Medical Definition of Tachycardia

Introduction

Tachycardia is a medical term used to describe a heart rate that is faster than normal while at rest. A normal resting heart rate for adults ranges between 60 and 100 beats per minute (bpm). When the heart beats faster than 100 bpm, this is classified as tachycardia.

Types of Tachycardia

There are several types of tachycardia, categorized based on where they originate in the heart:

1. Supraventricular Tachycardia (SVT)

• Originates above the ventricles in the atria.
• Common types include atrial fibrillation (AFib), atrial flutter, and AV nodal reentrant tachycardia (AVNRT).
• Symptoms may include palpitations, dizziness, shortness of breath, and chest discomfort.

2. Ventricular Tachycardia (VT)

• Originates from the ventricles (the lower chambers of the heart).
• Can be life-threatening, especially if it leads to ventricular fibrillation (VF).
• Often associated with underlying heart disease, including past heart attacks (myocardial infarction) or cardiomyopathy.

3. Sinus Tachycardia

• A natural increase in heart rate due to exercise, fever, anxiety, or other physiological stimuli.
• In some cases, inappropriate sinus tachycardia (IST) can occur, where the heart rate remains elevated without an obvious cause.

Causes of Tachycardia

Tachycardia can be caused by: - Heart-related conditions: Coronary artery disease (CAD), heart failure, hypertension. - Non-cardiac causes: Fever, dehydration, anemia, infections, hyperthyroidism, anxiety. - Medications or stimulants: Caffeine, nicotine, alcohol, certain drugs (e.g., decongestants, beta-agonists). - Electrolyte imbalances: Low potassium or magnesium levels.

Symptoms of Tachycardia

• Rapid heartbeat or palpitations
• Shortness of breath
• Chest pain or discomfort
• Dizziness or lightheadedness
• Fatigue
• Fainting (syncope) in severe cases

Diagnosis of Tachycardia

• Electrocardiogram (ECG): Identifies the type of tachycardia.
• Holter monitor: Records heart activity over 24–48 hours for intermittent tachycardia.
• Echocardiogram: Evaluates heart structure and function.
• Electrophysiology (EP) study: Assesses electrical conduction issues in the heart.

Treatment of Tachycardia

Lifestyle Modifications

• Reduce stress and anxiety.
• Limit caffeine, alcohol, and smoking.
• Maintain a healthy diet and regular exercise.

Medications

• Beta-blockers (e.g., metoprolol, propranolol): Reduce heart rate.
• Calcium channel blockers (e.g., diltiazem, verapamil): Slow electrical conduction.
• Antiarrhythmic drugs: Used in more severe cases.

Medical Procedures

• Cardioversion: An electrical shock to restore normal heart rhythm.
• Catheter Ablation: A procedure that eliminates abnormal electrical pathways.
• Implantable Cardioverter Defibrillator (ICD): Used in life-threatening cases.

Conclusion

Tachycardia is a condition where the heart beats faster than normal. It is crucial to diagnose its type correctly to ensure proper management. If you experience prolonged rapid heartbeats with other symptoms, seek medical attention immediately.

Source recommendations

1. American Heart Association Guidelines for the Management of Arrhythmias

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
2. https://www.heart.org/en/health-topics/arrhythmia
3. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
4. https://www.heart.org/en/health-topics/arrhythmia/prevention--treatment-of-arrhythmia
5. https://pubmed.ncbi.nlm.nih.gov/16949478/

2. European Society of Cardiology Guidelines on Supraventricular and Ventricular Arrhythmias

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Supraventricular-Tachycardia
2. https://academic.oup.com/eurheartj/article/41/5/655/5556821
3. https://www.ahajournals.org/doi/10.1161/cir.0000000000000311
4. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2019/09/10/12/36/2019-ESC-Guidelines-for-Supraventricular-Tachycardia
5. https://www.ahajournals.org/doi/10.1161/01.cir.0000091380.04100.84