Article Text

Download PDFPDF
Prediction of the effectiveness of long term β blocker treatment for dilated cardiomyopathy by signal averaged electrocardiography

Abstract

Objective To determine whether the effectiveness of long term β blocker treatment for idiopathic dilated cardiomyopathy can be predicted by signal averaged electrocardiography (ECG).

Patients 31 patients with dilated cardiomyopathy and without bundle branch block were included in a retrospective study and 16 in a prospective study.

Methods A signal averaged ECG was recorded before β blocker treatment, and three variables were measured from the vector magnitude: QRS duration, root mean square voltage for the last 40 ms (RMS40), and duration of the terminal low amplitude signals (< 40 μV) (LAS40). In the retrospective study, these variables were compared among good responders (showing ⩾ 0.10 increase in ejection fraction 12 months after start of β blocker treatment) and poor responders without such improvement. The validity of the signal averaged ECG criteria for prediction of the response to β blocker treatment was examined in the prospective study.

Results In the retrospective study, good responders (n = 16) had a shorter QRS duration (mean (SD): 122.9 (11)v 138 (14.4) ms, p < 0.005) and LAS40 (33.1 (8.9)v 42.5 (7.8) ms, p < 0.005), and a higher RMS40 (31.6 (16.3) v 19.0 (10.3) μV, p < 0.02) than poor responders (n = 15). Signal averaged ECG criteria for good response were defined as two or more of the following: QRS duration < 130 ms, RMS40 > 20 μV, LAS40 < 40 ms (sensitivity 81%, specificity 73%). In the prospective study, six of seven patients who met these criteria showed a good response to the β blocker treatment, while eight of nine who did not showed a poor response (χ2 = 6.1, p < 0.02). The signal averaged ECG criteria gave a sensitivity of 86% and a specificity of 89% for predicting the effectiveness of β blocker treatment.

Conclusions A signal averaged ECG might be useful in predicting the effectiveness of β blocker treatment for dilated cardiomyopathy.

  • signal averaged ECG
  • β blockers
  • dilated cardiomyopathy

Statistics from Altmetric.com

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.