Bedside prediction of increased filling pressure using acoustic electrocardiography

Abstract 

Background

Patients presenting with acute dyspnea are often a diagnostic dilemma. A bedside tool that accurately and rapidly identifies increased left ventricular (LV) filling pressure would be helpful. We evaluated acoustic electrocardiography for this purpose.

Methods

We pooled 3 cohorts of patients for this analysis. Inclusion criteria required acoustic electrocardiography and echocardiography within 4 hours of each other. Increased LV filling pressure was defined as a pseudonormal or restrictive filling pattern on echocardiography. Area under the receiver operating characteristic curve (AUC) assessed multivariable model accuracy.

Results

The median age of the 324 patients was 61 years (range, 19-90 years), 67% were male, and 82% had a history of heart failure. The final multivariable model included mean LV systolic time, S₃ score, maximum negative area of the P wave, and the QTc interval. The AUC was 0.83 (95% confidence interval, 0.78-0.88). Although B-type natriuretic peptide (BNP) was an independent predictor of estimated increased filling pressure when considered alone (odds ratio = 1.002, 95% confidence interval, 1.000-1.003, P = .002), when added to the acoustic model, it did not improve overall model accuracy. In the subset of patients with indeterminate BNP levels (100-500 pg/mL), the acoustic model was more accurate than BNP (AUC = 0.82 vs 0.71).

Conclusions

Bedside acoustic electrocardiography predicted echocardiographic correlates of increased pressures with high accuracy. For patients with an indeterminate BNP level (100-500 pg/mL), the acoustic electrocardiography model was superior to BNP. Prospective model validation is warranted.