Urinary syncope, also known as sudden urinary collapse, is mainly due to hypotension caused by impaired vasodilation and contraction, resulting in a momentary lack of blood supply to the brain. The disease occurs mostly in men aged 16-45 years, and occasionally in the elderly. Patients often faint suddenly in the early morning, at night or after a nap when they get up to urinate due to a brief loss of consciousness.
Most patients may experience dizziness, nausea, and panic before the onset of fainting, but some do not have any uncomfortable aura before fainting. This type of syncope usually occurs at the end of urination, but it can also occur before urination. The duration of the syncope can last as little as a few seconds or as much as half an hour. Although the disease has a tendency to recur, the frequency varies from patient to patient, with some having several episodes in a month and others having only one or two episodes in a year.
It has been clinically observed that the triggering factors of the disease are mainly alcohol consumption, lack of sleep, excessive fatigue, reduced diet and change of body position.
Pathogenesis.
The main pathogenesis has not been fully elucidated so far, and the following views are mainly held.
1. Increased vagal tone and slower heart rate at night. The sudden contraction of the filled bladder during urination, the sudden increase in pressure in the bladder, the huge mechanical pressure stimulates the vagus nerve in the bladder wall, while the contraction of the detrusor muscle (S2-4 and pelvic innervation, which is parasympathetic) can also cause strong vagal excitation, this strong vagal excitation caused by urination becomes the trigger point of syncope, the vagal impulse of the bladder is uploaded to the medulla oblongata via peripheral afferent nerves The vagal impulse from the bladder is transmitted to the medulla oblongata via peripheral afferent nerves, which triggers the vagal reflex in the vagus nerve center, and the heart is an important and sensitive target organ for the vagal reflex, which causes a decrease in heart rate and cardiac output.
On the other hand, the sympathetic tone is reduced by the integration of the central nervous system, which causes peripheral vasodilatation and consequent decrease in blood pressure. The combined effect of these changes is a momentary lack of cerebral perfusion, leading to a syncopal episode. The hemodynamic changes of sudden drop in heart rate and insignificant drop in blood pressure during the onset of voiding syncope and the autonomic dysregulation of vagal hyperactivity are very similar to those of vasovagal syncope of the cardiac inhibition type, and the effects of vagal hyperactivity in the post-exit pathways are basically the same between the two, except for the differences in syncope triggers and vagal impulse afferent pathways.
2, abrupt change in position, blood stagnation in the lower extremities.
3.The pressure in the thoracic cavity is increased by the breath-holding action during urination.
4, If holding urine too much and once voided, the intra-abdominal pressure drops sharply, which can open a large number of vascular beds in the abdominal cavity; the latter three factors can all impede venous return, which is the main factor in the pathogenesis.
On the other hand, when the intra-thoracic pressure increases the venous pressure also increases, and the intracranial pressure also increases, which reduces the cerebral blood flow. It has also been suggested that voiding syncope is a specific type of self-sustaining hypotensive syncope.
Clinical features.
(1) Patients are almost exclusively male, as men urinate in the upright position.
(2) The attack occurs most often when waking up at midnight to urinate, but can also occur in the early morning or when waking up from a nap to urinate, and is more likely to be triggered by cold weather or alcohol.
(4) The pre-syncope symptoms are mostly inconspicuous and may include very short periods of dizziness, blurred vision, and weakness of the lower extremities. The patient suddenly faints, the loss of consciousness lasts for tens of seconds, and wakes up on his own. Late syncope symptoms are mild, with individual patients experiencing convulsions. Some patients have injury during the attack. Voiding syncope may recur repeatedly.
Prevention and treatment.
Although the prognosis for voiding syncope is good, and most patients stop having episodes on their own as they age. However, because the patient will suddenly faint at the onset, it is easy to cause trauma and can be life-threatening in serious cases, so it is very important for the patient to prevent syncope. Clinical practice proves that the effective measures to prevent and control this disease are mainly as follows.
①Patients should take a sitting position when getting up to urinate, and then stand up slowly. Do deep breathing action when urinating (to prevent excessive breath holding).
② Do not hold urine, and urinate as soon as you have the urge to do so. Men who have frequent syncope episodes can take squatting or sitting urination.
③To actively treat various chronic diseases such as neurasthenia, tuberculosis, and gastroduodenal ulcer.
④To participate in more physical activities to enhance physical fitness.
⑤ Avoid alcohol abuse and overexertion.
⑥Patients can take oral atropine or 654-2 during frequent attacks of this disease.
⑦After a patient has syncope, he or she should be laid flat immediately, and then finger pressure should be applied to the patient’s acupuncture points such as Renzhong, Neiguan, and Feosanli to revive him or her as soon as possible. It should be noted that if the patient is suspected of having cranial trauma or cerebral hemorrhage, he should be quickly taken to the hospital for consultation and treatment to prevent accidents.
Precautions.
1, for people with frequent seizures, drink less water before going to bed, and when getting up to urinate, sit for a few moments before standing up to improve the response of the muscles.
2. Do not urinate too sharply or violently. If you have dizziness, blurred vision, panic, weak legs and other aura when urinating, you should immediately grab the object or immediately change to squatting to urinate.
3.People who have had urinary syncope in the past, take a squatting position when urinating.
4, patients suffering from tuberculosis, neurasthenia and qi and blood deficiency are prone to such syncope. In addition, weakness after illness, excessive fatigue and alcohol consumption can also induce this disease.