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QRS complex duration and dipyridamole gated SPECT findings in the left bundle branch block

Sabahat Inanir1, Billur Caliskan, Sena Tokay

  • 1Soyak Goztepe Sitesi, 50, Blok Daire: 901, Uskudar, Istanbul 34692, Turkey. sabahatinanir@yahoo.com

Annals of Nuclear Medicine
|August 30, 2008
PubMed

Insights

Longer QRS duration in patients with left bundle branch block (LBBB) is linked to artifactual perfusion abnormalities on SPECT scans. These abnormalities, particularly in the end-systolic phase, negatively impact left ventricular function.

Area of Science:

  • Cardiology
  • Nuclear Cardiology
  • Cardiac Imaging

Background:

  • Left bundle branch block (LBBB) can cause artifactual perfusion abnormalities on myocardial SPECT imaging.
  • Accurate assessment of left ventricular function in LBBB patients is crucial.

Purpose of the Study:

  • To investigate the relationship between QRS duration, artifactual perfusion abnormalities, and left ventricular function in LBBB patients.
  • To evaluate the impact of LBBB-induced artifacts on dipyridamole technetium-99m sestamibi SPECT findings.

Main Methods:

  • Analysis of 23 patients with complete LBBB undergoing rest-dipyridamole gated SPECT.
  • Inclusion of patients with normal end-diastolic stress images to identify artifactual abnormalities.
  • Measurement of QRS duration and calculation of summed defect scores (SRS, SSS, EDS, ESS).

Main Results:

  • Significantly longer minimum QRS duration at rest correlated with perfusion abnormalities (SRS, SSS).
  • Inverse correlation found between left ventricular ejection fraction (LVEF) and end-systolic score (ESS) (r: -0.671, P < 0.0001).
  • Patients with end-systolic perfusion abnormalities exhibited significantly lower LVEF.

Conclusions:

  • Artifactual perfusion abnormalities in LBBB are significantly related to QRS duration.
  • The severity of perfusion abnormalities, especially on the end-systolic phase, adversely affects left ventricular systolic function.
Abstract

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