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Transthoracic Doppler Echocardiographic Coronary Flow Imaging in Identification of Left Anterior Descending Coronary Artery Stenosis in Patients with Left Bundle Branch Block
Author(s) -
Soylu Ozer,
Celik Seden,
Karakus Gultekin,
Yildirim Aydin,
Ergelen Mehmet,
Zencirci Ertugrul,
Aksu Huseyin,
Tezel Tuna
Publication year - 2008
Publication title -
echocardiography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 62
eISSN - 1540-8175
pISSN - 0742-2822
DOI - 10.1111/j.1540-8175.2008.00729.x
Subject(s) - medicine , cardiology , coronary flow reserve , left bundle branch block , stenosis , diastole , dipyridamole , coronary artery disease , doppler echocardiography , scintigraphy , radiology , heart failure , blood pressure
Background: Conventional noninvasive methods have well‐known limitations for the detection of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). However, advancements in Doppler echocardiography permit transthoracic imaging of coronary flow velocities (CFV) and measurement of coronary flow reserve (CFR). Our aim was to evaluate the diagnostic value of transthoracic CFR measurements for detection of significant left anterior descending (LAD) stenosis in patients with LBBB and compare it to that of myocardial perfusion scintigraphy (MPS). Methods: Simultaneous transthoracic CFR measurements and MPS were analyzed in 44 consecutive patients with suspected CAD and permanent LBBB. Typical diastolic predominant phasic CFV Doppler spectra of distal LAD were obtained at rest and during a two‐step (0.56–0.84 mg/kg) dipyridamole infusion protocol. CFR was defined as the ratio of peak hyperemic velocities to the baseline values. A reversible perfusion defect at LAD territory was accepted as a positive scintigraphy finding for significant LAD stenosis. A coronary angiography was performed within 5 days of the CFR studies. Results: The hyperemic diastolic peak velocity (44 ± 9 cm/sec vs 62 ± 2 cm/sec; P = 0.01) and diastolic CFR (1.38 ± 0.17 vs 1.93 ± 0.3; P = 0.001) were significantly lower in patients with LAD stenosis compared to those without LAD stenosis. The diastolic CFR values of < 1.6 yielded a sensitivity of 100% and a specificity of 94% in the identification of significant LAD stenosis. In comparison, MPS detected LAD stenosis with a sensitivity of 100% and a specificity of 29%. Conclusions: CFR measurement by transthoracic Doppler echocardiography is an accurate method that may improve noninvasive identification of LAD stenosis in patients with LBBB.