Risk Factors For Cardiovascular Syncope
Cardiovascular syncope describes an abrupt, short loss of consciousness caused by a heart rhythm disorder. This condition occurs when the electrical signals that trigger heart contractions are interrupted by some mechanism. This malfunction causes the heart to have a short circuit where it beats too fast or a heart block where it beats too slow. Due to this malfunction, the blood pressure drops too low and does not allow a sufficient amount of blood to reach the brain. This poor blood flow to the brain causes the individual to faint. This type of fainting is transient, or recovery is quick after fainting.
The reason is that normal blood pressure and heart rhythm return upon falling to the ground because blood can flow back to the brain. Cardiovascular syncope not only indicates a serious heart condition, but it can cause serious injury. Individuals with certain risk factors have an increased risk of cardiovascular syncope.
Cardiomyopathy patients are at an increased risk of having cardiovascular syncope. Cardiomyopathy is a disease that occurs in an individual's heart muscle that makes it difficult for the organ to pump blood around the body effectively. Dilated cardiomyopathy is when a patient's left ventricle stretches and becomes dilated and too weak to pump blood. Hypertrophic cardiomyopathy is when an individual's heart muscle becomes too thick, decreasing the volume of blood it can fill with and pump out. Restrictive cardiomyopathy occurs when the heart muscle loses elasticity and becomes too stiff, resulting in an inability to expand and fill with blood.
Syncope has been seen due to dilated cardiomyopathy inducing an irregular heart rhythm called ventricular tachycardia. Between fifteen and twenty-five percent of all hypertrophic cardiomyopathy patients experience recurrent syncope, many of which are attributed to the induction of an arrhythmia called paroxysmal atrial fibrillation. Syncope in restrictive cardiomyopathy is less common, but it is attributed to a lack of adequate oxygen supply being pumped to the brain when blood backs up in the patient's upper chambers.
Angina increases an individual's risk of having cardiovascular syncope. Angina is characterized by pain in the chest from decreased blood flow to the affected individual's heart. Patients describe angina as pressure, tightness, squeezing, heaviness, or pain in the chest. Angina can occur spontaneously, or it can be chronic recurrent pain. The pain can radiate from the chest to the patient's arms, jaw, back, neck, or shoulder. An individual who experiences chronic angina has a higher chance of experiencing cardiac syncope because its underlying causes result in decreased heart function.
When the heart is unable to pump enough blood to tissues in the body with a high oxygen and nutrient demand, the tissues can begin to shut down. Some of the most demanding tissues of oxygen and glucose are the brain tissues. Because most angina causes result in poor blood supply, the tissues in the brain may be adversely affected by the decrease of oxygen and glucose. This mechanism can result in cardiovascular syncope.
Williams syndrome patients have a greater risk of having cardiovascular syncope than those who are not affected. Williams syndrome is an uncommon disorder that causes problems with an individual's development in many parts of the body. Learning problems, distinctive facial features, blood vessel abnormalities, and cardiovascular issues are classic symptoms of Williams syndrome. Supravalvular aortic stenosis is also a common occurrence in Williams syndrome patients.
With this cardiovascular problem, the aorta becomes too narrow. Long term high blood pressure has been an issue also seen in individuals affected by Williams syndrome. Both of these issues can cause further damage to the heart muscle and impair its ability to properly circulate oxygen-rich blood to the vessels that feed the tissues around the body. Blood can back up into the heart and lungs if it is not able to escape through a too narrow aorta. This mechanism can cause less blood to reach the brain, and syncope may occur.
Anyone who has an abnormal electrocardiogram result has a higher probability of experiencing cardiovascular syncope. An electrocardiogram is a diagnostic test to measure the electrical activity of the heart. This test is often utilized because it is non-invasive, not extremely costly, and widely available. An electrocardiogram tells the doctor how fast the patient's heart is beating, and if their heart chambers are conducting electrical signals correctly. One abnormal electrocardiogram can be a normal deviation of the individual's heart rhythm, but several abnormal electrocardiograms can indicate a serious heart condition. Numerous defects in the shape and size of the heart can cause both an abnormal electrocardiogram and cardiovascular syncope.
Imbalances in any of the minerals within the body responsible for managing the fluid levels and blood pressure can also result in cardiovascular syncope and manifest as an abnormal electrocardiogram. One of the most common causes of cardiovascular syncope is ischemia or a restriction of blood flow. Ischemia can be detected with an abnormal electrocardiogram in affected individuals. Abnormalities in heart rate and rhythm have the potential to result in cardiovascular syncope and can also show up on an electrocardiogram.
Coronary Artery Disease
Coronary artery disease can cause an affected individual to experience cardiovascular syncope. The coronary arteries are the arteries that run through the muscle tissues of the heart and supply the cells that make up the heart with oxygen and nutrients. The coronary arteries are some of the most important arteries in the body because the heart cannot beat without them. Coronary artery disease occurs when inflammation and cholesterol-containing plaques accumulate inside of them and cause damage. It often goes unnoticed until the advanced stages because it is a disease that takes decades to develop.
Syncope can easily occur in advanced stage coronary artery disease patients because a blockage can stop enough blood from reaching the muscle cells of the heart. After a few minutes of no oxygen and nutrients, the cells become damaged and cause tissues in the heart to die. This malfunction can cause one or more of the hearts chambers to stop pumping or slow down enough to where blood cannot reach the brain. When the brain is starved of oxygen, the patient can experience cardiovascular syncope.