AimsTo 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 resultsFourteen 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 theE/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).
ConclusionThe 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 theE/e′ ratio does not reflect the PCWP during LDDE, which warrants some caution in converting changes inE/e′ into changes in LV filling pressure. The sample size is, however, small and the observation need to be confirmed in a larger population.