Rapid recovery of consciousness after fainting Cardiac syncope should not be ignored

Text Zeng Yongtai
The occurrence of fainting is very short-lived, and the patient will wake up quickly after falling.
Fainting is not a disease, but a symptom caused by cerebral hypoxia. There are many reasons for cerebral hypoxia. Among them, the most lethal and high probability of sudden death is cardiac fainting, which cannot be ignored.
Lin Jianxian
(Dr Lim Kien Chien)
(Kuala Lumpur) Syncope is a sudden, transient loss of consciousness, often accompanied by loss of postural tone. With the assistance of resuscitation, the patient can regain consciousness autonomously.
cerebral hypoperfusion hypoxia
Cardiologist Dr Lim Kien Chien pointed out that the occurrence of fainting is very short-lived, and the patient will wake up quickly after falling. The briefness mentioned here refers to within a few seconds. Based on the findings of various large-scale studies, the average time for fainting is 12 seconds.
“Before losing consciousness, some people have a prodrome,
These include dizziness before fainting (pre-syncopal),
Night sweats, pale skin, blurred vision, nausea, vomiting, fast heartbeat, and feeling unusually warm. “
Fainting is not a disease, he explained, but a symptom caused by cerebral hypoxia, a lack of blood flow to the brain, usually caused by low blood pressure. Therefore, “falling” is actually a self-protection reflex mechanism adopted by the brain, because when a person is lying down, it helps to speed up the recovery of blood flow in the brain, and when the brain gets enough oxygen, the patient will wake up.
He said that there are many reasons for cerebral hypoxia, and the occurrence of syncope can therefore be divided into several categories, of which the three major categories are neurally mediated syncope (also known as reflex syncope), orthostatic syncope (orthostatic syncope). ) and cardiac syncope.
“Let’s first look at the most dangerous, most lethal, and high probability of sudden death, cardiogenic syncope. Although it does not occur commonly, accounting for only 10% of all syncope, it is a type of syncope that we cannot ignore.”
4 causes of cardiac syncope
He explained that the causes of cardiac fainting are:
Arrhythmia. The normal range is 60 to 100 heartbeats per minute. Too fast or too slow heartbeat is arrhythmia, and slow or too fast heartbeat will cause cerebral hypoxia.
Heart valve disease. For example, aortic stenosis or mitral stenosis can lead to a decrease in cardiac output, which in turn leads to insufficient blood flow to the brain and oxygen deprivation.
Cardiomyopathy. The most common is a weakening of the heart muscle. When the heart muscle cannot pump enough blood, cardiac output drops, resulting in insufficient blood flow to the brain and oxygen deprivation. Or hypertrophic obstructive cardiomyopathy, which is associated with many cases of sudden death in young people, when the ventricular muscles thicken abnormally, which can also affect cardiac output and lead to brain starvation. In addition, arrhythmogenic right ventricular cardiomyopathy (ARVD) can also cause fainting.
Large blood vessel problems such as pulmonary embolism or aortic dissection, which can starve the brain of oxygen.
Gathering under the hot sun can easily cause fainting
He gave an example of common neuromodulatory fainting. When students gather under the scorching sun, when the temperature rises, their nervous system is stimulated, resulting in slow heartbeat, sudden dilation of peripheral blood vessels, and low blood pressure, which eventually leads to cerebral hypoxia and fainting .
“This type of fainting is usually caused by a provoking event, such as seeing blood, sudden pain, strong sensations, standing for a long time in warmer temperatures, in crowded or confined spaces, etc. These stimuli make some people experience abnormal Autonomic nervous system reflexes that cause the heart and blood vessels to react reflexively, resulting in hypotension or bradycardia, decreased blood perfusion to the brain, and fainting.”
“In addition, some elderly people will also experience this type of fainting during urination, which is called micturition syncope. For example, an elderly person with enlarged prostate, when he has difficulty urinating and trying to expel urine, he will suddenly Fainting. Or some people have constipation problems and suddenly faint when he strains to defecate.”
Fainting in the elderly is mostly caused by drugs
He mentioned that postural fainting, as the name suggests, is related to posture. It generally occurs in the elderly. When the elderly stand up suddenly from a lying or sitting position, blood pressure will drop, leading to cerebral hypoxia, and fainting occurs.
“This type of fainting is usually related to drugs. Drugs that can cause this type of fainting include antihypertensive drugs, psychotropic drugs, drugs that improve dysuria due to enlarged prostate, diuretics, etc. Especially when hypertensive patients do not follow the doctor’s orders, During the follow-up consultation, the doctor found that the patient’s blood pressure was not well controlled, and mistakenly thought that the drug was not effective enough to increase the dose or other drugs, and when the patient took an excessive amount of drugs, it was easy to cause this type of fainting.”
“In addition, dehydration, blood loss and infection can also cause this type of fainting. Similarly, when the patient does not take diuretics correctly, such as not taking the new generation of blood sugar-lowering drugs SGLT2 inhibitors correctly, resulting in excessive excretion of water and even dehydration. If you don’t get enough water in your body, your blood pressure will drop, which can lead to fainting.”
rule out heart problems
Experienced should find out the cause
When a person experiences fainting, it is time to actively investigate and find out the cause, especially with tests to rule out heart problems.
“If a person experiences fainting that meets one of the following conditions, special attention is required. It is best to see a cardiologist for differential diagnosis to check whether the fainting that occurs is related to heart problems.”
detectable by electrocardiogram
1.If fainting is exercise related. When your fainting occurs when you exercise or exert yourself, such as running a few steps or walking up two flights of stairs and suddenly fainting, there is a high probability that it is related to cardiovascular problems.
2.If fainting is related to heart rhythm. Before you faint, your heartbeat becomes inexplicably fast, you sweat, you suddenly feel dizzy, and you faint, which may be related to heart rhythm problems.
3.If your family has a history of heart disease. When someone in the family has had sudden cardiac death or fainted, or has been diagnosed with a cardiovascular problem.
4.If you are older than 60 years old. Fainting is more likely to be related to cardiovascular problems as you get older.
5.If you are male. Fainting occurs more often in women, but in men it may be related to other serious problems.
6.If you have a history of cardiovascular or heart disease.
“Of course, many times, when a person faints, the people around them will be very nervous, and the patient is usually sent to the emergency room of the hospital. At this time, the emergency room will conduct a series of examinations. Usually, it will start by asking the patient’s medical history first, and then carry out A full body check, followed by an electrocardiogram (ECG), because 50% of heart problems can be found with an ECG.”
Monitor the patient’s heart rhythm
He reminded that if you want to check the structure of the heart, you can do an echocardiogram (ECHO), and other scans include computerized tomography (CT scan) and magnetic resonance imaging (MRI).
If a cardiologist suspects that a patient’s fainting is due to a heart rhythm problem, the patient may be advised to wear a 24-hour Holter ECG device or implant a loop recorder under the skin to monitor the patient’s heart rhythm.
Dizzinessuncertainsuffering from coronary heart disease
Question 1. Is dizziness a symptom of coronary heart disease?
Answer 1.Among the symptoms of coronary heart disease, 90% are chest pains, and fainting is not a common symptom. Unless it is a heart attack that causes arrhythmia and makes the patient faint. If it is just dizziness, it is said to be suffering from coronary heart disease. In fact, it is difficult to link the two unless there are other symptoms.
caused by drivingserious car accident
Question 2.Should a person be concerned if they have ever had neuromodulatory syncope?
Answer 2.There is no need to worry too much, because neuroregulated fainting is benign, and it will only occur under certain triggering factors and conditions. If you faint at the sight of blood, avoid seeing blood.
Even so, fainting itself is dangerous, and a sudden fall to the ground can easily cause trauma, especially if you faint while driving, it can cause a serious car accident.
dizzinessFainting is very different
Q3. Is dizziness or fainting?
Answer 3.Syncope must have 3 conditions: loss of consciousness, loss of postural tone, and rapid return of consciousness. And dizziness is a very common symptom, everyone will experience it in their life, and there are many factors that cause dizziness.
We need to distinguish between different dizziness. If we are talking about vertigo, its dizziness is very typical. The patient will feel that he or the surrounding environment is spinning, and some people will vomit after being dizzy. There are also many causes of vertigo, the most common of which is benign paroxysmal postural vertigo (BPPV).
elders will sayoften fall
Question 4.What is the dizziness before fainting?
Answer 4.There is no specific description or definition. Everyone has a different description of the feeling of dizziness. Some people say that walking is unsteady, floating or falling all the time, and there are various adjectives in different languages.
Many older people will not tell you that they have fainted, only that they have been falling, which is why the history and examination are very important.