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Biomedical subjects

H Mannebach

Publications and source records attributed to H Mannebach.

At least 73 records · Page 4Linked to original sources
PubMed1982

[Clinical follow-up of patients after valve replacement with Omniscience cardiac valves: can this valve be recommended? (author's transl)].

Clinical evaluation of 9 patients, after valve replacement with Omniscience cardiac valves (5 with aortic, 4 with mitral valve replacement) showed opening angles significantly lesser than the theoretical in-vitro valve of 80 degrees opening angles were essential by cineangiography. In 3 of 4 patients with mitral valve replacement, reoperation became necessary due to prosthetic valve dysfunction. Thus the implantation of Omniscience cardiac valves cannot be recommended.

Adult↗
PubMed1982

[Hemodynamics of the St. Jude Medical aortic prosthesis in comparison to the Björk-Shiley and Lillehei-Kaster prostheses].

Pre- and postoperative hemodynamic data in 10 patients in whom the aortic valve was replaced by a St. Jude Medical (SJM) prosthesis are compared with those in 29 patients who received a Lillehei-Kaster tilting disk (LK) valve prosthesis and 11 patients with a Björk-Shiley tilting disk (BS) valve prosthesis. The SJM aortic prosthesis of the small size (A 21) has advantages over the LK and BS types, and it is therefore particularly suited to use in a small aorta. There are also good hemodynamic results for the larger sizes of the SJM prosthesis. As a result of the 85-degree opening angle and the favorable ratio between the inner and outer diameters of the valve (suture ring), there is only minor impedance of blood flow. The SJM aortic prosthesis thus involves a lesser degree of hemolysis than the BS and the LK. In spite of the promising hemodynamic data, however, long-term findings on the durability of the SJM prosthesis in vivo have not yet been published. It therefore seems to us justifiable, especially where the aorta is large, to continue to use BS prostheses.

Aged↗
PubMed1981

Influence of heart rate on systolic time intervals: effects of atrial pacing versus dynamic exercise.

The effects of atrial pacing and dynamic exercise in the supine position on systolic time intervals (STI) were compared in 10 normals. In another group of 13 normals, the effect of exercise alone on STI was tested. A linear shortening of electromechanical systole (QS2) and left ventricular ejection time (LVET) with increasing heart rate was demonstrated with right atrial pacing and dynamic exercise in the frequency range between 60 and 140 beats/min. However, the shortening of LVET was significantly less (p less than 0.01) with exercise compared to pacing. This is explained by an increase in left ventricular stroke volume with exercise. The preejection period (PEP) was significantly (p less than 0.001) shortened with exercise, but there was no change with atrial pacing. Thus, changes in heart rate (HR) alone, without changes in the dynamic state of the heart, did not influence PEP. It is suggested that PEP at rest should not be corrected for heart rate. The supine exercise regression equations for correction of heart rate for LVET and PEP differ from both the resting and the upright exercise regression equations. With exercise a frequency correction of STI using regression equations should be abandoned. Instead, uncorrected STI at standard heart rates (e.g., 100, 110, and 130 beats/min) should be taken for comparison. Heart rate standardization should be employed using the formula: Formula (See Text).

Adult↗
PubMed1980

[Electrical standstill of the heart for 24 hours after intravenous administration of verapamil (author's transl)].

In a 47-year-old man suffering from sick-sinus syndrome the sinus node recovery time was determined. During rapid atrial stimulation a supraventricular tachycardia occurred. The intravenous administration of 10 mg Verapamil was followed by total electrical standstill of the heart lasting for more than 24 hours and requiring pacemaker therapy. This case demonstrates that the intravenous administration of Verapamil may be harmful.

Cardiac Pacing, Artificial↗
PubMed1979

[Long-term treatment of bradycardia by means of an atropine ester (SCH 1000). Electrophysiological and clinical results].

Electrophysiological effects of the atropin ester Ipatropiumbromide (SCH 1000) were investigated in 15 patients by His electrocardiography and high frequency atrial stimulation. Heart rate increased by 50% of base line heart rate, PA- and AH-intervals and sinus node recovery time decreased, the HF-interval remained unchanged. Physiological av-block by atrial stimulation occurred at significant higher stimulation frequencies with SCH 1000 than without medication. Additional 15 patients were treated for a longer follow-up period. Increase of resting heart rate averaged 15%. Equivocal effects on heart rate were found with exercise after SCH 1000. Non-cardiac side effects were found in 5 patients.

Adult↗
PubMed1979

[Non-invasive effects of cigarette smoking on left ventricular function at rest and with exercise in normal individuals (author's transl)].

The effect of cigarette smoking on systolic time intervals at rest, with volume overload and with dynamic exercise was studied in nine healthy cigarette smokers. For heart rate, PEP, LVET and blood pressure, reactions to smoking demonstrated considerable interindividual variations with comparable work loads and volume loads. More than half of the subjects developed significant left ventricular dysfunction by these parameters after smoking ten cigarettes. The negative inotropic effect was felt to be caused in these subjects by carbon monoxide. The remaining subjects did not show left ventricular dysfunction with smoking. In these subjects the stimulating effect of nicotine on the nervous system was covering the negative inotropic effect of carboxy hemoglobin.

Adult↗