Cardiovascular effects of catecholamines in dogs before and after beta-adrenergic blockade

Cardiac Haemodynamics under β-Receptor Blockade in Dogs

“…The values found with propranolol (Inderal) to some extent contradict results previously published [3,4,5] with nethalide, where an increase in stroke volume was also found, but where the displacement of Luthy's ratio towards failure only occurred under additional angiotensin load. The stronger and still measurable sympathomimetic action of nethalide may account for this.…”

Treatment of the Hyperkinetic Heart Syndrome with Propranolol

“…Experimental [7,10] and clinical [1 ,4] work has shown that /9-receptor blocking agents can elicit or worsen cardiac failure. If propranolol does not lead to considerable improvement in working capacity in cases of tachy cardia with reduced working capacity, then the diagnosis of hyperkinetic cardiac syndrome should be questioned.…”

“…These myocardiopathies with accelerated heart action may also lead to a reduction in working capacity. As has been shown in animal experiments, however, blocking of the /9-receptors leads to a deterioration in haemodynamic values [7,10], The line of demarcation between myogenic tachycardias and those based on excessive sympathetic tone, which can be very difficult to establish in exceptional cases, is of diagnostic and therapeutic importance.…”

Force-velocity Relationship of the Left Ventricle in the Closed-chest Dog

“…Since these values were taken from various experimental studies previously reported (7,8,15) the anesthesia was different: In 14 dogs chloralose was given intravenously in a dose of 95mg/kg (12). Force-velocity relationship of cat papillary muscle.…”

“…body weight; in 13 dogs morphine sulphate was injected sub cutaneously in a dose of 10 ing/kg body weight, in 4 dogs sodium ethyl-methyl-buthyl-barbiturate1 was administered intravenously in a dose of 20 mg/kg body weight. The cardiac output (CO) and the end-diastolic volume of the left ventricle (EDV) were determined using the thermodilution method as previously described (10,7). The injection catheter was introduced into the left ventricle via the left carotid artery.…”