Palpitations
If you have palpitations as a symptom of your heart failure, you will feel like your heart is racing or throbbing and your heartbeat may seem irregular, with beats of varying strength.
Palpitations indicate an irregular heartbeat and this may have been caused by the heart speeding up to compensate for its failing ability to pump blood normally. A common cause is the sudden onset of a rapid irregular heart rate (atrial fibrillation). This may lead to increasing dizziness and/or shortness of breath but is treatable.
If your palpitations get worse or are making you feel light-headed or dizzy, then you should seek medical attention immediately.