What is the Difference Between Bradycardia and Tachycardia

The main difference between bradycardia and tachycardia is that bradycardia is a slow heartbeat, whereas tachycardia is a fast heartbeat of more than 100 times per hour.

Bradycardia and tachycardia are two arrhythmia conditions. They occur in the tachy-brady syndrome. 

Key Areas Covered

1. What is Bradycardia
– Definition, Features, Importance
2. What is Tachycardia
– Definition, Features, Importance
3. Similarities Between Bradycardia and Tachycardia
– Outline of Common Features
4. Difference Between Bradycardia and Tachycardia
– Comparison of Key Differences

Key Terms 

Bradycardia, Tachycardia

What is Bradycardia

Bradycardia is a heartbeat that is slower than usual. There are three types of bradycardia: sinus bradycardia, sick sinus syndrome, and heart block. Sinus bradycardia occurs when the node of the sinus sends signals too slowly, or it fails to fire off a single pulse at all. Also, sick sinus syndrome is a bradycardia caused by abnormal heart rhythm. Additionally, a heart block occurs when the signals of the sinus node cut off the signals of the AV node. Furthermore, bradycardia symptoms include difficulty concentrating, fainting, dizziness, lightheadedness, and shortness of breath.

Figure 1: Sinus Bradycardia

Furthermore, lifestyle changes, medication changes, and pacemaker implantation are the treatments for bradycardia. Also, thyroid disease and sleep apnea are two conditions that slow the heartbeat. Besides that, bradycardia can co-occur with tachycardia in the tachycardia-bradycardia or tachy-brady syndrome. In this condition, the heartbeat fluctuates between beating too quickly and slowly. Notably, the tachy-brady syndrome occurs in atrial fibrillation, a type of arrhythmia. Here, atrial fibrillation is the presence of abnormal electrical impulses that suddenly fires the atria. These impulses override the pacemaker, not allowing it to control the heart’s rhythm. 

What is Tachycardia

Tachycardia is a heartbeat that is faster than a normal heartbeat. There are three types of tachycardia. They include supraventricular, ventricular, and sinus tachycardia. Here, supraventricular tachycardia occurs when the electrical signals of the heart’s upper chamber misfire. In comparison, ventricular tachycardia occurs when the electrical signals of the heart’s lower chamber misfire. On the other hand, sinus tachycardia is an elevated heartbeat in response to stress or exercise. Additionally, the symptoms of tachycardia include rapid heartbeats, lightheadedness, shortness of breath, and chest pain.

Figure 2: Sinus Tachycardia

Moreover, the treatments for tachycardia include medication and the implantation of devices. The treatments take action to keep away the heart from beating abnormally faster than the regular heartbeat. The normal heartbeat is 60-100 beats per hour. If another medical condition causes tachycardia, treating the underlying problem will help lessen or eliminate tachycardia. However, anxiety also causes tachycardia. It can severely interfere with the functioning of the heart, increasing the risk of sudden cardiac arrest. 

Similarities Between Bradycardia and Tachycardia

• Bradycardia and tachycardia are two conditions of arrhythmia.
• They occur in the tachy-brady syndrome.
• Medication and implantation of pacemakers are the treatment for these conditions.  

Difference Between Bradycardia and Tachycardia

Definition

Bradycardia refers to a slower-than-normal heartbeat, while tachycardia refers to a heartbeat over 100 beats a minute.

Types

The three types of bradycardia are sinus bradycardia, sick sinus syndrome, and heart block, while the three types of tachycardia are supraventricular, ventricular, and sinus tachycardia.  

Symptoms

The symptoms of bradycardia are difficulty in concentrating, fainting, dizziness, lightheadedness, and shortness of breath, while the symptoms of tachycardia are rapid heartbeats, lightheadedness, shortness of breath, and chest pain.

Conclusion

In brief, bradycardia and tachycardia are two conditions of arrhythmia, problems with heartbeat. Bradycardia is a slow heartbeat than usual. The normal heartbeat is 60-100 beats per hour. The three types of bradycardia are sinus bradycardia, sick sinus syndrome, and heart block. Also, the symptoms of bradycardia include rapid heartbeats, lightheadedness, shortness of breath, and chest pain. In comparison, tachycardia is a faster heartbeat than usual. Supraventricular, ventricular, and sinus tachycardia are the three types of tachycardia. Rapid heartbeats, lightheadedness, shortness of breath, and chest pain are the symptoms of tachycardia. Therefore, the main difference between bradycardia and tachycardia is the heartbeat rate. 

References:

1. Bradycardia: Symptoms, causes & treatment. Cleveland Clinic. 
2. Mayo Foundation for Medical Education and Research. (2022, October 22). Tachycardia. Mayo Clinic. 

Image Courtesy:

1. “ECG Sinus Bradycardia 49 bpm” By Ewingdo – Own work (CC-BY SA 4.0) via Commons Wikimedia
2. “ECG Sinus Tachycardia 125 bpm” By Ewingdo – Own Work (CC-BY SA 4.0) via Commons Wikimedia