Search PubMed⌕ Search

Biomedical subjects

H J Engel

Publications and source records attributed to H J Engel.

At least 37 records · Page 2Linked to original sources
PubMed1985

Microcomputer-assisted monitoring system for measuring and processing cardiorespiratory variables: preliminary results of clinical trials.

A microcomputer-assisted monitoring system was developed for the continuous measuring and processing of cardiorespiratory variables, including: systemic and pulmonary arterial pressures, CVP, minute ventilation, inspired and expired O2 and CO2 concentrations, temperature, and heart rate. The primary data were converted to digital form, processed, displayed on a CRT monitor, and also stored for later evaluation. This system automatically calculated and displayed on-line and in real-time both primary measurements and derived cardiorespiratory variables, including: oxygen consumption, CO2 production, left and right ventricular stroke work, pulmonary venous admixture, and systemic and pulmonary vascular resistances. Printouts of the variables and trend graphs could be obtained for any desired time period. During its development, we tested this monitoring system in 30 critically ill patients, finding that the real-time calculation of cardiorespiratory variables was a great advantage during monitoring and treatment.

Adult↗
PubMed1982

An interaction study between benoxaprofen and digoxin.

The influence of maintenance therapy with benoxaprofen, 600 mg daily, on digoxin steady-state plasma levels was studied in 12 patients with rheumatic disease. No difference could be shown during concomitant therapy or after withdrawal of benoxaprofen (p greater than 0.10 and p greater than 0.90, respectively). Toxic concentrations were not observed. There were no changes in renal function values.

Anti-Inflammatory Agents↗
PubMed1982

[Relation between coronary obstructions, left ventricular wall motion and regional myocardial blood flow in single-vessel coronary artery disease (author's transl)].

UNLABELLED: Regional myocardial blood flow was studied at rest in 72 patients with a typical history of angina pectoris and/or myocardial infarction using the 133Xenon clearance technique. 62 patients had isolated greater than 50% obstructions of the left anterior descending or of the left circumflex branch, 10 patients had segmental asynergy yet no or only minimal (less than 35%) coronary obstructions. In each patient, flow of the poststenotic (asynergic) LV wall area was related to flow of the normal area (= 100%). Coronary obstructions were measured in multiple projections using a vernier, and segmental wall motion was quantitated by systolic halfaxial shortening. RESULTS: A progressive decrease of poststenotic flow was found with increasing severity of coronary obstructions: in relation to the respective normal areas, poststenotic flow was reduced to 84% distal to 50-75% obstructions (p less than 0.01), to 75% distal to 76-90% obstructions (p less than 0.0005), and to 67% distal to less than 90% obstructions (p less than 0.0005). However, analysis of poststenotic LV wall motion suggested that flow was correlated more closely to poststenotic wall motion: in hypokinetic areas, flow was reduced to 75% (p less than 0.0005), and in akinetic areas to 55% (p less than 0.0005) whereas in poststenotic areas with normal wall motion resting flow was normal regardless of the severity of coronary obstructions. Furthermore, the reduction of flow in asynergic areas of patients without coronary obstructions was comparable to flow in asynergic areas supplied by severely stenosed vessels. Thus in chronic coronary heart disease, regional myocardial blood flow correlates not only to the severity of coronary obstructions but also to segmental left ventricular wall motion.

Adult↗
PubMed1981

Magnesium concentration in saliva -- an indicator of digitalis toxicity. ?

In a prospective study salivary magnesium was measured by atomic absorption spectrophotometry in 168 patients on chronic digoxin therapy. Magnesium concentration in saliva was correlated with clinical data and plasma digoxin levels. A significant elevation in salivary magnesium concentration was caused by digoxin therapy (0.58 +/- 0.39 mmol/l, n = 93) in comparison to patients with no digitalis treatment (0.17 +/- 0.07 mmol/l, n = 35). Magnesium concentrations in saliva were significantly higher in toxic patients (1.1 +/- 0.68 mmol/l, n = 32) than in nontoxic patients. Possibly toxic patients showed a magnesium level of saliva of 0.63 +/- 0.39 mmol/l (n = 40). In 89% of the intoxicated patients salivary magnesium concentrations were higher than 1.0 mmol/l. The overlap of magnesium between toxic and nontoxic patients was less as compared to calcium and potassium concentrations in saliva. No changes were noted in serum magnesium levels. Magnesium concentration in saliva was influenced by chronic digoxin therapy only. No significant increase of magnesium in saliva was observed within 24 h after i.v. injection of 1.0 mg digoxin in four healthy volunteers. It is concluded that salivary magnesium concentration is a valid method for monitoring digoxin therapy in addition to plasma digoxin levels.

Digoxin↗
PubMed1981

[Transluminal angioplasty of the coronary arteries--An analysis of the most important complications by a postmortal study in the human heart (author's transl)].

The technique of dilatation of coronary obstructions with balloon-catheters according to Grüntzig was performed in 12 hearts with 17 proximal, predominantly excentric coronary stenoses. In all stenoses we saw a significant effect of dilatation with a mean increase of the diameter from 1.2 to 1.7 mm (p less than 0.001). Histological examinations revealed the following alterations: stretching (and compression) of the normal wall segment in most of the obstructions, injury of the plaque (11 times), perforation of the free wall (twice) and dissection of the wall (five times). The possible significance of these postmortal findings for the intravital application of the technique is discussed.

Catheterization↗
PubMed1981

[201-thallium stress scintigram in patients with coronary artery disease after administration of the cardioselective betablocker atenolol (author's transl)].

UNLABELLED: Changes of regional myocardial perfusion before and after administration of Atenolol (AT) (5 mg i.v.) were investigated by 201-Tl stress-imaging in 14 patients (PAT) with greater than or equal to 70% coronary obstructions. Scintigrams were performed in 4 projections (AP, 30 degree LAO, 60 degrees LAO, left lateral); scintigraphic defects (SD) in one of the 6 LV segments (anterior, apical, inferior, septal, lateral, posterior) had to be identified in at least 2 projections and to show a decrease of activity greater than or equal to 25%. All PAT had at least one reversible SD. RESULTS: After AT, stress, induced SDs were unchanged in 11 of the 14 PAT at identical work loads (131 Watt). The total number of reversible defects was 33 before and 28 after AT (n.s.). However, not only the 3 PAT with improved stress scintigrams, but also 6 of the 11 PAT with unchanged abnormal stress scintigrams were clinically improved (ECG normalized, no angina). Thus in almost half of the patients (6/14), the stress ECG was normalized without normalization of perfusion pattern of thallium scintigrams. We conclude that in these patients subendocardial perfusion was enough improved to meet the reduced metabolic needs, but not enough to normalize stress images.

Adult↗
PubMed1980

Extracoronary collateral myocardial blood flow during cardioplegic arrest.

Extracoronary blood flow to the myocardium was studied in 54 patients during cold cardioplegic arrest. Coronary venous return was measured with the aorta and the pulmonary artery cross-clamped, both venae cavae occlusively snared, and the heart completely drained. Cold St. Thomas' cardioplegic solution was infused into either the aortic root or the coronary ostia. Myocardial septal temperature was continuously monitored. The amount of blood in the right atrial effluent was determined by means of the hematocrit and was considered to be the extracoronary collateral myocardial blood flow (QE), originating from the systemic circulation. QE ranged from 0 to 1470 ml-100 min-1 (x = 241.1 ml-100min-1). The myocardial spontaneous rewarming rate was not significantly correlated to QE. QE was lowest in pure mitral valve stenosis (x = 39.9 ml-100 min-1) and higher in aortic valve disease (x = 165.5 ml-100 min-1). Very high QE values (greater than 800 ml-100 min-1) were only observed in patients with severe three vessel coronary artery disease. Patients with angina at rest appear to have lower QE values than patients with equally severe coronary artery disease suffering from angina under excise only. It is concluded that extracoronary collateral blood flow may unpredictably influence the efficacy of clinical cardioplegia and may to some extent compensate for severe coronary artery disease.

Aortic Valve↗
PubMed1979

[Isosorbide-dinitrate in myocardial perfusion (author's transl)].

UNLABELLED: The effect of isosorbide dinitrate (ISDN) (10 mg sublingually) on myocardial perfusion during ischemic conditions was analyzed in 14 patients with angiographically severe coronary artery disease and typical angina pectoris, using the 201-Thallium-myocardial scintigraphy. All patients underwent two identical scintigrams with the same work load during bicycle ergometry; a control scintigram leading to angina and ST-depressions of greater than 0.1 mV was followed 4--6 weeks later by a scintigram after ISDN; all drugs -- except sublingual nitroglycerin -- were withheld for an entire week. -- RESULTS: 25 of 39 new or enlarged, exercise-induced defects (64%) were normalyzed after ISDN; 14 new or enlarged defects remained unchanged (p less than 0.0005). In the 11 patients, in whom ISDN led to complete abolishment of angina, 23 of 30 new defects (76%) were normalized against none in the 3 patients with persistent angina and ST-depressions. Quantitation of perfusion was attempted by calculating the average impulse rate (counts/min/matrix point): in those patients reacting favorably to ISDN average impulse rate decreased significantly especially in the normal area (p less than 0.001), resulting in a more homogeneous distribution of Thallium activity, indicating a marked reduction in local oxygen consumption.

Adult↗
PubMed1978

[Regional myocardial blood supply in coronary disease].

1. Value and limitations of the precordial Xenon-clearance technique are analyzed. The results of this technique are compared to the scintigraphic display of the initial Xenon distribution and to microsphere scintigraphy (Engel et al. 1976a). 2. The effects of coronary obstructions and of segmental LV dysfunction on regional myocardial blood flow are analyzed (Engel et al. 1977). Independent of coronary obstructions, a clear reduction of regional myocardial blood flow in areas of hypokinesis and akinesis was observed. Thus in coronary disease a decrease of regional myocardial blood flow may represent either a cause or a result of abnormal segmental wall motion. 3. The effects of nitroglycerin, beta-blockade (Atenolol), calcium-antagonists (Nifedipine) and coronary dilatation (Dipyridamole) on regional myocardial blood flow were investigated (Engel et al. 1976b). Regional flow at rest decreased after nitroglycerin and beta-blockade, increased mildly after Nifedipine and markedly after Dipyridamole.

Adrenergic beta-Antagonists↗
PubMed1978

Clinical application and results of the assessment of coronary blood flow by the regional precordial xenon residue detection technique.

Methodological and technical aspects as well as application and results of the precordial Xenon-residue-detection technique are critically reviewed. The results concern mainly normal flow in various regions of the heart esp. in the free wall of the right and left ventricle, poststenotic flow in patients with coronary artery disease in relation to the degree of proximal narrowings as well as wall motion of the corresponding LV segment, bypassgraft flow and flow after drug interventions esp. nitrates, betablockers, the calcium-antagonist Nifedipine and the coronary dilator Dipyridamole. In spite of its serious limitations (high affinity of Xenon for fatty tissue, geometrical problems in the assessment of flow and its relation to anatomy, gas exchange in situations of high flow etc.), the technique is found to be a useful investigatory tool. Due to its technical display and the related high costs routine application is, however, prohibitive.

Cardiomyopathies↗