Circulatory disorders (TV4101, Lecture 9 Notes)

Discuss feline arterial thromboembolism (FATE)

- Thrombi form in left heart > emboli lodge distally in aorta > occlude blood flow > release vasoactive substances > tissue ischaemia

- Present with ischaemic neuromyopathy (i.e. pallor, paresis, pain, pulselessness and poikilothermia)

- Low blood glucose and high blood lactate in affected limb

- Echocardiography with thrombus and underlying heart disease

- Assess CBC, biochemistry and UA (especially muscle enzymes and normal PT/APTT)

- Medical management with clopidogrel or LMW heparin (poor prognosis)

Discuss pulmonary thromboembolism

- Due to heartworm, IMHA, DIC, sepsis, neoplasia, pancreatitis or trauma

- Causes precapillary pulmonary hypertension with Va/Q mismatch, RV hypertrophy and CHF

- Present with dyspnoea unresponsive to oxygen supplementation

Discuss vasculitis

- Immune mediated inflammation of blood vessels (primary idiopathic or secondary to Ag)

- Causes fluid and protein leakage with local oedema and bleeding

- Present with petechiae, ecchymoses and haemorrhage

- Determine underlying disease

- Provide immunosuppression and supportive care

Discuss peripheral oedema

- Increased fluid in the interstitium with disrupted hydrostatic (increased) and plasma oncotic pressures (decreased) → increased vascular permeability and inadequate lymphatic drainage

- Present with diffuse pitting oedema and localised inflammatory response

- Assess CBC, biochemistry, UA and echocardiography

Discuss systemic arterial hypertension

- Sustained, repeatable elevation of SAP

- Target organs = eyes, brain, kidneys and heart

- Cause glomerular disease or hyperadrenocorticism (dogs), CKD or hyperthyroidism (cats), increased cardiac output and increased vascular resistance

- Present with ocular signs, PU/PD, neurological signs, epistaxis or mumur/gallop

- Assess BP, fundic exam, CBC, biochemistry, urinalysis, T4 or echocardiography

- Administer antihypertensives (ACE-inhibitor dogs or amlodipine cats +/- angiotensin receptor blocker and beta blockers), avoid vasoactive drugs and access salt, plus optimise body weight

Categories systemic arterial hypertension