Correlation of Two-Dimensional Echocardiography Parameters With Six-Minute Walk Test, Oxygen Saturation, and...

Interstitial lung disease (ILD) is often complicated by pulmonary hypertension (PH), a combination that strains the right side of the heart and worsens outcomes. Two bedside ultrasound measurements, tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP), have emerged as convenient ways to gauge right ventricular function and pulmonary vascular load. We set out to determine how well TAPSE and PASP reflect everyday exercise capacity (six-minute walk distance, 6MWD), oxygen saturation, and routine spirometric indices in adults with ILD, in hopes of identifying simple, clinically useful prognostic markers.

During a three-month prospective study at Rajarajeswari Medical College & Hospital, Bangalore, India, we enrolled 40 adults who met ATS/ERS criteria for ILD. Each participant underwent transthoracic two-dimensional echocardiography, spirometry, and a six-minute walk test. Patients were grouped according to their TAPSE and PASP results, and these groups were compared on exercise performance and lung function metrics. Statistical analysis involved t-tests, one-way ANOVA, Pearson correlation, and Bonferroni-adjusted post hoc tests.

Mildly reduced TAPSE was seen in 50% of the cohort, while 57.5% had elevated PASP. Participants with normal TAPSE and PASP walked farther, maintained higher pre- and post-exercise oxygen saturation, and demonstrated superior forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁). Both TAPSE and PASP correlated strongly and significantly (p<0.001) with all functional measures except the FEV₁/FVC ratio.

TAPSE and PASP closely mirror exercise tolerance, exertional desaturation, and spirometric performance in ILD. Exercise tests such as the six-minute walk test can provide practical prognostic insight in the assessment of ILD.

Bedside echocardiography using TAPSE and PASP can flag early right ventricular dysfunction and incipient PH, guiding timely intervention. The 6MWD provides an approximate estimate of disease progression even in resource-constrained settings. Thus, the 6MWD may serve as an effective alternative for early detection of complications such as PH where advanced resources are unavailable.