Biomedical subjects

Michael Weidenbach

Publications and source records attributed to Michael Weidenbach.

3 recordsLinked to original sources

PubMed2006

Hypoplastic left heart syndrome with intact atrial septum--attempt of an interventional palliation by ductal and interatrial stent implantation.

In patients with hypoplastic left heart syndrome (HLHS) and intact atrial septum, the blood entering the left atrium cannot egress. Emergency treatment interventionally or surgically is mandatory immediately after birth. We describe a patient with HLHS and intact atrial septum who underwent successful transvenous atrial septostomy immediately after birth. When the interatrial communication became restrictive, stent implantation into the arterial duct and into the atrial septum was performed on the 7th day of life. Despite good hemodymanic response, the lung damage was severe and persistent, rendering staged surgical correction impossible. The child died on the 23rd day of life. Autopsy showed patent and correct placed stents in the duct and the atrial septum. There was severe dilatation of pulmonary lymphatic and venous vessels, suggestive of long-standing pulmonary venous hypertension. In conclusion, this form of HLHS has a poor prognosis despite early and aggressive interventional treatment.

Catheterization↗

PubMed2006

Intracardiac thrombus causing systemic embolism in a child with idiopathic ventricular tachycardia and heterozygous activated protein C resistance.

Systemic embolism in childhood is rare but often disastrous. Most often the concomitant occurrence of more than one prothrombotic factor is responsible for the acute event. We report on a child in whom an intracardiac thrombus embolized into the descending aorta resulting in subtotal occlusion. Causative for thrombus formation was an idiopathic ventricular tachycardia and a heterozygous activated protein C resistance, both previously unknown. Immediate surgical thrombectomy was successful without sequelae. Antithrombotic and antiarrhythmispioproptylactic treatment was started afterwards. We suggest that in cases of longstanding or repeated tachycardia and in children after thromboembolic events diagnostic work-up for thrombophilia should be undertaken.

Child, Preschool↗

PubMed2005

Computer-based training in two-dimensional echocardiography using an echocardiography simulator.

Two-dimensional (2D) echocardiography is a user-dependent technique that poses some inherent problems to the beginner. The first problem for beginners is spatial orientation, especially the orientation of the scan plane in reference to the 3-dimensional (3D) geometry of the heart. The second problem for beginners is steering of the ultrasound probe. We have designed a simulator to teach these skills. On a computer screen a side-by-side presentation of a 3D virtual reality scene on the right side and a 2D echocardiographic view on the left side is given. The virtual scene consists of a 3D heart and an ultrasound probe with scan plane. The 2D echocardiographic image is calculated from 3D echocardiographic data sets that are registered with the heart model to achieve spatial and temporal congruency. The displayed 2D echocardiographic image is defined and controlled by the orientation of the virtual scan plane. To teach hand-eye coordination we equipped a dummy transducer with a 3D tracking system and placed it on a dummy torso. We have evaluated the usability of the simulator in an introductory course for final-year medical students. The simulator was graded realistic and easy to use. According to a subjective self-assessment by a standardized questionnaire the aforementioned skills were imparted effectively.

Adult↗