Causes of Fast Heart Beat – Diagnosing Palpitations

Q:  Is it bad that my resting heart rate is between 101 and 106? I never noticed this problem before. I started to look into it because two days ago I went to donate blood. I passed all the tests except one. My pulse while sitting in the chair was 125. Of course, I was nervous but not incredibly in a panic state.
– By Ashley, age 19 years, female.
Your heart rate appears to be fast. Increased rate of heart is medically termed as tachycardia.
Heart rate is controlled by electrical signals sent across heart tissues. Fast heart beat occurs when an abnormality in the heart produces rapid electrical signals.

Kinds of Tachycardias

They are of many kinds. The ones arising from the upper chambers of the heart are called atrial tachycardias and those arising from the lower heart chambers are called ventricular tachycardias.
Also, the rate of the heart may be irregular or regular. Irregular  rhythms are more difficult to treat.

Causes of Increased Heart Rate

The cause can be mere nervousness. When you feel nervous, signals from the brain reach the heart causing it to beat faster. However, there can be other reasons too.
Causes relevant in your case are-
  • Emotional stress
  • Anxiety
  • Intake of any stimulant, like drinking large amounts of alcoholic or caffeinated beverages
  • Medical conditions such as thyroid disease, lung diseases or electrolyte imbalance.
  • Alcohol or drug abuse
  • Anemia, iron deficiency
  • Heart-related conditions such as high blood pressure (hypertension)
  • Rarely, it can be due to poor blood supply to the heart muscle as in coronary artery disease (atherosclerosis), heart valve disease, heart muscle disease (cardiomyopathy), or infections.


Patients with rapid heartbeat may show no symptom at all or they may have any of the following complaints-
  • Shortness of breath
  • Dizziness
  • Sudden weakness
  • Palpitation in the chest
  • Lightheadedness
  • Fainting


I would suggest you to get evaluated further.
You can visit a cardiologist for this. He may suggest you investigations like Holter monitor study (used for 24 hours) in which your heart will be monitored for a period of 24 hours continuously. This will identify the type of rhythm problem.
Other tests may be done to look at heart function:
  • Coronary angiography
  • ECG (electrocardiogram)
  • Echocardiogram
A special test, called an electrophysiology study (EPS), is done to take a closer look at the heart’s electrical system.
Apart from this, you may be required to get screened for thyroid problems and anemia. This will be done by simple blood tests.


Treatment will depend upon the type of tachycardia you have. There are many treatment modalities available –
  • Anti-arrhythmic drugs are available.
  • In some cases, an implantable pacemaker is put underneath the skin near your heart. This regulates the heart beats to assure that they are delivered at a normal rate.
Take Care,
Buddy M.D.

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