The 2020 Democratic presidential candidate Bernie Sanders, 78, has cancelled campaign events after undergoing a heart procedure.Mr. Sanders was treated in hospital for an arterial blockage after experiencing chest pain at an event in Nevada on Tuesday.The Vermont senator tweeted that he was "feeling good". An aide said Mr. Sanders would rest over the next few days.Mr. Sanders had earlier announced his campaign had raised over $25m (£20m).The presidential hopeful tweeted that he was recovering, taking the opportunity to promote his healthcare policy inspired by Britain's National Health Service.

Thanks for all the well wishes. I'm feeling good. I'm fortunate to have good health care and great doctors and nurses helping me to recover.

None of us know when a medical emergency might affect us. And no one should fear going bankrupt if it occurs. Medicare for All!— Bernie Sanders (@BernieSanders) October 2, 2019

Senior adviser Jeff Weaver said in a statement: "Following medical evaluation and testing he was found to have a blockage in one artery and two stents were successfully inserted."Mr Weaver said Mr Sanders is "conversing and in good spirits" and will be "resting up over the next few days".A stent is a small mesh tube used to help keep arteries open. Receiving stents is "a minimally invasive procedure", typically with a short recovery time, the US National Heart, Lung and Blood Institute says.It is unclear how long Mr Sanders will need to recover from this procedure, and whether it will affect his appearance in the next Democratic debate on 15 October.Polls show Mr Sanders is third in the Democratic race behind Massachusetts Senator Elizabeth Warren and former Vice-President Joe Biden.