What Is Syncope?
Syncope means sudden transient loss of consciousness, commonly known as fainting, reversible with time. It occurs due to decreased blood flow to the brain. Pre-syncope is a condition before syncope when a person experiences lightheadedness or black-out. Other symptoms described by people having syncope are nausea, dizziness, and visual disturbances, or they can occur without showing any symptoms. It is a common medical occurring in 15 to 39% of individuals. Usually, syncope is not a life-threatening condition that gets cured on its own by taking rest. If it does not get normal for some time that cause situation can get worse. It can be a more critical situation in people with underlying systemic conditions such as diabetes, Cardiovascular diseases, etc.
What Are the Causes of Syncope?
Syncope occurs when there is insufficient blood flow reaches the brain. This could be due to many reasons. Some of them are discussed below-
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Cardiac Syncope (Due to Cardiovascular Disorders) - If fainting occurs frequently and is not due to dehydration, weakness suddenly occurs without dizziness or presyncope conditions. It could be a cardiac syncope caused commonly due to arrhythmias. In cardiac arrhythmia, the heart has an abnormal heart rhythm, and insufficiently oxygenated blood has reached the brain. Cardiac arrhythmias can be of various types like bradyarrhythmias (heart beats too slowly) and tachyarrhythmias (heart beats fastly).
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Reflex Syncope (Vasovagal Syncope) - This type of syncope is most common and results from a reflex response to some trigger in which the heart beats slowly, and the blood vessels dilate. This causes the blood pressure to drop, and less blood reaches the brain.
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Postural Syncope - This could be due to a long-standing or upright position when insufficient blood reaches the brain.
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Neurologic Syncope - This is caused due to any neurological condition like a seizure, it stroke, or transient ischemic attack.
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Situational Syncope - This occurs in certain situations, such as coughing, vomiting, etc. This is usually reversible in a very short span of time.
What Is the Canadian Syncope Risk Score (CSRS)?
Syncope is responsible for 3 to 5% of emergency department visits, out of which 40 % of patients are hospitalized. Canadian syncope risk score is the risk score that estimates the probability of adverse effects, including arrhythmia and death, within 30 days after disposition from the emergency department. This risk score could be used to identify between low and high-risk patients. Once validated, it can be used for the quick disposition of low-risk patients.
If the score indicates medium or high risks, the patient should be evaluated for underlying conditions such as hemorrhage, pulmonary embolism, and cardiac problems such as myocardial infarction. If no such problem is found and the patient is discharged home, it would be reasonable to apply an out-of-hospital external cardiac monitor on these patients. Depending upon the local and patient factors, hospitalization can be considered for high-risk patients using a shared decision model.
The Canadian syncope risk score uses nine clinical, electrocardiograph, and lab components to predict serious clinical outcomes after a complete emergency department (ED) evaluation for syncope.
What Was the Canadian Syncope Risk Score Study?
A cohort study was conducted on people above 40 years of age presenting to the ED within 12 hours of syncope.
Among 2283 patients with a mean age of 68, the primary composite outcome occurred in 7.2%, and the composite outcome excluding procedural intervention occurred in 3.1 % at 30 days. Prognostic performance was good for both 30-day composite outcomes and better when compared with OESIL (It was constructed by calculating the simple arithmetic sum of the number of endpoint predictors present in every single patient)
The Canadian syncope’s mean of the study was 4.9, and the score range was between -2 to 11. The mean percentage of risk of severe events at 30 days in the study group was 29.17 %, and it ranged from 0.7% to 83.6%. There was a statistically significant difference between means of Canadian Risk Score’s score regarding complication occurrence. Cases that showed complication had a mean score of 7.33 compared to a mean score of 1.25 in case of no complication occurrence.
The Canadian syncope risk score is a strong predictor of the risk of serious adverse events and a good indicator for admission, with 100% sensitivity and 85% specificity at a cutoff point of more than 3.
What Is the Relation Between Scores and Serious Adverse Effects?
A severe event is defined as any adverse effect related to syncope that occurred or was detected within 30 days after disposition from the emergency department. The composite outcomes include arrhythmias, myocardial infarction, hemorrhage, death, etc.
This study revealed that the complication seen were atrial defibrillation (22.2%), followed by a myocardial infarction (16.7%), supraventricular tachycardia 16.7% and the least frequent GI bleeding (8.3%), and pulmonary embolism (8.3%).
Conclusion
This article gives a detailed discussion of syncope, types of syncope, and Canadian syncope risk score in patients through a Cohort study. It also tells us that-
Syncopes account for 1 to 3% of all emergency departments.
The most prevalent type of syncope is cardiac syncope.
The CSRS is a strong predictor for risk of serious adverse events and a good indicator for admission with 100% sensitivity and 87% specificity at cut-off points more than 3, which means that for ruling out complications.
Further, this international validation of the Canadian syncope risk study showed promising results in identifying patients at low risk for serious outcomes outside Canada and superior performance compared to the OESIL score.
Patients with medium risk are involved in a shared decision approach regarding disposition.
Patients with high risk should be hospitalized for a short course.
Implementing CSRS will increase patient safety and reduce medical resource overuse, unnecessary investigation, and hospitalization.
