Arrhythmia: Causes, Classification, and Treatment

Arrhythmia is an abnormal heart rhythm that can manifest as a fast, slow, or irregular heartbeat. Arrhythmias can be caused by a variety of factors, including cardiovascular disease, electrolyte disturbances, medication use, or other factors.

Classification of Arrhythmias:

1. Arrhythmias due to disorders of the pacemaker system:

• Automatic tachycardia: Occurs when there is an ectopic focus outside the sinoatrial node (SA node is the main pacemaker of the heart).

• Recurrent tachycardia: Occurs when there are abnormal accessory pathways, leading to faster conduction of electrical impulses.

2. Arrhythmias due to disorders of the conduction system:

• Ventricular arrhythmias:

• Ventricular tachycardia: Heart rate faster than 100 beats per minute, due to abnormal stimulation in the ventricles.

• Ventricular fibrillation: Rapid and ineffective contraction of the ventricles, leading to loss of consciousness and cardiac arrest.

• Supraventricular arrhythmias:

• Sinus tachycardia: Heart rate faster than 100 beats per minute, due to excessive activity of the SA node.

• Atrial flutter: Fast and regular heartbeat, usually from 150-300 beats per minute, due to electrical impulses originating in the atria.

• Atrial fibrillation: Rapid and ineffective contraction of the atria, leading to a fast and irregular heartbeat, usually from 400-600 beats per minute.

• Supraventricular tachycardia: Fast heartbeat, usually from 100-120 beats per minute, due to abnormal conduction of electrical impulses from the atria to the ventricles.

Treatment of Arrhythmias:

The treatment of arrhythmias depends on the type of arrhythmia, the severity, and other risk factors. Treatment methods may include:

1. Medications:

• Group 1: Sodium channel blockers:

• IA:

• Quinidine: Used in chronic cases, prophylaxis. Contraindications: diarrhea, hypokalemia, prolonged QT interval.

• Procainamide: Used in acute and chronic cases. Contraindications: drug-induced lupus, prolonged QT interval.

• Disopyramide: Used in chronic cases, prophylaxis. Contraindications: left ventricular hypertrophy, glaucoma, prolonged QT interval, heart failure.

• IB:

• Lidocaine: Used in acute cases.

• Mexiletin: Used in chronic cases. Contraindications: Tremor.

• Phenytoin: Used in cases of arrhythmias caused by digitalis.

• IC:

• Flecainide: Contraindications: Cardiac inhibition, increased sudden death in patients with a history of myocardial infarction.

• Propafenone:

• Group 2: Beta-blockers:

• Effects: Inhibit the effects of the sympathetic nervous system on the heart, reducing sinus rate, reducing conduction velocity, and vasodilation.

• Types: Nadolol, propranolol, sotalol, acebutolol, esmolol, metoprolol.

• Uses:

• Nadolol: Premature ventricular contractions, atrial tachycardia, sinus tachycardia.

• Sotalol: Ventricular tachycardia/fibrillation.

• Acebutolol: Ventricular/supraventricular tachycardia.

• Esmolol: Antiarrhythmic during and after surgery.

• Metoprolol: All.

• Group 3: Potassium channel blockers:

• Contraindications: Prolonged QT interval, torsades de pointes.

• Types: Amiodarone, dronedarone, sotalol, ibutilide, dofetilide.

• Uses:

• Amiodarone: Ventricular, prophylaxis of ventricular fibrillation, atrial.

• Dronedaron: Prophylaxis of atrial fibrillation.

• Group 4: Calcium channel blockers:

• Types: Verapamil, diltiazem.

• Uses: Atrial tachycardia, atrial flutter, supraventricular tachycardia.

• Other:

• Digoxin:

• Magnesium: Arrhythmias caused by digitalis, in torsades de pointes.

• Potassium: Creates resting potential, stabilizes the membrane.

• Adenosine: Activates potassium channels, inhibits calcium channels, treats sudden ventricular tachycardia. Administered intravenously.

• Vernakalant: Blocks multiple ion channels, terminates atrial fibrillation.

2. Surgery:

• Pacemaker implantation: Implanting a pacemaker to regulate heart rate.

• Conduction surgery: Treats arrhythmias caused by abnormal accessory pathways.

• Ablation of ectopic foci: Removing the ectopic focus causing the arrhythmia.

3. Interventional measures:

• Electrocardiogram (ECG): Helps diagnose and monitor arrhythmias.

• Defibrillation: Using electrical current to terminate ventricular fibrillation.

• Medical management: Reduce the impact of risk factors such as smoking, alcohol consumption, and stress.

Note:

• Arrhythmia is a serious condition that can lead to many dangerous complications.

• The diagnosis and treatment of arrhythmias should be performed by a cardiologist.

• Do not self-medicate for arrhythmias without a doctor’s prescription.

• Always follow your doctor’s instructions on medication use, diet, and lifestyle to control the disease.

This information is for informational purposes only and is not a substitute for professional medical advice.