Haemodynamic response during low-dose dobutamine infusion in patients with chronic systolic heart failure: comparison of echocardiographic and invasive measurements.

Aims: To investigate whether left ventricular (LV) systolic shortening velocity (s'), diastolic lengthening velocity (e'), and non-invasively estimated LV filling pressure (E/e') during low-dose dobutamine echocardiography (LDDE) reflect invasive measures of cardiac output and pulmonary capillary wedge pressure (PCWP) in stable patients with chronic systolic heart failure.
Methods and Results: Fourteen patients with heart failure (aged 65 ± 8 years, LVEF 36 ± 8%) underwent simultaneous tissue Doppler echocardiography and invasive measurements of cardiac output and PCWP by right heart catheterization at rest and during dobutamine infusion at rates of 10 and 20 µg/kg/min. Cardiac output increased from rest to peak dobutamine (4.9 ± 1.2 to 6.6 ± 2.0 L/min, P < 0.001) and correlated with the peak systolic tissue velocity (s') at rest (R = 0.61, P = 0.02) and during dobutamine stimulation (R = 0.79, P < 0.001). Increases in early diastolic mitral inflow (E, 74.9 ± 29.0-90.8 ± 29.5 cm/s) and LV lengthening (e', 6.5 ± 2.4-8.2 ± 2.8 cm/s) velocities were observed during LDDE leaving the E/e' ratio unchanged. Although a mean PCWP was also unchanged from rest to peak dobutamine (16.6 ± 8.3-14.2 ± 9.2, P = 0.25), E/e' and PCWP only correlated at rest (R = 0.64, P = 0.014).
Conclusion: The LV systolic shortening velocity is closely associated with cardiac output during LDDE in CHF patients. Dobutamine stimulation increases early diastolic mitral inflow and lengthening velocities, but the E/e' ratio does not reflect the PCWP during LDDE, which warrants some caution in converting changes in E/e' into changes in LV filling pressure. The sample size is, however, small and the observation need to be confirmed in a larger population.