Definition of Tachycardia and Bradycardia

Introduction

The human heart beats at a particular rate to supply blood efficiently to the body. The normal resting heart rate for adults is typically 60-100 beats per minute (bpm). When the heart rate deviates significantly from this range, it may indicate an underlying condition that requires attention.

What is Tachycardia?

Tachycardia is a condition where the heart rate exceeds 100 bpm while at rest. It can be classified into different types based on its origin: - Supraventricular Tachycardia (SVT) – Originates in the atria or AV node. - Ventricular Tachycardia (VT) – Arises from the ventricles, which may be life-threatening. - Sinus Tachycardia – A normal response to factors like exercise, fever, or stress.

Causes of Tachycardia

• Fever, dehydration
• Anxiety, stress
• Anemia, blood loss
• Heart disease, structural abnormalities
• Hyperthyroidism
• Drug or caffeine use

Symptoms of Tachycardia

• Palpitations (fast or irregular heartbeats)
• Dizziness or fainting
• Shortness of breath
• Chest pain (if severe or related to heart disease)

What is Bradycardia?

Bradycardia is a condition where the heart rate falls below 60 bpm at rest. While some athletes naturally have lower resting heart rates, in other cases, bradycardia may indicate a medical problem, particularly if symptoms are present.

Causes of Bradycardia

• Aging and heart tissue degeneration
• Heart block (disturbance in electrical signal transmission)
• Hypothyroidism
• Certain medications (e.g., beta-blockers)
• Electrolyte imbalances

Symptoms of Bradycardia

• Fatigue
• Dizziness or fainting
• Weakness
• Shortness of breath
• Confusion in severe cases

When to Seek Medical Attention

• If you experience persistent palpitations, dizziness, fainting, or chest pain, seek medical care.
• If your pulse at rest is excessively high or low without an apparent reason, consult a doctor.
• Situations like ventricular tachycardia can be life-threatening and require emergency intervention.

Conclusion

Both tachycardia and bradycardia can be normal responses in certain situations, but if they occur without a clear trigger or cause distressing symptoms, medical evaluation is necessary. Monitoring your heart rate and recognizing signs can help in early diagnosis and treatment.

Source recommendations

1. American Heart Association Guidelines on Arrhythmias

1. https://www.heart.org/en/health-topics/arrhythmia
2. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
3. https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia
4. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
5. https://pubmed.ncbi.nlm.nih.gov/29084733/

2. European Society of Cardiology Guidelines on Bradycardia and Conduction Disturbances

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Cardiac-Pacing-and-Cardiac-Resynchronization-Therapy
2. https://www.jacc.org/doi/10.1016/j.jacc.2020.08.050
3. https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-4/Electrocardiographic-findings-in-athletes-Title-Electrocardiographic-findings
4. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000627
5. https://www.sciencedirect.com/science/article/pii/S0735109720364391