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Biomedical subjects

H W Heiss

Publications and source records attributed to H W Heiss.

At least 37 records · Page 2Linked to original sources
PubMed1987

Cardiac energetics after intravenous enoximone in idiopathic dilated cardiomyopathy.

The acute effects of enoximone on left ventricular (LV) function, myocardial oxygen metabolism and central and systemic hemodynamics were investigated in 12 patients with idiopathic dilated cardiomyopathy. Enoximone was administered intravenously at a rate of 12.5 mg/min; the average dose was 1.42 mg/kg. LV systolic pressure decreased significantly (p less than 0.01) from 128 +/- 18 to 96 +/- 16 mm Hg (mean +/- standard deviation), LV end-diastolic pressure from 16 +/- 3 to 5 +/- 3 mm Hg, LV end-diastolic volume from 288 +/- 43 to 210 +/- 58 ml, LV end-diastolic wall stress from 33 +/- 15 to 11 +/- 5 10(3) dynes/cm2 and LV peak systolic wall stress from 243 +/- 73 to 159 +/- 42 10(3) dynes/cm2. Heart rate increased from 86 +/- 18 to 100 +/- 20 beats/min, ejection fraction from 43 +/- 7 to 52 +/- 14% (p less than 0.05). Cardiac index, stroke volume index and dP/dtmax did not change significantly. Systemic vascular resistance decreased significantly (p less than 0.01) from 1,311 +/- 444 to 1,027 +/- 356 dynes s cm-5, mean pulmonary artery pressure from 13 +/- 6 to 8 +/- 2 mm Hg, mean right atrial pressure from 4 +/- 2 to 2.6 +/- 2 mm Hg and mean arterial pressure from 95 +/- 13 to 74 +/- 13 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Hemodynamics and myocardial oxygen metabolism of pulsus alternans in patients with dilative cardiomyopathy.

The hemodynamic and myocardial energetic changes due to pulsus alternans were investigated by left and right heart catheterization and by oxygen consumption measurements in three patients with dilative cardiomyopathy. In all three patients, pulsus alternans developed after intravenous administration of the phosphodiesterase inhibitor enoximone. Following enoximone (Patients 1/2/3), left ventricular peak systolic pressure was reduced, in the respective patients, from 100/103/115 mmHg (normal beat) to 91/96/94 mmHg (strong beat) and further to 59/80/85 mmHg (weak beat); left ventricular end-diastolic pressure was reduced from 24/23/22 mmHg (normal beat) to 5/10/6 mmHg (strong beat) and further to 3/7/4 mmHg (weak beat). Cardiac output increased by an average of 16%. Heart rate increased by an average of 12%. Stroke work (during pulsus alternans mean between strong and weak beats) did not change (less than 5%) in any of the three patients. Arterial-coronary-sinus oxygen content difference decreased by 5%/13%/22, respectively. Myocardial oxygen consumption per beat decreased in Patient 1 by 8%, in Patient 2 by 8% and remained unchanged in Patient 3. It is concluded that pulsus alternans occurred in consequence of alternating systolic performance. The alternation in systolic performance most probably resulted from a disturbance in excitation-contraction coupling induced by enoximone. The pronounced reduction of left ventricular preload following administration of enoximone may have augmented further the differences between the strong and the weak beat. A disturbance in myocardial oxygen metabolism was ruled out as the cause of pulsus alternans in these patients.

Adult↗
PubMed1987

Acute and chronic changes of myocardial energetics in the mammalian and human heart.

In earlier studies using papillary muscles of the rat left ventricle and highly sensitive thermopiles we demonstrated that the heat liberated per gram of myocardium per unit of developed tension-time integral is decreased when the rats suffered from hypothyroidism or renal hypertension. This increase in economy of force production was shown to be associated with a decrease in myosin-ATPase activity and a change in isomyosin composition. In a recent study we showed an increase in heat per gram of mammalian myocardium per tension-time integral of 70% after application of isoproterenol. In order to study the relationship between energy costs and developed tension-time integral in the human heart, haemodynamics and myocardial oxygen consumption were measured. The data were obtained using a Millar microtip catheter pressure transducer and the argon method. Haemodynamics and myocardial energetics were analysed in 8 patients without significant heart disease before and after application of isoproterenol and in 10 patients with dilative cardiomyopathy (NYHA II-III). During one cardiac cycle, myocardial oxygen consumption per gram of LV myocardium per beat (MVO2/g x beat) is related to LV stress-time integral (integral of sigma xt). The economy of myocardial contraction (EC) was calculated by (formula; see text) EC was 11.3 +/- 3.2 in normal and 14.3 +/- 4.7 dyn x s x g/cm2 x mu cal in dilative cardiomyopathic hearts (NS). Isoproterenol decreased EC from 11.3 +/- 3.2 to 5.5 +/- 1.6 dyn x s x g/cm2 x mu cal in the normal hearts (p less than 0.01). In the rat myocardium, changes in economy of force generation were found due to catecholamines, pressure overload and hypothyroidism. In the human heart, similar energetic changes were observed due to catecholamines. No significant differences in energy of force production were seen between normal and dilative cardiomyopathic hearts. The effect of catecholamines in the mammalian and human myocardium is explained by changes in activation processes and in chemomechanical energy transduction at the level of the contractile proteins.

Acute Disease↗
PubMed1987

[Angiologic diagnosis and therapy for radiologic interventions in arteriosclerosis obliterans of pelvic and leg vessels].

Angiographic diagnosis and therapy are discussed in relationship to the indications and follow-up of radiological interventions in patients with obliterative atherosclerosis located in the arteries of the pelvis and lower limbs. Various noninvasive diagnostic procedures permit reliable clinical information to be obtained on the localization, extent and geometry of arterial lesions, and the velocity of blood in the vascular system. Determination of symptom-limited ergometry and oscillographic, plethysmographic, Doppler sonographic, light microscopic and magnet resonance techniques are all described in more detail. The therapeutic interventions are mentioned with regard to angiography and percutaneous transluminal angioplasty (PTA), with particular emphasis on the treatment of risk factors, training, and medication. The long-term results are given after PTA for the Freiburg patient series. Thus, the cooperation of angiologists, radiologists and vascular surgeons considerably optimizes the treatment of patients suffering from occlusive arterial disease.

Angiography↗
PubMed1983

[Catheter dilatation of arteries supplying the brain].

Stenoses of the extracranial cerebral arteries can be successfully treated with percutaneous transluminal dilatation (PTD). Early and late results of PTD are comparable to those of vascular surgery, but are not accompanied by its morbidity and mortality rates. In 32 patients with subclavian steal syndrome PTD showed a technical success rate of 88% and a clinical cure rate of 72%. The fibrodysplastic carotid artery stenosis is well suited for PTD. These lesions often extend to the skull base causing difficulties for surgical correction. First experiences with PTD of atherosclerotic carotid artery stenosis are promising, but the efficacy of this procedure must be confirmed by a greater number of treated patients. PTD of the vertebral and basilar arteries present new therapeutic possibilities in the management of vertebrobasilar insufficiency demanding further evaluation.

Adolescent↗
PubMed1982

[Subclavian Steal syndrome-operation or dilation? (author's transl)].

Percutaneous transluminal angioplasty was performed in 15 patients with supra-aortic obstructions. One of two subclavian artery occlusions could not be recanalized. the intervention did ot improve the circulation disturbance in two patients. A favorable treatment effect was observed in 80% of the cases, a result not very different from operative corrections. No complications occurred. The risk of angioplasty of the carotid bifurcation is unknown and, therefore, vascular surgery will remain the preferable method of treating atherosclerotic lesions of this location. In our opinion, angioplasty should be considered when operative correction requires thoracotomy and when the operative risk is increased. This is especially valid in proximal subclavian artery stenosis with and without subclavian steal syndrome, as well as in stenosis at the origin of the vertebral artery.

Adolescent↗
PubMed1981

Comparative echocardiographic examinations in sitting and supine position at rest and during dynamic exercise.

Echocardiograms of 12 healthy male subjects in the supine and sitting positions were obtained. The end-diastolic (EDD) and end-systolic (ESD) diameters of the left ventricle were measured, and the stroke volume was calculated as the cube of the diameter. A significantly (P less than 0.001) smaller stroke volume was found in the sitting rest position (67.1 ml) compared to the supine rest position (92.3 ml). During dynamic exercise, the stroke volume increase in the sitting position (29.7%) was considerably higher than in the supine position (13%). The shortening fraction showed no difference in the sitting and supine positions at rest and during dynamic exercise. The results demonstrate good agreement between the echocardiographic method and other noninvasive procedures.

Adult↗
PubMed1980

[Percutaneous transluminal dilatation of the subclavian artery (author's transl)].

Percutaneous transluminal balloon-catheter dilatation successfully removed the stenosis in three out of four patients with obstruction of a subclavian artery. The arm oscillogram became normal and after an average of four months later the three patients remain without symptoms. The method is particularly suitable, as an alternative to operative intervention, if the stenosis is in the proximal part of the subclavian artery.

Aged↗