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...

Atria within buildings present an environment which allows smoke to spread around a building in fire situation. This could create dangerous conditions for the evacuation of people. Smoke control ventilation systems atria work case fire, keeping routes available They play significant role sustainable, holistic strategies, and are most often designed following prescriptive requirements. However, ...

Complete heart block implies an absolute independence between atria and ventricles that does not in fact always exist. Segers showed that, after complete block was artificially produced in the frog's heart, atria and ventricles would sometimes begin to beat exactly in phase, most commonly in a 2 to 1 ratio. He subsequently reported one clinical example of 2 to 1 A-V synchronization in a patient...

sacs,' which are main cavities of which the walls are constituted by alveoli or air-cells. By far the greater number of the lung alveoli belong to the air-sac system, but a very appreciable number belong to the atria, and the latter act partly as air-passages to the air-sacs, and partly perform the same respiratory functions as the air-sacs themselves. The walls of the atria have the same gener...

Complete heart block implies an absolute independence between atria and ventricles that does not in fact always exist. Segers showed that, after complete block was artificially produced in the frog's heart, atria and ventricles would sometimes begin to beat exactly in phase, most commonly in a 2 to 1 ratio. He subsequently reported one clinical example of 2 to 1 A-V synchronization in a patient...

The term SSS was coined by Ferrer in 1968 who grouped together all the anatomic etiologies of sinus node disease (SND).1 Table1. We will explore how some patients with underlying SND can have coexisting AF either the effect of SND on atria via various mechanisms or via the underlying disease of the atria. SND is frequently associated with AF, forming the basis of the ”tachycardia-bradycardia sy...

We developed and validated a new optical mapping system for quantification of electrical activation and repolarisation in murine atria. The system makes use of a novel 2nd generation complementary metal-oxide-semiconductor (CMOS) camera with deliberate oversampling to allow both assessment of electrical activation with high spatial and temporal resolution (128 × 2048 pixels) and reliable assess...

Norepinephrine (NE) incorporation by portal-mesenteric veins (P-M) veins) and atria of spontaneously hypertensive rats (SHR) were compared with that of age-matched Wistar Kyoto controls (WKY). Tissues were incubated in the presence of tritiated norepinephrine (3H-NE), and fractions were isolated by means by differential and sucrose density gradient centrifugation. The peak of radioactivity was ...

• 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 ...

Complete heart block implies an absolute independence between atria and ventricles that does not in fact always exist. Segers showed that, after complete block was artificially produced in the frog's heart, atria and ventricles would sometimes begin to beat exactly in phase, most commonly in a 2 to 1 ratio. He subsequently reported one clinical example of 2 to 1 A-V synchronization in a patient...