Accuracy and reliability of non-invasive pressure-strain loop for myocardial work assessment in functional single ventricle patients.

BACKGROUND: In biventricular circulation, myocardial work indices derived from pressure-strain loops (PSL) show potential for effectively evaluating ventricular function in both left and right ventricles. However, these novel myocardial work parameters have not been extensively investigated in patients with functional single ventricle (FSV). OBJECTIVES: To assess the relationship between myocardial work indices and parameters from cardiac catheterization in FSV patients, and to compare differences between functional single ventricle subtypes. METHODS: This retrospective study analyzed 38 FSV patients, including 17 with single left ventricle (SLV) patients and 21 with single right ventricle (SRV) patients. All patients underwent echocardiography and cardiac catheterization on the same day. To analyze correlations, Spearman’s rank correlation coefficient was applied, while receiver operating characteristic (ROC) curves were developed to evaluate predictive accuracy. RESULTS: Compared to SLV patients, SRV patients exhibited significantly higher global wasted work (GWW) (194.0 [132.5, 309.5] vs. 101.0 [66.5, 143.5] mmHg%, p = 0.012) accompanied by significantly reduced global work efficiency (GWE) (86.0% [81.5, 90.0] vs. 93.0% [89.5, 95.0], p = 0.004). In all FSV patients, global work index (GWI) (r=-0.540, p < 0.01), global constructive work (GCW) (r=-0.436, p < 0.01), and GWE (r=-0.831, p < 0.001) showed significant negative correlations with ventricular end-diastolic pressure (VEDP), while GWW demonstrated a significant positive correlation with VEDP (r = 0.738, p < 0.001). PSL parameters exhibited good intra- and inter-observer reproducibility and high predictive value for VEDP > 10 mmHg. CONCLUSIONS: Pressure-strain loop indices can effectively evaluate cardiac function in FSV patients and reveal functional differences between subtypes. Larger studies are needed to validate the value of these emerging indicators.