ABSTRACT
The QT interval dispersion [QTd] has been described as the maximum minus minimum QT intervals in simultaneously 12-lead electrocardiographic recording which reflect inhomogeneity in myocardial repolarization. Increased QTd has been illustrated in patients with a variety of cardiac diseases such as myocardial infarction and left ventricular dysfunction and was suggested as a risk factor for development of ventricular arrhythmias and sudden death. QTd may also be a prognostic factor in patients undergoing Coronary Artery Bypass Grafting [CABG]. The purpose of this study was to evaluate the influence of CABG on QTd in patients with coronary artery disease. In this retrospective study we evaluated the effect of CABG on QTd in 79 consecutive patients with coronary artery disease. Measurement of QTd was performed on ECGs taken before and 24 hours after operation. There was no significant QTd changes in post CABG patients compared with baseline QTd [0.06 +/- 0.04 vs. 0.06 +/- 0.03, P=0.18]. In subgroups analysis, decrease in QTd was observed following CABG only in those with two-vessel coronary involvement compared with baseline [0.05 +/- 0.04 SD seconds versus 0.07 +/- 0.02SD seconds, P<0.05]. The present study showed that CABG does not affect QTd except in few patients with two-vessel coronary involvement
ABSTRACT
Tecoma stans [L.] Juss or Yellow bells from Bignoniaceae is a ornamental tropical shrub or small tree predominantly found in central, and south America and in Latin America is used traditionally for reducing blood glucose. However, its other pharmacological effects have not been yet elucidated. The aim of present study was to investigate the effect of its leaves extract on rat ileum contractility and involved mechanism[s]. Tecoma stans Juss hydroalcoholic leaf extract [TLE] was prepared by macerated method using 70% alcohol. Distal segment of ileum [2 cm] from male Wistar rat was mounted in an organ bath containing Tyrode solution [10 ml, pH 7, 37 °C] and pre-contracted by carbachol [CCh, 10 micro M] or by KCl [60 mM]. The antispasmodic effects of TLE [0.125-2 mg/ml] were studied prior and after 20-30 min incubation of ileum with propranolol [1micro M], naloxone [1micro M], L-NAME [100 micro M], or 5 min incubation with glibenclamide [10 micro M] and tetraethylammonium [TEA, 1mM]. The effect of TLE on CaCl[2]-induced contraction in Ca[2+] -free with high K[+] Tyrode solution was also studied. The CCh- and KCl-induced ileal contractions were reduced by TLE [P<0.0001]. This effect was not attenuated by propranolol, naloxone, L-NAME, glibenclamide and TEA. In Ca[2+]-free Tyrode solution with high K[+], cumulative concentrations of CaCl2 induced contractions which were inhibited by TLE dose-dependently. Our results indicate that the Tecoma stans [L.] Juss leaf extract induces its antispasmodic effects without involvement beta-adrenoceptors, opioid receptors, potassium channels and NO production. It seems that, the calcium channels are involved in this spasmolytic effect