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Biomedical subjects

Ted Feldman

Publications and source records attributed to Ted Feldman.

At least 37 records · Page 2Linked to original sources
PubMed2004

Beating heart catheter-based edge-to-edge mitral valve procedure in a porcine model: efficacy and healing response.

BACKGROUND: Surgical edge-to-edge repair has been used in the treatment of mitral regurgitation. We evaluated the ability of a catheter-delivered clip (Evalve, Inc) to achieve edge-to-edge mitral valve approximation without cardiopulmonary bypass and the healing response of this technique. METHODS AND RESULTS: Twenty-one pigs underwent general anesthesia and left thoracotomy. A 10F flexible delivery catheter with a clip was placed into the left atrium. With echocardiographic and fluoroscopic guidance, the clip grasped and approximated the mid portion of the anterior and posterior leaflets. After a double orifice had been confirmed, the clip was detached and the catheter withdrawn. All animals survived and had successful clip placement. Three animals were euthanized at 4 weeks, 9 at 12 weeks, 1 at 17 weeks, 7 at 24 weeks, and 1 at 52 weeks. The clip was well positioned, with leaflet approximation in all animals except 1, in which the clip separated from the posterior leaflet at 4 weeks without affecting valve function. The clip was modified and implanted in 4 pigs; all were intact at 12 to 24 weeks. Scanning electron microscopy showed clip encapsulation with complete endothelialization. Mitral stenosis and thromboembolism did not develop. Two animals developed endocarditis (1 at 12 weeks and 1 at 17 weeks). Progressive healing occurred in all other animals. CONCLUSIONS: Edge-to-edge mitral valve approximation can be successfully and reliably achieved with a catheter-delivered clip without cardiopulmonary bypass, resulting in durable healing. The success of this device supports the development of a percutaneous catheter-based system for mitral valve repair.

Animals↗
PubMed2004

Non-invasive assessment of mitral valve area during percutaneous balloon mitral valvuloplasty: role of real-time 3D echocardiography.

BACKGROUND: In the last decade, multiple studies depicted discrepancies between mitral valvular orifice area (MVA) measurements obtained with the pressure half-time (PHT) method and invasive methods during the immediate post-percutaneous mitral valvuloplasty (PMV) period. Our aim was to assess the accuracy of Real-Time 3D echo (RT3D) to measure the MVA in the immediate post-PMV period. The invasively determined MVA was used as the gold standard. METHODS AND RESULTS: We studied 29 patients with rheumatic mitral stenosis from two centres (27 women; mean age 48.2+/-11.3 years), all of which had underwent PMV. MVA was calculated before and after PMV using the PHT method, 2D echo planimetry, RT3D echo planimetry and invasive determination (Gorlin's method). The RT3D MVA assessment showed a better agreement with the invasively derived MVA before and in the immediate post-PMV period (Bland-Altman analysis: Average difference between both methods and limits of agreement: 0.01 (-0.31 to 0.33) cm(2) and -0.12 (-0.71 to 0.47) cm(2)) before and immediately after the PMV, respectively. CONCLUSIONS: RT3D is a feasible and accurate technique for measuring MVA in patients with RMVS. It has the best agreement with the invasively determined MVA, particularly in the immediate post-PMV period.

Adult↗
PubMed2004

Management strategies for cardiogenic shock.

PURPOSE OF REVIEW: Cardiogenic shock remains the most serious complication of acute MI, with an incidence of 6 to 8% and a 30-day mortality rate that remains close to 50%. While cardiogenic shock is due primarily to left ventricular failure, other causes such as acute mitral regurgitation and ventricular septal rupture must always be considered as emergency surgery may be life saving. The purpose of this review is to summarize recent advances in the care of these critically ill patients including the consideration of etiology and pathophysiology as well as the influence of age and adjunctive therapies. RECENT FINDINGS: Early revascularization is now an American College of Cardiology/American Heart Association guideline class 1 indication for percutaneous coronary intervention (PCI) particularly for younger patients in cardiogenic shock. Recent studies suggest there may also be a benefit in elderly patients with cardiogenic shock. SUMMARY: Prompt triage of all patients in cardiogenic shock for early angiography, intra-aortic balloon pump counterpulsation, and early revascularization with PCI or bypass surgery is now the preferred management strategy.

Aged↗
PubMed2003

Endovascular edge-to-edge mitral valve repair: short-term results in a porcine model.

BACKGROUND: The edge-to-edge technique is an accepted method for the surgical repair of a regurgitant mitral valve. This study reports the initial use of an endovascular technology that enables a double-orifice edge-to-edge mitral valve repair without cardiopulmonary bypass in an animal model. METHODS AND RESULTS: Adult pigs (n=14) were anesthetized, and left thoracotomy was performed for epicardial echo imaging. Using femoral vein access, a steerable guide catheter was placed transseptally into the left atrium. An implantable clip designed to grasp and approximate the middle scallops of the anterior and posterior mitral leaflets was introduced through the guide catheter. The clip was opened in the left atrium, advanced through the mitral orifice, and retracted to grasp the leaflet edges. When a functional double-orifice valve was confirmed by echo, the clip was closed to coapt the leaflets and detached from the delivery catheter. Before final clip detachment, echo demonstrated a double orifice in all 14 animals. In 2 studies, the clip released from the anterior mitral leaflet. Retrospective analysis of echo images indicated an incomplete grasp of the anterior leaflet. Immediate postmortem examination revealed that the clip successfully approximated the middle scallops of the anterior and posterior leaflets in all 12 double-orifice studies. CONCLUSIONS: This study demonstrates for the first time that an endovascular system can be successfully used to perform the edge-to-edge repair technique in a nondiseased porcine model. This technique is potentially applicable as a percutaneous catheterization laboratory procedure for the treatment of mitral regurgitation in humans.

Animals↗
PubMed2003

Accuracy of mitral valve area measurements using transthoracic rapid freehand 3-dimensional scanning: comparison with noninvasive and invasive methods.

OBJECTIVE: The feasibility and accuracy of direct transthoracic 3-dimensional (3D) mitral valve area (MVA) measurements obtained using freehand scanning was investigated in patients with mitral stenosis. METHODS: A total of 30 patients (26 women, 4 men; aged 55 +/- 13 years) underwent a 2-dimensional (2D) and Doppler study 1 hour before percutaneous balloon mitral valvuloplasty. Transthoracic freehand data were acquired using a magnetic receiver attached to a broadband transducer, gated to electrocardiography and respiration. Volumetric MVA measurements from the left ventricle and left atrium were obtained and compared with MVA measurements derived from 2D planimetry, pressure half-time, and proximal isovelocity surface area. Invasive Gorlin MVA measurements were the gold standard for comparison. RESULTS: In all, 29 patients (97%) had 3D data allowing MVA measurements. Direct 3D measurements from the left ventricle had the least bias (0.06 +/- 0.19 cm(2)) and tightest limits of agreement (-0.44 to 0.32) compared with left atrium measurements (0.17 +/- 0.25 cm(2) and -0.67 to 0.33, respectively). The proximal isovelocity surface area method (bias: 0.09 +/- 0.34 cm(2)) was the most accurate of all 2D methods followed by pressure half-time (0.17 +/- 0.36 cm(2)) and planimetry (0.21 +/- 0.29 cm(2)). CONCLUSION: Direct 3D MVA measurements from the left ventricle using transthoracic freehand scanning are more accurate than traditional 2D methods.

Adult↗
PubMed2003

Status of femoral closure devices.

Both sealing and suturing closure devices have been shown to shorten hemostasis time, reduce the discomfort of manual or mechanical compression, and allow for earlier ambulation after cardiac catheterization and percutaneous coronary interventions without increasing vascular complications compared with conventional compression techniques. Several studies now report a reduction in vascular complications for percutaneous coronary intervention patients treated with closure devices compared with manual compression with pronounced benefit seen in patients receiving glycoprotein IIb/IIIa receptor inhibitors. Adoption of a simple predeployment femoral angiogram is now standard practice for use of a closure device. In an attempt to develop devices that are safer and more "user friendly," considerable modifications and improvements have been made in newer generation devices. Ultimately, the acceptance of femoral closure devices will depend on which device provides a simple approach with reliable hemostasis and a cost that can justify their incorporation into routine practice.

Cardiac Catheterization↗