TIA: Transient Ischemic Attack

BRADYCARDIA

Definition: A heart normally beats at 60-100 beats per minute. An average male at 70/min.Therefore bradycardia is defined as a condition when an individual has a heart beat of less than 60 beats per minute. However, a heart rate of less than 60 beats per minute is considered normal during sleep as well as being considered normal for a well trained athlete. Bradycardia is considered a problem usually once signs such as *fainting and shortness of breath appear.

Extra info: The adult heart (at rest) beats at about 60 to 80 beats per minute. Fifty-five to 60 beats per minute would be considered bradycardia for an adult. Infants, however, have a much higher at rest heart rate (110 to l30 beats per minute), thus; bradycardia in infants would be a rate below 100 beats per minute. Bradycardia can also occur secondary to certain illnesses (such as decreased thyroid function, certain gastrointestinal disorders, and jaundice), or the abuse of certain drugs. People with known heart disease (including hypertension) who are being treated with medications that slow the heart (such as beta-blockers and certain calcium channel blockers) can experience bradycardia. It may be a temporary consequence of certain types of heart attack). Bradycardia is common in elderly people (whether or not they suffer from arteriosclerosis) and infants with certain types of congenital heart disease.

Signs and symptoms:
The point to note is that with bradycardia, the arising symptoms are associated largely with the fact that there is a lack/decrease in the supply of blood to the various organs and tissue of the body. E.g.-
§ Near-fainting or fainting (syncope)
§ Dizziness
§ Weakness
§ Fatigue
§ Shortness of breath
§ Chest pains
§ Disturbed sleep
§ Confusion
§ Heart palpitations
When symptoms occur, they are usually fatigue, shortness of breath, light-headedness or fainting.

Conclusion:
With regards to Hans in the PCL:
1) the major risk factor that needs to be considered is his older age,
2)*this symptom of bradycardia ties in with the PCL as well,
3) the fact that the doctor notes a steady but slow pulse in Hans, all point in the direction that Hans may well be diagnosed with bradycardia!

Further testing to determine the cause may involve blood tests, an EKG or a heart monitor.
Reference:
http://www.mayoclinic.com/health/bradycardia
http://www.healthscout.com/ency/68/201/main.html

EKG/ECG

ECG

An electrocardiogram (ECG or EKG) is a recording of the electrical activity of the heart over time produced by an electrocardiograph, usually in a noninvasive recording via skin electrodes.
Electrical impulses in the heart originate in the sinoatrial node and travel through the heart muscle where they impart electrical initiation of systole or contraction of the heart. The electrical waves can be measured at selectively placed electrodes (electrical contacts) on the skin. Electrodes on different sides of the heart measure the activity of different parts of the heart muscle. An ECG displays the voltage between pairs of these electrodes, and the muscle activity that they measure, from different directions, also understood as vectors. This display indicates the overall rhythm of the heart and weaknesses in different parts of the heart muscle. It is the best way to measure and diagnose abnormal rhythms of the heart, particularly abnormal rhythms caused by damage to the conductive tissue that carries electrical signals, or abnormal rhythms caused by levels of dissolved salts (electrolytes), such as potassium, that are too high or low. In myocardial infarction (MI), the ECG can identify damaged heart muscle. But it can only identify damage to muscle in certain areas, so it can't rule out damage in other areas. The ECG cannot reliably measure the pumping ability of the heart.

- wiki/saladin

Glasgow Coma Scale (GCS)

In Part A of this week's PCL, Dr Perlman ascertains that Hans "appears to be OK" - "sensible verbal responses", "appropriate motor responses" and "normal eye openings".

What Dr Perlman seems to have used here is probably the Glasgow Coma Scale (GCS) or a simplified version of the GCS to ascertain Hans' conscious state.

Overview of GCS
A neurological assessment tool that is both reliable and objective in the recording of a person's conscious state. 3 types of responses are assessed.

• Best motor response (6 grades)

1. No response to pain
2. Pain causes limb extension
3. Pain causes abnormal flexion
4. Withdraws from pain
5. Makes effort to remove painful stimulus
6. Obeys commands

• Best verbal response (5 grades)

1. None
2. Incomprehensible speech
3. Inappropriate speech
4. Confused conversation
5. Oriented

• Eye opening (4 grades)

1. None
2. In response to pain
3. In response to speech
4. Spontaneous

Scoring
Summation of highest attained scores in each of the 3 sections. The score ranges between 3 and 15.

Interpretation
3-8: Severe injury
9-12: Moderate injury
13-15: Minor injury

Who can use it?

• Doctors
• First-aiders
• Emergency Medical Services (EMS)
• Nurses

Abbreviated coma scale (AVPU)
The abbreviated coma scale (AVPU) can be used as an initial assessment in critical situations.

• Alert
• Responds to vocal stimuli
• Responds to pain
• Unresponsive

Reference
Longmore M., Wilkinson I., & Rajagopalan S. (2004) Oxford Handbook of Clinical Medicine (6th ed.) Oxford, United Kingdom: Oxford University Press

Veins and Venous Pump

Types of veins

1. Postcapillary venules

· Smallest of veins and immediately follow capillaries

· Even more porous than capillaries and allow for fluid exchange with tissues

· Most leukocytes emigrate from the blood stream through the walls of these venules

2. Muscular venules

· Receive blood from postcapillary venules

· Slightly larger than postcapillary venules

3. Medium veins

· Many medium veins, especially in the limbs, exhibit infoldings of the tunica interna that meet in the middle of the lumen, forming venous valves directed towards the heart.

· The venous pressure alone is not enough to pump the blood towards the heart against gravity, the functional venous pump is partly responsible for it.

4. Venous sinuses

· Veins with very thin walls, large lumens and no smooth muscle. Examples include the coronary sinuses of the heart and dural sinuses of the brain.

5. Large veins

· Examples include venae cavae, pulmonary veins, internal jugular and renal veins.

Venous Return Mechanism – Valves and ‘pumps’

MUSCLE PUMP

Everytime you contract the muscles in your legs you compress the veins in or adjacent to the muscles which forces the blood to flow proximally in the veins, because of the unidirectional valves.

This is known as the venous or muscle pump and is efficient enough to reduce the venous pressure in the feet to about 20mmHg when walking, as opposed to the 90mmHg if there were no pump or valves. If a person stands perfectly still, therefore not making use of the venous pump, the venous pressure in their feet will rise to 90mmHg with time because of the gravitational force fighting against the return of the blood superiorly to the heart. There would also be a pressure increase in the capillaries inferiorly which would cause between 10 to 20 percent of the blood volume to leak into tissue spaces within 15 to 30 minutes of standing still. (possible reference to pcl case)

Saladin pp.760-761

Guyton pp176-

DRABC

DRABC
D - Possible danger to yourself, the patient and any bystanders.
R - If the person remains unconscious, roll him/her into the recovery position.
A - Ensure airway is clear and remove any foreign objects.
B - Tilt the patient's head to keep airway opens.
C - Some texts suggest checking pulse (carotid pulse) after completion of the first cycle.
D - Defibrillation

Different types of arrhythmia

Reasonably loose subject, so bear with me.
The term arrhythmia defines (broadly) the conditions in which there is abnormal electrical activity of the heart. Whilst some arrhythmia is a symptom of something underlyingly sinister, arrhythmia is also reasonably common an non-fatal. Some key types of arrhythmia in cardiac arrest are:
- (atrial/ventricular) Fibrillation
- Bradycardia
- Tachycardia
- Asystole

Each has its own specific treatments, pathophysiology, etc.
Fibrillation is an uncoordinated tremor of the heart, such that contractions (and thus blood flow) are ineffective.
Bradycardia is a slowed heart rate (can be regular), specifically under 60 beats per minute.
Tachycardia is the opposite, where the heart beats upward of 100 beats per minute (in years >15).
Asystole is the dummy answer for a type of arrhythmia in cardiac arrest - the state of no cardiac electrical activity (ie flatline, dead, etc).

Given this, under the setting of the PCL, where Han 'has a relatively steady but slow pulse', it would be a reasonable assumption to make that bradycardia is of particular relevance.

Sam

http://www.nlm.nih.gov/medlineplus/arrhythmia.html

Risk factors for fainting

Risk factors for fainting/unconsciousness:

1. Congestive heart failure: The heart is unable to pump enough blood to meet the body requirements, hence lead to fainting. Symptoms: breathing difficulty and swelling in both legs.
- not applicable because Han did not have any breathing difficulty before he fell on the ground.
2. Dehydration: Insufficient amount of water in the body making the body unable to function properly. Symptoms: dry mouth, faintness, dry skin, thirst, nausea and weakness.
- Han may not be drinking at all during the whole match, leading to dehydration that caused him to faint.
3. Extreme heat exposure – not applicable. It was a cool and breezy day.
4. Hx of cardiac arrhythmias, coronary artery disease or stroke (TIA)
5. Previous fainting episodes
6. Stressful events – perhaps Han lost his bet on the match and become stressed.
7. Previous surgical procedures

Source: http://www.freemd.com/fainting/risk-factors.htm

Other conventional risk factors for CVD which may lead to fainting:

1. Hyperlipidaemia
2. Hypertension
3. Smoking – smokers have 2-4 times greater risk of heart attack than non-smokers.
4. Diabetes
5. FHx
6. Obesity (overweight)
7. Physical inactivity
8. Age and gender - >83% of people died from coronary heart disease are >65y.o. Males tend to 9. have greater risk of heart attack than women.

Sources:
Theme 4 Clinical Skills: Cardiovascular lecture notes.

American Heart Association: http://www.americanheart.org/presenter.jhtml?identifier=4726

Stroke

Stroke
An interruption of blood supply (and thus oxygen) to the brain. It may result from -
- Embolism – A migrating clot causes blockage
- Thrombosis – A clot inside a vessel that causes blockage
- Haemorrhage - Bleeding
- Infarct – dead or dying tissue often resulting from diminished blood supply

- When somebody has a stroke...
o It is usually the result of one of the following 3 processes
 Embolism (usually from carotid, vertebral or basilar arteries) and subsequent brain infarction
 Thrombosis – causes occlusion in one of the main arteries, results in brain infarction
 Haemorrhage – in the brain (intracerebral or subarachnoid)
o The most common form of stroke is the Cerebral infarction

- So, Hans could have had a stroke...
o Because it is more common in males than in females
o It is uncommon before 40, but the risk increases with age (except for those on antihypertensive medication – where the risk decreases) (high blood pressure is a risk factor for stroke)
o With the limited information, it is difficult to know which stroke risk factors Hans is affected by, however some may be –
 Hypertension
 Inactivity
 Smoking
 Maintaining a healthy weight
o A cerebral infarction is associated with sudden onset – this correlates with Hans’ experience, who was fine one minute, but unconscious on the ground the next.

- However, it may not have been a stroke...
o The most common form of stroke – cerebral infarction (infarction in internal capsule which results from embolism in the middle cerebral artery branch) often results in
 Limb weakness on the opposite side of infarct (can take seconds, minutes, hours)
 Weak limbs are at first flaccid
 Facial weakness
 Slurred speech
 Consciousness is generally maintained
 This does not correlate with Hans’ intact reflexes or his apparent unconsciousness
 Reflexes usually do not return until at least a couple of days following the infarct
o Dr Perlman notes that while his pulse is steady, it’s quite slow (hypertension is a risk for stroke)
o Shortly afterwards his verbal, motor and eye responses have returned to normal – there is usually a delay in the return of response in stroke victims, particularly those afflicted with the most common form of stroke – cerebral infarction
o Quick recovery more typical of TIA (a type of stroke)
o A stroke is more common in black African populations than Caucasian (although they certainly occur in Caucasians)
- The artery which is blocked directly corresponds to a particular area of the brain being affected.
o Anterior cerebral artery – frontal, occipital and parietal lobes
o Middle cerebral artery – internal capsule
o Posterior cerebral artery – cerebellum, temporal lobe

Thanks everyone

Georgia Downing

Syncope (fainting)

FAINTING (SYNCOPE) Steph Parish
Transient loss of consciousness due to inadequate cerebral blood flow is termed syncope, and may be due to a variety of causes.

VASCULAR CAUSES
The most common cause of syncope is the vasovagal attack, also known as neurocardiogenic or situational syncope, or as a simple faint. It may be triggered by prolonged orthostatic stress, or strong emotion. The mechanism begins with peripheral vasodilation and venous pooling of blood leading to a reduction in the amount of blood returned to the heart. The near-empty heart responds by contracting vigorously, which in turn stimulates mechanoreceptors (stress receptors) in the inferoposterior wall of the left ventricle. These in turn trigger reflexes via the central nervous system, which act to reduce ventricular stress (ie. further vasodilation and sometimes profound bradycardia), but this causes a drop in blood pressure and therefore syncope. These episodes are usually associated with a prodrome of dizziness, nausea, sweating, tinnitus, yawning and a sinking feeling.

OBSTRUCTIVE CAUSES
A restriction of blood flow from the heart into the rest of the circulation, or between the different chambers of the heart can cause syncope. Causes include aortic stenosis, hypertrophic obstructive cardiomyopathy, pulmonary stenosis, pulmonary hypertension/embolism, defective prosthetic valve.

ARRHYTHMIAS
Stokes-adams attacks have been defined as sudden loss of consciousness unrelated to posture. It is usually due to intermittent high-grade atrioventricular block, profound bradycardia or ventricular standstill. Without warning, the patient falls to the ground, pale and deeply unconscious. The pulse is usually very slow or absent. After a few seconds the patient flushes brightly and recovers consciousness as the pulse quickens. Often there are no sequelae, but patients may injure themselves during falls.

SOURCES
Most of this is taken straight from Kumar and Clarke. None of our other textbooks (notably Saladin and Guyton) had any relevent info that I could find.

Epilepsy and fainting

Epilepsy and fainting
What is epilepsy?
• Basically, it is abnormal electrochemical activity in the brain that results in seizures
• Seizures can be partial or generalised
o Partial seizure can be mistaken for intoxication or daydreaming
 Involves only a part of the brain, but it can spread
 It can become a generalised seizure
 People often have no recollection of the event – if Hans had partial seizures before, he may have forgotten about them, or they may not have been noticed
o Generalised seizures involve a loss of consciousness at the beginning of the seizure
 Involves the whole brain
 Possible epilepsy types Hans may have:
• Tonic
o Brief stiffening of the muscles  the body becomes rigid  can fall to the ground
• Atonic
o Sudden loss of muscle tone  individual collapses to the ground
• HOWEVER  these attacks are likely to occur in people with severe epilepsy and multiple seizure types
• Partial seizures are most common in the elderly
o Are often unrecognised, and are thought to be due to dementia or old age
o Commonly, it is a:
 Simple partial seizure (no loss of consciousness, short-lived, can be sensory, motor, autonomic or psychological)
 Complex partial seizure (altered consciousness, vague and dream-like appearance, strange, random or repetitive behaviour)
• We would have to know a bit about Hans’ past history to determine the possibility of Hans having epilepsy
o Case history must be combined with a EEG (???)examination
Fainting can be confused with epilepsy
• Fainting = unconsciousness due to sudden decrease in blood flow to the brain
• A person can experience brief jerks, twitching or convulsive behaviour when unconscious
o Hans didn’t, so I’m not sure how applicable this is to the situation
• A good history can help to differentiate between a faint and a seizure
This didn't turn out like it did on word, so I'm sorry!

Neurological systems review, and quick tests

Neurological systems review
Things to ask
• Presenting Problem
o Symptoms R/V Qs – ask patient to answer yes/no
• Seizures/fits – have you ever experienced any fits/faints/ funny turns?
• Fainting
• Dizziness/vertigo – head spins (dizziness), room spins (vertigo)
• Headache LOC (loss of consciousness), blackout
• Meningism – neck stickness
• Visual disturbance – do you see stars/flashes? Any changes in vision?
• Weakness – in muscles – dropping things easily, clumsiness
• Movt problems – unusual twitches/ move of your muscles
• Parasthesia – pins and needles (odd sensations)
• Anaesthesia - numbness
• Bladder/bowel – do you have ever accidents? Lost control of your water works?
• Risk factors
o Smoking
o Diabetes
o Alcoholism
o Diet/metabolism
o Drugs/chemical exposure
• Past Hx
• Family Hx
• Social
o Diet
o Exercise
• Meds/allergies
• All other systems r/v qs
• + risk factors
Things to test
* The movements and reactions of the eye.
* An examination of the eye using an ophthalmoscope. (not applicable in this case)
* A test of smell, of each nostril. This is particularly important in concussion cases, as a compromised sense of smell can be an indicator of frontal lobe damage. Sadly, this is the part of the test most often neglected.
* The patient should be asked to whistle, smile and clenching his teeth.
* Hearing should be tested.
* The muscles required to move the head around should be palpatated.
* Then the patient is asked to do the classic hand and arm movements, in order to elicit evidence of tremors, unilateral or bilateral motor weakness and to evaluate coordination and position sense.

Check each of the cranial nerves briefly
* I. Olfactory - Smell.
* II. Optic - Vision.
* III. Oculomotor - Eye movement.
* IV. Trochlear - Eye movement.
* V. Trigeminal - Controls the muscle and senses of the face.
* VI. Abducens - Eye movement.
* VII. Facial - Taste, expression and facial and scalp movements.
* VIII. Vestibulolocochlear - Hearing and vestibular system.
* IX. Glassopharyngeal - Gag reflex, taste, throat and sinus reflex.
* X. Vagus - throat, voice, gag reflex, coughing, dilations of the stomach.
* XI. Accessory - rotate head, shrug shoulder, raising chin.
* XII. Hypoglossal - muscles of the tongue.

References
Tutorial 2008 – Neurological systems review
neurologicalexam.com

Test 12

Hello everyone