The number of hospital visits made by people suffering heart failure has risen by more than a third in the last decade, analysis shows.
Data for England studied by the British Heart Foundation (BHF) reveals a 36% rise, from 107,000 visits in 2004/05 to 146,000 in 2014/15.
Hospital visits include all admissions, outpatient appointments and A&E attendances.
The BHF said the rise was due to the fact people are living longer and more people are surviving heart attacks.
The charity also analysed GP data on the number of people diagnosed with heart failure and found there are 411,000 people with the condition in England.
This is up from 402,000 the previous year.
Heart failure often occurs after a heart attack but can happen for other reasons.
It means the heart fails to pump enough blood around the body and the heart muscle has become too weak or stiff to work properly.
Symptoms can come on quickly and include breathlessness and feeling very tired.
Up to a third of patients admitted to hospital with heart failure will die within a year.
Professor Peter Weissberg, medical director at the BHF, said: "It is deeply concerning that we are seeing such an alarming increase in the number of heart failure patients attending hospital.
"Our research has helped to drastically improve survival rates from heart attack and seven in 10 people now survive. But this means an increasing number of people are subsequently living with the debilitating impact of heart failure.
"Heart failure can leave sufferers constantly short of breath and sadly many will die within a year of being admitted to hospital. We urgently need to fund more research into the condition to find new and better ways to prevent, diagnose and treat heart failure."
Elaine Harris, 50, from Wigan, had a heart attack aged 48. She is now living with severe heart failure, is unable to work and is being assessed for a heart transplant.
She said: "The last thing I expected was to have a heart attack when I was 48, but to then be told I had severe heart failure was completely devastating.
"My life has completely changed now. I no longer work, I sleep at least 16 hours a day and I can't walk very far at all without resting.
"I still live my life to the fullest I can - but living with this condition has meant a new and restricted way of life and I am completely dependent on my family."