Does the rate of inappropriate therapy differ in implantable cardioverter–defibrillators from different manufacturers?

Objective We conducted this study to compare the rate of ≥1 inappropriate therapy between ICDs from two manufacturers which use different discriminatory protocols. Method One hundred sixty two patients (mean age 58 ± 13 years, 126 male) who received ICDs between January 2001 and 2005 were included in the study. Clinical, electrocardiographic, and ICD stored data and electrograms were collected and analyzed. Immediately after implantation all the detection and discrimination criteria were activated with the nominal values in order to compare the two discriminatory protocols under the default manufacturer’s settings. Results During the follow up period of 14.3 ± 10 months, 49 (30%) patients received ≥1 inappropriate ICD therapy. The rate of ≥1 inappropriate ICD therapy in manufacturer A and B ICDs was 26% (n = 29) and 41% (n = 20), respectively. Comparing the rate of ≥1 inappropriate ICD therapy between the two groups by Kaplan–Meier analysis and the log rank test resulted in P = 0.04. Conclusion Having all discriminatory variables activated with the nominal values, discriminatory performance differs between the two manufacturers. Further larger-scale studies are warranted to prospectively compare the performance of various available ICDs’ discriminatory protocols, and define the optimum combination of discriminators in each ICD to decrease the rate of inappropriate therapy.     

Comparison between Negative T waves characteristics in acute coronary syndrome and pulmonary embolism

Background

Electrocardiogram (ECG) is the first available modality used in patients with chest pain and dyspnea in emergency rooms.We aimed to study differences between acute coronary syndrome (ACS) and acute pulmonary embolism (APE) in patients presented primarily with abnormal negative T waves on their admission Electrocardiogram.

Spinal Manipulation for Subacute and Chronic Lumbar Radiculopathy: A Randomized Controlled Trial

ObjectiveWe evaluated the efficacy of spinal manipulation for the management of nonacute lumbar radiculopathy.MethodsIn a university hospital we performed a randomized controlled trial with 2 parallel arms. Patients (n = 44) with unilateral radicular low back pain lasting more than 4 weeks were randomly allocated to manipulation and control groups. The primary outcome was the intensity of the low back pain on a visual analog scale. The secondary outcome was the Oswestry Disability Questionnaire score. We also measured spinal ranges of motion. The assessments were carried out at the baseline, immediately after intervention, and at 3 months’ follow-up. All patients underwent physiotherapy. The manipulation group received three sessions of manipulation therapy 1 week apart. For manipulation, we used Robert Maigne's technique.ResultsBoth groups experienced a decrease in back and leg pain significantly (all P ≤ 0.003). However, only the manipulation group showed significantly favorable results in the Oswestry scores (P < 0.001), and the straight leg raise test (P = 0.001). All ranges of motion increased significantly with manipulation (all P < 0.001), but the control group showed favorable results only in right and left rotations and in extension (all P < 0.001). Between-group analyses showed significantly better outcomes for manipulation in all measurements (all P ≤ 0.009) with large effect sizes.ConclusionSpinal manipulation improves the results of physiotherapy over a period of 3 months for patients with subacute or chronic lumbar radiculopathy.     

Improved anticancer delivery of paclitaxel by albumin surface modification of PLGA nanoparticles

Background

Nanoparticles (NPs) play an important role in anticancer delivery systems. Surface modified NPs with hydrophilic polymers such as human serum albumin (HSA) have long half-life in the blood circulation system.

Methods

The method of modified nanoprecipitation was utilized for encapsulation of paclitaxel (PTX) in poly (lactic-co-glycolic acid) (PLGA). Para-maleimide benzoic hydrazide was conjugated to PLGA for the surface modifications of PLGA NPs, and then HSA was attached on the surface of prepared NPs by maleimide attachment to thiol groups (cysteines) of albumin. The application of HSA provides for the longer blood circulation of stealth NPs due to their escape from reticuloendothelial system (RES). Then the physicochemical properties of NPs like surface morphology, size, zeta potential, and in-vitro drug release were analyzed.

Results

The particle size of NPs ranged from 170 to 190 nm and increased about 20–30 nm after HSA conjugation. The zeta potential was about -6 mV and it decreased further after HSA conjugation. The HSA conjugation in prepared NPs was proved by Fourier transform infrared (FT-IR) spectroscopy, faster degradation of HSA in Differential scanning calorimetry (DSC) characterization, and other evidences such as the increasing in size and the decreasing in zeta potential. The PTX released in a biphasic mode for all colloidal suspensions. A sustained release profile for approximately 33 days was detected after a burst effect of the loaded drug. The in vitro cytotoxicity evaluation also indicated that the HSA NPs are more cytotoxic than plain NPs.

Conclusions

HSA decoration of PLGA NPs may be a suitable method for longer blood circulation of NPs.     

Automatic Computation of Left Ventricular Volume Changes Over a Cardiac Cycle from Echocardiography Images by Nonlinear Dimensionality Reduction

Curve of left ventricular (LV) volume changes throughout the cardiac cycle is a fundamental parameter for clinical evaluation of various cardiovascular diseases. Currently, this evaluation is often performed manually which is tedious and time consuming and suffers from significant interobserver and intraobserver variability. This paper introduces a new automatic method, based on nonlinear dimensionality reduction (NLDR) for extracting the curve of the LV volume changes over a cardiac cycle from two-dimensional (2-D) echocardiography images. Isometric feature mapping (Isomap) is one of the most popular NLDR algorithms. In this study, a modified version of Isomap algorithm, where image to image distance metric is computed using nonrigid registration, is applied on 2-D echocardiography images of one cycle of heart. Using this approach, the nonlinear information of these images is embedded in a 2-D manifold and each image is characterized by a symbol on the constructed manifold. This new representation visualizes the relationship between these images based on LV volume changes and allows extracting the curve of the LV volume changes automatically. Our method in comparison to the traditional segmentation algorithms does not need any LV myocardial segmentation and tracking, particularly difficult in the echocardiography images. Moreover, a large data set under various diseases for training is not required. The results obtained by our method are quantitatively evaluated to those obtained manually by the highly experienced echocardiographer on ten healthy volunteers and six patients which depict the usefulness of the presented method.