Cardiac Arrhythmia

Cardiac Arrhythmia

     Arrhythmia is an abnormal rhythm of the heart and is caused by problems with your heart's electrical system. Normally during resting, the heart beats regularly at the rate of 60-100 beats per minute. During an arrhythmia, the electrical impulses may happen too fast, too slowly, or erratically - causing the heart to beat too fast, too slowly, or erratically.  Arrhythmias may be completely harmless or life-threatening.

Arrhythmia classification 

There are two basic kinds of arrhythmias.

• Bradycardia is when the heart rate is too slow - less than 60 beats per minute.
• Tachycardia is when the heart rate is too fast - more than 100 beats per minute

What are the symptoms of Arrhythmia? 

     Arrhythmias can produce a broad range of symptoms from barely perceptible to cardiovascular collapse and sudden death.  For asymptomatic arrhythmia, you may be found to have arrhythmia during a routine examination.

For bradycardia, symptoms may be related to your heart not pumping enough blood to the body. This can cause you to feel tired, lightheaded, or pass out.

For tachycardia, you may feel a "fluttering" sensation in the chest, chest discomfort, shortness of breath, lightheadedness, fainting, in extreme cases, collapse and sudden cardiac death

For premature beats, it may be felt as a "palpitation" or "skipped beat."

The causes of arrhythmias

Many things or conditions can lead to, or cause, an arrhythmia, including: 

• Drinking too much alcohol or caffeine
• Certain prescription medications, dietary supplements, and herbal treatments
• Smoking
• High blood pressure
• Physical and emotional stress
• Overactive or underactive thyroid gland (hyperthyroidism or hypothyroidism)
• Acute heart attack
• Coronary artery disease
• Scarring of heart tissue from a prior heart attack
• Changes to your heart's structure, such as from cardiomyopathy
• Abnormal cardiac electrical pathway (short-circuit)

How do I know I have arrhythmia? 

     To diagnose an arrhythmia, a cardiac electrogram at the time of your symptom is the most essential document. It is evident not only to tell whether you have an arrhythmia but also to tell what kind of arrhythmia you have.

These are some cardiac monitoring to aid the diagnosis

• Electrocardiogram (ECG) It is the standard test for arrhythmia diagnosis but it is available only at the hospital. It is suitable for an arrhythmia that lasts long enough for you to get into the hospital.
• Holter monitor This portable ECG device can be worn for a day or more (usually 24-48 hours) to record your heart's activity as you go about your routine. For this type of monitoring to be helpful, the symptom must be occurring at least once a day.
• Event monitor  It is suitable for sporadic arrhythmias. You keep this portable ECG device available attach it to your chest and press a button whenever you have symptoms. This lets your doctor check your heart rhythm at the time of your symptoms.
• Implantable Loop recorder (insertable cardiac monitor) It is a small device about the size of a USB memory stick that is implanted just under the skin over the left chest wall. The device will continuously store the cardiac electrogram and automatically record the predefined arrhythmias. The battery longevity is about 2-3 years. It is the test of choice for very infrequent arrhythmia and disabling symptoms such as fainting or collapse.
• Cardiac Electrophysiology Study (EPS) This is a minimally invasive procedure to test the electrical conducting system of the heart. Multiple small catheters will be situated within the heart through the veins in the groins. Generally, the procedure will be considered only when all the non–invasive tests cannot preview the cause of your symptom. 

How is the arrhythmia treated? 

• Correct the correctable causes such as reducing or stopping taking caffeine, and quitting smoking.
• Treat related conditions such as high blood pressure, coronary artery disease, and heart failure
• A pacemaker to help your heart beat more regularly during slow heart rate.
• An implanted cardioverter defibrillator (ICD) to help restore a normal heartbeat with electric shock when your heartbeat goes too fast or chaotic.  
• Medicine to prevent and control fast heart rate
• Radiofrequency catheter ablation (RFCA)
• Surgery

Radiofrequency Catheter Ablation 

     It’s a way to fix an arrhythmia and get your heart to beat normally. It’s done by putting a thin wire (catheter) in your vein and guiding it to the heart muscle. The tip of the catheter delivers a burst of energy that destroys the very small areas of heart tissue that are causing the abnormal electrical signals. It is used to treat many types of arrhythmias with a high success rate and limited complication.

Am I a candidate for catheter ablation? 

Ablation may be a good option in any of these cases:

• If the arrhythmia cannot be controlled with lifestyle change or medicine.
• If you cannot tolerate the side effects of the medicine.
• If you don’t want to take long-term medicine.