Noninvasive Monitoring of Potassium Fluctuations During the Long Interdialytic Interval

Abstract

Hemodialysis patients are susceptible to life-threatening arrhythmias whose incidence is markedly higher during the long interdialytic interval due to electrolyte fluctuations. Noninvasive monitoring of electrolyte fluctuations, particularly those of potassium, would enable restoring electrolyte balance before the onset of arrhythmias. This study investigates the feasibility of continuous long-term monitoring of potassium fluctuations using a single-lead electrocardiogram. We evaluate patient-specific T-wave morphology changes in the electrocardiogram using two descriptors: (i) a model-based descriptor, , developed to account for overall morphology changes, and (ii) the currently available descriptor, , sensitive to potassium levels in single-lead electrocardiograms. Electrocardiograms of 15 hemodialysis patients with pre-existent cardiac diseases were acquired continuously over the long interdialytic interval along with blood samples at predetermined time instants. Results reveal that and respond concordantly with potassium levels, and reacts to potassium lowering medication. The overlapping index of the daily distributions of and are moderately correlated with changes in potassium levels (= − 0.56 and = − 0.57, respectively). exhibits circadian variation, peaking amidst morning and decreasing until evening. appears to be less affected by motion-induced noise, which is preferable for ambulatory monitoring. Although long-term monitoring of potassium fluctuations is feasible even in complicated hemodialysis patients, the presence of concomitant electrolyte (calcium and bicarbonate) imbalances should be accounted for since it can hamper a reliable estimation. Considering that intradialytic T-wave morphologies may differ from the ones manifested between hemodialysis sessions, future studies should also strive to collect blood samples outside of hemodialysis to improve electrolyte estimation methods.

ECG Signal Classification for Detection of Hyperkalemia

“…Hyperkalemia is a potential threat especially in patients suffering from Chronic Kidney Disease [1]. An automatic, non invasive method for detection hyperkalemia is crucial for timely intervention, appropriate treatment, and preventing potential complications.…”

“…Hyperkalaemia, characterized by elevated potassium levels (>5.3mEq/L) in the blood, is one such condition that leaves a dis-tinct footprint on the ECG waveform. High levels of potassium can lead to sud-den cardiac deaths in patients suffering from Chronic Kidney Disease [1]. Early detection of hyperkalaemia-induced ECG changes can aid in rapid clinical inter-vention, preventing potential lifethreatening complications.…”

Differences in ventricular wall composition may explain inter-patient variability in the ECG response to variations in serum potassium and calcium

“…Some of these estimators are based on the QRS complex duration, the QT interval and the T wave amplitude, slope or slope-to-amplitude ratio ( Parham et al, 2006 ; Severi et al, 2009b ; Corsi et al, 2012 ; Astan et al, 2015 ; Dillon et al, 2015 ; Attia et al, 2016 ; Corsi et al, 2017 ; Weiss et al, 2017 ; Yoon et al, 2018 ; Noordam et al, 2019 ; Pilia et al, 2020 ). Other studies have investigated model-based markers of T wave morphology ( Rodrigues et al, 2020 ), sympathetic activity-related T wave instability during HD ( Schüttler et al, 2021 ) and descriptors of the sine wave shape, amplitude and time voltage area of the QRS complex ( Ojanen et al, 1999 ; An et al, 2012 ; Curione et al, 2013 ; Pilia et al, 2020 ). To characterize overall variations in the morphology of the QRS complex and the T wave, in previous studies we have developed [K + ] and [Ca 2+ ] estimators using non-linear dynamics and time-warping techniques and we have evaluated them during and after HD in ESRD patients ( Bukhari et al, 2019 ; Srinivasan et al, 2020 ; Palmieri et al, 2021a ; Palmieri et al, 2021b ; Bukhari et al, 2021 ; Bukhari et al, 2022a ; Bukhari et al, 2022b ).…”

Monitoring of Serum Potassium and Calcium Levels in End-Stage Renal Disease Patients by ECG Depolarization Morphology Analysis

“…Although the QT interval has long been used to monitor CKD patients during HD [16][17][18][19][20][21], contradictory findings have been presented, with many studies reporting QT prolongation [18,19,[21][22][23] and others showing QT shortening or no effects during HD [24,25]. Other recent studies have investigated changes in markers of sympathetic activity-related T wave instability during HD [26] and in model-based descriptors of T wave morphology in the interdialytic interval [27]. These studies, however, have not established a tight correlation between the proposed markers and [K + ], thus limiting their possibilities for ambulatory [K + ] monitoring.…”