Plasma potassium concentration and cardiac repolarisation markers, Tpeak–Tend and Tpeak–Tend/QT, during and after exercise in healthy participants and in end-stage renal disease

Abstract

The cardiac T-wave peak-to-end interval (Tpe) is thought to reflect dispersion in ventricular repolarisation, with abnormalities in Tpe associated with increased risk of arrhythmia. Extracellular K + modulates cardiac repolarisation and since arterial plasma K + concentration ([K + ]) rapidly increases during and declines following exercise, we investigated the relationship between [K + ] and Tpe with exercise. MethodsSerial ECGs (Tpe, Tpe/QT ratio) and [K + ] were obtained from 8 healthy, normokalaemic volunteers and 22 patients with end-stage renal disease (ESRD), at rest, during and after exhaustive exercise. ResultsPost-exercise [K + ] nadir was 3.1 ±0.1, 5.0 ±0.2 and 4.0 ±0.1 mmol.L -1 (mean ± SEM) for healthy participants and ESRD patients before and after HD, respectively. In healthy participants, compared to pre-exercise, recovery-induced low [K + ] was associated with a prolongation of Tpe (110 ±8 vs. 87 ±5 ms, respectively, p=0.03) and an increase in Tpe/QT ratio (0.28 ±0.01 vs. 0.23 ±0.01, respectively, p=0.01). Analyses of serial data revealed [K + ] as a predictor of Tpe in healthy participants (β = -0.54 ±0.11, p=0.0007), in ESRD patients (β = -0.72 ±0.1, p < 0.0001) and for all data pooled (β = -0.64 ±0.52, p = 0.0007). The [K + ] was also a predictor of Tpe/QT ratio in healthy participants and ESRD patients. ConclusionsTpe and Tpe/QT ratio are predicted by [K + ] during exercise. Low [K + ] during recovery from exercise was associated with increased Tpe and Tpe/QT, indicating accentuated dispersion of ventricular repolarisation. The findings suggest that variations in [K + ] with physical exertion may unmask electrophysiological vulnerabilities to arrhythmia.

A century of exercise physiology: effects of muscle contraction and exercise on skeletal muscle Na+,K+-ATPase, Na+ and K+ ions, and on plasma K+ concentration—historical developments

“…No studies have detailed [K + ] dynamics in elite rowers to ascertain whether greater K + shifts are elicited. Prolongation of the cardiac QT interval and T wave peak-to-end interval after exercise were related to [K + ] a , suggesting the possibility of vulnerability to arrhythmias (Atanasovska et al 2018 ; Tran et al 2022 ). In contrast to rowing, cross country skiing, for traditional events, is usually for much longer duration and at a lower intensity, with only modest [K + ] found “immediately after” skiing, although the timing of sampling is unclear.…”

Sociodemographic and clinical factors influencing serum potassium concentration: A retrospective cohort study

“…Adaptive control is driven by circadian rhythm [1] . In addition, some studies have focused on the effect of the external environment on serum potassium concentrations and found that age, sex, exercise, diet, and occupation could play a role [2] , [3] , [4] , for example, the male sex and administrative occupations were associated with a higher potassium intake [5] . Moreover, serum potassium concentrations show continuous and parallel decreases with age in both sexes, which may be related to physiological aging [6] , [7] .…”

Oral digoxin effects on exercise performance, K+ regulation and skeletal muscle Na+,K+‐ATPase in healthy humans

“…During intense cycling, running or rowing, [K + ] in arterial plasma reaches 6−8 mmol l −1 and even higher in femoral venous plasma; this is followed by rapid post‐exercise reductions in [K + ], often to sub‐resting values or even hypokalaemia (Atanasovska et al., 2014, 2018; Lindinger et al., 1992; McKenna, Heigenhauser, McKelvie, MacDougall et al., 1997; Medbo & Sejersted, 1990; Vollestad et al., 1994). Post‐exercise hypokalaemia is also associated with impaired cardiac repolarisation and increased risk of arrhythmias (Atanasovska et al., 2018; Lindinger & Cairns, 2021; Tran et al., 2022). Hence, K + regulation is critical both during and after exercise.…”