ventricular arrhythmia

Ventricular arrhythmia: Meaning, types, causes, treatment, and complications

Ventricular arrhythmia (VA) is an abnormal heart rhythm of the ventricles. These are the two lower chambers of the heart that work to pump blood throughout the body. To pump blood in an effective manner, the heart needs to contract in a synchronized manner. If this doesn’t occur, as in the case of ventricular arrhythmia, severe complications are likely to result.

The human heart is made up of four chambers: the right and left atriums and the right and left ventricles. Each one of these compartments helps to pump deoxygenated blood from the venous system of the body to the lung to become oxygenated, then pump it back out to the arterial system. The heart plays a vital role in the circulatory system, with any abnormality potentially being life-threatening.

Types of ventricular arrhythmia

Ventricular tachycardia

Characterized by an abnormal heart rhythm due to the SA node (a natural pacemaker of the heart) no longer controlling the beating of the ventricles. Contraction is instead lowered and electrical pathways take over the peacemaking role, which causes the ventricles to be abnormal. That may cause those affected to experience shortness of breath, dizziness, or syncope (fainting).

Ventricular fibrillation

Considered a very serious condition. It is characterized by uncontrolled and irregular heartbeats that occur due to several impulses being at the same time and in different locations, all contracting the heart simultaneously. Heartbeats can reach as high as 300 beats per minute, which are too chaotic to efficiently pump blood from the heart to the brain or the rest of the body. This can easily result in a loss of consciousness, with medical attention needed right away in all cases of ventricular fibrillation. About 220,000 deaths from heart attacks are thought to be attributed to ventricular fibrillation.

Premature ventricular contractions (PVC)

A condition where ventricular contraction occurs too soon. It is not as serious as the previously mentioned types of arrhythmia but can still lead the heart to become out of sequence with the normal heartbeat. PVC is generally not a cause for concern and often does not require treatment. However, if the affected patient has a history of ventricular tachycardia, PVCs can possibly lead to a more serious arrhythmia. PVCs can occur in response to caffeine and some kinds of over-the-counter cough and cold medication.

Benign or malignant ventricular arrhythmia

Management of a ventricular arrhythmia can be clinically challenging, as some will be at high risk of sudden cardiac death. Although ventricular arrhythmias can be dangerous, there is a spectrum of risk that ranges from being immediately life threatening to very benign. Ventricular arrhythmias occur more frequently with advancing age, the severity of heart disease, and ventricular hypertrophy.

There are three forms of malignant ventricular arrhythmias that have a high one-year mortality rate. These include:

  • Out-of-hospital ventricular fibrillation (VF)
  • Recurrent sustained ventricular tachycardia
  • Torsades de pointes (ventricular tachycardia in the long QT syndrome)

What are the causes and symptoms of ventricular arrhythmia?

Ventricular arrhythmias can be considered “normal variants” that occur in otherwise healthy individuals. Other causes may include:

  • Coronary artery disease, cardiomyopathy, mitral valve prolapse
  • Abnormalities in electrolyte levels, with decreases in magnesium and potassium having the greatest effect on the contraction of the heart. Deficiencies in these minerals may occur due to water pill use (diuretics).
  • Familial (congenital) causes
  • Abnormalities in thyroid hormone
  • Alcohol and other such toxins
  • Stimulants. This may include caffeine, nicotine, and/or cocaine. Some over-the-counter medication may also contain stimulants
  • Infection, inflammation, or degeneration of the heart muscle or at any other site in the body
  • Lack of sleep
  • Increase stress levels

Ventricular arrhythmia complications

Abnormal heart rhythms lead to an inefficient pumping of blood throughout the body. Adequate blood supply is an absolute necessity for normal functioning. If this is compromised in any way, as in the case of ventricular arrhythmias, several complications can result. The following are some examples:

Angina

Chest pain due to reduced blood flow to the heart. Symptoms are often described as squeezing, pressure, heaviness, tightness, or pain in the chest. Angina can be difficult to distinguish from other forms of chest pain such as indigestion, but it’s a symptom of coronary artery disease.

Heart attack

Due to the lack of oxygenated blood being supplied to the heart muscles. If blood flow is not restored promptly, it will lead to cell death. Heart damage can be mitigated with immediate medical attention and prompt heart attack treatment. Heart attacks are also known as myocardial infarction (MI).

Related: Myocardial infarction patients with other diseases are at an increased risk of mortality

Heart failure

A condition described as the heart not being able to pump blood efficiently to the rest of the body. This is most likely the result of a previous heart injury that can significantly compromise its overall function. Conditions such as coronary artery disease or high blood pressure can gradually damage the heart over time, leading to fill and pump inefficiently.

Stroke

Occurs when the blood supply to the brain becomes compromised or reduced. The brain is considered the control center for all the function your body exhibits, with the blood its being supplied providing it with the oxygen and nutrients it needs to remain functional. Reduced blood supply from heart problems can lead to a stroke.

Ventricular arrhythmia diagnostic tests

When a heart condition such as ventricular arrhythmia is suspected, a full work up including medical history and physical exam will be done. This will provide any additional clues that can be used as evidence to proceed to further testing. Additional tests for diagnosing include:

  • Electrocardiogram (ECG/EKG): This test is used to measure electrical signals that are produced when the heart contracts. A normal pattern can be cross referenced to determine if the typical patterns of left ventricular hypertrophy are present.
  • Echocardiogram: The use of sound waves that are able to produce real time images of the heart muscles. It can reveal thickened muscle tissue of the left ventricle, blood flow through the heart with each beat, and other cardiac abnormalities.
  • Magnetic resonance imaging (MRI): A sensitive imaging device that allows for detailed images of the heart to be taken revealing any abnormalities.
  • Treadmill stress test: Used to monitor the heart’s activity during exercise
  • Cardiac catheterization/coronary angiography: Looking directly at how narrow the heart vessels are
  • Myocardial biopsy: A sample collected from the heart muscle to be analyzed under a microscope if necessary.

Treating and preventing ventricular arrhythmia

If a ventricular arrhythmia is acute in nature and leads to a loss of consciousness, CPR and electroshock therapy (defibrillation) is the recommended emergency treatment. Once the condition is more manageable, the following treatment recommendation will be in order.

Lifestyle changes

To help lower your risk of complications, eating a healthy diet that is low in saturated fats, cholesterol, and sodium goes a long way. Exercising in a manner that doesn’t excessively strain the heart will also help reduce your risk. The avoidance of smoking cigarettes and drinking excessive amounts of alcohol are already recommended. The only way for these lifestyle changes to have a significant impact on your heart health is to make them a part of your everyday life.

Medications

The use of prescribed heart medication can help reduce the workload of the heart and prevent arrhythmias. Certain medications can also be used to improve heart function depending on your particular circumstance. Cardiac medication may include:

  • Beta-blockers: Reduce blood pressure and heart rate
  • Calcium channel blockers: Relax and widen arteries and lowers blood pressure
  • Aldosterone inhibitors: Help lower blood pressure and aid in the elimination of edema
  • Diuretics: Helps to eliminate excess fluid, lowers blood pressure, and reduces the amount of work need to be done by the heart
  • Blood thinners: Help prevent the development of blood clots
  • Medications to control heart rate and rhythm

Surgery and other procedures

In more severe cases of ischemic cardiomyopathy, more invasive methods of treatment will be required. These may include:

  • Implantable pacemaker or defibrillator, or even both
  • Angioplasty: To open narrowed arteries and place a stent to keep it open
  • Catheter ablation: Used to destroy abnormal pacemaker cells causing arrhythmias
  • Atherectomy: A minimally invasive procedure for removing plaque from blood vessels

Related: Prevention of heart arrhythmia by predicting abnormal heartbeats


https://www.dignityhealth.org/sacramento/services/heart-and-vascular-care/heart-conditions-we-treat/ventricular-arrhythmia
https://www.ncbi.nlm.nih.gov/pubmed/6194681

Related Reading:

Unstable angina a common cause of heart attack: Causes, symptoms, treatment, and prevention

What causes an anteroseptal infarct? Symptoms, treatment, and prevention

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