Impaired left ventricular filling is associated with decreased pulse oximetry values

The aim of this study was to investigate the association between echocardiographic measures of diastolic left ventricular dysfunction and decreased arterial oxyhaemoglobin saturation measured with pulse oximetry (SpO₂).

This is a cross-sectional population-based survey of Norwegian adults. Values obtained using echocardiography, pulse oximetry, and spirometry were included. The primary outcome was abnormal mitral Doppler inflow, defined as normal: E/A ratio 0.75-1.5 and EDT ≥ 140 ms; abnormal: E/A ratio <0.75 or >1.5 or EDT <140 ms. The associations between this outcome and possible predictors, including SpO₂ ≤ 95%, were analysed using univariable and multivariable logistic regression.

A total of 1782 participants aged 50 years or older (54% women, mean age 67.5 years) were included in the analysis. Abnormal mitral Doppler inflow was found in 595 participants. After adjusting for age, gender, previous myocardial infarction, smoking history, dyspnoea, obesity, and decreased lung function, SpO₂ ≤ 95% predicted abnormal mitral Doppler flow with an odds ratio (OR) of 1.6 [95% confidence interval (CI) 1.1-2.4]. Hypertension and BMI > =30 were also significant predictors of impaired filling, with OR of 1.7 (95% CI 1.1-2.7) OR and 1.5 (95% CI 1.2-1.9), respectively.

Decreased SpO₂ was a significant predictor of abnormal mitral Doppler flow. Diastolic dysfunction should be considered when SpO₂ ≤ 95% is found.