About Arrythmia

Functioning of the normal heart

An arrhythmia is a disorder of the heart rate (pulse) or heart rhythm.
A heart may beat too fast (tachycardia), too slow (bradycardia), or irregular; that is called arrhythmia.

The human heart is a four-chambered pump consisting of two upper chambers called the atria and two lower chambers called the ventricles. The heart works to pump blood to the lungs and the rest of the body. The two upper chambers (the atria) pump simultaneously, acting as booster pumps into the lower chambers (the ventricles) that pump blood to the lungs and the rest of the body. In a normal human being, impure blood from all over the body drains to the right upper chamber, called the right atrium, which empties it to the right lower chamber, called the right ventricle. The right ventricle pumps blood to the lungs through the pulmonary arteries where it gets oxygenated. The oxygenated blood drains through four pulmonary veins into the left upper chamber, called the left atrium, that then pumps blood to the left ventricle. The left ventricle is the main pumping chamber; it is responsible for pumping blood to the whole body. When a normal human being is at rest, the heart pumps approximately 5 liters of blood per minute.
About Us Image
About Us Image
To help this happen, heart has an electrical system that makes sure it contracts (squeezes) in an orderly way. An electrical impulse or spark of electricity is generated from the top of the right upper chamber by a group of cells that comprise the sinoatrial node; it is similar to a spark plug in an engine, and is the natural pacemaker of the heart. In a normal human being, approximately 50 to 100 impulses are generated per minute causing the heart to pump 50 to 100 times a minute, resulting in a normal heart rate or pulse rate of 50 to 100 beats per minute. The electrical signal, after leaving the sinoatrial node, activates both the upper chambers simultaneously.
The impulse then passes through the atrioventricular node situated in the central part of the heart, and descends to the lower chamber which is activated by the right and left bundles. These are like nerves, and activate the lower chambers rapidly. The electrical conducting system consists of the SA node that produces electricity, and the AV node and the bundle branches that conduct electricity.

Types of Arrhythmia

1 Tachycardia or rapid heart beats.

Tachycardia, or rapid heartbeats, can arise from the upper, middle, or lower chambers of the heart, either from the right or the left side. Some of the abnormal heart beat disorders include

From the upper chamber /the atria: Atrial fibrillation, a trial flutter, and atrial tachycardia. From the middle of the heart: Paroxysmal supraventricular tachycardia (PSVT), and WPW syndrome. From the lower chamber/the ventricle: Ventricular tachycardia, andventricular fibrillation.

2 Bradycardia or slow heart beats.

Bradycardia, or slow heartbeats, are either caused by decreased production of electrical impulses or by electrical conduction being blocked because of weak nerves. This commonly happens due to damage to the nerves, which may be caused by ageing, surgery or infections. The common disorders include

Sick sinus syndrome (decreased impulse production)
Complete AV blocks/complete heart blocks.

3 Irregular or "skipped beats".

Irregular, or skipped beats, occur because of extra impulse being produced either in the upper, middle or
lower chambers. These are called
Atrial ectopics
Ventricular ectopics
Junctional ectopics


Some of the common symptoms that may occur when the arrhythmia is present include:
Fainting or near fainting
Light-headedness, dizziness
Chest discomfort
Shortness of breath
Sudden cardiac arrest
The majority of sudden cardiac arrests are caused by heart rhythm disorder

The most important thing to do if you suspect an arrhythmia, is to record your pulse rate and heart rate during the symptoms of arrhythmia. To measure the pulse at the wrist, place your index and middle finger over the underside of the opposite wrist, below the base of the thumb. Press with flat fingers until you feel the pulse. Once you find the pulse, count the beats for 1 full minute. Or count the beats for 30 seconds and multiply by 2. This will give you the beats per minute.

Normal resting pulse rate:
Newborns (0 - 1 month old) 70 - 190 beats per minute
Infants (1 - 11 months old) 80 - 160 beats per minute
Children (1 - 2 years old) 80 - 130 beats per minute
Children (3 - 4 years old) 80 - 120 beats per minute
Children (5 - 6 years old) 75 - 115 beats per minute
Children (7 - 9 years old) 70 - 110 beats per minute
Children (10 years and older) 50 - 100 beats per minute
Adults (including senior citizens) 50 - 100 beats per minute
Well-trained athletes 40 - 60 beats per minute


Arrhythmias are caused by problems with the heart's electrical system. These include:
  • Decreased production or blocks in the conducting system, resulting in a slow heart rate.
  • Rapid electrical impulse production from various areas of the heart, resulting in a fast heart rate or skipped beats.
  • Abnormal and rapid conduction of electrical signals, similar to an electrical short circuit, resulting in rapid heart beats
Some common causes of abnormal heartbeats are:
  • Abnormal levels of potassium or other substances in the body.
  • A heart attack, or a damaged heart muscle from a past heart attack.
  • Heart disease that is present at birth (congenital).
  • Heart failure or an enlarged heart.
  • An overactive thyroid gland.
Causes Image
Substances or drugs may also cause arrhythmias. They include:
  • Alcohol, or stimulant drugs.
  • Heart or blood pressure medicines.
  • Cigarette smoking (nicotine).
  • Drugs that mimic the activity of the nervous system.
  • Medicines used for depression or psychosis.
  • Medicines that are used to treat arrhythmia


Emergency treatment of arrhythmias may be needed to restore normal rhythm. These include:
Medicines given through a vein (intravenous) to terminate a fast heart rate. Electrical "shock" therapy (defibrillation or cardioversion) if medicines fail or are contraindicated because of low blood pressure, etc. Implanting a short-term heart pacemaker in cases of slow heart rate.

The long-term treatment of arrhythmias may include one of the following modalities:
Medication in the form of tablets: Medicines that treat heart rhythm disorders are called anti-arrhythmic drugs. These are given to prevent an arrhythmia from happening again. The disadvantages of medications are
They need to be taken everyday, for life.
They do not cure the rhythm problem, but only suppress it.
They are only modestly effective in about 50 – 60 % cases.

Some of them may have significant side effects and should be taken under medical supervision.
It is to be remembered that these medications, once started, should not be stopped or changed, unless under medical supervision. Sudden stoppage of these medications may precipitate abnormal heart rhythms and can sometimes be life threatening.
Radiofrequency Catheter ablation
This is also commonly called catheter ablation or RFA. Thin electrodes introduced into the heart, in angiogram areas of abnormal tissue, use electrical energy to prevent arrhythmias. The procedure is performed under local anesthesia, takes about 1 – 2 hours, and can cure arrhythmia in 90 – 99% of patients. It is a low risk procedure and, once successful, will not require any medication.

This is an electronic device which is implanted under local anesthesia to restore normal heart rhythm in patients with slow heart beats. It works similar to an uninterrupted power supply (UPS) in a building.
Implantable cardiac defibrillator
This is a device similar to a pacemaker, and is placed in people who have extremely rapid heart rates and who are at high risk of sudden cardiac arrest that may result in death. Cardiac resynchronization therapy pacemaker/defibrillator
This is similar to a pacemaker or defibrillator and is implanted in patients with heart failure.


An electrocardiogram (ECG), which is the most important test, recording heart activity during the symptoms.
Heart monitoring devices such as Holter monitors (used for 24 hours), event monitors or loop recorders (worn for 2 weeks or longer), and implantable loop recorders.
An Electrophysiological Study (EPS), which is a special test that is performed to take a closer look at the heart's electrical system and to accurately diagnose the arrhythmia
When should you contact an electrophysiologist or heart rhythm specialist?
  • If you develop any of the symptoms of a possible arrhythmia.
  • If you have been already diagnosed with an arrhythmia.
  • If symptoms worsen or do not improve with treatment.


Dr. Jayaprakash Shenthar

Consultant Electrophysiologist

MD (Internal Medicine), DNB (Internal Medicine), DM (Cardiology), DNB (Cardiology), FACC, FICC,
Dr. Jayaprakash Shenthar brings to Fortis Hospitals, Bangalore a rich experience of more than 20 years and vast knowledge in the field of Cardiac Electrophysiology. He underwent his professional training from reputed institutes in India and abroad.
View More
Jayaprakash Shenthar
Dr. Jayaprakash Shenthar brings to Fortis Hospitals, Bangalore a rich experience of more than 20 years and vast knowledge in the field of Cardiac Electrophysiology. He underwent his professional training from reputed institutes in India and abroad.

Professional Qualification

He completed his MBBS degree from J J M Medical College, Davangere, Mysore University and post graduation qualification in MD (internal medicine) from Karnataka Medical College, Hubli, Karnataka University. He then pursued DNB (internal medicine) from National Board of Examinations, New Delhi followed by DM (Cardiology) from T N Medical College & B Y L Nair Hospital, Bombay University. He went back to National Board of Examinations, New Delhi to complete his DNB (Cardiology). Dr. Jayaprakash is also a Fellow of American College of Cardiology (FACC) and Fellow of Indian College of Cardiology (FICC). After his training in Cardiology, he underwent 2 years of extensive training in cardiac electrophysiology from Royal Melbourne Hospital, Australia.

Dr. Jayaprakash has always exhibited excellence in academic. He had secured SECOND RANK in Mysore University and stood FIRST in College in finals of MBBS Examination for the year 1985. He was awarded the best outgoing student for 1980 - 85 batch, in MBBS and also stood first in DM. He has many publications in international and national journals including chapters in text books.

Expertise & Areas of Interest

As a cardiologist, Dr. Jayaprakash is an expert in cardiac electrophysiology, and device implants. His special areas of interest include ablations of all varieties of arrhythmias including ablation of atrial fibrillation and ventricular arrhythmias. He is also an expert in device implants including cardiac defibrillator & biventricular device implantation.

Started the first University Recognized Electrophysiology and Pacing Program in India

He has conducted many live implant workshops and training programs for physicians and cardiologists.

Performs 3D mapping and ablation of complex arrhythmia on both Carto and Ensite system

Conducted live workshops in device implants and Electrophysiology At present Dr. Jayaprakash is associated with Fortis Hospital, Cunningham Road

Performs approximately 600 ablations and 300 pacemakers and more than 100 device implants per year on a regular basis as a individual operator for more than 15 years

Contact Us

Cunningham Road

14, Cunningham Road, Bengaluru,
Karnataka 560052
080 4199 4444