Relationship between the degree of XXXX and of left ventricular function and the duration of the QT-interval in ECG.

@entity1164 @entity1 @entity1162 @entity944 @entity3979 @entity3980 @entity453 @entity850 @entity204 @entity1002
Advanced @entity453 ( @entity453 ), @entity1162 are considered risk factors for @entity1164 in @entity453 - @entity1 . So far, however, there are no studies investigating in detail whether there is a correlation between the QT-interval and changes in coronary anatomy or changes in left ventricular function. Therefore, coronary angiographic data were related to @entity1162 in 304 @entity1 , who were catheterized because of suspected @entity453 . @entity1162 were expressed as QTc = QT/square root RR (Bazett's correction for heart rate), left ventricular function was assessed by the ejection fraction of the ventricular angiogram, and coronary angiograms were classified according to the Gensini score as well as into 1-, 2- and 3-vessel disease ( @entity850 greater than or equal to 50%). A multidimensional linear regression model was employed to eliminate the effects of varying mean rates still present after application of Bazett's formula. In @entity1 with 1-, 2- and 3-vessel disease, significant changes of QTc were observed only in @entity1 with @entity1002 (EF less than 60%). In these @entity1 the QTc-interval increased significantly from 1- to 3-vessel disease. If the critical degree of @entity3979 was changed from greater than or equal to 50% to greater than or equal to 90% further prolongations of QTc were noted. In @entity1 with 1-, 2- and 3-vessel disease the QTc-duration difference was further enhanced if either the proximal part of the descending branch of the left coronary artery ( @entity3980 ) or the left main stem were affected ( @entity850 greater than or equal to 50%). The data reveal that prolongation in the duration of electrical systole correlates with known cardiac risk factors for @entity944 , i.e. 3-vessel-disease, proximal @entity3980 or left main stem @entity850 and @entity1002 . In the individual @entity1 , however, the prognostic value of a single @entity204 is limited because of a large interindividual variation of the data.
