APPROACH TO SYNCOPE
History taking in cardiology cont.
Syncope has been defined by the European society of cardiology as “A transient loss of consciousness due to transient global cerebral hypoperfusion characterized by rapid onset, short duration, and spontaneous recovery.”
Syncope is a common problem, it causes significant agony and apprehension and may result in serious injury to the patient. Analysing and making an etiologic diagnosis of syncope is a difficult problem and even after investigations a significant number of patients still remain unexplained.
A detailed history is of paramount importance in the evaluation of syncope. Because all evaluation is usually retrospective. We will discuss in this article an approach to syncope and how to make a probable diagnosis from history.
STEPS IN THE EVALUATION OF SYNCOPE:
Patients present with the complain of loss of consciousness. From here we have to proceed in a systematic fashion to make a diagnosis. We will approach syncope under two headings
1. Taking the history of the episode
2. Analysing the history to reach at a diagnosis
RECORDING THE HISTORY OF SYNCOPE:
Below is a sample questionnaire for recording the history
WHAT WERE THE CIRCUMSTANCES JUST PRIOR TO THE ATTACK?
• The physical position of the patient is important. Inquire whether the patient was supine, sitting or standing.
• Activity related to syncope episode (rest. change in posture, during or after exercise, during or immediately after urination, defecation cough, or swallowing)
• Predisposing factors (e.g. crowded or warm places, prolonged standing. post-prandial period) and of precipitating events (e.g. fear, intense pain, neck movements)
HOW THE ATTACK STARTED ?
• Nausea, vomiting, abdominal discomfort, feeling of cold, sweating, aura, pain in neck or shoulders, blurred vision, dizziness
QUESTIONS ABOUT THE ATTACK (EYEWITNESS)
• Way of falling (slumping or kneeling over), skin color (pallor, cyanosis, flushing), duration of loss of consciousness, breathing pattern (snoring) movements (tonic, clonic, tonic-clonic, minimal myoclonus or automatism), duration of movements, onset of movement in relation to fall, tongue biting
HOW THE ATTACK ENDED?
• Nausea, vomiting, sweating, feeling of cold, confusion, muscle aches, skin color, injury, chest pain, palpitations, urinary or fecal incontinence
BACKGROUND HISTORY OF THE PATIENT
• Family history of sudden death, congenital arrhythmogenic heart disease or fainting
• Previous cardiac disease
• Neurological history (Parkinsonism, epilepsy, narcolepsy)
• Metabolic disorders (diabetes, etc.)
• Medication (antihypertensive, antianginal, antidepressant agent, antiarrhythmic, diuretics, and QT-prolonging agents) or other drugs including alcohol
• In the case of recurrent syncope, information on recurrences such as the time from the first synopal episode and on the number of spells
ANALYSIS OF HISTORY
Once the history is recorded, the next step is to differentiate syncope from other causes of transient loss of consciousness.
Causes of transient loss of consciousness (T-LOC)
1. Syncope – we will discuss
2. Neurologic or cerebrovascular disease – e.g. seizure, posterior circulation TIA
3. Metabolic syndromes and coma – e.g. hypoglycaemia, drug or alcohol intoxication, hypoxia, hypocapnea
4. Psychogenic syncope- anxiety disorders, panic disorders, somatization disorders
DIFFERENTIATING SYNCOPE FROM OTHER CAUSES OF T-LOC
Following questions help in differentiating syncope from other causes of T-LOC
(1) Did the patient experience a complete loss of consciousness?
(2) Was the loss of consciousness transient with rapid onset and short duration?
(3) Did the patient recover spontaneously, completely, and without sequelae?
(4) Did the patient lose postural tone?
If the answer to one or more of these questions is negative, other nonsyncopal causes (as listed above) of transient loss of consciousness should be evaluated.
ESTABLISHING THE CAUSE OF SYNCOPE
Features of some of the common causes of syncope
||Neutrally mediated syncope
|EpidemiologyAnd clinical setting
||Female>malesYounger age (<55)Frequent episodes(>2)
Prolonged standing, extreme emotions, hot humid surrounding
|Structural heart diseaseMales>femalesOlder age (>55 years)
In supine position or during exertion
Family history of sudden cardiac death
|Younger age (<45yrs)Any clinical situation
||Females>malesOccurs in others presenceYoung age (<40 yrs)
Many episodes (many episodes in a day)
No definite trigger
||Longer duration(>5s)PalpitationsBlurred vision
|Shorter duration(<6s)Palpitation less common
||Sudden onsetBrief aura (déjà vu, olfactory, gustatory, visual
|During the episode
||Pallor & diaphoresisDilated pupilHypotension
Urine and fecal incontinence
Brief clonic movements may occur
|Cyanosed not paleIncontinenceClonic movements may occur
||Cyanosed, no pallorTongue bitingFrothing at mouth
Prolonged syncope(>5 mins)
Horizontal eye deviations
|Normal colourNormal pulse and BPProlonged duration
||Residual symptoms uncommon (unless prolonged unconsciousness)
Salient features of syncope due to less common causes
|Cause of syncope
- Vascular steal syndromes (subclavian steal syndrome)
|Syncope in association with symptoms of brain stem ischemia (i.e.,diplopia,tinnitus,focal weakness or sensory loss, vertigo, dysarthria.
- Migraine associated syncope
|Throbbing unilateral headache, scintillating scotomata, nausea, vomiting, photophobia, phonophobia
- Orthostatic hypotension
|History of orthostatic symptoms and syncope, features of autonomic failure and other neurological symptoms (e.g.,parkinsonism, disturbances of bowel, bladder , thermoregulatory and sexual function, ataxia)-volume depletion-drug and alcohol induced
- Carotid sinus hypersensitivity
|Common in elderly, relationship to specific neck positions (neck collar, shaving etc.), carotid sinus massage reproduces symptoms or bradycardia
- Situational syncope
|Related to specific situations ( cough, defecation, laugh, swallow, after food, sneeze, micturition etc.)
- Glossopharyngeal syncope
|Associated with glossopharyngeal neuralgia
These tables provide enough information to help in diagnosis. Clinical history and physical examination has around 25% sensitivity for etiologic diagnosis of syncope. Most of these patients need further evaluation.
Special note for students about to appear in exams:
Remember the structural heart diseases which result in syncope. Important ones
1. LVOTO- aortic stenosis, HCM, coarctation of aorta
2. RVOTO – pulmonary stenosis
3. Pulmonary hypertension
4. Atrial myxoma
These conditions will have a lot of other cardiac symptoms which will help in making a clinical diagnosis. You will have to remember the natural history of important structural heart diseases and exam cases.
This article is part of the series about history taking in cardiology and is intended primarily for medical students. Physicians and practitioners are referred to ESC guideline on evaluation and management of syncope (http://www.escardio.org/guidelines-surveys/esc-guidelines/guidelinesdocuments/guidelines-syncope-ft.pdf).
Keywords : history taking in cardiology, medical students, syncope, symptoms of heart disease, analysis of symptoms