Segmented nitinol guidewires with stiffness-matched connectors for cardiovascular magnetic resonance catheterization: preserved mechanical performance and freedom from heating.

BACKGROUND: Conventional guidewires are not suitable for use during cardiovascular magnetic resonance (CMR) catheterization. They employ metallic shafts for mechanical performance, but which are conductors subject to radiofrequency (RF) induced heating. To date, non-metallic CMR guidewire designs have provided inadequate mechanical support, trackability, and torquability. We propose a metallic guidewire for CMR that is by design intrinsically safe and that retains mechanical performance of commercial guidewires. METHODS: The NHLBI passive guidewire is a 0.035 CMR-safe, segmented-core nitinol device constructed using short nitinol rod segments. The electrical length of each segment is less than one-quarter wavelength at 1.5 Tesla, which eliminates standing wave formation, and which therefore eliminates RF heating along the shaft. Each of the electrically insulated segments is connected with nitinol tubes for stiffness matching to assure uniform flexion. Iron oxide markers on the distal shaft impart conspicuity. Mechanical integrity was tested according to International Organization for Standardization (ISO) standards. CMR RF heating safety was tested in vitro in a phantom according to American Society for Testing and Materials (ASTM) F-2182 standard, and in vivo in seven swine. Results were compared with a high-performance commercial nitinol guidewire. RESULTS: The NHLBI passive guidewire exhibited similar mechanical behavior to the commercial comparator. RF heating was reduced from 13 °C in the commercial guidewire to 1.2 °C in the NHLBI passive guidewire in vitro, using a flip angle of 75°. The maximum temperature increase was 1.1 ± 0.3 °C in vivo, using a flip angle of 45°. The guidewire was conspicuous during left heart catheterization in swine. CONCLUSIONS: We describe a simple and intrinsically safe design of a metallic guidewire for CMR cardiovascular catheterization. The guidewire exhibits negligible heating at high flip angles in conformance with regulatory guidelines, yet mechanically resembles a high-performance commercial guidewire. Iron oxide markers along the length of the guidewire impart passive visibility during real-time CMR. Clinical translation is imminent

Psychometric Properties of Turkish Version of Survey of Activities and Fear of Falling in the Elderly Among Patients with Parkinson's Disease

Objective: Fear of falling (FOF) is one of the important risk factors for falling, is higher in patients with Parkinson's disease (PD). The Survey of Activities and Fear of Falling in the Elderly (SAFFE) differs from other scales in terms of considering the accompanying activity limitation. The aim of the study was to show the psychometric properties of the Turkish version of SAFFE (SAFFE-T) in PD, and to correlate SAFFE FOF subscale scores with age, disease duration, and the Turkish version of Movement Disorder Society Unified Parkinson's Disease Rating Scale-III (MDS-UPDRS-TR-III) motor score

Rare Postsurgical Complication of Atrial Septal Defect Closure: Right Inflow Obstruction Due to Inadvertent Suturing of Eustachian Valve to Interatrial Septum

WOS: 000297990600039PubMed: 22014857We report the case of a 20-year-old woman who received corrective surgery for a secundum atrial septal defect, during which right atrial inflow obstruction developed because of inadvertent suturing of the eustachian valve to the interatrial septum. Although reliable cardiac surgical techniques are available, this rather rare complication may have deleterious results for patients. If a previously absent murmur is detected in the lower left parasternal border after atrial septal defect surgery, right atrial inflow obstruction caused by the eustachian valve should be kept in mind and further careful examination undertaken