Collapse, Weakness, Exercise Intolerance

Question 1

What is the problem with a ‘collapsing’ patient?

What is important for you to spend enough time doing?

Answer 1

• Patient is often “normal” at presentation.
• Differential diagnosis list is huge -collapse, weakness, syncope, fainting, fits, seizures, funny turns etc,etc,etc.
• SIGNALMENT.
• HISTORY AND OWNER’S DESCRIPTION OF THE EVENTS IS VITAL, TAKE YOUR TIME.
• FULL GENERAL HISTORY –OFTEN BEST LEFT UNTIL AFTER DESCRIPTION OF THE EVENT.

Question 2

What kind of information do you want to get from a history?

Answer 2

• Full general history –do first?
• Then full description of episode(s)
• History –should identify episode as:
  
  • Syncope (faint)
  • Seizure
  • Episodic weakness
• Number of events
• Age at onset
• Duration
• Time of day
• Association with:
  
  • Exercise/excitement - If after exercise –more likely cardiorespiratory disease
  • Feeding
  • Rest/waking If after just woken up, far more likely to consider seizure

Question 3

If collapse is associated woth exercise/excitement - which body system is most likely to be affected?

Answer 3

More likely to be cardiorespiratory

Question 4

If collapse is associated with rest/waking - which body system is most likely to be affected?

Answer 4

If after has just woken up, far more likely to consider seizure

Question 5

What are some more specific things you should ask about the history with a collapsing patient?

Answer 5

• All the same –specific, predictable?
• Prodrome/post ictalbehaviour
• Tonic/clonic or flaccid
• Autonomic signs –Has it lost control of bladder or defecate at the time?
• Consciousness lost?
• MM pallor/cyanosis
• Heart rate
• Normal between episodes –e.g. ex tolerance
• Medication –any response/cause of episode
• Toxin/drug access

Question 6

What are some significant findings you are looking for in a patient that has collapsed previously?

Answer 6

• Significant findings??
  
  • MM pallor
  • Dysrhythmia
  • Heart murmur
  • Neurological abnormality
  • Musculoskeletal abnormality

Significant findings may not always be relevant to the epidoes its having

Question 7

After physical exam and moving onto diagnostic tests in a collpasing patient, what is done next?

Answer 7

What is done next is determined by:

• Findings on physical examination
  
  • Pursue clinical abnormalities
  • Pursue breed-specific abnormalities?
• RISK –breed associated disease?
• Severity and/or frequency of episodes
• Financial constraints

Question 8

Define syncope

Answer 8

• Sudden, short-lived loss of consciousness
• Temporary failure of delivery of energy substrate to CNS - Oxygen and glucose in the blood, failure to thebrain
• Typically failure of perfusion
  
  • ?? 6 seconds+

Question 9

What are some clinical signs of syncope?

Answer 9

• Sudden onset
• Generalised weakness/ataxia
• Flaccid collapse -motionless
• Consciousness lost
• Maybe autonomic signs
• Maybe generalised mm activity

Question 10

What are some differential diagnoses for syncope relating to inappropriate vascular reflexes?

Answer 10

• Inappropriate vascular reflexes –will be clinically quite normal!
  
  • Vasovagal
  • Carotid sinus
  • Situational e.g. tussive
  • BP falls
  • perfusion fails
  • Clinically normal?
  • Lots of boxers faint
  • Often associated with excitement

Question 11

What are some cardiac differential diagnoses for syncope?

Answer 11

Cardiac

• Dysrhythmia
• Flow obstruction
• Pump failure
• Tamponade/preload failure
  
  • Effusion can cause tamponade
• Perfusion fails
• Clinical abnormality likely
• Exertional?

Question 12

What are some non-cardiac differential diagnoses for syncope?

Answer 12

Non-cardiac

• Metabolic
  
  • Non-motorseizure so no obvious tonic clonic signs
• Central neurological
• Clinical abnormality?

Question 13

What are some diagnostic tests you can perform when you have suspected syncope in a patient?

Answer 13

The underlined ones are the highest yield tests, especially if the animal is clinicallynormal

• Haematology and clinical biochemistry
• ECG
  
  • 24 hour/event recorder/monitor
• Thoracic/abdominal radiography
• Echo

Question 14

What is wrong with this ECG? Patient presented with syncope

Is this animal going to collapse?

Answer 14

Ventricular tachycardia, almost ventricular flutter

is this animal going to collapse? YES - heart will be going so fast it will not be able to fill properly

Question 15

Describe findings on this ECG of a patient that presented with syncope

Why does the ECG go off the paper at one point?

Answer 15

• Normal sinus rhythm
• Then goes into complete heart block
• P waves without QRS
• Escape beats
• ECG goes right up as the cat fell over
• This cat has COMPLETE HEART BLOCK

Question 16

If you have a patient with episodes of syncope, and there are no findings on an ECG - what should you do?

Answer 16

Monitor

Try to re-record ECG during profound collapse

Question 17

If you have a patient with episodes of syncope, and there are positive findings on the ECG but there is unknown significance to the episodes - what should you do?

Answer 17

Monitor

Question 18

What is wrong with this ECG?

Answer 18

Supraventricular tachycardia

Question 19

Describe findings on this ECG

Answer 19

Wide and bizarre complexes

Ventricular complexes

Question 20

Describe what the arrow is pointing at here on this ECG

Answer 20

Inverted P waves

Sinoatrial node disease

Question 21

Define episodic weakness

What does it worsen and improve with?

Answer 21

• Intermittent/persistent exercise intolerance
• Worsens with exercise
• Improves with rest

Question 22

What are some differential diagnoses for episodic weakness?

Answer 22

• Muscular
• Neuromuscular
• Orthopaedic
• Respiratory
• Cardiac
• Metabolic

Question 23

What are some different diagnostic tests you should consider for different differentials for episodic weakness?

Answer 23

• For metabolic disease
  
  • ACTH/TSH/insulin levels etc
• For neuromuscular disease
  
  • Edrophonium respose test/anti Ach Ab
• For muscular disease
  
  • EMG, mm biopsy
• For cardio-respiratory disease
  
  • As discussed
  • Blood gases

Question 24

What are the 3 things seziures can break down into?

Answer 24

• Extracranial disease
• Structural intracranial disease
• Functional intracranial disease

Question 25

What are some things that can cause extracranial disease?

Answer 25

* Toxins * Metabolic disease * Hypoglycaemia * Hepatic disease * Severe uraemia * Hypocalcaemia

Question 26

If you think you have structural intracranial disease with seizures, what diagnostic tests should you think about doing?

Answer 26

* CSF analysis * Skull radiography * CT or **_MRI_** * Want to rule out structural diseases within the brain * Functional intracranial disease * EEG?

Question 27

If the episodes of collapse/weakness/exercise introlerance are infrequence and/or benign, what should you do going forward?

Answer 27

* Reassurance –this is good news * Monitor * Train owner to do the following: * Heart rate * MM * Video –get to see the circumstances in which the animal is doing what the owner says its doing

Question 28

You can go on a fishing trip if you find nothing of significance with regards to collapsing patients, what kind of things could you do?

Answer 28

* Try and induce * Typically exercise-related problem * BS before and after * ECG before and after (during) * Take temperature * Haematology & clinical biochemistry * Inc mm enzymes * Inc electrolyte levels * Timing w.r.t feeding * ECG +/-monitoring * Radiography

Question 29

If there is NAD with collapsing patients, and nothing can be found - what is the prognosis?

Answer 29

* Collapse, syncope, ex intolerance * No obvious diagnosis * Long term follow up * Very good prognosis likely!!!

Question 30

Dogs seem to fall into 4 groups when there is NAD with collapse/wekaness/exercise intolerance etc - what are they?

Answer 30

1. Syncope 2. Collapse, no consciousness loss ONLY with exercise/excitement 3. Collapse, no consciousness loss NOT only with exercise/excitement 4. TENOD –tires easily, no obvious diagnosis 1. Dogs that don’t exercise well

Question 31

What is hyperthermia? Clinical signs?

Answer 31

* Many breeds/ages * Is a cause of ex intolerance –variable severity * Worse on hot days * Pant excessively * Lay down * Rectal temperature 107 o F + -hugely high * Seek water/wet grass/shade * High blood lactate