My heart is beating quite hard and it is quite tender. i've also felt a bit dizzy on and off?

Palpitations: Can be due to a variety of causes. When they are associated with dizziness it is very important to rapidly exclude the possibility (albeit less common) of a heart rhythm disorder that rarely can be serious. Recommend presenting to an A and E or emergency department for an urgent ECG (heart tracing) if not yet done. Otherwise if this is normal a consultation with a doctor is next step.

Palpations: You will need to get evaluated because of your recent surgery with at least and ECG but maybe more. If it happens again I would recommend you sooner rather than later.

See a doctor: Chest pain and palpitations can be signs that that something worrying is going on. You need to visit your nearest Accident and Medical Clinic or Emergency Dept immediately where you can have a thorough examination, ECGs and blood work done to determine the cause of your pain. Causes may include pericarditis or arrhythmias.

Best to get checked: The subjective perception of your own heart beating too hard is called palpitations. This may be from an abnormal heart rhythm but it may also not be a heart issue at all. You should see a Dr for a heart tracing (ECG).

Palpitations: Palpitations can be due to various reasons like heart related conditions or thyroid problems. Some of these need to be addressed at the earliest .Please consult your doctor immediately