution width (RDW) and benign prostatic hyperplasia (BPH). METHODS: The overall study population consisted of 942 men with lower urinary tract symptoms (LUTS), ranging in age from 60 to 85 years old. Patients with disorder or medication that can influence lower urinary tract or erythrocytes were excluded from the study. The relationship between RDW, white blood cell (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and prostate volume, International Prostate Symptom Score (IPSS) were assessed with multivariate linear regression model. Patients were analyzed in four groups stratified according to the quartiles of prostate volume. The one-way analysis of variance (anova) was used to compare RDW, WBC CRP, and ESR between different quartiles of prostate volume. RESULTS: A graded and independent association of RDW with the prostate volume was identified (P = 0.001). RDW was significantly associated with prostate volume in multivariate linear regression model that was adjusted for age and hemoglobin. IPSS was significantly correlated with RDW, CRP and ESR. However significance was lost after adjustment for age and prostate volume. The RDW was significantly associated with the surgical treatment in the multivariate linear regression model that was adjusted for age and prostate volume. CONCLUSIONS: A correlation between an increased RDW and prostate volume was suggested by the new data from this study. This relation may be a consequence of inflammatory stress arising from BPH. The significant association between the easy, inexpensive RDW may provide a rational basis to include the RDW in algorithms for surgery risk prediction.

Implantable cardioverter defibrillator implantation without using fluoroscopy in a pregnant patient.

Conventional lead implantation requires fluoroscopic guidance. This may be problematic in certain patient groups such as pregnant patients. We report a case of an implantable cardioverter defibrillator implantation without fluoroscopy in a pregnant patient.

Improved accuracy using recursive bayesian estimation based language model fusion in ERP-based BCI typing systems.

RSVP Keyboard™ is an electroencephalography (EEG) based brain computer interface (BCI) typing system, designed as an assistive technology for the communication needs of people with locked-in syndrome (LIS). It relies on rapid serial visual presentation (RSVP) and does not require precise eye gaze control. Existing BCI typing systems which uses event related potentials (ERP) in EEG suffer from low accuracy due to low signal-to-noise ratio. Henceforth, RSVP Keyboard™ utilizes a context based decision making via incorporating a language model, to improve the accuracy of letter decisions. To further improve the contributions of the language model, we propose recursive bayesian estimation, which relies on non-committing string decisions, and conduct an offline analysis, which compares it with the existing naïve bayesian fusion approach. The results indicate the superiority of the recursive bayesian fusion and in the next generation of RSVP Keyboard™ we plan to incorporate this new approach.

Comparison of apoptotic gene expression profiles between Peyronie's disease plaque and tunica albuginea.

BACKGROUND: The fibrotic plaques of Peyronie/s disease and other localized fibrotic conditions have been considered to be the result of an abnormal wound healing process. The potential role of regulatory disorders of apoptosis in abnormal wound healing may also play a role in the development of Peyronie's disease. OBJECTIVES: To examine the phenomenon of apoptosis in Peyronie's disease, authors quantified differential levels of gene expression of apoptotic proteins, Fas, Fas Ligand, Bcl-2, p53, Caspase 3 and 8 in Peyronie's plaque and tunica albuginea. MATERIAL AND METHODS: Eight patients with Peyronie's disease undergoing surgical correction of the curvature had biopsy specimens taken from both the Peyronie's plaque and normal tunica albuginea. Messenger RNA expression of the apoptotic proteins in the plaque and normal tunica was measured by reverse transcriptase PCR. RESULTS: Apoptotic gene expression was lower than the housekeeping gene's in half of the tunica albuginea samples and two thirds of the plaque samples. Overall mRNA expressions in the plaque were not significantly different from the normal tunica albuginea. CONCLUSIONS: The fibrotic plaques of Peyronie's disease and other localized fibrotic conditions have been considered to be the result of an abnormal wound healing process. The potential role of regulatory disorders of apoptosis in abnormal wound healing may also play a role in the development of Peyronie's disease. In this study, the lower expression of apoptotic genes may cause the persistence of collagen producing cells which were up-regulated for unknown reasons and consequently result in plaque formation. Similar expression levels of apoptotic genes in both tunica albuginea and Peyronie's plaques may be due to the generalized physiopathologic alterations in tunica albuginea that lead to plaque formation at a vulnerable region subjected to recurrent traumas.

Successful elimination of significant arrhythmia burden with flecainide in an adolescent with long QT syndrome type 3.

Congenital Long QT syndrome (LQTS) is a cardiac channelopathy, which leads to prolongation of the QT interval. This prolongation can lead to ventricular tachyarrhythmias, syncope, and sudden cardiac death. There are various types of LQTS associated with the mutations, which affect the genes coding the ion channels in the myocardial cells. Because of the differences in the ion channel physiology, clinical presentation of the subtypes can show significant differences. The most common types of LQTS are LQT1, LQT2, and LQT3. In LQT1 and LQT2, mutations are in the genes encoding Potassium channels (KCNQ1 and KCNH2 genes). These two subtypes show sensitivity to adrenergic stimuli. In LQT1, episodes are usually exercise-triggered, and in LQT2, episodes are more likely to be related to sudden arousal and emotional stress. Therefore treatment of LQT1 and LQT2 is mainly based on antiadrenergic therapy. LQT3 on the other hand, is a result of a mutation of SCN5A gene, which encodes the Sodium channels. In this type, patients are sensitive to vagal stimuli and episodes tend to occur at rest. Therefore, treatment choices between different subtypes of LQTS vary. In this case report, we report a patient with congenital LQT3 (Y1795C mutation) presenting with implantable cardioverter defibrillator (ICD) storm. Patient's arrhythmia burden was eliminated following successful treatment with flecainide.

On Visually Evoked Potentials in EEG Induced by Multiple Pseudorandom Binary Sequences for Brain Computer Interface Design.

Visually evoked potentials have attracted great attention in the last two decades for the purpose of brain computer interface design. Visually evoked P300 response is a major signal of interest that has been widely studied. Steady state visual evoked potentials that occur in response to periodically flickering visual stimuli have been primarily investigated as an alternative. There also exists some work on the use of an m-sequence and its shifted versions to induce responses that are primarily in the visual cortex but are not periodic. In this paper, we study the use of multiple m-sequences for intent discrimination in the brain interface, as opposed to a single m-sequence whose shifted versions are to be discriminated from each other. Specifically we used four different m-sequences of length 31. Our main goal is to study if the bit presentation rate of the m-sequences have an impact on classification accuracy and speed. In this initial study, where we compared two basic classifier schemes using EEG data acquired with 15Hz and 30Hz bit presentation rates, our results are mixed; while on one subject, we got promising results indicating bit presentation rate could be increased without decrease in classification accuracy; thus leading to a faster decision-rate in the brain interface, on our second subject, this conclusion is not supported. Further detailed experimental studies as well as signal processing methodology design, especially for information fusion across EEG channels, will be conducted to investigate this question further.

A urachal leiomyoma misdiagnosed as an ovarian tumor.

A case of leiomyoma of the urachus occurred in a 39-year-old woman with an abdominal mass. It was initially diagnosed as an ovarian tumor.