Left atrial inflow propagation rate derived by transesophageal color M‐mode echocardiography is a promising index of preload

Abstract

SummaryBackground: Pulmonary capillary wedge pressure (PCWP) is a useful index of preload and an important determinant of cardiac function.Hypothesis: We postulated that the rate of blood propagating into the left atrium (LAIF-PR) would be a useful measure of PCWP in critically ill patients.Methods: Fifty-two critically ill patients (36 men/16 women) receiving mechanical ventilation were studied by multiplane transesophageal echocardiography (TEE). Left atrial inflow propagation rate was measured in systole and diastole as the slope of the color M-mode signal entering the left atrium from the right upper pulmonic vein.Results: Systolic and diastolic LAIF-PRs were feasible in 49 and 44 patients, respectively. Mean (± 1 standard deviation) LAIF-PR in systole was 40 ± 26 cm/s (range 11-132) and in diastole 34 ± 22 cm/s (range 5-102). Negative correlations with PCWP (mean 19 ± 9 mmHg; range 3-40) were good for LAIF-PR in systole (r = Ϫ0.71, standard error of estimate [SEE] = 6 mmHg; p < 0.0001) and diastole (r = Ϫ0.71, SEE = 6 mmHg; p < 0.0001). Mean ejection fraction was 52 ± 22% (range 15-88) and cardiac output was 6.97 ± 3.52 l/min (range 2.26-17.93). Multivariate regression showed PCWP as the only independent predictor of systolic (p < 0.0001) and diastolic (p < 0.0001) LAIF-PR among age, heart rate, cardiac output, ejection fraction, or left atrial diameter.Conclusions: Left atrial inflow propagation rate derived by color M-mode TEE aligned with the right upper pulmonic vein is a promising new index of preload. Future studies addressing the determinants of LAIF-PR, such as left atrial compliance, are needed.

Left atrial inflow propagation velocity derived by color M-mode Doppler in acute heart failure

“…Mean LAIF-PV in our study was 24.2 cm/s, which is markedly lower than that previously reported in healthy volunteers (228 cm/s) and in critically ill patients (40 cm/s) [ 12 , 22 ]. A discrepancy likely explained by different clinical settings.…”

“…Stoddard et al found LAIF-PV feasible in 94% of a heterogeneous cohort of critically ill patients treated with mechanical ventilation [ 22 ]. Importantly, the LAIF-PV measurements in this study were obtained from transesophageal echocardiography (TEE).…”

“…Importantly, the LAIF-PV measurements in this study were obtained from transesophageal echocardiography (TEE). They analyzed both systolic LAIF-PV and diastolic LAIF-PV, with lower feasibility for diastolic LAIF PV (85%) [ 22 ]. The superior acoustic windows for visualizing the atria provided by TEE compared to TTE likely accounts for the higher feasibility.…”

“…A discrepancy likely explained by different clinical settings. Mechanically ventilated patients experience elevated intrathoracic pressures from the treatment itself which likely influenced pulmonary venous flow and LAIF-PV [ 22 ]. Excluding patients with low-grade mitral regurgitation and AF may add to the heterogeneity [ 13 ].…”

“…Stoddard et al studied a wider range of clinical phenotypes from septic shock to patients with prior HF. Their patients had higher mean LVEF (52%) and smaller LA diameters [ 22 ]. The clinical and cardiac structural features in patients with AHF may well affect hemodynamic parameters such as LV filling pressures and LAIF-PV, as well as the feasibility.…”