When life looks easy street, there's trouble at your door

So there I was all set to get my knee replacement op in March,when out of the blue , I started getting pains in my chest..... After a trip to the Chest Pain clinic and being wired up to ECG and echo machines, they tell me I may possibly have had a heart attack! So now I have to have an angioplasty and the knee op is on hold for at least a year while they sort me out. Meanwhile I was told to " carry on life as normal just not to overdo it!"  I wonder if that involves hauling a narrow boat about?