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Biomedical subjects

F W Amann

Publications and source records attributed to F W Amann.

At least 91 records · Page 5Linked to original sources
PubMed1986

[Long-term course over three years in a patient with unstable angina pectoris].

The long-term follow up in 48 patients with unstable angina pectoris was analyzed retrospectively. All patients were hospitalized in a coronary care unit during the acute phase and responded favourably to a medical regimen consisting of nitrates in 45 patients, betablockers in 23, calcium channel blocking agents in 22 and i.v. nitroglycerin in 12. 30 patients (group 1) responded promptly to oral medication with one or a combination of two drugs, whereas in 18 patients a combination of at least three drugs or intravenous nitroglycerin were necessary. After 42 +/- 6 months 21 patients remained asymptomatic, with 8 still on antianginal therapy. In 27 patients (56%) complications had occurred. These complications were severe limiting angina pectoris in 16, of whom 11 were treated surgically after 3.5 +/- 3 months, and myocardial infarction in 11 patients after 16 +/- 9 months, of whom 4 patients died. Complications occurred in 10 of the 30 patients in group 1 and in 16 of the 18 patients in group 2 (33% vs. 89%, p less than 0.01). This study confirms that the long-term course in patients with unstable angina is often complicated by severe angina pectoris or myocardial infarction. The late response to initial therapy and the need for the combination of more than two antianginal drugs or of i.v. medications identifies a subgroup of patients with a high complication rate.

Adrenergic beta-Antagonists↗
PubMed1986

Relationship between ease of inducibility of arrhythmia with electrophysiologic testing and response to antiarrhythmic therapy.

Electrophysiologic studies are an important tool for guiding the selection of an effective antiarrhythmic drug. The purpose of this study was to determine if there was a relationship between the number of extrastimuli necessary to induce arrhythmia and the response to antiarrhythmic drugs. A group of 56 patients with sustained ventricular tachycardia or ventricular fibrillation who were inducible underwent 235 single-drug studies (4.2 per patient). During the control study, one extrastimulus provoked an end point in 12 patients (group 1) and in only two patients (17%) was at least one drug effective. Of the 18 patients requiring two extrastimuli for induction during baseline (group 2), at least one drug was effective in 11 patients (61%). At least one drug was effective in 20 of 26 patients (77%) who required three extrastimuli (group 3). There were no significant differences among the three groups with respect to presenting arrhythmia, presence of coronary artery disease, or left ventricular ejection fraction. When single drugs or a combination of drugs were used, 58% of group 1, 72% of group 2, and 85% of group 3 were rendered noninducible. During a follow-up of 28 to 32 months, yearly recurrence of arrhythmia was 9.4%, 4.6%, and 1.7%, for the three groups, respectively.

Anti-Arrhythmia Agents↗
PubMed1986

Withdrawal of the long-acting beta blocker bopindolol is not associated with beta-adrenoceptor supersensitivity.

beta-Adrenoceptor sensitivity after abrupt withdrawal of long-term therapy (5-12 months) with bopindolol (1-2 mg/day), a long-acting beta-adrenoceptor blocking agent with intrinsic sympathomimetic activity, was assessed in five patients with uncomplicated essential hypertension. The chronotropic dose 25 of isoproterenol (CD 25), plasma concentrations of catecholamines, triiodothyronine and thyroxin, plasma renin activity and aldosterone, hemoglobin, hematocrit and oxyhemoglobin dissociation were measured on the last day of bopindolol administration and 1, 2, 3, 6, and 13 days after abrupt replacement by placebo tablets. The chronotropic dose 25 of isoproterenol (microgram/m2) was greater than 25.6 in all patients on the last day of bopindolol therapy. On day 1 in patients who had been taking 2 mg/day of bopindolol, CD 25 remained greater than 25.6 but fell to 12.1 in the one patient who had been taking 1 mg/day. On day 2, CD 25 was 10.19 +/- 2.97 and felt gradually to the lowest value of 3.76 +/- 1.19 on day 13. Throughout the study, plasma concentrations of catecholamines, triiodothyronine and thyroxin, and oxyhemoglobin dissociation remained unchanged. Plasma renin activity and plasma aldosterone, which were suppressed during bopindolol therapy, rose during placebo, coinciding with a fall in hemoglobin and hematocrit. No subjective symptoms of increased beta-adrenoceptor-mediated functions were reported by the patients throughout the whole study period. Therefore, hypersensitivity of beta-adrenoceptor-mediated responses was not demonstrated within the first 13 days after sudden withdrawal of bopindolol.

Adrenergic beta-Antagonists↗
PubMed1985

Increased beta-adrenoceptor binding capacity is associated with blunted beta-adrenoceptor-mediated cardiovascular responses in essential hypertension.

Age and elevated blood pressure are associated with blunted beta-adrenoceptor-mediated cardiovascular effects. To investigate a possible relationship between beta-adrenoceptor cardiovascular function and receptor density, beta-adrenoceptor binding capacity in mononuclear leucocytes and cardiac isoproterenol sensitivity were compared in 12 essential hypertensive and 17 normotensive subjects of comparable age. The bolus dose of isoproterenol which increased heart rate by 25 beats/min (CD25) as well as plasma norepinephrine, epinephrine, and renin activity were measured. In a radioreceptor assay using [3H]dihydroalprenolol, the antagonist binding capacity (Bmax) and the affinity constant (KD) of mononuclear leucocytes were determined. Bmax in patients was higher than in normotensive subjects (66.8 +/- 4.1 versus 48.0 +/- 3.8 SEM fmol/mg, p less than 0.05), and KD was identical in both groups. In hypertensive patients, Bmax correlated positively with age (r = 0.639, p less than 0.05) and CD25 (r = 0.593, p less than 0.05) and negatively with plasma renin activity (r = 0.679, p less than 0.05), while in normotensive subjects, Bmax correlated with CD25 only (r = 0.615, p less than 0.05). Thus, in patients with essential hypertension, a decrease in cardiac isoproterenol sensitivity and plasma renin activity is associated with an age-related increase in antagonist binding capacity. This suggests a defect in the membrane coupling of the beta-adrenoceptor effector system distal to the receptor recognition site in patients with essential hypertension.

Adult↗
PubMed1984

Efficacy and tolerance of the new long-acting vasodilator RO 12-4713 in hypertensive patients not managed on beta blockers and diuretics.

The new vasodilator Roche 12-4713, an oxodiazolo-pyrimidine with long-acting direct arteriolar dilating properties, was tested in 13 patients (ages 33-66 years, mean 53 +/- 7 SD) previously uncontrolled on a beta blocker-diuretic combination. The addition of Ro 12-4713 (30-180 mg per day) for 134 +/- 62 days resulted in a fall of blood pressure from 191 +/- 24/110 +/- 8 to 150 +/- 23/88 +/- 8 (p less than 0.001) without changes in heart rate (73 +/- 8 vs 74 +/- 11 bpm). Edema occurred in five patients, this was controlled in four by increasing the dose of the diuretic. Hypertrichosis appears to limit the drug's use in females. This new vasodilator proved highly effective in the treatment of severe hypertension. The long duration of action makes once a day administration possible.

Adrenergic beta-Antagonists↗
PubMed1984

[Medical aspects of the treatment of acute coronary disease].

Progress in the drug therapy of arrhythmias and congestive heart failure following acute coronary heart disease and attempted infarct size reduction are discussed. A schedule of diagnostic and therapeutic procedures is proposed. Corresponding to present knowledge of the pathophysiology of "unstable angina pectoris" drug therapy can be more specifically administered in this form of acute coronary heart disease.

Angina, Unstable↗
PubMed1983

Verapamil-induced vasodilator response is enhanced in essential hypertension.

Forearm blood flow response to the calcium channel inhibitor verapamil, 1 75 micrograms/100 ml tissue, as measured by venous occlusion plethysmography, was found to be significantly greater in 11 patients with essential hypertension as compared to 11 age-matched normotensive subjects whereas there was no significant difference in increase in forearm blood flow between both groups to non-specific vasodilatation with sodium nitroprusside (1.2 micrograms/100 ml tissue). The increase in forearm blood flow to verapamil correlated positively with basal plasma epinephrine concentration in hypertensives. These findings support the concept of an increased dependency of arteriolar tone on calcium influx in patients with essential hypertension, an abnormally related to the activity of the sympathetic nervous system.

Adult↗
PubMed1983

Alpha-adrenoceptors, adrenaline, and exaggerated vasoconstrictor response to stress in essential hypertension.

Stressful sympathetic stimulation by cold pressor test in patients with essential hypertension results in an exaggerated response of the already elevated plasma adrenaline, heart rate, blood pressure, and alpha-adrenoceptor-mediated vasoconstriction when compared with normotensive subjects. The stress-induced increase in adrenaline was correlated with the attendant increase in blood pressure. The stress-induced reduction in forearm flow was reversed during infusion of the postjunctional alpha 1-adrenoceptor blocker prazosin. Therefore, enhanced responses to sympathetic stress, as reflected and perhaps caused by an exaggerated rise in plasma adrenaline, may contribute to an increased alpha 1-adrenoceptor-mediated vasoconstriction in essential hypertension.

Adult↗
PubMed1982

[Non-invasive evaluation of pressure gradients in aortic stenosis using Doppler ultrasound].

In 35 consecutive patients with aortic stenosis, noninvasive assessment of pressure gradients was performed using a continuous wave Doppler ultrasound technique prior to left heart catheterization. Maximum blood flow velocity in the ascending aorta and time from aortic valve opening to peak velocity in relation to left ventricular ejection time (TPV) were measured. Doppler data proved reliable in predicting a pressure gradient above or below 50 mm Hg (sensitivity 89% and specificity 88%). Pressure gradients calculated from the frequency shift of the ultrasound wave correlated well with pressure measurements obtained at cardiac catheterization in 31 patients with adequate Doppler velocity signals (r = 0.85, p less than 0.001). In all 4 patients with inadequate velocity signals a pressure gradient above 50 mm Hg could still be predicted by an abnormally delayed timing of peak velocity in systole (TPV greater than 0.5).

Adolescent↗
PubMed1982

[Non-invasive determination of pressure gradients of heart valve prostheses using Doppler ultrasound].

Noninvasive measurements of pressure gradients by continuous wave Doppler ultrasound technique were carried out in 40 patients with correctly functioning heart valve prostheses (10 Björk-Shiley in aortic position, 10 Björk-Shiley in mitral, 10 St. Jude Medical in aortic and 10 St. Jude Medical in mitral) and in 10 patients with normal aortic and 10 patients with normal mitral valves. The pressure gradients were slightly but significantly higher in prosthetic than in normal heart valves (p less than 0.005). Pressure gradients in Björk-Shiley prostheses were higher than in St. Jude Medical prostheses both in aortic (18.4 +/- 2.6 vs 9.6 +/- 1.9; p less than 0.01) and in mitral position (8.2 +/- 1.1 vs 5.4 +/- 0.8; p less than 0.05). The pressure gradient was inversely related to valve size in Björk-Shiley prostheses (r = -0.60 for aortic and r = -0.42 for mitral valves; p less than 0.05) but not in St. Jude Medical prostheses. The non-invasive Doppler technique should be useful in the diagnosis of prosthetic valve obstruction.

Aortic Valve↗
PubMed1982

Effects of a new long-acting beta-blocker bopindolol (LT 31-200) on blood pressure, plasma catecholamines, renin and cholesterol in patients with arterial hypertension.

Bopindolol (LT 31-200), a new, long-acting, non-selective beta-blocker, was given as monotherapy to 13 patients, 12 with essential hypertension and 1 with renovascular hypertension. After a placebo period of 4-6 weeks, bopindolol was given once daily, starting with 1 mg and subsequently increasing at two-weekly intervals to 2 and 4 mg once daily until a diastolic blood pressure less than or equal to 90 mmHg was achieved. The effective dose was continued for 12 weeks. In 10 patients plasma levels of renin, noradrenaline, adrenaline and cholesterol were measured during placebo and after 3 months of therapy. Blood pressure and heart rate were lowered significantly during bopindolol treatment. The mean effective dose was 2.2 mg per day. In 10/13 patients a diastolic blood pressure less than or equal to 90 mmHg was achieved. Side effects were minimal. Changes in plasma noradrenaline and adrenaline were small and not significant, but renin and cholesterol were significantly reduced. Thus, LT 31-200 is an effective and well tolerated beta-blocker when given in a once daily dosage.

Adrenergic beta-Antagonists↗
PubMed1982

Antihypertensive and renal effects of captopril in relation to renin activity and bradykinin-induced vasodilation.

The effect of captopril on blood pressure and renal hemodynamics in relation to plasma renin activity (PRA) was assessed together with the vasodilator responses to brachial artery infusions of bradykinin (BK) and sodium nitroprusside (NP) before and after 4 wk of therapy with doses of up to 450 mg/day in patients with essential hypertension. The average blood pressure reduction of captopril was from 174.4/110.6 to 155.3/96.6 mm Hg (n = 12, P less than 0.001) without increases in heart rate or body weight. It was effective in the eight patients with normal renin, but showed little effect in the four with a low renin. There was a correlation between the changes in blood pressure after captopril and the pretreatment PRA (r = -0.82, P less than 0.01 for mean pressure). Brachial artery infusions of BK and NP induced dose-dependent rises in forearm blood flow (FBF), but this was not related to the captopril blood pressure-lowering effect. Repeat measurements during captopril therapy showed a shift to the left of the BK/FBF, but not of the NP/FBF, dose-response curve, indicating effective vascular kininase II inhibition. Captopril decreased renal vascular resistance. Our data are compatible with the view that captopril's antihypertensive action mainly involves blockade of the renin-angiotensin-aldosterone system and not cumulation of BK. The favorable effects on renal hemodynamics and the lack of tachycardia and volume retention after captopril make it a valuable drug for the treatment of hypertension.

Adult↗