Board Certified Cardiologist and Clinical Cardiac Electrophysiologist, Dr. Michelle Khoo, has extensive experience with conditions related to irregular heartbeats, also known as Cardiac Arrhythmia

What is Cardiac Arrhythmia?

An arrhythmia is a disturbance in the normal rhythm of your heartbeat. The rhythm may be too fast (tachycardia), too slow (bradycardia), too early (premature contraction) or irregular (fibrillation). It is caused by a problem with the electrical signals that tell your heart muscle when to contract – they occur when the electrical impulses to the heart that coordinate heartbeats are not working properly, making the heart beat too fast, too slow or inconsistently.

Cardiac Arrhythmia

Some heart arrhythmias can be harmless and pose little or nor health risk. Everyone has experienced an irregular heartbeat at some time in their life. It can feel like the heart is racing or fluttering. Some arrhythmias, especially if they vary extensively from a normal heartbeat or are the result of weak or damaged heart muscle, may cause symptoms that can be detrimental to your overall heath or in some cases, the be so severe as to be potentially fatal.

What are the Signs and Symptoms of a Cardiac Arrhythmia?

In some cases, patients may be completely asymptomatic and experience no symptoms at all. Even if a patient does experience symptoms, that does not necessarily indicate there is a serious problem. Some patients with life-threatening arrhythmias may have no symptoms, while others with symptoms may not have a serious problem.

Symptoms of Tachycardia

  • Breathlessness
  • Dizziness
  • Syncope (fainting, or near-fainting)
  • Fluttering in the chest
  • Lightheadedness
  • Sudden weakness

Symptoms of Bradycardia:

  • Chest Pain (angina)
  • Concentration problems
  • Confusion
  • Dizziness
  • Fatigue (tiredness)
  • Lightheadedness
  • Palpitations
  • Shortness of breath
  • Syncope (fainting or near-fainting)

Symptoms of Atrial Fibrillation:

  • Chest pain (angina)
  • Breathlessness
  • Dizziness
  • Palpitations
  • Syncope (fainting, or near-fainting)
  • Weakness

What are the causes of arrhythmia?

In order for the heart to function properly, the electrical impulses that cause the heart to contract must follow a precise sequence or “circuit”. Any type of interruption of these impulses can result in an irregular heart beat or “arrhythmia”. The heart consists of four chambers, two atria (upper chambers) and two ventricles (lower chambers).

During a normal heartbeat the smaller atria contract which causes the relaxed ventricles to become filled with blood. This contraction begins when a small mass of specialized tissue in the right atrium (SA node) sends an electrical impulse which triggers the right and left atria to contract. The impulse then moves to the AV node, located near the center of the heart, on the pathway between the atria and ventricles. The impulse leaves the AV node and travels through the ventricles which cause them to contract and pump blood – this oxygenated blood is circulated throughout the body. A person with a healthy heart should have a resting heart rate of between 60 and 100 beats per minute.

Arrhythmias can occur due to changes of the structure of the heart

Changes to the structure of the heart can cause cardiac arrhythmia to occur. These changes include reduction in blood flow or damaged heart tissue.

These structure alterations to the heart can be caused by:

Coronary Artery Disease – Coronary artery disease occurs when the arteries that supply blood to the heart muscle become clogged with plaque. This build up of plaque is due to cholesterol that has built up over many years. This process is called atherosclerosis. Narrowed coronary arteries can result in a heart attack, a condition where some of the heart muscle dies due a lack of blood flow. A heart attack causes scarring of the heart muscle. The resulting scarred heart tissue interferes with the proper “pathway” of electrical impulses which allow the heart to beat properly. The heart may beat too fast (ventricular tachycardia) or irregularly (ventricular fibrillation).

Cardiomyopathy – Cardiomyopathy refers to diseases of the heart muscle. The walls of the ventricles may stretch or enlarge, or the left ventricle wall may thicken and constrict. The heart’s blood-pumping efficiency can be greatly affected, resulting in heart tissue damage.

Valvular Heart Diseases – Valvular heart disease occurs when the valves of your heart do not function properly. It can be caused by “valvular stenosis” or valvular insufficiency. If the heart valves narrow or leak the heart muscle can stretch and thicken. If valves are tight or leaking there is a significant risk of developing arrhythmia.

Arrhythmias are classified based to two factors:

1. Point of Origination – the atria or ventricles.

2. Heart Rate – fast (tachycardia – over 100 beats per minute), slow (bradycardia – less than 60 beats per minute).

A fast or slow heart rate is not a definitive diagnosis of heart disease. It is normal for the heart rate to increases during exercise. It is not uncommon for professional athletes have a resting heart rate of less than 60 beats per minute.

Types of Cardiac Arrhythmias

Tachycardia in the Artia

  • Atrial Fibrillation
  • Atrial Flutter
  • Supraventricular Tachycardia (SVT)
  • Wolf-Parkinson White Syndrome

Tachycardia in the Ventricles

  • Ventricular Tachycardia (VT)
  • Ventricular Fibrillation
  • Long QT Syndrome


  • Sick Sinus
  • Conduction Block

How is Cardiac Arrhythmia Diagnosed?

Dr. Khoo will attempt to determine what is “triggering” the patient’s arrhythmia. This will involve a detailed interview which includes the patient’s medical history, family history, diet, lifestyle, etc. In addition, the following tests may be performed:

  • Blood or Urine Testing
  • Electrocardiogram
  • Holter Monitor
  • Event Recorder
  • Echocardiogram
  • Chest X-Ray
  • Stress Test
  • Tilt Table test
  • Electrophysiological Testing (EP Study)

What are the Treatment Options for Cardiac Arrhythmia?

If you have an arrhythmia, treatment may or may not be necessary. Usually it’s required only if the arrhythmia is causing significant symptoms or if it’s putting you at risk of a more serious arrhythmia or arrhythmia complication.

Treatment for Bradycardia (heartbeat is too slow)

If the bradycardia is caused by an underlying problem, such as an underactive thyroid gland, or a drug side effect, that problem should be addresses first. If no underlying problem is found, the doctor may advise implanting a pacemaker. Click here to read more about Pacemakers.

Treatment for Tachycardias (heartbeat too fast)

  • Medication
  • Cardioversion
  • Ablation
  • Defibrillator Implantation
  • Mazer Procedure
  • Coronary Bypass Surgery

Alternative Treatments for Cardiac Arrhythmia

Research is ongoing regarding the effectiveness of several forms of complementary and alternative medical therapies for arrhythmia.

Some types of complementary and alternative therapies may be helpful to reduce stress, including Yoga, Meditation and other Relaxation techniques

To prevent heart arrhythmia, it’s important to live a heart-healthy lifestyle to reduce your risk of heart disease.

We encourage you to ask as many questions as necessary until you are confident that you understand your heart condition, medications or procedures you may be considering.

In her practice as a top heart doctor in Albuquerque, Dr. Michelle Khoo wants you to be informed, comfortable and confident about your treatment plan.

Quality Healthcare is at the Heart of Everything We Do.

To schedule a consultation with Dr. Khoo call 1-505-248-1802 or click here to request an appointment online.

Khoo & Associates Cardiology and Wellness is a boutique Cardiovascular Health & Wellness practice that is focused on delivering outstanding, comprehensive and ethical cardiovascular care to patients in Albuquerque and the surrounding counties of Bernalillo, Sandoval, Torrance and Valencia in New Mexico.

Our experienced and dedicated team offers our patients the combined collective experience and knowledge necessary to ensure the highest level of patient care in two convenient office locations – Downtown Albuquerque and Rio Rancho.