A new hybrid echocardiography and arterial pressure waveform approach for non-invasive reconstruction of the entire left ventricular pressure waveform.

AIMS: Non-invasive estimation of left ventricular pressure (LVP) is crucial for managing cardiovascular diseases such as heart failure and myocardial infarction (MI). Current clinical practices rely on invasive catheterization, limiting its feasibility for routine or longitudinal monitoring. This study evaluates the accuracy of a novel LVP reconstruction algorithm in preclinical (rat) experiments.

METHODS AND

RESULTS

Using a standard coronary occlusion/reperfusion model (n = 39 rats), we validated our algorithm across three physiological states: baseline, myocardial ischaemia, and MI. LVP waveforms were reconstructed using only carotid pressure waveforms and echocardiographic measurements. Algorithm performance was assessed by comparing reconstructed LVP waveforms to invasively measured LVP, using key haemodynamic metrics such as left ventricular end-diastolic pressure (LVEDP) and the subendocardial viability ratio (SEVR). Agreements between waveforms were assessed using intraclass correlation coefficients (ICC), normalized Euclidean distance (NED), and differences in harmonic modulus. The algorithm accurately estimated LVEDP across all physiological states (mean absolute error: 1.5 mmHg), with strong correlation to invasively measured LVEDPs (r = 0.91). Predicted SEVR also showed strong agreement with measured values (r = 0.96). The algorithm captured the expected LVEDP elevation and SEVR reduction during myocardial ischaemia, and the metric's partial recovery after reperfusion. Waveform-level agreement demonstrated near-perfect alignment, with high ICC (98.5%), low NED (0.062), and minimal harmonic modulus differences (0.043) for all tested cases.

CONCLUSION

This study demonstrates that LVP can be accurately reconstructed using the proposed algorithm in rats. Our algorithm reliably captured key LVP metrics and waveform features across varying physiological states, supporting its potential for cardiac monitoring.