Syncope

Done ByAbdulwahab k. NeyaziMBBS

content•Introduction•Epidemiology•Approach•Classifications•American Heart Association

Recommendation•Home messages•References

Introduction• Defined as a transient loss of consciousness (T-

LOC)

• Due to transient global cerebral hypoperfusion

• characterized by rapid onset, short duration (average 12 sec), and spontaneous complete recovery

• Fainting, swoon, blackout.

Epidemiology•Common medical problem, with a

frequency between 15% and 39%

•Similar incidence between genders

•Significant increase in the incidence of syncope after 70 years of age

Approach•History

•Examinations

Classification•NeurocardiogenicVasovagal, carotid sinus hypersensitivity •Orthostatic Hypotension

•CardiovascularArrhythmia, Mechanical

•Miscellaneous

NeurocardiogenicA. Vasovagal

B. Carotid sinus hypersensitivity

A. Vasovagal Syncope• most common in young people

•Usually Preceded by Symptoms pallor, diaphoresis, nausea, vomiting

•Triggering factorsprolonged sitting position or standing positionemotional stress, pain, heat, venous puncture

PathophysiologyNormal ResponseStanding up causes blood to pool in the lower extremities ( leading to decrease cardiac out put, stroke volume and BP )

Compensated by increase sympathetic tone(vasoconstriction and tachycardia ) and decrease parasympathetic tone (vagal)

Spot Point for Diagnosis•History Young age, Precipitating factors emotional stresspain, heat, venous puncture.

•ExaminationTilt table test limited specificity, sensitivityRespond will to elevation of lower limb

Tilt Table Test

Treatment•Pt Education to avoid fatal fall down and

head injury and Avoiding the Triggering factors

•Some studies have found that isometric activity, such as crossing the legs and the arms could decrease Syncope attack.

•  higher-salt diet 

B. Carotid sinus hypersensitivity

•Its incidence is 35–40 patients/year/million individuals.

•Predominance in males (male: female ratio of 4:1)

B. Carotid sinus hypersensitivity • more frequent in the elderly especially diabetics

with coronary or carotid atherosclerosis.

• Precipitating factors sudden movements of the head and neck, cervical compressions and use of tight neck tie.

• Independent to the Position

Pathophysiology•Blood pressure and heart rate are

normally controlled in part by input from baroreceptors

•Stimulation of Baroreceptors result in bradycardia and vasodilatation a drop in blood pressure

At base of the internal carotid just superior to the bifurcation 

Spot point for Diagnosis•HistoryOld age, DM Precipitating factors sudden movements of the head and neck, cervical compressions and use of tight neck tie

•Examinationcarotid sinus massage but first Auscultation for carotid artery bruit

Treatment• Most patients can be treated with education,

lifestyle changes, and routine follow-up.

• Recurrent symptoms may need According to pilot study (2005) suggest that

treatment midodrine significantly reduced the rate of symptom reporting and but increased mean 24-hour ambulatory BP.

• Surgical Rarely, the insertion of an electrical pacemaker

Orthostatic Hypotension•Syncope that occur during rapid changing

in position It is more common in the elderly.

•Defined as  fall in BP with Standing - Systolic blood pressure of at least 20 mm Hg - Diastolic blood pressure of at least 10 mm Hg

Pathophysiology• autonomic reflexes are impaired.

• intravascular volume is markedly depleted.

Orthostatic Hypotension•EtiologyVolume depletion:-

Poor nutrition. Underlying disease : Vomiting, diarrhea Blood loss3rd SpaceRenal failure : Post-dialysis

Orthostatic Hypotension•EtiologyAutonomic failure and Aging 

Orthostatic Hypotension•EtiologyAutonomic failure

Neurodegenerative disease : Parkinson disease, Dementia with Lewy bodiesNeuropathies : Diabetes is the most common cause of autonomic neuropathyB12 deficiency

Orthostatic Hypotension•EtiologyMedications:-

Alpha blockers: Terazosin

Antidepressant drugs: Selective serotonin receptor reuptake inhibitors, tricyclic antidepressants

Beta-blocker drugs: Propranolol

Diuretic drugs: Hydrochlorothiazide, furosemide

Narcotic drugs: MorphineVasodilator drugs: Hydralazine, nitroglycerin, calcium channel blockers

Treatment•Pt education

•Treating underlying cause

•Review all pt medication

•Nutritional support specially for old age

Postprandial hypotension•common elderly

•have a 20 mmHg or greater fall in systolic blood pressure within 75 minutes after eating a meal 

pathophysiology

•inadequate sympathetic compensation

•pooling of blood in the splanchnic circulation, leading to impaired maintenance of cardiac output and systemic vascular resistance

Treatment• The patient should be informed about the risk of

falling and of syncope within 15-120 minutes after taking meals.

• Alcoholic beverages should be avoided before and after meals.

• Meal size and composition should be adjusted and frequent small meals

• Walking exercise after a meal may help to reduce

SYNCOPE

Cardiovascular•Arrhythmias

•Mechanical

Arrhythmias•Generally most of  Electrical

abnormalities can presented with Syncope.

• Can be fatal Leading to Sudden Death.

•E.g.Sinus node Dysfunction, AV Block, Pacemaker malfunction, Atrial Fib, Vent Tachycardia.

Pathophysiology •Inappropriate blood flow

Mechanical• Decreased blood flow and lead to

systemic hypoperfusion and syncope

•E.g. aortic stenosis, hypertrophic cardiomyopathy, pulmonary hypertension, and pulmonary embolus

Spot Point for Diagnosis •Detailed History.

•Examination.

•Investigations. ECG, Echo, Chest X-ray.

American Heart Association Recommendation• young adults with syncope have no structural

heart disease or significant arrhythmia (abnormal heart rhythm). So, extensive medical work-up is rarely needed.

• A careful physical examination by a physician, including blood pressure and heart rate measured lying and standing, is generally the only evaluation required

American Heart Association Recommendation•

In other cases an electrocardiogram (EKG or ECG) is used to test for abnormal heart rhythms , echocardiogram may be needed to rule out other cardiac causes of syncope..

• Tilt test. The blood pressure and heart rate will be measured while lying down on a board and after the board is tilted up.

American Heart Association Recommendation• Prevention of vasovagal syncope

• higher-salt diet

• avoid dehydration and maintain blood volume.

• warning signs of fainting — dizziness, nausea and sweaty palms

• sit or lie down if they feel the warning signs. Some people also may need medication

Miscellanies • Disorders with partial or complete LOC but without

global cerebral hypoperfusion

SeizureMetabolic :Hypoglycemia, hypoxia, hyperventilation with hypocapnia

Miscellanies

Seizure SyncopeUsually prolonged Rapid recovery

Loss of bladder control with tong bit

No Loss of bladder control

Home Messages•Common

•Serious

•History and Physical

•Pt education

References• Uptodate.• MedScape • American Heart Association• da Silva, Rose MFL. "Syncope: epidemiology, etiology, and

prognosis."Frontiers in physiology 5 (2014).

• Costantino, Giorgio, et al. "Syncope clinical management in the emergency department: a consensus from the first international workshop on syncope risk stratification in the emergency department." European Heart Journal(2015): ehv378.

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