When I was in residency, my favorite Nephrologist told the story of his patient with chronic kidney disease who had "killed himself with V8 juice". The patient had been instructed a number of times regarding the potassium present in V8 but he liked it and did not want to stop drinking it and he eventually passed away with hyperkalemia.
I was reminded of this story recently when I was called to a code. There was an elderly male who was on our rehab floor who had the sudden loss of consciousness and pulselessness. CPR was started and the monitor showed persistent asystole. While the code was running, I was able to quickly scan through his chart and see that his creatinine had been rising and he had been on potassium supplementation three times a day and his potassium had been elevated that morning. I quickly have calcium, dextrose and insulin. He regained a rhythm and pulse and was transferred the ICU.
Hyperkalemia is known to cause cardiac conduction abnormalities. The usual progression is peaked T waves with shortening of the QT interval. This followed by progressive lengthening of the PR interval and QRS. The P wave eventually falls and the rhythm goes to asystole or ventricular fibrillation.
Whether is it V8 ingestion or iatrogenic potassium supplementation, we need to remember to be very careful with the potassium level in patients with renal disease.