Vascular diseases Flashcards
Why would you measure BP?
- Anaesthetic monitoring
- Assessing severity of disease
- Identification of hypertension
- Assessing response to drugs
How would you measure BP?
- Direct - anaesthetised patient
- Indirect - doppler technique / oscillometric technique
What can be consequences of systemic hypertension?
- Ocular (retinal haemorrhage, hyphaema, retinal detachment, blindness)
- Central Nervous System (Seizures, Dull & Depressed, Bad-tempered, Overt Neuro. Deficits)
- Renal (Failure, Proteinuria etc)
- Cardiac (Pressure overload causes concentric left ventricular hypertrophy; heart murmurs may be due to LVOTO or MR)
What diseases are associated with secondary systemic hypertension?
- Chronic renal disease
- Hyperthyroidism (cats)
- Hyperadrenocorticism
- Diabetes mellitus
- Liver diseases
- Hypothyroidism
- Acromegaly
- Phaeochromocytoma
- Hyperaldosteronism
- Chronic anaemia (cats)
- Obesity
- CNS disease
How would you treat systemic hypertension?
- Amlodipidine - calcium channel antagonist with vasuclar effect
- Protect kidneys -
– reduce glomerular capillary pressure (GCP), so reducing protein loss and also further loss of nephrons
– ACE inhibitors (e.g. Benazepril)
– ACE-I have greater vasodilator effect on efferent than afferent arteriole, so reduce GCP.
– Telmisartan (Semintra) (Angiotensin II
receptor blocker)
What are factors of virchows triad?
- Circulatory stasis
- Endothelial injury
- Hypercoagulable state
- all may lead to a thrombus
Where do cats tend to get feline arterial thrombo-embolism?
- Left atrium
- Travel through aorta to external iliacs = saddle thrombus
- V painful + loss of hindlegs
What occurs in feline thromboembolism?
- Initial embolus
- Further platelet aggregation & adhesion
- Further activation of coagulation cascade
- Vasoconstriction of collateral vessels
= more emboli
How would you treat FATE?
- Priority = analgesia - Methadone
- Clopidogrel - anti-platelet drug
- ‘clot busting’ drugs - tissue Plasminogen activator
- Heparin - anticoagulant
- Poor prognosis - 50%
How do you prevent FATE in at-risk cats?
- Aspirin at low dose (every 3 days)
- Clopidogrel
- Treat cardiac disease as appropriate
- Low molecular weight heparin (LMWH) - anti-factor Xa
What is arterial thromboembolism associated with in dogs?
- Not heart disease
- Endocrinopathy - cushings, hypothyroidism
What are different types of pulmonary hypertension?
- Type 1 = pulmonary arterial hypertension ( Vascular changes w shunting defects + eisenmengers)
- Type 2 = Associated with left heart failure (High LA pressure)
- Type 3 = Associated with respiratory disease / hypoxia
- Type 4 = pulmonary thromboembolism
- Type 5 = parasitic = dirofilariasis
How would you treat pulmonary hypertension?
- Treat underlying disease
- Sildenafil (PDE V inhibitor)
- Pimobendan?
- Pulmonary thromboembolism prevention
How do you detect dirofilaria?
- Direct smear
- Knott’s test
- ELISA test
How can you prevent dirofilaria?
- Selamectin
- Milbemycin
- Moxidectin
What is Wolbachia? Where is it found?
- Obligate intracellular Gram -ve bacteria
- Found in uterus of female Dirofilaria immitis
Tx = doxycycline - treat prior to dirofilaria
What are clinical signs of angiostrongylosis?
- Often young dogs; signs variable
- Chronic, unresponsive coughing
- Dyspnoea, haemoptysis
- Ill-thrift; exercise intolerance; CHF.
- Subcutaneous & retinal haemorrhages
- Paresis; ocular changes
- Can have coagulopathy + neurological signs
How is angiostrongylosis diagnosed?
- Thoracic radiography
- Angio detect SNAP test
- Larvae in faeces
What is tx of angiostrongylosis?
- Fenbendazole
- Moxidectin
- Milbemycin
