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Biomedical subjects

W Bircks

Publications and source records attributed to W Bircks.

At least 109 records · Page 6Linked to original sources
PubMed1980

[Demonstration of retrograde block in a patient with preexcitation syndrome by intraoperative electrophysiological studies (author's transl)].

In a patient with a WPW syndrome, the electrophysiological investigation revealed a left-sided bypass conducting only in antegrade (A-V) direction. During right ventricular stimulation, there was a complete retrograde (V-A) block. Therefore no reentry tachycardia could be initiated. The patient was operated upon because of an aortic valve lesion. During operation the bypass was localized at the free wall of the mitral annulus by epicardial mapping. Even during direct stimulation at the ventricular insertion of the bypass, no retrograde conduction to the left atrium could be demonstrated. After ablation of the bypass by surgery, intra- and postoperative electrophysiological studies showed a normal antegrade activation pattern of the ventricles. The case reported demonstrates that the "heterodromia" of an accessory bypass can markedly influence the clinical setting in the WPW syndrome.

Action Potentials↗
PubMed1979

[The clinical relevance of intraoperative electrophysiologic mapping (author's transl)].

Electrophysiological intraoperative mapping is described as a technique for identification of the specialized AV conduction system during open heart surgery; furthermore it is suitable for delineating the morphological origin of ventricular tachycardias which requre surgical therapy. The mapping technique is described with respect to its methodical aspects and illustrated by means of congenital and acquired heart disease.

Bundle of His↗
PubMed1979

Surgery of life-threatening ventricular tachyarrhythmias associated with ventricular aneurysm.

In 11 patients with left ventricular aneurysm and ventricular tachyarrhythmia unresponsive to conventional antiarrhythmic therapy surgical treatment was performed by resection of the aneurysm. One patient underwent epicardial electrophysiological mapping intraoperatively, and the site of earliest activation during tachycardia was established. One patient did 11 hours postoperatively. Three patients are cured from their tachycardia 3 to 22 months after surgery. Six patients have still persistent premature ventricular beats which are now controlled satisfactorily with antiarrhythmic drugs. Our results demonstrate the therapeutic value of aneurysmectomy in the treatment of related ventricular tachyarrhythmias. The practical relevance of intraoperative electrophysiological mapping procedures for localizing the origin of ventricular tachyarrhythmias is a subject which merits further discussion.

Adult↗
PubMed1979

Intraoperative electrophysiologic mapping during cardiac surgery.

Intraoperative mapping is a method to document the surgical anatomy of cardiac tissues with electrophysiologic importance cartographically at time of surgery. The presented communication gives a survey of the present status of the technique of electrophysiologic mapping and its essential clinical applications. Special attention in this regard is directed to the intraoperative identification of the specialized AV conduction system in congenital cardiac malformations with unpredictable location of His bundle, to the detection of accessory AV bundles in patients with the Wolff-Parkinson-White syndrome and to the intraoperative morphological study of ventricular reentry tachycardias. Suitable technical equipment for "clinical" intraoperative electrophysiologic mapping is described in detail.

Cardiac Surgical Procedures↗
PubMed1979

Flow measurements and simultaneously performed angiography of aorto-coronary bypass grafts during bypass surgery.

The function of aorto-coronary bypass grafts is usually assessed by the run-off, determined from postoperatively performed cineangiograms. The reliability of this method was tested by comparing the electromagnetically measured graft flow with the run-off, qualitatively estimated from cineangiograms. The electromagnetic flow measurements and cineangiography were performed simultaneously during bypass surgery. The run-off was classified by three independent observers into three classes (poor, moderate, and good). The average mean flow rates corresponding to the three classes were: poor: Q = (43 +/- 11)ml/min; moderate: Q = (48 +/- 14)ml/min; good; Q = (63 +/- 22)ml/min. Although the differences between the flow rates of the three classes were found significant (except between poor and moderate run-off), there was a wide range of overlapping. Especially in grafts with low flow rates (Q less than 70 ml/min) there were pronounced disagreements between the qualitative estimation of flow and the electromagnetically measured flow. Using videodensitometric flow measurements as a check test, the uncertainties in classification proved to be caused by the lack of reliability of the observer. The flow rates in aorto-coronary bypass grafts can be determined reliably only by means of quantitative methods, e.g., electromagnetic or videodensitometric flow measurements.

Angiography↗
PubMed1979

[Echocardiographic observations in malfunctioning heart valves due to thrombosis (author's transl)].

The study includes two patients with obstruction of prosthetic heart valves by thrombosis. In the first patient, a thrombus attached to the ventricular side of the cage of a Smeloff-Cutter mitral prosthesis caused incomplete excursion of the ball in most cardiac cycles, which was detected by echocardiography. In the second patient a thrombosis of the atrial and ventricular side of a Lillehei-Kaster mitral prosthesis delayed opening of the disc. The initial part of the opening movement was "rounded", the excursion of the disk diminished. The cases presented indicate that in patients whose condition deteriorates after prosthetic valve replacement, echocardiography can help identify the cause. In particular, the technique makes it possible to differentiate between valvular dysfunction and muscular insufficiency of the left ventricle. Comparison with recordings obtained in the early postoperative period facilitate the detection of a malfunctioning prosthesis.

Echocardiography↗
PubMed1979

Mitral atresis with normal-sized ventricles, ventricular septal defect, and dextro-transposition of the great arteries.

A case is described of mitral atresia, patent foramen ovale, subcristal ventricular septal defects (VSD), and dextro-transposition of the great arteries (d-TGA), coexisting with a normal-sized left ventricle and normal-sized great arteries in a 6 8/12-year old girl. The discussion is related to anatomic, embryologic, and surgical aspects of this particular condition, which, to our knowledge, has never been documented before.

Angiocardiography↗
PubMed1979

[Electrophysiological mapping during open-heart surgery (author's transl)].

Intraoperative electrophysiological mapping provides a method to identify the specialized atrioventricular conduction system and to localize the morphological origin of different tachycardiac rhythm disorders at time of surgery. The basic technical aspects and methodical implications are presented with respect to its clinical applications.

Atrioventricular Node↗
PubMed1979

[Cardiac surgery in the 7th and 8th decade (author's transl)].

Progress in cardiovascular surgery and the growing amount of older people made it possible and necessary to extend open-heart-surgery to patients between 60 and 75 years of age. From 1970 to 1978 174 cardiac procedures (mostly for valve replacement and aorto-coronary-vein-bypass) were performed in this group of older patients. The total mortality rate was 18.3%. These results which have to be improved in several areas demonstrate clearly that surgery is of real benefit for these older, properly selected patients; the operative risk seems to be acceptable.

Aged↗
PubMed1978

[The dissecting of aortic aneurysm].

In the light of the literature and a critical analysis of the author's own results, guidelines for therapy of aortic dissection from the surgical viewpoint are recommended. In cases of dissection of the ascending aorta, surgery should be performed as soon as possible. Only in special cases without complications can surgery be delayed with pump team standby. In uncomplicated cases of dissection of the descending thoracic aorta, medical therapy appears to be the method of choice. Some life-threatening situations render surgery inevitable. Surgical treatment of dissection of the aortic arch is indicated only on an ultima ratio basis.

Aortic Dissection↗
PubMed1978

[Results of endarterectomy in coronary artery surgery (author's transl)].

In a series of 432 aortocoronary bypass procedures endarterectomies were performed in 58 patients (13.4%) on 60 coronary arteries. Except of two vein patch grafts all endarterectomized arteries were bypassed with a saphenous vein graft. The majority of the patients had an endarterectomy of the right coronary artery. Clinical control investigations were performed in 43 out of 47 survivors including 30 with coronary angiograms 5.2 months (mean) after surgery. 26 out of 31 endarterectomized arteries (83.9%) were open angiographically whereas the patency rate to non-endarterectomized arteries of the same patients was 86.4%. The hospital mortality was high; 11 out of 58 patients (19%) deceased. All patients who died postoperatively had a three vessel disease with diffuse coronary sclerosis. Only three had no myodardial infarction prior to surgery, seven had one to four infarctions before surgery. The relatively high mortality intends for the future a more strict revision of the indications for coronary surgical procedures. But not in all cases the preoperative coronary angiograms and ventriculograms allow a clear estimation of the local arterial conditions.

Coronary Artery Bypass↗