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Biomedical subjects

U Gleichmann

Publications and source records attributed to U Gleichmann.

At least 127 records · Page 7Linked to original sources
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

[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↗
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

[Preliminary experience with the catheter dilatation of coronary artery stenoses (author's transl)].

The method of percutaneous transluminal coronary angioplasty (PTCA) may in selected cases dramatically improve myocardial blood supply. Seven attempts were made between September and December 1978 at the Gollwitzer-Meier Institute of Cardiology; three dilatations were unsuccessful, two were moderately successful and two highly successful. The problems as to methodology and selection of patients submitted to this procedure are discussed.

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↗
PubMed1978

[Left ventricular dynamics with exercise after revascularization in advanced coronary heart disease (author's transl)].

66 patients with 2 and 3 vessel coronary heart disease were studied before and after complete successful revascularization. Hemodynamic measurements and biplane left ventricular angiograms were obtained at rest and during supine bicycle exercise.--After operation a significant overall decrease of LVEDP with exercise was seen; exercise LVEF increased in cases with left main disease and in most cases with double vessel disease and double bypass. Inconsistant response was present in 3 vessel disease. Improvement of left ventricular dynamics with exercise in advanced coronary disease after complete revascularization can be expected mainly in 2 vessel disease and left main coronary disease.

Angiocardiography↗
PubMed1977

[Cardiac output determination by respiratory gas exchange measurement during submaximal exercise (author's transl)].

Under linearly increasing work load the point of rise of the ventilatory equivalent for oxygen (VEO = V(E)/V(O2) depends upon the degree of cardiac output increment. The latter being low, the slope of the minute ventilation (V(E) curve is correspondingly steep and that of the oxygen consumption (V(O2) curve flat. Consequently, the upslope of VEO (after an initial downslope) begins earlier in case of a poor cardiac exercise performance, and vice versa. By means of continuous measurement of respiratory data with a pneumotachygraphic system and on the basis of the values of V(O2), O2-pulse and Relative Ventilatory Equivalent (= VEO/V(O2) determined at the point of rise of VEO it was possible to divide 126 patients (mostly with coronary heart disease) into 4 groups of different cardiocirculatory capacity. These differed significantly with respect to the values measured at the point of rise of VEO as well as with respect to those related to work load. There ist good reproducibility of the values determined at the point of rise of VEO. The described method represents a rapid non-invasive means of determining different stages of impairment of cardiac pump function.

Blood Gas Analysis↗