Effects of enriched-potassium diet on cardiorespiratory outcomes in experimental non-ischemic chronic heart failure

BACKGROUND: Chronic heart failure (CHF) is a global health problem. Increased sympathetic outflow, cardiac arrhythmogenesis and irregular breathing patterns have all been associated with poor outcomes in CHF. Several studies showed that activation of the renin-angiotensin system (RAS) play a key role in CHF pathophysiology. Interestingly, potassium (K(+)) supplemented diets showed promising results in normalizing RAS axis and autonomic dysfunction in vascular diseases, lowering cardiovascular risk. Whether subtle increases in dietary K(+) consumption may exert similar effects in CHF has not been previously tested. Accordingly, we aimed to evaluate the effects of dietary K(+) supplementation on cardiorespiratory alterations in rats with CHF. METHODS: Adult male Sprague–Dawley rats underwent volume overload to induce non-ischemic CHF. Animals were randomly allocated to normal chow diet (CHF group) or supplemented K(+) diet (CHF+K(+) group) for 6 weeks. Cardiac arrhythmogenesis, sympathetic outflow, baroreflex sensitivity, breathing disorders, chemoreflex function, respiratory–cardiovascular coupling and cardiac function were evaluated. RESULTS: Compared to normal chow diet, K(+) supplemented diet in CHF significantly reduced arrhythmia incidence (67.8 ± 15.1 vs. 31.0 ± 3.7 events/hour, CHF vs. CHF+K(+)), decreased cardiac sympathetic tone (ΔHR to propranolol: − 97.4 ± 9.4 vs. − 60.8 ± 8.3 bpm, CHF vs. CHF+K(+)), restored baroreflex function and attenuated irregular breathing patterns. Additionally, supplementation of the diet with K(+) restores normal central respiratory chemoreflex drive and abrogates pathological cardio-respiratory coupling in CHF rats being the outcome an improved cardiac function. CONCLUSION: Our findings support that dietary K(+) supplementation in non-ischemic CHF alleviate cardiorespiratory dysfunction. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40659-021-00365-z.