Arrhythmias: Common types, symptoms and treatments

An arrhythmia (also referred to as a dysrhythmia) is an irregular or abnormal heartbeat. It also refers to any change from the normal sequence of electrical conduction in the heart. The electrical conduction or impulses in the heart may occur too fast, too slow, erratically or not at all – causing the heart to not beat effectively. When this occurs, the heart cannot pump blood effectively, which can lead to damage to the organs of the body such as the brain, lungs, kidneys and liver. An arrhythmia may be felt by the patient – i.e. palpitations, skipped or extra beats, feeling the heart pounding or racing. However, the patient may also not feel anything.

Common types:

  • Atrial fibrillation: Also referred to as AFib or AF, is the most common form of arrhythmia that affects patients in the U.S. and the world. It can also lead to the formation of blood clots and stroke, as well as heart failure, and other cardiac complications. During atrial fibrillation, the upper chambers of the heartbeat erratically and essentially quiver as well as beating rapidly. This erratic contraction can lead to the development of blood clots in the upper chambers of the heart, which can lead to stroke. Patients may experience irregular heart rate, rapid heart rate, dizziness, shortness of breath, weakness, chest pain and discomfort. The treatment goals are twofold. Rhythm and/or rate control as well as anticoagulation and stroke prevention. Discussion and examination with a rhythm specialist, such as an electrophysiologist, can address all goals. There are also surgical procedures that can be done to restore regular rhythm. 
  • Bradycardia: Refers to a slower heart rate – in general, a rate below 60 beats per minute (BPM). This can be both physiologic as well as pathologic. Individuals who are very athletic may have lower resting heart rates. Pathologic causes of bradycardia, which may cause problems and symptoms, include: 
    • Problems with the sinus node – the heart’s natural “pacemaker.”
    • Problems in the conduction system of the heart – i.e. blocks that can prevent the conduction of electricity in the heart.
    • Metabolic problems such as hypothyroidism.
    • Damage to the heart from heart disease or heart attacks.
    • Certain medications can cause slow heart rates as a side effect.
    • A heart rate that is too slow can cause your brain to not receive an adequate supply of blood which can cause dizziness or passing out. Symptoms of bradycardia are due to lack of blood flow to the entire body and can manifest as light-headedness, confusion, fatigue, feeling weak, shortness of breath, difficulty with activity and exercising, as well as in extreme cases cardiac arrest. If the bradycardia is serious, the patient may require consideration of a pacemaker or adjustment of medications. 
  • Conduction system disorders: Refer to how electrical impulses travel through your heart causing it to beat. Conduction system disorders can cause the heart to not beat effectively and can manifest in various symptoms. Three common conduction system disorders are: 
    • Bundle branch block: Normally, electrical impulses travel down both the right and left branches of the conduction system to cause the bottom chambers of the heart (ventricles) synchronously – precisely at the same time. However, if there is a “block” in one of the branches, electrical signals take a different path through the ventricles and lead to asynchrony. This may or may not cause symptoms. An electrocardiogram (ECG) can reveal if an individual has a bundle branch block. This disorder often will not require treatment but may be indicative of other health problems.
    • Heart block: Is an abnormal heart rhythm, which results in the electrical signals of the heart being partially or totally blocked between the upper chambers (atria) and lower chambers (ventricles). There are several degrees of heart block:
      • First-degree heart block: This is not a true block but rather refers to a slowed conduction from the top chamber through to the bottom chamber via a conduction system called the atrioventricular or AV Node. Usually, this condition does not cause any symptoms.
      • Second-degree heart block: This occurs when electrical signals from the atria do not reach the ventricles. This can lead to “dropped beats” and result in feelings of dizziness and fainting as well as fatigue. Depending on the severity, the patient may require consideration of a pacemaker.
      • Third-degree heart block: Also referred to as a complete heart block. This means that no electrical signals pass or conduct from the atrium to the ventricles. In the absence of electrical impulses from the sinoatrial node, the ventricles may or may not contract. If they do, it will be at a lower rate because every level of the heart has some form of automaticity, meaning each level has its own intrinsic pacemaker function – similar to a backup generator. This situation is an emergency and an individual with this needs to seek immediate care. Symptoms may include dizziness, fainting, fatigue, chest pain and shortness of breath. A pacemaker is most often always indicated.
    • Long QT Syndrome (LQTS): This is a particular disorder of the heart’s electrical system, which makes an individual more susceptible to a cardiac or electrical arrest. In LQTS, the lower chambers of the heart (ventricles) take too long to contract and release. This can cause possible cardiac arrest. LQTS can be both hereditary as well as acquired. It can be acquired because sometimes medications can cause this condition. Symptoms include fainting, fluttering in the chest or an abnormal heart rate or rhythm. Treatment options vary depending on the type of LQTS. Referral to an electrophysiologist can help determine if one has LQTS and how to best manage it. Treatment options include certain medications such as beta blockers, surgical procedures or possibly devices such as an implantable cardioverter defibrillator (ICD). 
  • Tachycardia: Refers to when the heart rate is too fast, typically greater than 100 bpm. There are various types of tachycardia:
    • Atrial or supraventricular tachycardia (SVT): This refers to a tachycardia that originates in the upper chambers of the heart (atrium). Different types include atrial tachycardia, atrioventricular reentrant tachycardia and atrioventricular nodal reentrant tachycardia. With these disorders, an electrical signal in the atrium fires abnormally and/or conducts through another electrical pathway making the heart beat faster than normal. This rapid heartbeat keeps the heart’s chamber from filling completely between contractions which compromises blood flow to the rest of the body. Some people may not experience any symptoms with this condition, while others may experience fainting, heart palpitations, fluttering in the chest, bounding pulse, chest pressure/tightness, shortness of breath, lightheadedness, dizziness or fatigue. Treatments include medications as well as procedures called electrophysiology studies (EP study) and ablations – which are procedures that can get rid of the abnormal conduction.
    • Sinus tachycardia: This is a normal increase in your heart rate. The sinoatrial node sends out electrical signals faster than usual, but the heart beats properly. A rapid heartbeat may be caused by anxiety, fright, emotional distress, exercise, fever and certain medications. Treating the cause of sinus tachycardia is more important than treating the condition itself.
    • Ventricular tachycardia (VT): Refers to a fast heart rate that begins in the lower chambers of the heart (ventricle). The seriousness depends on whether other cardiac problems are present and on the degree and extent of the condition. Some causes of VT are medication side effects, lack of blood flow in the heart, cardiomyopathy/congestive heart failure (CHF), illicit drug use such as cocaine and crystal meth, as well as systemic disease such as sarcoidosis. Common symptoms include dizziness, palpitations, shortness of breath, chest pain and, in extreme cases, cardiac arrest. Treatment options include medications, ICDs and EP study with possible ablation.
  • Ventricular fibrillation: Ventricular fibrillation is considered one of the most serious arrhythmias. Disturbed electrical activity causes the lower chambers to fibrillate (quiver) instead of beating normally. This stops the heart from pumping blood, causing a cardiac arrest because there is no blood flow to the body. Ventricular fibrillation (VFib) can have several causes, including cardiomyopathy and CHF, myocardial infarction and drug toxicity, as well as sepsis. This type of arrhythmia can cause sudden cardiac arrest and death. Signs of this include loss of responsiveness and no normal breathing and sudden collapse. This is an emergency. Call 911 immediately if you or someone near you is experiencing this. Treatments for VFib include immediate administration of medications and external defibrillation with consideration of an ICD. 
  • Premature contractions – PACs or PVCs: Premature contractions are said to feel like your heart skips a beat. These contractions are usually normal and most common in younger individuals. Usually, there are no causes for this condition and most go away on their own. Premature contractions that start in the atrium are referred to as premature atrial contractions (PACs) while beats that originate in the lower chambers are called premature ventricular contractions (PVCs). Treatments include lifestyle changes, medications or consideration of an EP study and possible ablation. 

Any of these conditions can be life threatening. If you or a loved one is experiencing any related symptoms as outlined above, please do not delay seeking care.


Located close to your home, UofL Health – Emergency Departments are located throughout Jefferson, Bullitt and Shelby counties, all of which are equipped to provide advanced cardiac care specific to arrhythmia care and other advanced cardiac issues.

Is your heart not feeling well? Schedule an appointment with UofL Physicians – Cardiology today. Learn more about Dr. Rajdeep Gaitonde at https://uoflphysicians.com/provider/rajdeep-gaitonde/.