The acoustic field on the forehead of echolocating Atlantic bottlenose dolphins (Tursiops truncatus)

Author Posting. © Acoustical Society of America, 2010. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 128 (2010): 1426-1434, doi:10.1121/1.3372643.Arrays of up to six broadband suction cup hydrophones were placed on the forehead of two bottlenose dolphins to determine the location where the beam axis emerges and to examine how signals in the acoustic near-field relate to signals in the far-field. Four different array geometries were used; a linear one with hydrophones arranged along the midline of the forehead, and two around the front of the melon at 1.4 and 4.2 cm above the rostrum insertion, and one across the melon in certain locations not measured by other configurations. The beam axis was found to be close to the midline of the melon, approximately 5.4 cm above the rostrum insert for both animals. The signal path coincided with the low-density, low-velocity core of the melon; however, the data suggest that the signals are focused mainly by the air sacs. Slight asymmetry in the signals were found with higher amplitudes on the right side of the forehead. Although the signal waveform measured on the melon appeared distorted, when they are mathematically summed in the far-field, taking into account the relative time of arrival of the signals, the resultant waveform matched that measured by the hydrophone located at 1 m.This work was supported by the U.S. Office of Naval Research

Carotid artery stenting protected with an emboli containment system

Background and Purpose—Fear of distal embolization and stroke has aroused concern regarding carotid stenting. Devices to protect the cerebral circulation may make carotid stenting safer. Methods—A multidisciplinary study group tested a balloon occlusion-aspiration emboli entrapment device in conjunction with carotid stenting. The device consists of an elastomeric balloon on a steerable wire with a detachable adapter that inflates and deflates the distal temporary occlusion balloon. An aspiration catheter is used to remove trapped emboli after stenting and before occlusion balloon deflation. Results—Seventy-five patients with severe internal carotid artery stenosis were treated with stents deployed with this cerebrovasculature protection system. All 75 patients (100%) had grossly visible particulate material aspirated, and all were treated successfully without major or minor stroke or death at 30 days. Preintervention stenosis was 81 10%, and residual stenosis was 5 7%. Nine patients (12%) had angiographic evidence of thrombus before intervention, but no patient had thrombus or vessel cutoff after the procedure. Four patients (5%) developed transient neurological symptoms during protection balloon occlusion, but symptoms resolved with balloon deflation. The 22 to 667 particles aspirated per patient ranged from 3.6 to 5262 m in maximum diameter (mean, 203 256 m). These particles included fibrous plaque debris, lipid or cholesterol vacuoles, and calcific plaque fragments. Conclusions—Protected carotid stenting was performed successfully and safely in this study early in the experience with cerebrovascular protection devices. Particulate emboli are frequent with stenting, and cerebral protection will likely be necessary to minimize stroke. Randomized trials comparing protected carotid stenting with endarterectomy are warranted. (Stroke. 2002;33:1308-1314.)Fil: Whitlow, Patrick L.. No especifíca;Fil: Lylyk, Pedro. No especifíca;Fil: Londero, Walter Hugo. No especifíca;Fil: Mendiz, Oscar A.. No especifíca;Fil: Mathias, Klaus. No especifíca;Fil: Jaeger, Horst. No especifíca;Fil: Parodi, Juan. No especifíca;Fil: Schönholz, Claudio. No especifíca;Fil: Milei, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentin

Clinical angiographic and histologic correlates of eetasia after directional coronary atherectomy

Directional coronary atherectomy can cause ectasia (final area stenosis = 75%, was present in 50% of patients without procedural ectasia and in 70% of patients with marked ectasia (residual area stenosis <-20%; P = 0.12). It is concluded that excision beyond the normal arterial lumen may occur after directional coronary atherectomy, related, in part, to angiographic and procedural features noted at the time of atherectomy. Restenosis tends to occur more often in patients with marked ectasia after coronary atherectomy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30232/1/0000626.pd

Quantitative analysis of factors influencing late lumen loss and restenosis after directional coronary atherectomy

Although encouraging initial results have been demonstrated after directional atherectomy, the mechanisms and predictors of late lumen loss and restenosis after this procedure have not been evaluated. To examine these issues, clinical and angiographic follow-up were obtained in 262 (96%) and 212 (77%) of 274 patients undergoing successful directional coronary atherectomy. Symptom recurrence developed in 87 (33%) patients and angiographic restenosis was found in 93 (44%). Restenosis was highest in restenotic lesions in saphenous vein grafts (78% [95% confidence interval (CI): 56 to 100%]) and lowest in new-onset lesions in the left anterior descending (27% [95% CI: 15 to 39%]) and circumflex (14% [95% CI: 0 to 43%]) coronary arteries. Residual lumen diameter immediately after atherectomy was smaller in re-stenotic lesions (p = 0.002) and in lesions >=10 mm in length (p = 0.02). Late lumen loss was associated with the minimal lumen diameter immediately after atherectomy (p =10 mm in length (p = 0.018), saphenous vein graft lesion location (p = 0.025) and male gender (p = 0.045) were independent predictors for restenosis. It is concluded that restenosis after directional atherectomy is related both to factors resulting in a suboptimal initial result and to factors contributing to excessive late lumen loss. These results may have implications for lesion selection in patients undergoing directional coronary atherectomy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30957/1/0000629.pd

ACC/AHA/SCAI 2005 Guideline Update for Percutaneous Coronary Intervention - Summary article: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention)

The American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions (ACC/AHA/SCAI) 2005 Guideline Update for Percutaneous Coronary Intervention (PCI) contains changes in the recommendations, along with supporting text. For the purpose of comparison, this summary contains a list of the updated recommendations (middle column) alongside a list of the 2001 recommendations (left column), with each set accompanied by a comment (right column) that provides the rationale for the changes, additions, or deletions (see Table 1). References that support either the 2001 recommendations that have changed or the new or revised recommendations are cited in parentheses at the end of each recommendation or comment. A list of abbreviations is included in the Appendix. The reader is referred to the full-text guideline posted on the World Wide Web sites of the ACC, the AHA, and the SCAI for a more detailed explanation of the changes discussed here. Please note that we have changed the table of contents headings in the 2001 ACC/AHA Guidelines for Percutaneous Coronary Intervention from roman numerals to unique identifying numbers