The mechanism through which the repartitioning agent clenbuterol increases heart rate was investigated. First, the relative importance of the beta 1- and beta 2-adrenoceptors was established in rat and bovine right atria in vitro. The positive chronotropic and inotropic effects of (+/-)isoproterenol in rat and bovine right atria, respectively, were markedly antagonized (P < .001) by the beta 1-...

The conduction disturbances in atrioventricular block are well known from numerous electro-cardiographic studies, but the effect on the heart work, especially on the individual chambers, could not be recorded before the introduction of visualization of the heart chambers by angio-cardiography. Rapid biplane angiocardiography with simultaneous electrocardiographic yields information on cardiac d...

Nature of the problem Many congenital cardiac malformations result in a heart with only one effective ventricle. In most of these there is a second ventricle present, but it is too small to sustain cardiac output making construction of a biventricular circulation impossible. These hearts may be classified according to the atrioven-tricular connection. There are two possibilities: the atria are ...

To cite: Haththotuwa HR, Dubrey SW. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013201046 DESCRIPTION At first glance these chest radiographs appear similar. Closer inspection suggests ‘dextrocardia’ (figure 1A) and ‘dextroposition’ (figure 1B). Confusing terminology is helped if the heart’s position within the thorax and point of direction of the apex is des...

A monoclonal antibody (anterior latissimus dorsi 58 [ALD58]; antimyosin heavy chain, MHC) directed against myosin from slow tonic muscle was found to react specifically with the striated muscle cells of the conductive system in the adult chicken heart. This monoclonal antibody was used to study the expression of myosin in the conductive system of the adult and developing heart. Using immunofluo...

We report a case of a 41-year-old man admitted with respiratory distress and found to have masses in both atria of the heart and in the testicle. The patient received palliative radiotherapy to relieving obstruction of blood flow tract caused by the intracardiac masses, followed by radical orchiectomy. After the diagnosis of testicular seminoma, he was treated successfully with 4 cycles of syst...

In adults a tachycardia is any heart rate greater than 100 beats per minute. Supraventricular tachycardias may be divided into two distinct groups depending on whether they arise from the atria or the atrioventricular junction. This article will consider those arising from the atria: sinus tachycardia, atrial fibrillation, atrial flutter, and atrial tachycardia. Tachycardias arising from re-ent...

• In 1958, Thomas and co-workers observed that ouabain caused an increased uptake of Ca in frog heart. Holland and Sekul later reported the same effect in rabbit atria and were able to establish a reasonably good correlation between Ca uptake and changes in resting tension induced by ouabain. Recently, Liillmann and Holland found a small but significant increment in an exchangeable Ca fraction ...

• In 1958, Thomas and co-workers observed that ouabain caused an increased uptake of Ca in frog heart. Holland and Sekul later reported the same effect in rabbit atria and were able to establish a reasonably good correlation between Ca uptake and changes in resting tension induced by ouabain. Recently, Liillmann and Holland found a small but significant increment in an exchangeable Ca fraction ...