What is Coronary Flow Effects of Arterial Spasm or Microembolization?
The heart gets its blood from the coronary arteries, which split into two major branches, right and left. Most of the heart muscle is nourished by the left coronary artery, which itself divides into two: the left anterior descending and left circumflex arteries. On the other side, the right coronary artery mainly nourishes the right side of the heart, and it provides blood to the sinoatrial (SA) node system in most people. These coronary arteries, being medium-sized, have a muscle component, that can sometimes lead them to constrict or spasm under different conditions. When this spasm happens in the coronary artery because of various reasons, it can cause the artery to narrow or even block completely, limiting blood supply to the heart muscle. This can cause chest pain and can result in severe issues like heart muscle damage, irregular heart rhythms, or even sudden cardiac death.
Another complication is when microembolization occurs, which blocks small vessels in the heart. This often results in malfunctioning of tiny blood vessels and can increase the pressure in the heart’s blood vessels. This can also result in heart muscle damage and the symptoms that accompany it. Microembolization typically happens when an existing heart artery disease causes fragments of plaque to become disturbed. Whether this happens naturally or because of a heart procedure, these fragments then move to small vessels where they can block the tiny arteries and capillaries.
What Causes Coronary Flow Effects of Arterial Spasm or Microembolization?
The flow of blood in your heart’s arteries, or coronary arteries, is influenced by your autonomic nervous system. The sympathetic part of this system can increase the effects of certain hormones that result in the narrowing of the blood vessels, which reduces blood flow. When there’s too much of such narrowing without any opposite effect, this could trigger a spasm (or sudden contraction) in the coronary artery.
The other part of the autonomic nervous system, the parasympathetic system, doesn’t directly cause spasms, but if it isn’t active enough, it can contribute to more unopposed activity of the aforementioned hormones, leading to spasms.
Such spasms can also be caused by smoking, problems in the blood vessel lining, physical stress, and drugs like cocaine. Spasms are likelier to occur in younger patients compared to older ones, and whether or not you get them can also depend on your genes.
Small blockages called microembolizations are commonly associated with heart disease. They originate from blockages in the coronary arteries and block the smaller blood vessels and the circulation of blood towards the more distant parts of your body.
Risk Factors and Frequency for Coronary Flow Effects of Arterial Spasm or Microembolization
Coronary artery spasm is a condition that is more frequently found in the Japanese compared to U.S. populations. It tends to be more prevalent in women and older individuals as opposed to men and younger people. Those who already have a coronary lesion are at a higher risk. Research suggests that Japanese people may have this condition more commonly due their bodies producing less endothelial nitric oxide and experiencing more autonomic dysfunction. These factors might be responsible for the difference in coronary artery activity between races.
Signs and Symptoms of Coronary Flow Effects of Arterial Spasm or Microembolization
Patients often experience a sudden, intense chest pain that resembles pressure and spreads out from the chest. This pain typically lasts for 5 to 20 minutes. These painful episodes come back again and again, and each one is similar to the last. If medicine does not relieve these symptoms, the person can have a heart attack, and even die suddenly. While these symptoms can be confused with typical chest pain from heart disease (angina), there is a key difference: people experience no pain between episodes.
Doctors should perform a physical examination to understand the patient’s heart and blood vessel health at a normal (baseline) state for comparison during these pain episodes. During an episode, a patient might experience a faster heart rate (tachycardia), low blood pressure (hypotension), or a heard heartbeat sound (third heart sound). These symptoms return to normal after the episode ends. If the right coronary artery, a major heart blood vessel, is involved, the patient might develop a slower heart rate (bradycardia) and low blood pressure due to disrupted blood flow to the right side of the heart.
Testing for Coronary Flow Effects of Arterial Spasm or Microembolization
If you go to the doctor with chest pain, one of the first tests you’ll likely get is an electrocardiogram, also known as an EKG or ECG. This test records the electrical signals in your heart and can help find different types of heart problems. Not everyone who has chest pain has abnormal EKG results. But sometimes, changes in a part of the EKG called the ST-segment can show that there’s a problem. Often, these changes go away on their own or after treatment.
Another test you might have is called a cardiac troponin test. This can check if a heart attack has happened. If your EKG results aren’t showing any heart problems but you keep having chest pain, you could have an EKG while you go about your normal day to try and catch these moments. This is called an ambulatory EKG.
Doctors can also use exercise to try and bring on a spasm in your heart. To do this, they’ll first rule out a condition called acute coronary syndrome using an ECG and the cardiac troponin test. After that, an exercise test combined with imaging tests might be able to find problems in the blood flow to certain areas of your heart.
If your doctor still isn’t sure what’s causing your chest pain, they might order a test called invasive coronary angiography. This can usually make it clear if the chest pain is due to a problem with blood flow to your heart. If this test doesn’t find anything, the next step might be to check how well your smaller heart vessels are functioning. This can involve tests like fractional flow reserve (FFR), coronary flow reserve (CFR), instantaneous wave-free ratio (iFR), and index of microcirculatory resistance (IMR).
Lastly, a technique called provocative testing might be used to check for something called coronary vasospasm. This condition happens when the arteries to your heart suddenly tighten up or spasm.
An invasive coronary angiography with provocative testing is often considered the best test for diagnosing the cause of mysterious chest pain.
Treatment Options for Coronary Flow Effects of Arterial Spasm or Microembolization
Non-drug treatments for this condition include quitting smoking, which can prevent symptoms from recurring.
Drug-based treatments depend on the patient’s symptoms and changes seen in their EKG (a test that measures heart activity). Nitrates can help reduce symptoms, but a coronary angiography (a test that uses dye and special X-rays to see how blood flows through your heart) is usually performed to make sure there aren’t any active sores in the arteries that supply blood to the heart. If the coronary arteries appear normal, long-acting nitrates with or without calcium channel blockers can help improve symptoms.
If someone is experiencing an acute attack, they can use a type of nitrate medication that is placed under the tongue for quick relief. Calcium channel blockers can affect the muscles of the heart and blood vessels to prevent recurring attacks. The dose of these medications should gradually be increased until the maximum tolerated dose is reached.
Beta-blockers, which are drugs that slow down your heart rate, should be avoided as they can increase the risk of spasms. However, if the patient has dysfunction in the left ventricle (one of the heart’s main pumping chambers), beta-blockers may need to be used due to their potential benefits in reducing death rates. An ICD (implantable cardioverter defibrillator), a device that can correct irregular heart rhythms, should also be considered for patients as a preventative measure.
What else can Coronary Flow Effects of Arterial Spasm or Microembolization be?
- Unstable Angina: This is chest pain that occurs when your heart doesn’t get enough blood flow and oxygen. It can lead to a heart attack if not treated quickly.
- Myocardial Infarction: This is a medical term for a heart attack. It happens when blood flow to a part of your heart is blocked, often by a blood clot.
- Coronary Artery Anomalous Origin: This is a rare condition where the coronary arteries (the ones that supply blood to your heart muscle) are in the wrong place.
- Pulmonary Embolism: This happens when a blood clot travels to your lungs, and can be very serious. People often experience chest pain and difficulty breathing.
- Aortic Dissection: This is a serious condition where the largest artery in your body (the aorta) tears. It can cause severe chest or back pain.
- Esophageal Spasm: These are sudden, painful contractions in your esophagus (the tube that carries food from your mouth to your stomach). It can feel like heart pain.
What to expect with Coronary Flow Effects of Arterial Spasm or Microembolization
The outlook for coronary spasm, a temporary tightening of the muscles in the wall of one of the coronary arteries, is generally positive if it’s detected quickly. Patients often respond well to medical treatment.
However, the situation is different with microembolization, a condition where tiny blood clots or other particles block small blood vessels in the body. This doesn’t usually respond very well to treatment, especially if accompanied by acute coronary syndrome (heart-related chest pain or discomfort) or after a procedure to open blocked or narrow coronary arteries. It commonly leads to problems with the small blood vessels.
Possible Complications When Diagnosed with Coronary Flow Effects of Arterial Spasm or Microembolization
- Heart attack (Myocardial infarction)
- Heart muscle dysfunction (Myocardial dysfunction)
- Irregular heart rhythms (Arrhythmias such as ventricular tachycardia or fibrillation)
- Sudden heart failure (Sudden cardiac death)
- Fluid in the lungs (Acute pulmonary edema)
- Heart failure
Preventing Coronary Flow Effects of Arterial Spasm or Microembolization
The patient should be informed about the importance of quitting smoking, as it can help prevent the return of symptoms.
If the patient sees improvements from taking prescribed medication, it’s crucial for them to continue following the medication schedule. Not doing so could cause symptoms to come back in a more intense form, known as a rebound spasm.
