Patient-specific multivariable estimators combining QRS and T wave markers estimated serum potassium and calcium levels with average differences of <0.035 mM and 0.010 mM, respectively.
Observational (n=29)
Do QRS morphology-based markers from ECG recordings allow accurate non-invasive estimation of serum potassium and calcium levels in patients undergoing hemodialysis?
ECG-based QRS and T wave morphological markers can accurately and non-invasively estimate serum potassium and calcium levels in hemodialysis patients, potentially aiding in arrhythmia risk prediction.
OBJECTIVE: Non-invasive estimation of serum potassium, K+, and calcium, Ca2+, can help to prevent life-threatening ventricular arrhythmias in patients with advanced renal disease, but current methods for estimation of electrolyte levels have limitations. We aimed to develop new markers based on the morphology of the QRS complex of the electrocardiogram (ECG). METHODS: ECG recordings from 29 patients undergoing hemodialysis (HD) were processed. Mean warped QRS complexes were computed in two-minute windows at the start of an HD session, at the end of each HD hour and 48 h after it. We quantified QRS width, amplitude and the proposed QRS morphology-based markers that were computed by warping techniques. Reference K+ and Ca2+ were determined from blood samples acquired at the time points where the markers were estimated. Linear regression models were used to estimate electrolyte levels from the QRS markers individually and in combination with T wave morphology markers. Leave-one-out cross-validation was used to assess the performance of the estimators. RESULTS: ranging from 0.61 to 0.76). QRS morphology markers showed very low sensitivity to heart rate (HR). Actual and estimated serum electrolyte levels differed, on average, by less than 0.035 mM (relative error of 0.018) for K+ and 0.010 mM (relative error of 0.004) for Ca2+ when patient-specific multivariable estimators combining QRS and T wave markers were used. CONCLUSION: QRS morphological markers allow non-invasive estimation of K+ and Ca2+ with low sensitivity to HR. The estimation performance is improved when multivariable models, including T wave markers, are considered. SIGNIFICANCE: Markers based on the QRS complex of the ECG could contribute to non-invasive monitoring of serum electrolyte levels and arrhythmia risk prediction in patients with renal disease.
Bukhari et al. (Tue,) conducted a observational in End-Stage Renal Disease (n=29). QRS and T wave morphology markers vs. Blood sample reference levels was evaluated on Difference between actual and estimated serum electrolyte levels. Patient-specific multivariable estimators combining QRS and T wave markers estimated serum potassium and calcium levels with average differences of <0.035 mM and 0.010 mM, respectively.