Cardiac arrhythmia is a condition that affects the rate and rhythm of the heart. An adult’s heart usually beats between 60 to 100 times per minute. This gets altered in certain conditions called arrhythmia. In arrhythmia, the heartbeats are irregular and can be either too fast (> 100 beats per minute) or too slow (< 60 beats per minute).

Types of Cardiac arrhythmia

There different types of arrhythmia are:

• Conduction disorders – Impairment of the electrical impulse involved in maintaining normal heart rhythm.
• Premature ventricular contraction – Extra heartbeats or palpitations beginning from the ventricles.
• Ventricular fibrillation – Life-threatening, abnormal heart rhythm due to erratic electrical activity of the heart.
• Fetal arrhythmia – Abnormal heart rate beyond 160 or below 110 beats per minute in the fetus.
• Atrial flutter – Rapid contractions of the atria followed by the ventricles resulting in abnormal heart rate.

What Causes Cardiac arrhythmia?

Cardiac arrhythmias may occur due to one or more of the following reasons:

• Abnormality in the heart’s natural pacemaker.
• Disruption of the normal conduction pathway anywhere between the sinoatrial node to the Purkinje fibers.
• Disruption of the normal heart beat when another part of the heart starts acting as the pacemaker.
• Scarring, or fibrosis of the heart tissue or reduced blood flow to the heart.
• Release of excess stress hormones due to anxiety, strong emotional stress, anger, and pain.
• Vomiting, cough, or other physical activity that induces the release of adrenaline.
• Dehydration, and excess or deficiency of electrolytes such as potassium, calcium, and magnesium.
• Thyroid hormone imbalance and low blood sugar level.
• Medications used for treating high blood pressure, depression, and psychosis.

What are the Risk factors?

• Age – Risk increases with age due to changes in the anatomy of the heart.
• Environment – Particulates causing air pollution contribute to the short – term risk of cardiac arrhythmia.
• Genetics – Family history and genes are linked with arrhythmias. Genetic mutation of the ion channels that transmit electrical impulses is a major risk factor.
• Lifestyle habits – Smoking, drinking alcohol, and substance abuse of cocaine, amphetamine, and other such drugs increases the likelihood of getting arrhythmia.
• Other health conditions – Heart failure, heart inflammation, obesity, high blood pressure, and rheumatoid arthritis are some of the medical conditions that increases the chances of getting arrhythmias.
• Race – White Americans are at a higher risk as compared to African Americans.
• Sex – Men are at a higher risk of atrial fibrillation than women. Risk factor for women rises while consuming certain medications.
• Pregnancy – Benign heart beats and increased frequency of existing arrhythmias are more common as compared to non – pregnant women.
• Surgery – Chances of atrial flutter are higher post-surgery of the heart, lungs, or esophagus.

Signs and symptoms

• Fatigue
• Dizziness
• Rapid heartbeat or pounding in the chest
• Difficulty in breathing
• Sweating, blurred vision and anxiety
• Pain or pressure in the chest
• Sudden cardiac arrest following collapse seen in extreme cases.

What are the Complications?

If cardiac arrhythmias are left untreated, they give rise to potentially fatal complications of the heart and brain such as:

• Stroke
• Heart failure
• Sudden cardiac arrest
• Alzheimer’s disease
• Vascular dementia
• Sudden infant death syndrome
• Aggravation of existing arrhythmia

Diagnosis: How to diagnose Cardiac arrhythmia?

• The physician assesses medical history – Diet, physical activity, and other risk factors.
• Physical examination – Pulse rate, heart rate, rhythm, and other signs are monitored for any abnormality.
• Diagnostic tests – The tests performed are:
  • Blood tests
  • Chest x-ray
  • Echocardiography (echo)
  • Electrocardiogram (ECG)
  • Cardiac catheterization
  • Sleep study – To ascertain if sleep apnea is responsible for arrhythmia or not.
  • Holter or event monitor – Electrical activity of the heart monitored for longer periods while the patient follows his normal routine.
  • Implantable loop recorder – Helps to identify the reason for the rare palpitations experienced by the patient by continuously recording the electrical activity of the heart.
  • Exercise stress test – For detecting abnormal heartbeats that occurs during physical exercise.
  • Tilt table testing – Heart rate, blood pressure, and ECG are monitored to identify the cause of fainting spells.
  • Ultrasound – This is done to diagnose fetal arrhythmia in the mother’s womb.

Treatment: How is Arrhythmia treated?

Restoring normal heart rhythm or controlling the heart rate to a relatively normal range is the prime goal of treatment. Improving the other causative underlying conditions and preventing the aggravation of health due to arrhythmia are the other rationale behind treatment.

• Vagal maneuver – Physical techniques that slow down or stop the arrhythmias especially supraventricular tachycardia.
• Other treatment approaches – Application of electricity either externally or internally to the heart using implanted electrodes can treat arrhythmia. These include :
  • Cardioversion
  • Defibrillation
  • Cardiac pacing
  • Catheter ablation
• Medications – Antiarrhythmic drugs are commonly used for treating this condition. This includes different classes of drugs as follows:
  • Sodium channel blockers – Moricizine, oxcarbazepine, etc.
  • Beta-adrenergic blockers – Propranolol, esmolol, etc.
  • Potassium channel blockers – Amiodarone, bretylium, etc.
  • Calcium channel blockers – Verapamil, diltiazem, etc.
  • Adenosine, digoxin, and atropine (Slows rapid heart rate).
  • Others – Blood thinners to reduce the chances of clot formation.

Prevention: Can we prevent it?

• Living with arrhythmia –
  • Following the prescribed treatment plan and going for regular checkups.
  • Maintaining a healthy diet.
  • Managing stress.
  • Avoiding alcohol and quitting smoking.
• Prevention of arrhythmia –
  • Monitoring pulse and blood pressure regularly.
  • Losing excess weight.
  • Keeping cholesterol levels in check.
  • Eating a heart–healthy diet.
  • Regular exercising.

When to see a doctor? :

It is wise to consult with a cardiologist immediately if the symptoms persist for long, or if the patients feels lightheaded and difficulty breathing along with a rapid heart rate. The typical consultation fee for a cardiologist ranges from Rs. 500 to Rs. 3000 in India.

References:

• ^[1] health-topics– arrhythmia
• ^[2] -Arrhythmia#Management
• ^[3] – prevention and treatment of arrhythmia
• ^[4] –Article Review
• ^[5] – treatment