Difference Between Tachycardia and Atrial Fibrillation

Main Difference – Tachycardia vs Atrial Fibrillation

Tachycardia and Atrial Fibrillation are two abnormalities of the heart rhythm. Heart is one of the most important organs in our body. It is muscular in texture, contracts and relaxes around 60-100 times per minute and helps in pumping blood all throughout the body. The Lub-dub sound produced by the heart corresponds to the contraction and relaxation of the heart. This particular pattern, taking place in a regular rhythm may vary in range when you are doing exercises when you are sick, etc. But the problem arises when this rhythm alters due to a certain underlying condition of the heart itself or due to some systemic diseases. The main difference between Tachycardia and Atrial Fibrillation is that Tachycardia is a condition where the normal electrical impulses that control the rate of your heart’s pumping action are disrupted whereas atrial fibrillation  is a quivering or irregular heartbeat that can lead to blood clots, stroke, heart failure and other heart-related complications.

This article explains,

1. What is Tachycardia?
     – Features, Causes, Signs and Symptoms, Diagnosis, Treatment

2. What is Fibrillation?
     – Atrial fibrillation, Ventricular fibrillation

3. Difference Between Tachycardia and Atrial Fibrillation

Difference Between Tachycardia and Atrial Fibrillation - Comparison Summary

What is Tachycardia

Tachycardia is a condition where the heart rate is abnormally high with a value of 100 or more beats per minute. Increased heart rate often means that our heart is pumping quickly with an extra effort. In most patients, this happens due to an increased pumping rate of one heart chamber, but occasionally it can occur in both chambers. This may be due to an increased requirement of energy or due to a pathological condition where heart muscle fails to regulate its own pace.

When our heart pumps quicker, the efficiency of blood circulation will progressively come down, causing a reduction in the blood supply to the heart muscle. Persistent heart rate of a high valve can ultimately result in myocardial infarction or heart attack  – the death of your heart muscle which is fatal.

As far as the pathophysiology of Tachycardia is concerned, it happens due to altered electrical signals emitted through the heart muscle. These electrical signals, initially generated in the sino-atrial node (SA node-natural pacemaker of the heart) located in the superior part of the right atrium, will travel passing the atrioventricular node (AV node) and regulate the contraction and relaxation of lower heart chambers as well.

Tachycardia is observed, when the above-mentioned electrical signals are transmitted in a higher pace than required.

Causes of Tachycardia

  • Following certain medications
  • Certain abnormalities of the heart’s electrical pathways since birth (congenital)
  • Congenital abnormalities of the heart
  • Alcohol abuse
  • Usage of Cocaine and recreational drugs
  • Electrolyte imbalances
  • Coronary heart disease, Atherosclerosis, heart failure
  • Hypertension
  • Hyperthyroidism
  • Chronic smoking
  • Chronic stress
  • Advanced age

Signs and Symptoms of Tachycardia

Most patients with tachycardia will indicate no symptoms; the condition will be identified only during a routine heart checkup or a physical examination. However, patients with moderate-severe tachycardia will usually experience signs and symptoms like

  • Increased heart rate
  • Panting (shortness of breath)
  • Palpitations
  • Chest pain or discomfort, if heart muscle gets a poor blood supply (ANGINA)
  • Hypotension (low blood pressure)
  • Dizziness and lightheadedness
  • Confusion
  • Syncope attacks (sudden faints)

Diagnosis and Treatment Methods of Tachycardia

The diagnosis of Tachycardia will be made with a complete history from the patient along with a thorough physical examination. Certain investigations such as ELECTROCARDIOGRAM (ECG), event recorder, halter monitoring, tilt-test and echocardiogram will be helpful in confirming the diagnosis.

Other investigations include:

Chest XRAY – to identify congenital heart defects

Full blood count –  for hemoglobin to check for anemia

Thyroid function test –  for hyperthyroidism,

Serum electrolyte levels – for electrolyte imbalances

Due to the recent advancements in medical technology, there are several successful interventions can be made for tachycardia patients. Treatment options may vary based on the root cause, patient’s age, overall health, and co-morbidities.

However, the major objectives of treatment include, slowing down the heart rate when necessary, prevention of subsequent attacks and reduction of potential complications (blood clots, heart failure, fainting spells, and sudden death).

It is also important to treat the root cause depending on the diagnosis

Ex: Hyperthyroidism can be treated with anti-thyroid drugs or surgery; anemia can be treated with iron supplements or blood transfusions, etc.

Major treatment methods available to treat patients with tachycardia are,

  • Vagal maneuvers
  • Anti-arrhythmic drugs
  • Cardio-version
  • Radio-frequency catheter ablation

Difference Between Tachycardia and Atrial Fibrillation

What is Fibrillation

This is a pathophysiological condition of the heart where a fast, irregular and unsynchronized rhythm of contractions is observed. There are two major types of fibrillation known as atrial fibrillation and ventricular fibrillation.

Atrial Fibrillation

Irregular and unsynchronized contractions of the atrial heart muscle due to a disruption of electrical pulses initiated at the sino-atrial node (SA node), leading to haphazard conduction of impulses to the ventricles, thus giving rise to an irregular heartbeat.

This is usually a persistent heart condition but can be effectively treated with anticoagulation and cardio-version (conversion to normal sinus rhythm).     

Ventricular Fibrillation

Irregular and unsynchronized contractions of the ventricular heart muscle. This is a very common cause of heart failure and sudden cardiac arrest and should be promptly treated with defibrillation.

Main Difference - Tachycardia vs Atrial Fibrillation

Difference Between Tachycardia and Atrial Fibrillation

Tachycardia is a condition where the electrical impulses generated in the SA node are replaced by an ectopic pacemaker. This can also occur due to an influence of certain drugs or medications. The heart muscle will contract at regular intervals but at a very increased rate, usually more than 100 beats per minute.

Fibrillation is a condition where the electrical impulse conducting system is functioning in a haphazard manner; the contractions will not be coordinated, resulting in an irregular rhythm with irregular intervals. In contrast to tachycardia, the rate ad rhythm will both get affected. Fibrillation is a life-threatening condition which should be treated as soon as possible after the diagnosis is made.

Image Courtesy:

“Atrial fib stroke” By National Heart Lung and Blood Institute (NIH) – National Heart Lung and Blood Institute (NIH) (Public Domain) via

“Ventricular Tachycardia” By BruceBlaus – Own work via

About the Author: Embogama

Embogama is a passionate freelance writer for several years. Her areas of interest include general medicine, clinical medicine, health and fitness, Ayurveda medicine, psychology, counseling and piano music

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