Atrial double potential associated with electrical connection between the coronary sinus musculature and the left atrium in a patient with Wolff-Parkinson-White syndrome.

We reported a case of Wolff-Parkinson-White syndrome with atrial double potential in coronary sinus (CS) electrograms during paroxysmal supraventricular tachycardia and ventricular pacing. The first component was low in frequency, and its timing was the same as atrial potential recorded by ablation catheter above the mitral annulus by transseptal approach; the second portion was high in frequency. The accessory pathway conduction was completely eliminated after ablation on the atrial site. We speculated that the discrete musculature connection between left atrium and CS was responsible for the pattern of double potential activation in the CS electrograms during paroxysmal supraventricular tachycardia and ventricular pacing.

Vascular protective effects of Astragalus membranaceus and its main constituents in rats with chronic hyperhomocysteinemia.

Hyperhomocysteinemia (HHcy) is an important factor in cardiovascular disease. However, is currently no cure available in western medicine for HHcy-evoked cardiovascular disease. The present study explored the vascular protective effects of Astragalus membranaceus (AM), a traditional Chinese medicine. Rats with HHcy were induced by feeding high-methionine diets and treated with total extract of AM (TEA) and its constituents, including Astragalus saponins (ASP), Astragalus total flavonoids (ATF) and Astragalus polysaccharides (APS). Examination of the rats indicated that TEA and ASP controlled blood pressure and ameliorated HHcy-induced impairment of endothelium-dependent vasorelaxation by increasing the nitric oxide content and nitric oxide synthase activity of the abdominal aorta. Furthermore, they decreased the accumulation of hydrogen peroxide and superoxide anion, and attenuated the inhibition of superoxide dismutase and catalase activities in rats with HHcy. Additionally, TEA and ASP attenuated the HHcy-induced increases of matrix metalloproteinase (MMP)-2 and -9 concentrations. However, similar effects were not observed for ATF and APS. In conclusion, TEA and ASP are beneficial to vascular disease, and their effects may be attributed to protective actions against oxidation, activity of the MMPs and endothelial dysfunction.