Baseline Drifting Correction for Automated MTWA Measurements
Thaís Winkert, Jurandir Nadal, Paulo Roberto Benchimol‐Barbosa · Computing in cardiology · 2023
To reduce the incidence of sudden cardiac death (SCD), risk stratification markers have a relevant role.Microvolt T-wave alternans (MTWA) is a marker of SCD risk, defined as T-wave amplitude variation in the ECG.Usually, MTWA tests are carried out in noisy environments when interferences are expected.Baseline drifting correction methods may distort ECG signals, compromising MTWA analysis.This work assesses the impact of baseline drifting removal (BLDR) by two approaches.Signals with controlled baseline drifting, respiratory fluctuations and MTWA were analyzed.The classical BLDR approach (CA) estimates baseline signals using ECG fiducial points.The time-space cancellation approach (TSC) uses only T-wave information to assemble a vector with T-wave amplitudes, calculated by the difference between the maximum T-wave value and its endpoint.The squared coherence between the spectrum from each approach and the spectrum of the ECG without baseline drifting was calculated.At the alternation frequency (0.5 cycles-per-beat) a higher coherence occurred with TSC (0.57) as compared to CA (0.19).Results indicate that CA adds a distortion to the ECG, compromising MTWA.Conversely, the TSC approach preserves MTWA oscillations and has the potential to improve MTWA quantification.