Syncope

Clinic

• Here Syncope is an Umbrella which refers to Reflex syncope/ Vasovagal Syncope / Orthostatic hypotension
• It is a brief loss of consciousness due to a neurologically induced drop in blood pressure and/or a decrease in heart rate.
• Before an affected person passes out, there may be sweating, a decreased ability to see, or ringing in the ears.
• Occasionally, the person may twitch while unconscious

Signs / Symptoms

• Loss of consciousness

• Lightheadedness
• Nausea
• Feeling of hot / cold + sweating)
• Ringing in the ears
• Uncomfortable feeling in the heart
• Confusion, a slight inability to speak or form words
• Visual disturbances such as lights seeming too bright, fuzzy or tunnel vision, black cloud-like spots in vision
• Nervousness

Causes

• Reflex syncope occurs in response to a trigger due to dysfunction of the heart rate and blood pressure regulating mechanism.
• When heart rate slows or blood pressure drops, the resulting lack of blood to the brain causes fainting.

• Regardless of the trigger, the mechanism of syncope is similar in the various vasovagal syncope syndromes.
• The nucleus tractus solitarii of the brainstem is activated directly or indirectly by the triggering stimulus, resulting in simultaneous
  • Enhancement of parasympathetic nervous system (vagal) tone
  • Withdrawal of sympathetic nervous system tone.

This results in a spectrum of hemodynamic responses:

1. On one end of the spectrum is the cardioinhibitory response, characterized by a drop in heart rate (negative chronotropic effect) and in contractility (negative inotropic effect) leading to a decrease in cardiac output that is significant enough to result in a loss of consciousness. It is thought that this response results primarily from enhancement in parasympathetic tone.
2. On the other end of the spectrum is the vasodepressor response, caused by a drop in blood pressure (to as low as 80/20) without much change in heart rate. This phenomenon occurs due to dilation of the blood vessels, probably as a result of withdrawal of sympathetic nervous system tone.
3. The majority of people with vasovagal syncope have a mixed response somewhere between these two ends of the spectrum.

One account for these physiological responses is the Bezold-Jarisch reflex.

Vasovagal syncope may be part of an evolved response, specifically, the fight-or-flight response.

Types

Reflex syncope is divided into three types:

1. Vasovagal: Typically triggered by seeing blood, pain, emotional stress, or prolonged standing.
2. Situational: Triggered by urination, swallowing, or coughing
3. Carotid sinus: Due to pressure on the carotid sinus in the neck

Orthostatic hypotension

• Also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when standing up or sitting down.
• Primary orthostatic hypertension is also often referred to as neurogenic orthostatic hypotension.
• Hypotension may be
  • Sudden (vasovagal orthostatic hypotension)
  • Within 3 minutes (classic orthostatic hypotension)
  • Gradual (delayed orthostatic hypotension)

• It is defined as a fall in systolic blood pressure of at least 20 mmHg or diastolic blood pressure of at least 10 mmHg after 3 mins of standing. It occurs predominantly by delayed (or absent) constriction of the lower body blood vessels, which is normally required to maintain adequate blood pressure when changing the position to standing. As a result, blood pools in the blood vessels of the legs for a longer period, and less is returned to the heart, thereby leading to a reduced cardiac output and inadequate blood flow to the brain.

Very mild occasional orthostatic hypotension is common and can occur briefly in anyone, although it is prevalent in particular among the elderly and those with known low blood pressure. Severe drops in blood pressure can lead to fainting, with a possibility of injury.

• Moderate drops in blood pressure can cause confusion/inattention, delirium, and episodes of ataxia.

Related diseases

• Addison's disease
• Atherosclerosis
• Diabetes
• Pheochromocytoma
• Porphyria

Related neurological disorders

• Autoimmune autonomic ganglionopathy
• Multiple system atrophy
• Other forms of dysautonomia
• Ehlers–Danlos syndrome
• Anorexia nervosa
• Parkinson's disease
• Lewy body dementias : Resulting from sympathetic denervation of the heart or as a side effect of dopaminomimetic therapy. This rarely leads to fainting unless the person has developed true autonomic failure or has an unrelated heart problem. Chronic orthostatic hypotension is associated with cerebral hypoperfusion that may accelerate the pathophysiology of dementia.

Another disease, dopamine beta hydroxylase deficiency, also thought to be underdiagnosed, causes loss of sympathetic noradrenergic function and is characterized by low or extremely low levels of norepinephrine, but an excess of dopamine.

Quadriplegics and paraplegics also might experience these symptoms due to multiple systems' inability to maintain normal blood pressure and blood flow to the upper part of the body.

• Patients prone to orthostatic hypotension are the elderly, post partum mothers, and those having been on bed rest. People with anorexia nervosa and bulimia nervosa often develop orthostatic hypotension as a common side effect. Consuming alcohol may also lead to orthostatic hypotension due to its dehydrating effects

Mechanism

Orthostatic hypotension happens when gravity causes blood to pool in the lower extremities, which in turn compromises venous return, resulting in decreased cardiac output and subsequent lowering of arterial pressure. For example, changing from a lying position to standing loses about 700 ml of blood from the thorax, with a decrease in systolic and diastolic blood pressures. The overall effect is insufficient blood perfusion in the upper part of the body.^{[citation needed]}

Normally, a series of cardiac, vascular, neurologic, muscular, and neurohumoral responses occurs quickly so the blood pressure does not fall very much. One response is a vasoconstriction (baroreceptor reflex), pressing the blood up into the body again. (Often, this mechanism is exaggerated and is why diastolic blood pressure is a bit higher when a person is standing up, compared to a person in the horizontal position.) Therefore, some factor that inhibits one of these responses and causes a greater than normal fall in blood pressure is required. Such factors include low blood volume, diseases, and medications.^{[citation needed]}

My Theory

Like other issues, here we have a lot of medical condition such as Orthostatic Hypotention, Fainting, Vasavagal Syncope and Situational syncope with a lot of related disease and underlying mechanisms, which means that we know but cannot classify our knowledge, since we do not pay attention to miasm.

Here I suggest a binary categorization. (1) Cardiogenic AND (2) Neurological Syncope. Here we already have a good defenition, Neurocardiogenic syncope

• Hypotention of Cardiogenic origin occurred in 2-3 min, but in Neurologic one, Hypotention occurred immediately.
• Cardiogenic syncope is accompanied by valvular heart diseases, myocardial diseases, and cardiac arrhythmia, while neurologic syncope is accompanied by neurologic disorders.
• Neurologic Syncope is more often in elderly people.

Entities / Miasms

	SAHF	YF	HFRS	WNE	CXB ECHO	HSV-1	STLE NPH	RBS	TBE
Hypotention	+++	+++	+++		+++	+++		+++
Orthostatic Hypotention	+++					+++			+
Coma	+++	+++		+++	+++	+++	+++	+++	+++
Dizziness	+++		+++				+++
Shock	+++	+++	+++	+++	+++
Flushed face	+++	+++	+++	+++
Nervous system	+++	+++		+++	+++		+++	+++	+++
Blood	+++	+++	+++

• SAHF is the best for both of them. Intrestingly SAHF has Vasoconstriction which is very Consonant to circulatory origine
• Obviously HFRS and HSV-1 do not Neurogenic syncope
• HFRS is special for Cardiogenic Syncope
• YF, WNE, CXA-B, ECHO, STLE and RBS are good candidates of Neurogenic Syncope

Dysautonomia

• I know syncope is not one entity.
• I consider it as a cluster of entities
• I suggest this cluster for Autonomic dysfunction