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Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test
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Diagnostic accuracy of exercise electrocardiogram in patients with left anterior hemi-block

Stefano F Rimoldi1, Stefano F de Marchi, Marc Gertsch

  • 1Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland.

Swiss Medical Weekly
|September 23, 2008
PubMed

Insights

Left anterior hemiblock (LAHB) reduces the accuracy of exercise ECG tests for detecting ischaemia. This common condition lowers test sensitivity and negative predictive value, impacting diagnosis.

Area of Science:

  • Cardiology
  • Diagnostic Imaging
  • Electrocardiography

Background:

  • Left anterior hemiblock (LAHB) is the most prevalent cardiac conduction abnormality.
  • The diagnostic implications of LAHB for exercise electrocardiography (ECG) remain understudied.

Purpose of the Study:

  • To evaluate the diagnostic accuracy of ST depression on exercise ECG for predicting myocardial ischaemia in patients with LAHB.
  • To compare the accuracy of exercise ECG in patients with and without LAHB.

Main Methods:

  • Analysis of consecutive patients with suspected coronary heart disease undergoing exercise ECG and 99mTc-sestamibi SPECT.
  • Exclusion of patients with left bundle branch block, myocardial infarction-related QRS changes, or pharmacological stress testing.

Main Results:

  • Exercise ECG demonstrated lower sensitivity (38% vs. 86%) and negative predictive value (82% vs. 92%) in 69 patients with LAHB compared to those with normal baseline ECG.
  • Reduced sensitivity was observed across subgroups including isolated LAHB, right bundle branch block, and bifascicular block.
  • The positive predictive value of exercise ECG for ischaemia remained excellent despite the presence of LAHB.

Conclusions:

  • The diagnostic accuracy of exercise ECG for predicting myocardial ischaemia is significantly reduced in the presence of LAHB.
  • Clinicians should consider the impact of LAHB when interpreting exercise ECG results for ischaemia detection.
Abstract

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