Cardio Flashcards
what are complications related to HR, pressure and volume?
Heart rate
o Bradyardia
o Tachycardia
o Arrhythmias
Pressure
o Hypotension
o Hypertension
Volume
o Hypovolemia
o Hypervolemia
what considerations do we have to think about when it comes to heart rate?
-age; neonatal animals will have higher HR than adults
-size/breed; especially for dogs
-resting heart rate; know what their normal is because it could be different from what you would expect
what does a high ETCO2 indicate
good cardiac output
what happens when there is bradycardia
- Adequate diastolic filling
o Volume (Preload)
o Time (Heart Rate) - Too low will directly decrease CO and BP
what is the most important parameter for HR
cardiac output
causes of increased parasympathetic activity in bradycardia cases and examples
Vagal tone
▪ Oculocardiac reflex (trigeminovagal)
▪ Increase pressure in GI
▪ During expiration
Drug induced
▪ Alpha 2-agonists (xylazine, romifidine, detomidine, dexmedetomidine)
▪ Opioids (morphine, butorphanol, hydromorphone, fentanyl)
Reflex mechanism due to hypertension
▪ Baroreflex response (Alpha 2 agonists, Cushing reflex, primary
hypertension…)
what is the most common change we see with anesthesia
Hypotension
when there is bradycardia there is an ______ in parasympathetic activity
increase
what can cause bradycardia? (4)
▪ Cardiac disease; Sick sinus syndrome
▪ Increased intracranial pressure; Cushing’s response
▪ Electrolyte abnormalities; Hyperkalemia
▪ Hypothermia (less than 35 °C)
when do we want to treat bradycardia
▪ Treat if marked bradycardia
▪ For example: Dog with a HR of 38 versus 58
▪ Treat if hypotension or low cardiac output is associated. Is your BP high or low?
▪ Treat if rhythm is markedly irregular and/or dysrhytmias are also present
how to treat bradycardia if the cause is due to vagal tone
anticholinergics
how to treat bradycardia if the cause is drug induced
-reversal, lidocaine
-anticholinergics
how to treat bradycardia if the cause is due cardiac disease
-anticholinergics
-isoproterenol
-pacemaker
how to treat bradycardia if the cause is due to hypertension
control hypertension
how to treat bradycardia if the cause is due to increased intracranial pressure
-control ICP
how to treat bradycardia if the cause is due to hypothermia
warm up
how to treat bradycardia if the cause is due to electrolyte abnormalities
-decrease K+
-calcium gluconate
what happens to CO/BP and filling of chambers when there is tachycardia
- Increases CO and BP
- Too fast will decrease filling time and decrease SV
- Increase O2 consumption, can lead to myocardial ischemia and arrythmias
treatment of tachycardia if the cause is due to superficial plane and/or pain
check depth/analgesia
what can cause tachycardia as a result of increased sympathetic activity (6)
▪ Superficial anesthetic plane and/or pain
▪ Hypotension/hypovolemia
▪ Hypercapnia/Hyperthermia
▪ Drug induced
-Ketamine
-Sympathomimetics
-Anticholinergics
▪ Specific diseases: Phaeochromocytoma, Hyperthyroidism, Heart disease
▪ Hypoxia/Shock
tachycardia is from ______ sympathetic activity
increased
treatment of tachycardia if the cause is due to hypotension/hypovolemia
correct fluids/sympathomimetic
treatment of tachycardia if the cause is due to hypercapnia/hyperthermia
adjust ventilation/cool down
treatment of tachycardia if the cause is drug induced
stop administration