Topic category: Basic Science

Topic category: Basic Science European Journal of Cardiovascular Prevention and Rehabilitation, 2007, 14 (suppl 1):S1–S12 017 Tissue velocity imaging with dobutamine stress echocardiography– a quantitative technique for identification of coronary artery disease in patients with left bundle branch block H. Badran Background Patients with left bundle branch block exhibit abnormal septal motion which may limit the interpretation of stress echocardiograms and persuade great number of false-positive tests using myocardial scintigraphy. Objectives To analyze whether the use of tissue velocity imaging (TVI) during graded dobutamine infusion is useful to identify and predict coronary artery disease (CAD) in patients with complete left bundlebranch block (LBBB). Methods Sixty-two left bundle branch block patients (mean age 62 years, 34 men) with suspected CAD underwent dobutamine stress – Tissue Doppler echocardiography (DS-TDE) within 6 weeks before coronary arteriography. Dobutamine infusion started at 5 m/k/min and increased up to 40m/k/min with additional atropine during submaximal heart rate responses. Beside wall motion analysis pulsed wave Doppler tissue sampling of mitral annulus at 5 corners were performed at rest in the apical four-chamber plus aorta and two-chamber apical views. The measurements were repeated at low dose (10–15m/k/min), and at peak stress. TDE measurements included peak early systolic (PSV), post systolic shortening (PSS), peak early diastolic (Ve), and peak late diastolic (Va) velocities. The results were compared to 20 healthy subjects as a control. Patients were classified into two groups according to angiographic results, LBBB with CAD (n = 32) and LBBB without CAD (n = 30). Results There was no significant difference between LBBB groups in global WMSI at rest, the D changes in each group was almost similar during peak stress test (P > 0.05). In LBBB with CAD group PSV increased during peak stress to a smaller extent (6.3 ± 1.1 to 7.2 ± 2.0 cm/s, B 24% P < 0.03) than in non CAD group (6.8 ± 1.0 to 9.6 ± 2.7 cm/s, B 46% P < 0.01). Similarly, Ve increased to less extent in CAD group (D Ve 0.2 ± 2.9 versus 2.8 ± 1.7 cm/s, B25% versus 42% P < 0.0001). No significant difference in D Va between LBBB groups and control or between each of them. PSS could be recorded at rest in 24/32 (75%) in CAD and 17/30 (57%) in non CAD group. In LBBB with CAD group PSS was developed and significantly augmented from 4.7 ± 3.1 to 6.3 ± 3.4 cm/s (P < 0.001) during stress. Increment of < 2.5 cm/s in PSV and Ve during peak stress identified CAD with 88% sensitivity and 90% versus 87% specificity, respectively. The cut-off values of PSS velocity > 4 cm/sec at peak stress have strong diagnostic power for prediction of obstructive CAD in LBBB patients (82% accuracy). Conclusion DTE with dobutamine stress allows a diagnostic benefit in the detection of CAD in patients with LBBB. The magnitude of change of peak systolic velocity and early diastolic velocity in addition to PSS are quantitative parameter to identify CAD in patients with LBBB where subjective wall motion analysis failed.