What is Syncope and Related Paroxysmal Spells?
Paroxysmal spells are unexpected incidents that can mimic seizures, but unlike seizures, they are not associated with the rhythmic discharging of brain cells (cortical neurons). These incidents are characterized by a temporary loss of consciousness, which can happen suddenly, sometimes with warning signs (prodrome). They can be triggered by psychological problems, including substance abuse and mental health issues, or physiological problems, such as low blood sugar (hypoglycemia), brain injury, and fainting (syncope).
Psychological issues like mental health disorders can increase the likelihood of these episodes. Therefore, if a patient has an unexplained loss of consciousness, doctors might consider mental health screening. Similarly, research indicates that among patients with a history of substance abuse, almost half experience unexplained fainting episodes. This suggests that past and current substance use may also increase the likelihood of unexplained temporary loss of consciousness. As a result, these patients might benefit from a toxicology screening and possible referral for detoxification.
Hypoglycemia, or low blood sugar, can cause symptoms like feeling lightheaded, seeing flashes light, temporary loss of consciousness, and, in some cases, seizures. It’s crucial that individuals experiencing these spells or fainting have their blood sugar levels checked.
Traumatic brain injury, which refers to brain damage caused by external forces like blunt or sharp head trauma, could also lead to temporary loss of consciousness. Depending on the severity of the injury, individuals might experience a rapid return of consciousness (often altered) or might progress to confusion or coma over hours to days due to increased pressure within the skull. The diagnosis usually involves a clinical history and CT scan, although an MRI scan may provide more information.
Many of these episodes are actually cases of syncope, a temporary loss of consciousness resulting from a decrease in blood supply to the brain. Syncope is a symptom of an underlying condition rather than a disease itself, and this underlying condition could be anything from benign (non-life threatening) to serious, even life-threatening. The likelihood of such underlying conditions prompts doctors to divide patients into “low-risk” and “high-risk” groups. The causes, frequency, evaluation, treatment, and management vary greatly for these different groups. Because extensive tests can be expensive, time-consuming, and often unnecessary, there is growing emphasis on creating strategies to identify causes and treat high-risk patients with syncope effectively and efficiently.
What Causes Syncope and Related Paroxysmal Spells?
Syncope, or fainting, can happen for a wide variety of reasons. Some of these reasons are harmless, like dehydration or a condition called vasovagal or neurocardiogenic syncope. Vasovagal syncope, which is the most common cause of fainting around the world —particularly in young people— happens when your body overreacts to certain triggers, like the sight of blood or extreme emotional distress.
However, there are also more serious causes of fainting, such as heart rhythm problems (dysrhythmias), issues with the electrical system in your heart (cardiac conduction disease), problems with the heart valves (valvular heart disease), or diseases you are born with (congenital heart disease) like Brugada syndrome, hypertrophic cardiomyopathy, arrhythmogenic right ventricular dysplasia, and long QT syndrome. Fainting can also be caused by sudden anemia or bleeding in the digestive tract, or by a blockage in one of the arteries in the lungs (pulmonary embolism).
All of these reasons lead to not enough blood going to the brain (hypoperfusion), and they all require an urgent medical evaluation in the emergency room.
Risk Factors and Frequency for Syncope and Related Paroxysmal Spells
Syncope, a condition characterized by a sudden loss of consciousness, is quite common and is found in about 20% of all people. It has a chance to recur, with the risk of recurrence around 13.5%. It’s reported to be more prevalent in females than in males.
- In 37% of cases, the cause of syncope can’t be determined even after a thorough study.
- The majority of syncope cases, particularly in younger individuals, are reflex-mediated neurocardiogenic and generally not harmful.
Signs and Symptoms of Syncope and Related Paroxysmal Spells
When a person faints, medical professionals rely on two main processes to determine the reason: a person’s medical history and a physical exam. Getting a thorough medical history is especially important and can help save a lot of time and money. Over time, different guidelines to help with this process have been developed; the Boston Syncope Pathway is one of them and is highly reliable.
A medical history should focus on ‘prodrome’, which means any symptoms experienced before fainting, like chest pain. It should also cover a person’s personal and family history of heart disease and any heart-related deaths in the family. Lastly, a thorough physical exam should be carried out, which involves listening to the heart for any abnormal sounds.
Testing for Syncope and Related Paroxysmal Spells
When doctors look into incidents of fainting, also known as syncope, their first goal is to decide if the cause is low-risk or high-risk. This decision is made based on the patient’s complete health history and a physical exam. Things like medications the patient is currently taking (like beta-blockers, nitrates, diuretics, and antiarrhythmics) are also looked into as they could be causing the fainting. Additionally, a family history of sudden cardiac death could indicate a higher risk.
Low-risk causes of fainting typically won’t cause serious harm. These causes could be seen in younger people, usually under 40, and might include standing up too quickly, feeling warm or nauseous, coughing, or needing to urinate before fainting. Other times, fainting can be traced back to a specific trigger, such as pain or emotional distress. For kids, these triggers are often related to the mind, not a physical issue. If a young patient has recurring fainting episodes but they’re connected to these low-risk events, the overall risk is usually low. Dehydration is a common cause of fainting in young people, as well.
However, some circumstances can be more serious. If the fainting happens during physical activity, or the person has chest pain or a history of heart conditions, this likely puts them in the high-risk category. Such heart conditions could include heart failure, valve disease, and coronary artery disease, among others. Additionally, if someone has fainted several times in a six-month period, this could warrant further investigation, regardless of the person’s age.
When seeing a patient for fainting, doctors also check vital signs like blood pressure. Low blood pressure could suggest internal bleeding. In older patients and women on their periods, a pale complexion or signs of gastrointestinal bleeding could lead to fainting due to a drop in blood flow to the brain. Therefore, testing the patient’s hemoglobin or hematocrit levels could be necessary. Other vital sign irregularities, like slow heart rate, might hint at a disconnect between the heart and blood vessels. Low oxygen levels could point to a lung clot. New heart murmurs found during a physical exam could suggest severe valve issues.
All patients should receive an electrocardiogram (ECG) screening. This is a test that checks how your heart is functioning by measuring the electrical activity generated by the heart as it contracts. An ECG can provide clues to a variety of heart conditions. Signs like a new left bundle branch block, Brugada pattern, arrhythmogenic RV dysplasia, prolonged QTc, and hypertrophic cardiomyopathy patterns on the ECG suggest the patient is at high risk and will require further investigations. Similarly, certain heart rate abnormalities and blockages should also be looked into more deeply.
Treatment Options for Syncope and Related Paroxysmal Spells
If you faint for no apparent reason, doctors usually evaluate your situation as low-risk. This happens by taking your medical history, conducting a physical examination, and using an EKG test that checks your heart activity. Most of the time, this type of fainting is harmless and usually comes from common issues like dehydration or a sudden drop in blood pressure called vasovagal syncope. After receiving some fluids and making sure your symptoms have resolved, most people can then return home. Even when a young person has repeated fainting spells without warning signs of a severe condition, if needed, an ultrasound of the heart (echocardiogram) can be carried out later in a non-emergency setting. The next steps might include medications such as beta-blockers, wearing compression stockings, or taking a drug called fludrocortisone.
However, if you faint and have high-risk features, such as chest pain or abnormal EKG results, you’ll require further tests. Observation units in the emergency department have been created for this purpose. Research has shown that these units are effective, safe, and can result in significant healthcare savings.
Depending on the reason for your fainting, your doctors will decide what other tests are needed. For example, if there’s a chance you have a heart problem (acute coronary syndrome), additional blood tests (serial troponins) or a stress test might be necessary.
People with a worrying history of heart problems, such as severe coronary artery disease, heart failure, or a thickened heart muscle (hypertrophic cardiomyopathy), are high-risk patients. They should have an echocardiogram to check for conditions that could obstruct blood flow from the left side of the heart. The doctors might then suggest a device that regulates your heartbeat (Implantable Cardioverter Defibrillator or ICD). As well, those who have experienced specific types of abnormal heart rhythms are at high risk of them happening again. In these cases, if an ICD or pacemaker is already in place, it should be checked to see if any abnormal heart rhythms occurred.
All patients with a troubling heart history should have 24-hour heart monitoring (telemetry) and evaluation for an ICD placement. If you have abnormalities in the electrical activity of the heart as shown by an EKG, a new heart murmur, or a family history of sudden cardiac death, doctors might require you to get an echocardiogram, telemetry, and home monitoring as well. Some of these patients might also need a pacemaker or ICD.
If anemia due to a lower than normal volume of blood (hypovolemia) is causing the fainting, doctors will take a complete blood count (CBC), and determine your blood type and screen for other issues. They’ll also look for the origin of the blood loss.
In some cases, fainting can result from a sudden bleed in the brain. Patients with concerns about this should have a brain CT scan and likely a consultation with a brain (neuro) surgeon.
If a lack of oxygen in the blood (hypoxia) is causing the fainting, doctors should investigate the possibility of a blood clot in the lung, known as a pulmonary embolism.
What else can Syncope and Related Paroxysmal Spells be?
These are some of the different medical emergencies, drug toxicities, and cardiovascular disorders that doctors might encounter:
- Acute aortic dissection (a serious condition where the inner layer of the aorta, the large blood vessel branching off the heart, tears)
- Acute hypoglycemia (very low blood sugar)
- Adrenal crisis in emergency medicine (a severe, possibly life-threatening condition that can occur in people who have Addison’s disease)
- Antidepressant toxicity (when someone has taken a dangerous amount of antidepressant medication)
- Aortic stenosis imaging (testing numerous parts of the aorta, usually with an x-ray)
- Asystole (also known as a flatline, a state of no cardiac electrical activity)
- Atrial fibrillation (an irregular heart rate that can increase the risk of strokes, heart failure and other heart-related complications)
- Beta-blocker toxicity (poisoning due to an excessive amount of beta-blocker medication)
- Brugada syndrome (a genetic disorder that is associated with abnormal electrocardiogram (ECG) findings and an increased risk of sudden cardiac death)
- Cocaine toxicity (when someone has taken a dangerous amount of cocaine)