+1 on what gangzoom said. No easy way out, i am afraid. There's lot of fast track programme all over the country these days or more commonly known as "the graduate entry programme". Derby, coventry are some of the example. Some of the medical students i have met from these programmes has non-medical background whatsover prior to med school..so it's doable..where there's a will there's a way I have met medical students usually a bit more mature than others who had worked as fire fighter, investment bankers, plant scientist, etc. These programme wasn't available back in my days. Been qualified for 8 years.
Cardiology is very competitive..it's one of the most competitive training programme. Very popular amongst junior doctors. It's life long learning as a doctor and very long working hours and training in addition to 5 years in medical school (4 yrs via graduate entry route). i was once young