title: Assessment of left ventricular function from the electrocardiogram in left bundle branch block.
abstract: The QRS duration, maximum right precordial S amplitude, sum of amplitudes of the maximum right precordial S and T wave and T wave polarity in lead I have been analyzed in order to identify electrocardiographic predictors of left ventricular end-diastolic volume index and ejection fraction in 165 patients with complete left bundle branch block and various forms of heart disease. Multivariate analysis selected the duration, maximal amplitude of the S wave and polarity of the T wave in decreasing order of discriminatory power, which correctly identify 76.6% of the patients with a normal end-diastolic volume index less than or equal to 90 ml/m2 and a normal ejection fraction greater than or equal to 60% (n = 64) and 73.3% of those with an end-diastolic volume index greater than 90 ml/m2 or an ejection fraction less than 60% (n = 101). The comparisons of the QRS duration with the end-diastolic volume index and the ejection fraction give the best single correlations: r = 0.57 and -0.63, respectively. Multiple correlations lead to no substantial improvement of the r values: 0.06 and -0.65, respectively. A QRS duration less than 140 msec is almost always predictive of the presence of a normal end-diastolic volume index and a normal ejection fraction (sensitivity 100%, specificity 91.9%, positive predictive value 73.3%). A QRS duration greater than 170 msec is most accurate in predicting depressed left ventricular ejection fraction less than 55% (sensitivity 36.5%, specificity 98%, positive predictive value 92%). Thus, only the QRS duration provides a useful reference and guide for the evaluation of left ventricular function in the presence of left bundle branch block.
authors.affiliation: University Heart Centre, Erlangen, F.R.G.
authors.forename: S H
authors.initials: SH
authors.lastname: Recke
authors.forename: H D
authors.initials: HD
authors.lastname: Esperer
authors.forename: U
authors.initials: U
authors.lastname: Eberlein
authors.forename: R
authors.initials: R
authors.lastname: Gansser
authors.forename: J
authors.initials: J
authors.lastname: von der Emde
mesh_terms: D000328:Adult; D000368:Aged; D002037:Bundle-Branch Block / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D006332:Cardiomegaly / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013318:Stroke Volume