Ensemble empirical mode decomposition based feature enhancement of cardio signals

This paper presents an application of ensemble empirical mode decomposition method for enhancement of specific biological signal features. The application for two types of cardiological signals is presented in this article. Detection of fiducial points is a routine task for analyzing these signals. In a clinical situation, cardiological signals are usually corrupted by artifacts and finding exact time instances of various fiducial points is a challenge. Filtering approach for signal to noise ratio enhancing is traditionally and widely used in clinical practice. Methods, based on filtering, however, have serious limitations when it is necessary to find compromise between noise suppression and preservation of signal features. The proposed method uses ensemble empirical mode decomposition in order to suppress noise or enhance specific waves in the signal. Performance of the method was estimated by using clinical electrocardiogram and impedance cardiogram signals with synthetic baseline-wander, power-line and added Gaussian noise. In electrocardiogram application, an average estimation error of QRS complex length was 2.06–4.47%, the smallest in comparison to the reference methods. In impedance cardiogram application, the proposed method provided the highest cross-correlation coefficient between original and de-noised signal in comparison to reference methods. When the signal to noise ratio of the input signal was ?12 dB, the method provided signal to error ratio of 33 dB in this case. The proposed method is adaptive to template and signal itself and thus could be applied to other non-stationary biological signals.     

The safety and efficacy of multiple consecutive cryo lesions in canine pulmonary veins-left atrial junction

OBJECTIVE: The purpose of the study is to evaluate the safety and efficacy of multiple cryo lesions in canine pulmonary veins-left atrial junction. BACKGROUND: The use of radiofrequency to achieve electrical isolation of the pulmonary veins (PVs) has been associated with PV stenosis. No information is currently available concerning the safety and the electrophysiological effects of multiple and consecutive cryo applications at the PV-left atrial junction. METHODS: Liquid N(2)O was delivered into semi-compliant 15 to 22-mm-diameter balloons. In 13 dogs weighing 34 +/- 2 kg, one to four consecutive cryo lesions were randomly applied to each PV for 3 minutes in 6-minute intervals. The pre- and post-PV sizes were recorded by angiography. Electrogram activity and pacing thresholds were recorded before and after cryo. PV patency and the PV-atrial tissue characteristics were evaluated grossly and histologically. RESULTS: Pacing capture was not possible with 10 mA postablation in 26/46 (57%) electrodes, and in 20 (43%) electrodes pacing threshold increased from 1.6 +/- 1.7 mA to 7.8 +/- 3.2 mA. The total elimination of recorded electrograms was noted in 22%, 29%, and 18% following 1, 2, and 3 cryo lesions respectively. After 4 lesions this value increased to 53%. No significant changes in PV diameter were recorded in any of the veins pre vs the terminal study. The PVs and PV-atrial interface tissue were soft, compliant, and without collagen or cartilaginous tissue. There was no hemoptysis in any of the dogs. CONCLUSION: In this study, cryo balloon technology is effective and safe regardless of the number of lesions applied and the freezing temperatures achieved. Four consecutive cryo applications result in a significant increase in pacing threshold and a decrease in activity of local atrial electrograms.     

Ablation of atrial fibrillation in the rapid pacing canine model using a multi-electrode loop catheter

OBJECTIVES: This investigation details our experience using a loop catheter to ablate atrial fibrillation (AF) in dogs. BACKGROUND: Atrial fibrillation is the most common arrhythmia and has significant morbidity. Maintenance of normal sinus rhythm (NSR) after conversion in many patients is still a challenge. METHODS: A multi-electrode loop catheter was used to create linear atrial lesions to ablate AF in a rapid atrial pacing model in 29 dogs. Rhythm status was assessed over a six-month recovery period, after which tissue analysis was performed. RESULTS: Acute conversion to NSR or atrial tachycardia (AT) was achieved in 90% of cases. Six of 26 conversions occurred after only left atrial (LA) lesions, and two after just right atrial lesions. Sixteen (62%) of 26 lesions that resulted in AF conversion were in the LA, and 11 of these 16 conversions occurred during a lesion connecting the mitral ring to the pulmonary veins. Acute conversion rate was similar with ring and coil electrodes, but AT was more frequent with coil electrodes (63% vs. 31%). At six months 80% of dogs were in NSR, 14% were in AT, and 7% remained in AF. There was an average reduction in P-wave amplitude of 64 +/- 26% after power application. Tissue analysis revealed transmural contiguous lesions when final outcome was NSR, and nontransmural/noncontiguous lesions where AF persisted. CONCLUSIONS: Multi-electrode loop catheters can create contiguous transmural lesions in either atrium to safely and effectively ablate AF and provide a stable long-term rhythm outcome in this dog model. The left atrium appears to be the dominant chamber that sustains AF. Atrial tachycardia is a frequent acute outcome with coil electrodes.     

Long‐term safety and efficacy of acotiamide in functional dyspepsia (postprandial distress syndrome)—results from the European phase 3 open‐label safety trial

Backgrounds

Acotiamide is a novel acetylcholinesterase inhibitor for treatment of postprandial distress syndrome (PDS) symptoms of functional dyspepsia (FD). This European phase 3 open‐label safety trial has been conducted to evaluate the long‐term safety of acotiamide and explore the efficacy of acotiamide on PDS symptoms using the validated LPDS, quality of life using SF‐36 and SF‐NDI, and work productivity using WPAI.

Methods

FD‐PDS patients (defined by ROME III criteria) aged ≥18 years with active PDS symptoms and without predominant overlapping symptoms of epigastric pain syndrome and related disorders were enrolled to receive 100 mg acotiamide three times daily for 1 year. Patients' safety profile and efficacy of acotiamide were monitored.

Key Results

The majority of patients (81.6%) maintained exposure to acotiamide for >50 weeks, with a mean duration of 320.3 days. No specific clinically significant safety concerns have been shown, with no deaths, treatment‐related severe/serious adverse events, or any clinically significant laboratory test results. Although being an open‐label trial, acotiamide showed a change in severity larger than the minimum clinically important difference at weeks 1 and 2 for postprandial fullness and early satiation (meal‐related symptoms), and showed improvement of quality of life and work productivity from the first measurement (at week 12) up to 1 year.

Conclusions & Inferences

The long‐term safety of acotiamide treatment was confirmed. A clinically important change for PDS symptoms, QoL, and work productivity was suggested; however a controlled trial is required to confirm this hypothetic efficacy of acotiamide. (NCT01973790).     

Narrow line between benefit and harm: Additivity of hyperthermia to cisplatin cytotoxicity in different gastrointestinal cancer cells

AIM To investigate the response to hyperthermia and chemotherapy, analyzing apoptosis, cytotoxicity, and cisplatin concentration in different digestive system cancer cells.METHODS AGS(gastric cancer cell line), Caco-2(colon cancer cell line) and T3M4(pancreatic cancer cell line) were treated by cisplatin and different temperature setting(37 ℃ to 45 ℃) either in isolation, or in combination. Treatment lasted for one hour. 48 h after the treatment viability was evaluated by MTT, cell apoptosis by Annexin V-PE and 7 ADD flow cytometry. Intracellular cisplatin concentration was measured immediately after the treatment, using mass spectrometry. Isobologram analysis was performed to evaluate the mathematical combined effect of temperature and cisplatin.RESULTS AGS cells were the most sensitive to isolated application of hyperthermia. Hyperthermia, in addition to cisplatin treatment, did not provoke a synergistic effect at intervals from 37 ℃ to 41 ℃ in neither cancer cell line. However, a temperature of 43 ℃ enhanced cisplatin cytotoxicity for Caco-2 cells. Moreover, isobologram analysis revealed mathematical antagonistic effects of cisplatin and temperature combined treatment in AGS cells; variations between synergistic, additive, and antagonistic effects in Caco-2 cells; and additive and antagonistic effects in T3 M4 cells. Combined treatment enhanced initiation of cell apoptosis in AGS, Caco-2, and T3 M4 cells by 61%, 20%, and 19% respectively. The increase of intracellular cisplatin concentration was observed at 43 ℃ by 30%, 20%, and 18% in AGS, Caco-2, and T3 M4 cells, respectively.CONCLUSION In addition to cisplatin, hyperthermia up to 43 ℃ does not affect the viability of cancer cells in a synergistic manner.     

International Nosocomial Infection Control Consortium (INICC) report, data summary of 36 countries, for 2004-2009

The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia).     

The ablation of atrial fibrillation with the loop catheter design: what we have learned from the animal model

Ablation of chronic atrial fibrillation (AF) with the use of transcutaneous catheter ablation is yet to become a clinical tool. This article summarizes the development of the technology and the technique for the ablation of AF that was tested on the rapidly paced AF dog model. The current ablation technology using the standard ablation technique used in humans is not suitable for the creation of transmural contiguous linear lesions, and such technology is subjecting the patient to the prolonged procedures with considerable risk of complication. The use of the loop catheter design or other designs of ablation technology, which is specifically targeted for the creation of linear lesions, should be developed if the catheter approach for the ablation of AF is to succeed. This article describes the data available for the loop catheter design that is currently undergoing human feasibility studies.