Pericardial disease in small animals

Question 1

pericardial effusion

Answer 1

Common acquired cause of right sided heart failure in the dog
Main causes:
Idiopathic pericarditis
Neoplasia - Right atrial haemangiosarcoma, chemodectoma, mesothelioma
Also (but rarely if ever causing heart failure) - Trauma, Hypoproteinaemia, RCHF, foreign bodies, FIP

Question 2

pericardial effusion - pathophysiology

Answer 2

Increase in pressure within pericardial sac compromises diastolic function
Right side affected more due to thin walled right ventricle
Results in the development of right sided congestive heart failure
If acute in onset may see signs of syncope and forward failure

Question 3

pericardial effusion - history

Answer 3

Typically acute onset
Lethargy
RCHF - Ascites, dyspnoea due to pleural effusion
Possibly collapse
Possibly history of coughing

Question 4

pericardial effusion - clinical exam

Answer 4

Signs of RCHF - Jugular pulses/distension, Ascites, Hepatomegaly
Signs due to fluid around heart, Muffled heart sounds, Pulsus Paradoxus (Decreasing femoral pulse strength on inspiration)

Question 5

pericardial effusion - diagnostics

Answer 5

ECG - Small QRS complexes, Electrical alternans
Radiography - generalised enlargement of the cardiac silhouette, Clear outline to silhouette
Signs of RCHF - ascites, pleural effusion etc.

Question 6

pericardial effusion - ultrasound

Answer 6

presence of fluid
May indicate a cause for the effusion e.g. neoplasia
May show evidence of cardiac tamponade - collapse of right atrium and ventricle during diastole
May help indicate the best site to carry out pericardiocentesis

Question 7

pericardial effusion - treatment

Answer 7

removal of fluid from the pericardial sac
Drug therapy contraindicated - limited cardiac output + compromised diastolic function
Pericardiocentesis

Question 8

pericardiocentesis

Answer 8

drainage of fluid from pericardium
Level of costochondral junction RHS thorax ribspace 5 or 6 (ultrasound guidance if available)
ECG monitor throughout
Local anaesthetic in skin, intercostal muscles and down to pleura
Aseptic preparation of site
14 gauge catheter with closed drainage system
Collect for cytology, culture, pH and protein

Question 9

pericardial effusion - prognosis

Answer 9

Dependent on underlying disease
Idiopathic disease may be cured by drainage but tends to recur
Neoplastic disease generally has a poor prognosis, particularly with right atrial haemangiosarcoma
Chemodectomas may be slow growing
Foreign bodies or infectious causes may be manageable with surgery