Electrocardiogram to Determine Mitral and Aortic Valve Opening and Closure.

PURPOSE: Knowledge of the timing of cardiac valve opening and closing is important in cardiac physiology. The relationship between valve motion and electrocardiogram (ECG) is often assumed, however is not clearly defined. Here we investigate the accuracy of cardiac valve timing estimated using only the ECG, compared to Doppler echocardiography (DE) flow imaging as the gold standard. METHODS: DE was obtained in 37 patients with simultaneous ECG recording. ECG was digitally processed and identifiable features (QRS, T, P waves) were examined as potential reference points to determine opening and closure of aortic and mitral valves, as compared to DE outflow and inflow measurement. Timing offset of the cardiac valves opening and closure between ECG features and DE was measured from derivation set (n = 19). The obtained mean offset in combination with the ECG features model was then evaluated on a validation set (n = 18). Using the same approach, additional measurement was also done for the right sided valves. RESULTS: From the derivation set, we found a fixed offset of 22 ± 9 ms, 2 ± 13 ms, 90 ± 26 ms, and - 2 ± - 27 ms when comparing S to aortic valve opening, Tend to aortic valve closure, Tend to mitral valve opening, and R to mitral valve closure respectively. Application of this model to the validation set showed good estimation of aortic and mitral valve opening and closure timing value, with low model absolute error (median of the mean absolute error of the four events = 19 ms compared to the gold standard DE measurement). For the right-sided (tricuspid and pulmonic) valves in our patient set, there was considerably higher median of the mean absolute error of 42 ms for the model. CONCLUSION: ECG features can be used to estimate aortic and mitral valve timings with good accuracy as compared to DE, allowing useful hemodynamic information to be derived from this easily available test.

Constrictive Pericarditis Presenting as Isolated Ascites.

Constrictive pericarditis is a rare cause of right-sided heart failure secondary to a stiff, non-compliant pericardium. Clinical presentation can vary considerably and requires a high suspicion for diagnosis. A 31-year-old male presented to the emergency department with complaints of abdominal distension. An abdominal ultrasound revealed large volume ascites; thus, it was initially suspected he had underlying cirrhosis. However, an echocardiogram revealed a diagnosis of constrictive pericarditis. It's important for clinicians to consider constrictive pericarditis in a patient presenting with unexplained right-sided heart failure.

Systematic review and meta-analysis of outcomes of anatomic repair in congenitally corrected transposition of great arteries.

BACKGROUND: Treatment of congenitally corrected transposition of great arteries (cc-TGA) with anatomic repair strategy has been considered superior due to restoration of the morphologic left ventricle in the systemic circulation. However, data on long term outcomes are limited to single center reports and include small sample sizes. AIM: To perform a systematic review and meta-analysis for observational studies reporting outcomes on anatomic repair for cc-TGA. METHODS: MEDLINE and Scopus databases were queried using predefined criteria for reports published till December 31, 2017. Studies reporting anatomic repair of minimum 5 cc-TGA patients with at least a 2 year follow up were included. Meta-analysis was performed using Comprehensive meta-analysis v3.0 software. RESULTS: Eight hundred and ninety-five patients underwent anatomic repair with a pooled follow-up of 5457.2 patient-years (PY). Pooled estimate for operative mortality was 8.3% [95% confidence interval (CI): 6.0%-11.4%]. 0.2% (CI: 0.1%-0.4%) patients required mechanical circulatory support postoperatively and 1.7% (CI: 1.1%-2.4%) developed post-operative atrioventricular block requiring a pacemaker. Patients surviving initial surgery had a transplant free survival of 92.5% (CI: 89.5%-95.4%) per 100 PY and a low rate of need for pacemaker (0.3/100 PY; CI: 0.1-0.4). 84.7% patients (CI: 79.6%-89.9%) were found to be in New York Heart Association (NYHA) functional class I or II after 100 PY follow up. Total re-intervention rate was 5.3 per 100 PY (CI: 3.8-6.8). CONCLUSION: Operative mortality with anatomic repair strategy for cc-TGA is high. Despite that, transplant free survival after anatomic repair for cc-TGA patients is highly favorable. Majority of patients maintain NYHA I/II functional class. However, monitoring for burden of re-interventions specific for operation type is very essential.

Measuring Efficiency of Semi-automated Brain Tumor Segmentation by Simulating User Interaction.

Traditionally, radiologists have crudely quantified tumor extent by measuring the longest and shortest dimension by dragging a cursor between opposite boundary points across a single image rather than full segmentation of the volumetric extent. For algorithmic-based volumetric segmentation, the degree of radiologist experiential involvement varies from confirming a fully automated segmentation, to making a single drag on an image to initiate semi-automated segmentation, to making multiple drags and clicks on multiple images during interactive segmentation. An experiment was designed to test an algorithm that allows various levels of interaction. Given the ground-truth of the BraTS training data, which delimits the brain tumors of 285 patients on multi-spectral MR, a computer simulation mimicked the process that a radiologist would follow to perform segmentation with real-time interaction. Clicks and drags were placed only where needed in response to the deviation between real-time segmentation results and assumed radiologist's goal, as provided by the ground-truth. Results of accuracy for various levels of interaction are presented along with estimated elapsed time, in order to measure efficiency. Average total elapsed time, including loading the study through confirming 3D contours, was 46 s.

Survey of Conventional and Complementary and Alternative Therapy in Patients With Low Back Pain.

UNLABELLED: Both conventional and alternative medical therapies are used by patients to treat low back pain, a condition that affects approximately 33% of the U.S. POPULATION: Little is known about patients' perceptions of conventional versus alternative therapies. Patients recruited from an orthopedic spine clinic completed surveys containing questions about their use of many conventional and alternative therapies. Patients rated perceived helpfulness, side effects, and their recommendation for each therapy. They also completed a questionnaire that detailed demographic information, stress, and pain. Questionnaires were completed by 166 patients. Conventional medications were used by 154 (95%) patients, most commonly acetaminophen and opioid derivatives. Alternative therapies were used by 159 (96%) patients, including therapeutic exercises, salves, supplements, and stress management techniques. Generally, patients reported that alternative therapies are more effective and have fewer side effects and would more likely recommend their use. These data can be used to counsel patients and guide future research.

Relative contribution of haptic technology to assessment and training in implantology.

BACKGROUND: The teaching of implant surgery, as in other medical disciplines, is currently undergoing a particular evolution. AIM OF THE STUDY: To assess the usefulness of haptic device, a simulator for learning and training to accomplish basic acts in implant surgery. MATERIALS AND METHODS: A total of 60 people including 40 third-year dental students without knowledge in implantology (divided into 2 groups: 20 beginners and 20 experiencing a simulator training course) and 20 experienced practitioners (experience in implantology >15 implants) participated in this study. A basic exercise drill was proposed to the three groups to assess their gestural abilities. RESULTS: The results of the group training with the simulator tended to be significantly close to those of the experienced operators. CONCLUSION: Haptic simulator brings a real benefit in training for implant surgery. Long-term benefit and more complex exercises should be evaluated.

Increased gingival crevicular fluid levels of soluble triggering receptor expressed on myeloid cells (sTREM) -1 in severe periodontitis.

AIM: This study was designed to evaluate the presence of a new regulator of innate immunity in periodontitis: the soluble form of triggering receptor on myeloid cells-1 (sTREM-1) in gingival crevicular fluid (GCF). MATERIAL AND METHODS: GCF was collected at four sites, three pathological and one healthy from 17 patients with periodontitis, and at one healthy site from 23 control patients. An enzyme-linked immunosorbent assay (ELISA) kit was used to quantify sTREM-1 levels in collected crevicular fluid. Recorded clinical parameters were probing pocket depth (PPD), bleeding upon probing, tooth mobility, plaque index (PlI), and gingival index (GI). RESULTS: The mean sTREM-1 level in collected fluid was significantly higher in pathological sites than in healthy sites from either periodontal or control patients: 353.9 pg/ml, 50.2 pg/ml and 25.4 pg/ml respectively. Soluble TREM-1 concentration was significantly correlated with PPD. The sTREM-1 levels increased with the augmentation of the PlI and GI scores and levelled off at score 2 for both indexes. In multivariate analysis, periodontal pocket depth and smoking status were statistically associated with highest sTREM-1 concentrations. CONCLUSION: sTREM-1 was detected in crevicular fluid and its concentration was higher in pathological sites. It could be a marker of periodontal tissue destruction.

Measuring and reducing college students' procrastination.

We examined college students' procrastination when studying for weekly in-class quizzes. Two schedules of online practice quiz delivery were compared using a multiple baseline design. When online study material was made available noncontingently, students usually procrastinated. When access to additional study material was contingent on completing previous study material, studying was more evenly distributed. Overall, the mean gain in percentage correct scores on weekly in-class quizzes relative to pretests was greater during contingent access than during noncontingent access conditions.