Understanding Abnormal Cardiac Rhythms

Introduction

The heart beats in a very precise rhythm, controlled by electrical signals that ensure proper circulation of blood throughout the body. When these electrical signals become disorganized or irregular, it can lead to abnormal cardiac rhythms (arrhythmias). Some arrhythmias are harmless, while others can be life-threatening.

Types of Abnormal Cardiac Rhythms

1. Bradycardia (Slow Heartbeat) - The heart rate drops below 60 beats per minute. Common causes:

   • Aging and degeneration of the heart’s electrical system
   • Hypothyroidism
   • Medications (e.g., beta-blockers, calcium channel blockers)
   • Heart block (a delay or blockage in electrical conduction)

2. Tachycardia (Fast Heartbeat) - The heart rate exceeds 100 beats per minute. Common types of tachycardia:

   • Atrial Fibrillation (AFib) – Irregular and often rapid heart rate, increasing stroke risk.
   • Supraventricular Tachycardia (SVT) – Rapid heart rhythm starting from the atria.
   • Ventricular Tachycardia (VT) – Rapid rhythm originating from the ventricles, which can be life-threatening.
   • Ventricular Fibrillation (VFib) – Disorganized, chaotic heartbeats, leading to sudden cardiac arrest.

Symptoms of Arrhythmias

Different arrhythmias present with various symptoms: - Palpitations (fluttering or racing heart) - Dizziness or lightheadedness - Fainting (syncope) - Shortness of breath - Chest pain - Fatigue

Causes and Risk Factors

Certain factors increase the likelihood of developing arrhythmias: - Heart disease (coronary artery disease, heart failure) - Hypertension (high blood pressure) - Metabolic disorders (thyroid dysfunction, diabetes, electrolyte imbalances) - Excessive alcohol or caffeine intake - Smoking and drug use - Genetics (some arrhythmias have a hereditary component)

Diagnosis

Doctors use various tests to diagnose arrhythmias: - Electrocardiogram (ECG/EKG) – Measures the heart’s electrical activity. - Holter monitor – A 24- or 48-hour portable ECG recording to detect intermittent arrhythmias. - Echocardiogram – Uses ultrasound to assess heart structure and function. - Electrophysiological Studies (EPS) – A detailed examination of electrical conduction within the heart.

Treatment Options

Treatment depends on the type and severity of the arrhythmia: - Medications – Antiarrhythmics, beta-blockers, calcium channel blockers, anticoagulants (for AFib patients). - Lifestyle Changes – Reducing caffeine, alcohol, and stress; increasing physical activity. - Cardioversion – Electrical or pharmacological shock to restore normal rhythm. - Ablation Therapy – Destroying abnormal electrical pathways causing arrhythmias. - Pacemaker – Device that regulates slow heartbeats. - Implantable Cardioverter Defibrillator (ICD) – For patients at risk of life-threatening arrhythmias (e.g., ventricular fibrillation).

Conclusion

Arrhythmias range from benign to life-threatening conditions. Regular check-ups and ECG exams help detect arrhythmias early. If you experience persistent heart palpitations, dizziness, or fainting, seek medical help immediately.

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 Cardiac Arrhythmias

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Ventricular-Arrhythmias-and-the-Prevention-of-Sudden-Cardiac-Death
2. https://academic.oup.com/eurheartj/article/43/40/3997/6675633
3. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Supraventricular-Tachycardia
4. https://pubmed.ncbi.nlm.nih.gov/36017572/
5. https://www.ahajournals.org/doi/10.1161/01.cir.0000091380.04100.84