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Harald Schmidt

Publications and source records attributed to Harald Schmidt.

24 records · Page 2Linked to original sources
PubMed2003

Mechanical occlusion of the left atrial appendage.

INTRODUCTION: Oral anticoagulation therapy reduces significantly the risk of thromboembolism in patients with atrial fibrillation. However, effective oral anticoagulation therapy is not feasible in all patients. The interventional occlusion of the left atrial appendage may reduce the risk of thromboembolism in the latter patients. The aim of this prospective study was to assess the feasibility, safety, and technical aspects of interventionally occluding the left atrial appendage. METHODS AND RESULTS: The left atrial appendage was interventionally occluded with the new PLAATO device in nine patients. Serial transthoracic and transesophageal echocardiographic studies and neurologic assessment were performed prior to and during the procedure, and <48 hours, 3 months, 6 months, and 1 year after the procedure. Contraindications to oral anticoagulation were bleeding complications in 6 of 9 cases, cerebral aneurysm in 1, and allergies to warfarin therapy in 2 of 9. Baseline echocardiographic studies demonstrated spontaneous echo contrast grade 3 +/- 1, peak emptying velocities of 0.26 +/- 0.12 m/sec, and excluded atrial thrombi in all cases. Interventional occlusion was feasible in all cases. One patient had a minor plexus paresis that resolved within 4 weeks after the procedure. Neurologic assessment during a mean follow-up of 5 +/- 4.4 months did not demonstrate any new neurologic complications. Serial echocardiographic assessment excluded the formation of thrombi on the implanted device and demonstrated its complete thrombosis after 6 months. One patient developed a minimal pericardial effusion 48 hours after the procedure that resolved within 3 months. CONCLUSION: Interventional occlusion of the left atrial appendage is feasible and safe in patients with atrial fibrillation and contraindications to oral anticoagulation therapy. Furthermore, no neurologic complications, development of atrial thrombi, or thrombus formation on the device were observed during follow-up. Future prospective studies are needed to clarify the long-term treatment effect of this new technique.

Anti-Arrhythmia Agents↗
PubMed2003

A prospective and randomized comparison of the safety and effects of therapeutic levels of enoxaparin versus unfractionated heparin in chronically anticoagulated patients undergoing elective cardiac catheterization.

Consecutive patients with atrial fibrillation and/or prosthetic heart valves, receiving chronic anticoagulation with phenprocoumon and scheduled to undergo cardiac catheterization, were randomized to subcutaneous enoxaparin twice daily (n = 32) or intravenous UFH (n = 36). Cardiac catheterization was performed at an international normalized ratio <1.5. Activated partial thromboplastin times and levels of anti-Factor Xa activity were measured daily. The time until effective anticoagulation (primary endpoint) was significantly shorter for enoxaparin than for UFH (1.1 +/- 0.4 days versus 3.7 +/- 2.5 days, p<0.0001). The percentage of days of effective anticoagulation was significantly higher in the enoxaparin group than in the UFH group (93.3 +/- 9.5% versus 53.7 +/- 26.6%, p <0.0001). In conclusion, enoxaparin achieves therapeutic levels of anticoagulation more rapidly and consistently than UFH in chronically anticoagulated patients with prosthetic heart valves and/or atrial fibrillation undergoing cardiac catheterization.

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PubMed2002

DUG is a novel homologue of translation initiation factor 4G that binds eIF4A.

To elucidate the molecular mechanisms of cell death, we have cloned a new gene, designated death-upregulated gene (DUG), from rat insulinoma cells. DUG is constitutively expressed at very low levels in normal cells but is dramatically upregulated in apoptotic cells following serum/glucose starvation or death receptor ligation by Fas ligand. The DUG mRNA is present in two splicing forms: a long form that encodes a protein of 469 amino acids and a short form that gives rise to a polypeptide of 432 amino acids. The predicted DUG protein sequence contains two putative nuclear localization signals and multiple phosphorylation sites for protein kinases and two conserved MA3 domains. Importantly, DUG is homologous to eukaryotic translation initiation factor (eIF) 4G and binds to eIF4A presumably through MA3 domains. Upon transfection, DUG inhibits both intrinsic and extrinsic pathways of apoptosis. Thus, DUG is a novel homologue of eIF4G that regulates apoptosis.

Amino Acid Sequence↗
PubMed2002

Software-supported image quantification of angiogenesis in an in vitro culture system: application to studies of biocompatibility.

Healing of soft tissue trauma and bone discontinuities following implantation involves acute inflammatory reactions and the formation of blood vessels (angiogenesis). During angiogenesis new capillary vessels arise from the existing vasculature. Endothelial cells (EC) are the major cell type involved in angiogenesis. Corrosion of orthopaedic metallic implant materials (e.g. CoCr alloys) can cause locally high concentrations of heavy metal ions in the peri-implant tissues. Some divalent metal ions (Co2+, Ni2+, Zn2+) lead to the activation of EC in vitro. Upon exposure to these ions. EC release cytokines and chemokines and increase the expression of cell surface adhesion molecules, which represents the pro-inflammatory phenotype. In this study we have examined whether metal ions influence the other endothelial aspect of wound healing, the angiogenic response. Therefore, we utilized an in vitro model of angiogenesis and examined the effects of divalent cobalt ions on the in vitro vessel formation. The quantification of the cobalt/ion-exerted effects on angiogenesis in vitro was performed using a contrast-rich vital staining and analysed by software-supported image quantification.

Alloys↗
PubMed2002

Use of transesophageal contrast echocardiography for excluding left atrial appendage thrombi in patients with atrial fibrillation before cardioversion.

Transesophageal echocardiographic (TEE) guidance of cardioversion in patients with atrial fibrillation is an alternative method to conventional anticoagulation. Although TEE is considered the gold standard for excluding left atrial (LA) thrombi, in some patients dense spontaneous echo contrast (SEC) and artifacts may hamper the identification or exclusion of LA thrombi. Often those patients are refused cardioversion. The purpose of this study was to determine whether the application of echo contrast (Optison, Mallinckrodt, San Diego, Calif) facilitates the exclusion of LA appendage thrombi in this patient group and allows for safer cardioversion. Forty-one patients with atrial fibrillation and dense SEC or inconclusive TEE findings were given echo contrast. Fourteen patients with sinus rhythm served as control participants. Echo contrast completely reduced artifacts in 13 of 22 patients. In 12 of 19 patients with SEC, the LA appendage was completely filled after the application of echo contrast and, thus, SEC was completely suppressed. In 13 of 41 patients, it was filled incompletely and in 9 of 41 patients, a new mass resembling a thrombus was detected. In total, of 25 of 41 patients with inconclusive TEE findings an atrial thrombus was definitively excluded. Those patients underwent cardioversion. None of those patients had a cerebral embolic complication as assessed by cranial magnetic resonance imaging. Thus, the application of echo contrast may facilitate the TEE exclusion of LA appendage thrombi and, hence, improve the safety of TEE-guided cardioversion.

Aged↗