Added Value of Tissue Doppler to Dobutamine Echocardiography in Diagnosis of Coronary Artery Disease in Patients Presenting with Chest Pain

Background: Coronary artery disease is a leading cause of morbidity and mortality world-wide and this makes its early diagnosis before occurrence of complications essential for favorable outcome and this can be obtained by various non-invasive tests. This study aimed at clarifying the added role of TDI as a new ultrasound quantitative technique to DSE in overcoming its limitation of being subjective and increasing its sensitivity in diagnosis of CAD taking CA as a gold standard. Methods: We studied prospectively 26 patients with chest pain classified into patients group (16) and a control group (8 with normal CA) and LV segments were classified into non-ischemic and ischemic segments in patients group and control (normal) segments in control group. DSE was done in all study population in a four stages protocol. PW-TDI were traced along the LV from PL, apical 2, 4 and 5-C views. Measured Velocities included Peak velocities of systolic waves, SI and S2 waves and diastolic waves, e and waves and e/a ratio. Measured durations included IVCT, IVRT, ATS1, ATS2, DTS2, ET, ATe, DTe, ATa, DTa and IVA both as absolute and indexed to HR values. Results: DSE revealed sensitivity and specificity of 66.65 and 100% and was inconclusive in 30.7% of study population. PW-TDI: There was significant differences in the change from rest to peak between ischemic and control segments and between patients and control in many diastolic parameters as e, e/a and ATe also in systolic parameters as IVA, IVCT, ATS, TPS, PSV and this was explained by presence of ischemia that decreases e wave e/a ratio and IVA and prolongs ATe, IVCT, ATS, TPS. We chose 4 parameters with the highest sensitivity and specificity and used them in a proposed protocol to reach a final sensitivity and specificity of 94.4% and 100% respectively. Conclusion: From these results we can conclude that TDI added a great value to DSE by increasing its sensitivity in the diagnosis of CAD.