Weakness, Syncope, and Sudden Death Flashcards
who is syncope common in?
dogs with cardiac disease +/- systemic diseases
less in cats and horses
does syncope usually progress to sudden death?
sometimes
some have no progression
what are some causes of syncope?
hypoglycemia
hypoxemia
mild to severe anemia
hyperviscosity syndromes
hypotension
is vasovagal syncope usually benign?
yes: usually benign cause of syncope
rarely results in fatal event
is syncope often precipitated by exercise or cough?
yes
is the physical exam often normal in animals with syncope?
yes
what is a holter recorder useful for?
frequent syncope
what is sudden death defined as?
unexpected death (from cardiac disease) generally occuring within one hour of onset of signs
what are some causes of sudden death?
cardiac causes
thromboembolism
pulmonary hemorrhage
CNS event
aortic rupture or anomalous coronary artery
“found dead at home”
what are the two most likely cardiac causes of sudden death?
ventricular fibrillation
bradycardia: AV block
what cardiac rhythms are associated with syncope or sudden death?
asystole
pulseless electrical activity
advanced AV block
ventricular tachycardia
ventricular fibrillation
supraventricular tachycardia (syncope only)
what is the preferred treatment of advanced AV block?
cardiac pacing
which waveforms are easier to defibrillate?
coarser waveforms
higher frequency waveforms
what can cause hypotension?
hypovolemia
inadequate vascular tone
cardiovascular causes
what are some cardiovascular causes of syncope?
bradycardia
tachycardia
low cardiac output
cardiac restriction
cough
vasovagal or neurocardiogenic syncope
how can you treat tachyarrhythmias that cause syncope?
antiarrhythmic drugs
what cardiac rhythms are associated with syncope and sudden death?
asystole
pulseless electrical activity
advanced AV block
ventricular tachycardia
ventricular fibrillation
supraventricular tachycardia
what are the indications for defibrillation?
ventricular fibrillation
ventricular flutter
torsades de pointes
pulseless ventricular tachycardia
what leads to vasovagal syncope?
cardiac mechanoreceptors and aortic baroreceptors sense overstimulation
CNS: less sympathetic tone, increased parasympathetic tone
CV: bradycardia, plummeting blood pressure, reduced CNS perfusion: syncope
what is syncope often precipitated by?
exercise or cough
what are some cardiac causes of sudden death?
arrhythmias
cardiomyopathy
myocardial infarction
pericardial hemorrhage
what are some drug therapies for advanced AV block?
propantheline
terbutaline
theophylline
cilostazol
what long-term treatments can be used for prevention of sudden death in dogs with serious ventricular arrhythmias?
sotalol
mexiletine
beta-blockers
amiodarone
what is the dose for intrathoracic defibrillation?
0.2 J/kg
what can coarsen and increase the frequency of waveforms?
epinephrine
vasopressin
