OBJECTIVETo assess the feasibility of evaluation of CFR for LAD and right coronary artery (RCA) as well as diagnostic accuracy for patency of each vessel by transthoracic Doppler echocardiography (TTDE).

METHODS65 consecutive patients (age 58 +/- 14, ejection fraction 49% +/- 8%, 48 men and 17 women) were studied for CFR by TTDE with adenosine infusion (140 microg.kg(-1).min(-1)). LAD flow was interrogated nearby the apex in modified 2-ch apical view. RCA flow was interrogated at mid posterior wall on distal part of the posterior descending branch (PDA) in modified 2-ch apical view for PDA.

RESULTSFlow for LAD was detected in all patients (4 with use of contrast agent) and for RCA in 55 patients (5 with contrast agent). Two patients had an occluded RCA. Feasibility of RCA flow detection was 55/63 (87%). In all patients maximal flow of each branch was detected in less than 2 min of adenosine infusion (140 mg.kg(-1).min(-1)). Total time for both CFR estimation was 7.3 +/- 1.6 min. Selecting 2.0 or 1.8 as CFR cut-off value for diagnosis of coronary stenosis (> or = 50% in diameter) or severe stenosis (> or = 70%) was found fitted for both LAD and RCA with similar diagnostic performance (sensitivity 89%/93%, specificity 86%/84%, area under curve 0.89/0.92 respectively, in stenosis diagnosis and sensitivity 88%/89%, specificity 90%/83%, area under curve 0.94/0.95 respectively in severe stenosis diagnosis).

CONCLUSIONSCFR evaluation of both distal LAD and PDA is of high feasibility and can provide high diagnostic yield for relevant vessel patency.