Cardiac emergencies II Flashcards
Thromboembolism is the
Formation of a blood clot in an artery or vein.
Causes of thromboembolism: (3)
Blood stasis (LA dilatation secondary to the underlying cardiac disease results in blood stasis within the heart)
Vascular Injury
Hypercoagulability
Feline aortic thromboembolism is
One of the most devastating complications associated with feline heart disease.
Most cats with FATE have severe heart disease with a severely enlarged left atrium.
Uncommonly, FATE has been associated with neoplasia in cats, particularly pulmonary carcinomas.
The most common site of Feline aortic thromboembolization is
the caudal aortic trifurcation (the major
arterial supply to the hind limbs).
A thrombus affecting both hindlegs is a
saddle thrombus
Clinical signs of FATE. (7)
Acute pain
Acute onset paraparesis or paralysis
Absent or diminished femoral pulses
Cool temperature of the hindlegs
The affected footpads or nail beds may be pale or cyanotic in appearance
Vocalization and anxiety are common
Tachypnea or respiratory distress
(concurrent congestive HF)
The majority (up to 72%) of cats with aortic
thromboembolism presented with
a low rectal temperature.
It is considered to be a poor prognostic parameter when the temperature is below 37.2 C (less than 50% survival is conferred).
Differential measurements of blood what? between affected and unaffected
limbs may provide supportive evidence of FATE.
Differential measurements of blood glucose and serum lactate between affected and unaffected limbs may provide supportive evidence of FATE.
In peripheral venous blood samples from affected limbs, blood glucose is lower and lactate is higher than that in venous samples from nonaffected limbs or central veins.
What are the 5 P’s in FATE diagnosis?
Pain
Poikilothermy
Pulselessness
Pallor
Paresis or Paralysis
Prognosis in FATE cases.
Owners should be aware of the guarded short- and long-term prognosis.
In 2 large retrospective studies, approximately 55% to 66% of cats were euthanized or died during the initial
thromboembolic episode.
Expected course of recovery is days to weeks for a possible return of hind limb function.
About 10% to 15% of cases will have some degree of permanent musculoskeletal deficiency.
If a cat survives an episode of FATE, expected long-term survival varies between a few months to 1 year.
Medical management of FATE if not euthanasia (what drugs). (4)
Analgesics (methadone, fentanyl)
Anticoagulants (heparin)
Antithrombotics (aspirin, clopidogrel)
Managing the HF that is probably behind the thrombus formation.
Even with chronic anticoagulant therapy, re-embolization is a common terminal event.
Because of the guarded short-term and long-term prognosis with ATE, euthanasia is often considered an ethical and humane option.
Medical management of FATE, hospitalization and nursing care,
During hospitalization, nursing care of the affected legs is of the utmost importance (e-collar to avoid self-mutilation).
No venipuncture should be performed on the affected legs.
Cats may have difficulty posturing to urinate and may need to have their bladders expressed periodically (or catheter).
ECG monitoring is recommended because of possible hyperkalemic arrhythmias cause by ischemia-reperfusion injury.
Even with chronic anticoagulant therapy, re-embolization is a common terminal event.
Because of the guarded short-term and long-term prognosis with ATE, euthanasia is often considered an ethical and humane option.
Arrhythmias Etiology?
Cardiogenic or
Non-cardiogenic
Non-cardiogenic arrhythmias can be due to: (6)
- Pain
- Bleeding
- Hypoxia
- Hypercapnia
- Electrolyte disorders
- Hypothermia
absent P wave
very high T wave
wide QRS complex
4 most common types of arrhythmias
Bradyarrhythmias
Tachyarrhythmias
Junctional arrhythmia
Ventricular arrhythmia (like PVCs)
Bradyarrhythmias can be either
Sinus bradycardia or
Blocks like,
Atrioventricular blocks
mostly absent P waves
big and wide T wave
brady cause its a cat
The above 3 are typically to hyperkalemia.
Treat with glucose and insulin (and obv fluids).
absent P waves
weird T waves
a little brady
check potassium
Respiratory sinus arrhythmia
Its sinus if every P wave has a QRS complex and if every QRS complex has a P wave.
Bradycardia is how much in
large dogs
small dogs
cats
<50 large dogs
<70 small dogs
<100 cats
Etiology of Sinus bradycardias: (4)
Hypothermia
Administration of vagotonic drugs (opioids, alpha-2-agonists)
Stimulation of nervus vagus
Hyperkalemia
Sinus bradycardia
“regular”
“slow”
Sinus tachycardia
the gap between the P wave gradually becomes longer and longer until no QRS complex follows it
2nd degree AV-block
is mostly non-cardiogenic and connected to alfa-2s or opioids
no need to treat or if you really want to, you can give a little ketamine.
Extrasystoles can be dangerous when?
When they’re too frequent
sporadic wide and bizarre QRST complex
Premature ventricular contractions aka extra systoles: treat with Lidocaine
ventricular escape rhythm
nothing happening other than a ventricular contraction
do NOT use lidocaine in this one! you’ll stop the heart completely!
Extrasystoles
(in this case a GDV case which basically always comes with extrasystoles)
cardiac Indications for atropine use (2)
bradycardia, AV-blocks
Don’t use if the animal received dexmedetomidine.
cardiac Indications for lidocaine use (2)
tachycardia, extrasystoles
Don’t use in case of escape rhythm, you’ll stop the heart.
escape rhythm
give atropine to wake up the sinus node, NOT lidocaine, that would stop the heart
