Detection of K+ concentration alterations from the ECG

Potassium homeostasis is impaired in patients with cardiovascular diseases due to a number of pathologies, including renal dysfunction. In patients undergoing hemodialysis three times a week the sudden death rate triples in the 12 hours prior to scheduled dialysis following a two-day weekend hiatus, the time at which life-threatening hyperkalemia is most likely to happen, usually asymptomatic [6].

For these situations, it would be extremely relevant to have a method allowing to detect hyperkalemia in a frequent, non-invasive and remote way, and to drive subsequent therapeutic decisions in order to prevent the sudden death events. Hyperkalemia does affect the cardiac cell electrophysiology since K⁺ has a relevant role, both at the repolarization and the depolarization phases of the cardiac cell activation process. The hypothesis of this project is that biomarkers derived from a comprehensive analysis of the ECG, both at depolarization and repolarization phases, can provide robust enough ambulatory markers, able to trigger alarms of hyperkaliemia concentration when the related cardiac risk makes therapeutic actions advisable.

The project will recruit patients under hemodialysis treatment at the renal service of the “Hospital Clinico” de Zaragoza, and record both, ECG and blood samples at different stages of their dialysis cycle: basal stage before a dialysis process (both Monday and other day), during the dialysis itself, at the end of the process, and in the Hospital, if the patient is referred because of decompensations during the weekend hiatus. The development of the ECG analysis methodology will be performed by the BSICoS group, looking for ECG-based biomarkers correlated with the [K⁺] concentrations measured from the blood samples.

After one or more reliable biomarkers of hyperkalemia have been identified, a second step in the overall project will be the implementation to be used in mobile devices, compatible with ambulatory monitoring and/or wearable sensor for comfortable use. For this task,  the GBIO Group will study the best implementation strategy and will develop a prototype system for the ambulatory use, where a pilot study can be designed to perform an evaluation of the system.