Heart Palpitations

Possible causes of heart palpitations include:

strenuous exercise

excess caffeine or alcohol use

nicotine from tobacco products such as cigarettes and cigars

stress
anxiety
lack of sleep
fear
panic
dehydration
hormonal changes, including pregnancy
electrolyte abnormalities
low blood sugar
anemia
overactive thyroid, or hyperthyroidism
low levels of oxygen or carbon dioxide in the blood
blood loss
shock
fever
over-the-counter (OTC) medications, including cold and cough medications, herbal supplements, and nutritional supplements
prescription medications such as asthma inhalers and decongestants
stimulants such as amphetamines and cocaine
heart disease
arrhythmia, or an irregular heart rhythm
abnormal heart valves
smoking
sleep apnea

Some heart palpitations are harmless, but they can indicate an underlying illness when you also have:

congestive heart failure
a diagnosed heart condition
heart disease risk factors
a defective heart valve

So heart palpitations are the symptoms of another problem, not the problem itself

Also consider Heart arrhythmia: Heart rhythm problems (heart arrhythmias) occur when the electrical impulses that coordinate your heartbeats don’t work properly, causing your heart to beat too fast, too slow or irregularly. Heart arrhythmias  may feel like a fluttering or racing heart and may be harmless.

Arrhythmias, Cardiac: 0.09, 0.78, 0.83, 7.5, 8, 225.33, 510.25, 689.93, 750, 936.42

Heart Abnormalities: 0.14, 0.22, 0.73, 5.25, 7.25, 52.51, 167.53, 326.16, 569.71, 719.34,