Relation of global longitudinal strain to left ventricular geometry in aortic valve stenosis

Background: In patients with aortic stenosis (AS), increased afterload induces changes in left ventricular (LV) geometry to preserve a normal ejection fraction (EF). Nevertheless, myocardial dysfunction may occur in spite of a normal EF. Global longitudinal strain (GLS) analysis can detect subtle contractile dysfunction at a pre-clinical stage. The aim of our study was to assess LV function deteriorations with GLS analysis and the association with geometric changes in patients with AS and normal EF. Methods: Forty four patients with moderate to severe AS and 40 controls were enrolled. All patients underwent echocardiography, including two-dimensional strain imaging. The relative wall thickness and LV muscle mass measurements were performed with magnetic resonance imaging and patients were subdivided into four groups: Group 1 with normal LV, Group 2 with concentric remodeling, Group 3 with eccentric hypertrophy, and Group 4 with concentric hypertrophy. Results: The total group of patients with AS showed a GLS of -15.3 &#177; 3.6% while the control group reached -18.9 &#177; 3.2% (p < 0.001). GLS was lower in the hypertrophy Groups 3 and 4 compared to Groups 1 and 2 (12.9 &#177; 3.4% vs 17.2 &#177; 2.5%, p < 0.05, respectively). Splitting the patients into Groups 1 to 4, the GLS was -17.2 &#177; 2.4%, -17.2 &#177; 2.7%, -12.4 &#177; 3.8% and -13.1 &#177; 3.3, respectively (p = 0.002). Conclusions: In subjects with AS, lower GLS is related to LV hypertrophy, but not to the presence of concentric remodeling. Assessment of GLS can identify subtle contractile dysfunction independent of a preserved EF, and might be useful in identifying patients at high risk for the transition from compensatory to pathological remodeling. (Cardiol J 2011; 18, 2: 151-156

Single Center Retrospective Analysis of Conventional and Radial TIG Catheters for Transradial Diagnostic Coronary Angiography

Current guidelines favor the radial approach for coronary angiography. Therefore, specialty radial diagnostic catheters were designed to engage both coronary arteries with a single device. However, it is unclear if single catheters are superior to conventional catheters. A retrospective analysis was performed of consecutive right radial coronary angiographies to determine catheter use, fluoroscopy time, radiation dosage, and consumption of contrast. Procedures were performed with a single TIG catheter or conventional catheters (CONV). Procedures with coronary artery bypass grafts or ventricular angiographies were excluded. 273 transradial procedures were performed successfully. 95 procedures were performed with CONV and 178 procedures with a TIG. Crossover to additional catheters was higher in TIG (15.2%) compared to CONV (5.3%, p=0.02). Fluoroscopy time was comparable between CONV and TIG, without crossover (2.2±1.2 min versus 2.3±1.2 min; n.s.), however, greater in the case of crossover for CONV (5.8±0.7) and TIG (7.6±3.0; p=0.0001). Radiation dosage was similar in CONV and the TIG, without crossover (1419±1075, cGy∗cm2 versus 1690±1138; n.s.), however, greater for CONV (2374±620) and TIG (3733±2281, p=0.05) with crossover. Overall, the amount of contrast was greater in TIG (56±13 mL) versus CONV (48±3 mL; p=0.0003). CONV femoral catheters may be the primary choice for radial approach

Reduced global longitudinal strain in association to increased left ventricular mass in patients with aortic valve stenosis and normal ejection fraction: a hybrid study combining echocardiography and magnetic resonance imaging

<p>Abstract</p> <p>Background</p> <p>Increased muscle mass index of the left ventricle (LVMi) is an independent predictor for the development of symptoms in patients with asymptomatic aortic stenosis (AS). While the onset of clinical symptoms and left ventricular systolic dysfunction determines a poor prognosis, the standard echocardiographic evaluation of LV dysfunction, only based on measurements of the LV ejection fraction (EF), may be insufficient for an early assessment of imminent heart failure. Contrary, 2-dimensional speckle tracking (2DS) seems to be superior in detecting subtle changes in myocardial function. The aim of the study was to assess these LV function deteriorations with global longitudinal strain (GLS) analysis and the relations to LVMi in patients with AS and normal EF.</p> <p>Methods</p> <p>50 patients with moderate to severe AS and 31 controls were enrolled. All patients underwent echocardiography, including 2DS imaging. LVMi measures were performed with magnetic resonance imaging in 38 patients with AS and indexed for body surface area.</p> <p>Results</p> <p>The total group of patients with AST showed a GLS of -15,2 ± 3,6% while the control group reached -19,5 ± 2,7% (p < 0,001). By splitting the group with AS in normal, moderate and severe increased LVMi, the GLS was -17,0 ± 2,6%, -13,2 ± 3,8% and -12,4 ± 2,9%, respectively (p = 0,001), where LVMi and GLS showed a significant correlation (r = 0,6, p < 0,001).</p> <p>Conclusions</p> <p>In conclusion, increased LVMi is reflected in abnormalities of GLS and the proportion of GLS impairment depends on the extent of LV hypertrophy. Therefore, simultaneous measurement of LVMi and GLS might be useful to identify patients at high risk for transition into heart failure who would benefit from aortic valve replacement irrespectively of LV EF.</p

Enhanced susceptibility to infections in a diabetic wound healing model

<p>Abstract</p> <p>Background</p> <p>Wound infection is a common complication in diabetic patients. The progressive spread of infections and development of drug-resistant strains underline the need for further insights into bacterial behavior in the host in order to develop new therapeutic strategies. The aim of our study was to develop a large animal model suitable for monitoring the development and effect of bacterial infections in diabetic wounds.</p> <p>Methods</p> <p>Fourteen excisional wounds were created on the dorsum of diabetic and non-diabetic Yorkshire pigs and sealed with polyurethane chambers. Wounds were either inoculated with 2 × 10⁸Colony-Forming Units (CFU) of <it>Staphylococcus aureus </it>or injected with 0.9% sterile saline. Blood glucose was monitored daily, and wound fluid was collected for bacterial quantification and measurement of glucose concentration. Tissue biopsies for microbiological and histological analysis were performed at days 4, 8, and 12. Wounds were assessed for reepithelialization and wound contraction.</p> <p>Results</p> <p>Diabetic wounds showed a sustained significant infection (>10⁵CFU/g tissue) compared to non-diabetic wounds (p < 0.05) over the whole time course of the experiment. <it>S. aureus</it>-inoculated diabetic wounds showed tissue infection with up to 8 × 10⁷CFU/g wound tissue. Non-diabetic wounds showed high bacterial counts at day 4 followed by a decrease and no apparent infection at day 12. Epidermal healing in <it>S. aureus</it>-inoculated diabetic wounds showed a significant delay compared with non-inoculated diabetic wounds (59% versus 84%; p < 0.05) and were highly significant compared with healing in non-diabetic wounds (97%; p < 0.001).</p> <p>Conclusion</p> <p>Diabetic wounds developed significantly more sustained infection than non-diabetic wounds. <it>S. aureus </it>inoculation leads to invasive infection and significant wound healing delay and promotes invasive co-infection with endogenous bacteria. This novel wound healing model provides the opportunity to closely assess infections during diabetic wound healing and to monitor the effect of therapeutical agents <it>in vivo</it>.</p

Changes of the eSheath Outer Dimensions Used for Transfemoral Transcatheter Aortic Valve Replacement

Innovative catheter systems with lower-profile sheaths and a dynamic expansion mechanism (DEM) were recently introduced for transcatheter aortic valve replacement (TAVR). However, the labeling of 14 F and 16 F eSheaths denote the inner nominal diameter. Exact changes of the clinically relevant outer diameters during usage are not available. eSheaths were measured every 30 mm using a digital caliper. Unused 14 F and 16 F eSheaths served as controls. Maximum eSheath diameters were measured after insertion of the Edwards Commander Delivery System (ECDS) into 14 F and 16 F eSheaths.Finally, eSheaths were retrieved and measured after TAVR. Outer diameters of control 14 F eSheaths were 5.8 mm and 6.50 mm for the 16 F eSheath. Introduction of the 23 mm and 26 mm ECDS into 14 F eSheaths showed a maximum diameter of 7.65 mm and 7.64 mm (P=NS). Introduction of the 29 mm ECDS into the 16 F eSheath showed the greatest diameter of 8.18 mm (P=0.03). After TAVR, diameters of the 14 F eSheaths were 7.14 mm (23 mm valve) and 7.26 mm (26 mm valve) (P=NS), while 16 F eSheaths were 8.10 mm (29 mm valve) (P≤0.03). Nominal 14 F and 16 F eSheaths showed a significant increase of the outer diameter during advancement of the ECDS and after TAVR implantation