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Biomedical subjects

J Buch

Publications and source records attributed to J Buch.

At least 37 records · Page 2Linked to original sources
PubMed1984

Cardiovascular effects of intramuscular or inhaled terbutaline in asthmatics.

8 stable asthmatics were at random given placebo, 0.125 mg, 0.25 mg, 0.5 mg and 1 mg terbutaline intramuscularly or 2.5 mg as inhalation. Systolic time intervals, echocardiographic parameters and peak expiratory flow (PEF) were measured. Maximal circulatory and respiratory response was obtained after 0.5 mg and 0.25 mg, respectively. The circulatory effect of 2.5 mg inhaled terbutaline equalled 0.125 mg given intramuscularly, while this dosage elicited maximal bronchodilator effect. Thus, nebulized terbutaline has only a minimal circulatory effect, and even the intramuscular dosages were without dramatic circulatory side effects.

Adolescent↗
PubMed1984

Non-invasive evaluation of the haemodynamic effects of amiodarone.

Sixteen patients were examined hemodynamically with echocardiography, calibrated apexcardiography, and systolic time intervals before treatment, after 1 week treatment with amiodarone 600 mg daily and after 2-4 months treatment with 300 mg daily. During the treatment thyroid function was controlled. The echocardiogram showed a small increase in shortening fraction, while left ventricular dimensions did not change significantly. The apexcardiogram revealed minor changes, which could not be interpreted as being due to changes in contractility. The systolic time intervals showed marked decreases in preejection period index and preejection period/left ventricular ejection time. These changes could not be correlated to changes in serum thyroxine, which was the only thyroid parameter to change significantly. The hemodynamic changes during amiodarone treatment were interpreted as mainly being due to a decrease in afterload while possible changes in preload and myocardial contractility were of minor importance.

Adult↗
PubMed1983

Interactions between digoxin and potassium-sparing diuretics.

A kinetic and hemodynamic study of digoxin was performed in six healthy subjects and similar studies were performed during digoxin with spironolactone and with triamterene. Spironolactone reduced renal tubular secretion of digoxin and attenuated its positive inotropic effect (evaluated by systolic time intervals and echocardiography) and triamterene reduced the extrarenal elimination of digoxin, but induced no changes in digoxin-elicited inotrophy. It is suggested that the renal handling of digoxin is influenced by the intracellular potassium concentration in the renal tubular cell. The results indicate a drug-receptor interaction between spironolactone metabolites and digoxin at the hypothetical inotropic digitalis receptor. Amiloride has been reported to suppress digoxin inotropism, whereas spironolactone induces minor inhibition and triamterene does not affect digoxin inotropism.

Adult↗
PubMed1983

Sustained effect of zinc-protamin-glucagon in hyperlipidaemic patients.

Is is well known from laboratory investigations and acute intervention studies that glucagon is involved in lipid metabolism. The present study was undertaken in order to evaluate a possible sustained effect of zinc-protamin-glucagon in moderately hyperlipidaemic patients. 4 patients were investigated after an acute bolus dose of glucagon 5 mg intravenously and 16 patients were given zinc-protamin-glucagon 5 mg subcutaneously, b.i.d. for 5 days. A similar degree of decrease of plasma cholesterol and triglycerides was obtained in the acute and chronic study, while the increase in fasting blood sugar and plasma insulin seen in the acute study was not present after 5 days treatment. The effect on plasma triglycerides was much more variable than the effect on plasma cholesterol. Five days after treatment the lipid concentrations had returned to the pretreatment values. The effect could not be predicted from the pretreatment lipid concentrations, neither by the type of hyperlipidaemia present. The decrease in plasma cholesterol and triglycerides were not correlated. The drug might prove useful in the long term research of lipid metabolism and the various complex hormonal interactions.

Aged↗
PubMed1983

Endocarditis caused by Cardiobacterium hominis. Two case reports.

Two cases of endocarditis caused by Cardiobacterium hominis are reported. There were no unusual clinical features of endocarditis in the patients except for the extensive valvular damage present at time of hospitalization. Properties with distinguish C. hominis from other fastidious, gram negative rods are oxidase and catalase reactions, indole production and carbohydrate fermentation pattern.

Adult↗
PubMed1983

Non-invasive measuring of the circulatory effect of afterload reduction in order to monitor the pharmacodynamic effect of drugs in normal volunteers.

In order to measure the effect of a decrease in afterload on systolic time intervals, left ventricular end-systolic diameter, and left ventricular wall stress, eight healthy young persons underwent a randomised placebo controlled trial of terbutaline before and during atenolol treatment. Pre-ejection period index, left ventricular end-systolic diameter, and wall stress all decreased after terbutaline, the decrease being clearly dose dependent. This was identical before and during atenolol administration. Consequently the observed changes were induced by beta-2 elicited vasodilatation, possibly combined with some decrease of parasympathetic tone. A close correlation between changes in pre-ejection period index (PEPI) and changes in left ventricular end-systolic diameter (LVESD) and wall stress was shown both before and during atenolol treatment. When using non-invasive methods in the evaluation of changes in contractility, it is important to correct for changes in preload and afterload. For normal subjects it is suggested that the relation between delta PEPI and delta LVESD as a percentage of the mean values should be used for evaluation of afterload changes. A method is suggested for estimating changes in pre-ejection period index induced by changes in left ventricular end-systolic diameter or wall stress.

Adult↗
PubMed1983

The use of systolic time intervals in the evaluation of antihypertensive treatment with metoprolol, labetalol and prazosin.

26 patients with moderate hypertension and no signs of heart failure were treated with metoprolol, labetalol or prazosin. Systolic time intervals (STI) were measured before and after several months of treatment. During treatment with metoprolol, a decrease in the preejection period index (PEPI), and preejection period/left ventricular ejection time ratio (PEP/LVET), was found. During treatment with labetalol or prazosin, a minor decrease in PEPI was observed, so that a significant decrease in PEP/LVET was not obtained. A decrease in PEPI and PEP/LVET may be due to improved cardiac performance, but in the given type of patients it is more dependent on the reduction in afterload. The STI measurement is less sensitive in discerning different mechanisms involved in lowering the blood pressure and cannot therefore be used for selecting the optimal antihypertensive drug.

Adult↗
PubMed1982

Systolic time intervals during spironolactone treatment of digitalized and non-digitalized patients with ischaemic heart disease.

The effect of spironolactone on cardiac contractility indices was studied by externally recording systolic time intervals in four digitalized and four non-digitalized patients with ischaemic heart disease. A negative inotropic effect was found after spironolactone 100mg b.i.d. in all eight patients, as measured by an increase in pre-ejection period index PEPI (p less than 0.01), and the ratio between pre-ejection period and left ventricular ejection time PEP/LVET (p less than 0.001), while pre- and afterload remained constant. As expected, digoxin exerted a positive inotropic effect, as a decrease was observed in PEPI (p less than 0.01), and PEP/LVET (p less than 0.001). It was not possible to ascertain whether the observed effect was caused by a pharmacological interaction at receptor level between spironolactone and digoxin, or indirectly to changes in endogenous substances e.g. aldosterone. The results suggest that spironolactone may have unintended side effects in patients with severe heart failure and that its use be reevaluated.

Aged↗
PubMed1982

Development of aortic stenosis in a patient with formerly pure aortic incompetence.

A 42 year old man with severe aortic incompetence and hypertension, but no aortic stenosis, responded so well to medical treatment that the planned operative treatment was postponed. 8 years later he was re-admitted with severe aortic stenosis and only minimal aortic incompetence. It is concluded, that a short trail of medical treatment may be warranted even in patients with severe aortic incompetence, before surgery is performed, especially if the patient is hypertensive.

Adult↗
PubMed1981

Amiloride-induced changes in digoxin dynamics and kinetics: abolition of digoxin-induced inotropism with amiloride.

Digoxin dynamics and kinetics were studied in six healthy subjects with and without amiloride. Amiloride increased mean renal digoxin clearance from 1.3 to 2.4 ml . kg-1 . min-1 (p less than 0.001) due to increased tubular secretion of digoxin, while the glomerular filtration rate was unchanged. This might be caused by an increase in intracellular potassium concentration in the tubular cells provoked by amiloride. In contrast, the extrarenal clearance of digoxin was almost blocked by amiloride; it fell from a mean of 2.1 to 0.2 ml . kg-1 . min-1 (p less than 0.025). Total body clearance tended to fall, but the decrease was not statistically significant. EValuation of myocardial contractility by systolic time intervals revealed a concentration-response relationship between digoxin and changes in preejection period index when digoxin was given alone (rs = 0.750, p less than 0.001). Pretreatment with amiloride abolished this relationship (rs = 0.307, p = NS). Blood pressure and echocardiographically determined left ventricular end-diastolic diameter measurements indicated no changes in the left ventricular post- and preload. It is concluded that amiloride suppressed digoxin-induced inotropism.

Adult↗
PubMed1981

Hazards of diazoxide in pulmonary hypertension.

The use of diazoxide in the treatment of pulmonary hypertension has been advocated recently. We describe three patients who responded less favourably. The first patient had cardiac arrest (asystole) after the acute bolus dose. After recovery only a slight increase in cardiac index was seen while pulmonary vascular resistance was unchanged. The second patient developed total atrioventricular block after the acute bolus dose. Ater recovery the cardiac index was unchanged while pulmonary vascular resistance was decreased. The third patient felt ill after the acute bolus dose, and the blood pressure dropped, but no conduction abnormalities were noted. The cardiac index rose slightly and the pulmonary vascular resistance was essentially unchanged. Long term treatment with oral diazoxide could not be administered to this patient because abdominal pain and distension developed. Because we lack reliable alternative treatment, it is justifiable to try diazoxide, provided great care is taken.

Abdomen↗
PubMed1981

Noninvasive evaluation of the hemodynamic effects of closure of atrial septal defects of the secundum type.

In order to examine the feasibility of using multiple noninvasive methods in monitoring the hemodynamic changes induced by operation for atrial septal defect of the secundum type, 12 consecutive patients were examined before operation and 8 days afterwards. 10 of the patients were re-examined after one year. The methods used were echocardiography calibrated apexcardiography and systolic time intervals. It was possible with echocardiography to demonstrate a decrease in right ventricular end diastolic diameter and left atrial dimension already at the first postoperative study, but these changes were more marked after one year, though the right ventricular end diastolic diameter continued to be larger than normal. The left ventricular end diastolic diameter initially increased in size probably due to increased filing, but later returned somewhat towards the preoperative value. Functionally the apexcardiogram revealed an early decrease in left ventricular compliance probably due to the increased filling, but normal compliance after one year, where also the initially prolonged early relaxation time returned towards the normal value. The other apexcardiographical measurements did not change. Systolic time intervals showed an improved cardiac performance, as evaluated by preejection period index and preejection period/left ventricular ejection time, most marked at the early postoperative measurement. This is considered to be due to the improved left ventricular filling (The Starling effect) and not to changes in the myocardium itself.

Adolescent↗
PubMed1980

Reduction of digoxin-induced inotropism during quinidine administration.

A kinetic and dynamic study of digoxin was performed in 6 healthy subjects, and repeated in the same subjects after administration of quinidine for 1 wk. Myocardial performance evaluated by systolic time intervals increased in parallel with plasma digoxin concentration, whereas left ventricular end-diastolic diameter on echocardiography and arterial blood pressure remained constant. The positive inotropic effect of digoxin was abolished during concomitant treatment with quinidine. Quinidine has been reported to increase the risk of digitoxicity, and therefore the treatment with digoxin and quinidine in combination should be reconsidered.

Adult↗