Small animal pericardial dx

What are the layers of the pericardium?

• Outer —> fibrous

• Inner —> serous

  • Parietal layer

  • Visceral layer —> epicardium

Where is the pericardial sac on this echo?

effusion = black sack of fluid

How much pericardial fluid is normal?

0.25 mL/kg

What is the function of the pericardium?

• Prevents over dilation

• Systolic function (torsion)

• Coordinates LV-RV interaction

• Protects

• Maintains position

What are the different acquired pericardial dxs you can get?

• Pericardial effusion —> Haemorrhagic (trans-/exudate)

  • Idiopathic

  • Neoplasia

  • CHF (LA rupture, 1° change in cats) - if a dog is in R-CHF then do not forget pericardial effusion as ddx but more common cause in cats

  • Coagulopathy (rat bait)

  • Hypoproteinaemia (effusions in lots of places)

  • PPDH —> peritoneopericardeal diaphragmatic hernia

  • Infections —> FIP in cats, migrating FB in dogs

  • Renal failure (more common in cats)

• Constrictive/effusive-constrictive Pericarditis

  • clinical signs of effusion but no actual effusion —> difficult to diag

What are the congential pericardial diseases you can get?

• Peritoneal pericardial diaphragmatic hernia (can predispose to pericardial effusion)

• Pericardial cyst

• Pericardial defect/absence

What are the main causes of pericardial effusion and how does this differ between dogs and cats?

DOGS:

• Idiopathic

• Neoplasia

• Older, large breed dogs

CATS:

• CHF

• FIP

• Infectious, lymphoma, mesothelioma, rhabdomyosarcoma, coag, uraemia

How do you diagnose Idiopathic PE Dogs?

• Exclusion diagnosis

  • No mass on echo

  • Cytology -ve for neoplasia

    (warn the owner they might still have neo you just haven't found it —> occult neoplasia? mesothelioma?)

What are the causes of idiopathic PE in dogs?

Pericardial fibrosis or mixed inflam response

How do you treat Idiopathic PE Dogs?

What would you do if it recurs more than 3 times?

• Drain it

• Can recur

• Pericardectomy if recurrence more than 3 times

What are the neoplasias that can cause pericardial effusion?

• Haemangiosarcoma —> likes RA, spleen & liver

  • quick recurrence of PE

• Chemodectoma —> Aortic body tumour

  • brachy breeds

• Mesothelioma —> can cause multicavity effusions (hard to diagnose, this is on differentials if there is no mass found)

  • multicavitary effusions

What breeds are predisposed to Haemangiosarcoma?

GSD, golden retrievers, Setters

How do you treat PE due to Haemangiosarcoma in Dogs?

• Grave prognosis (malignant)

• Pericardiocentesis —> will be draining blood from the mass

• Pericardectomy

  • not recommended because can cause bleeding into thorax

• Balloon pericardiotomy

• Often palliative —> elective euthanasia

• Chemo ± surgery

What is being shown here?

• Black above the heart is the pericardial effusion

• There is a mass on the right atrium (haemangiosarcoma)

What is the treatment of a chemodectoma pe?

• Generally reasonable prognosis (slow growing and low metastatic rate)

• Drain PE

• Palliative pericardiectomy

What is the treatment for mesothelioma?

• Poor prog

• Palliative —> drain

• Chemotherapy

What are some other neoplastic causes of PE?

• Ectopic thyroid carcinoma

• Lymphoma

• Rhabdomyosarcoma

all rare

What is the impact of a pericardial effusion?

• Reduced R ventricular filling (lower pressure system → easier to squash → collapses during filling = tamponade → less vol returns into vena cavae)

• Reduced SV —> collapse, tachycardia, RAAS activation

• Venous congestion → R-CHF → organomegaly (bowel signs), ascities & poss pleural effusion

• During inspiration normally right heart fills better —> with PE you will get pulses paradoxus (pulse weaker on insp)

  (with these signs it will be a chronic effusion)

How would a patient present with an acute effusion and what would you suspect?

• Will present with shock —> haemorrhaging into pericardium & can’t pump blood properly

• Would suspect malignant process —> hemangiosarcoma

How are cats likely to present with PE?

CHF (don’t tend to tamponade)

What are the non-specific vs specific clinical signs of PE in dogs?

Nonspecific signs

• Decreased appetite

• Lethargy

• Gastrointestinal upset

Specific signs

• Abdominal enlargement

• Decreased exercise tolerance

• Mild coughing

• Syncope/collapse

What are the signs of Chronic PE in Dogs?

• R-CHF

  • Organomegaly

  • Abdominal effusion

  • Postive hepatojugular reflux

  • Jugular distension/pulsation

  • Tachycardia

• Femoral pulses

  • Weak

  • Pulsus paradoxus

• Muffled heart sounds

What are the signs of Acute PE in Dogs?

• Weak

• Collapsed

• Tachycardic

• Pale MM

• Arrhythmic potentially

• Signs of haemorrhagic shock

• Signs of forward failure

• Weak pulses

• Very poor prognosis

What do you need to do for diagnostics before pericardiocentesis?

• Patient PCV BEFORE pericardiocentesis (checking to see if its haemorrhage)

• Haem, biochem, CTnI BEFORE pericardiocentesis

• Coags

• BP

• ECG

• Rads (looks like football)

• Abdo U/S to check for fluid & look at spleen

• FLUID ANALYSIS

What will you see on ECG for a PE?

• Sinus tachycardia HR 180bpm

• Small QRS because heart smaller

• Electrical alternans —> because heart is swinging (QRS alternate in height)

• Will see improvements once it has been drained

  • reduced HR

  • QRS enlarge

  • loss of alternans

How does pericardial effusion appear on rads?

• crisp edges —> fluid

• venous distension

What is an important take home message about treatment of PE in dogs?

• Do NOT use Furosemide in dogs with active PE

  • cats can have PE from CHF so CAN use furosemide

  • dogs already struggling to fill heart —> heart needs to be filled to force vol in because being put under pressure from outside

• Do not want to reduce blood volume because the filling is reduced anyway

  (not the same for cats because they come in with CHF)

How do you carry out pericardiocentesis?

• DO NOT USE DIURETIC , check patient PCV

• Mild sedation —> Opiates ideal

• Left lateral recumbency (3rd-8th ICS)

  • right lateral access 5th-6th ICS, avoid coronary artery

• Echo to check incision point

• LA —> lidocaine

• 14G over the needle catheter, extension, 3 way tap

• ECG

• Check the PCV of the fluid pre and post procedure

  • if it is 35 then may be haemangiosarcoma and you don't want to keep draining this and euthanasia will have to be considered

Describe pericardial fluid analysis

• Measur amount

• EDTA tube for PCV

• Cytology —> reactive mesothelial cells, RBCs, phagocytic cells, bacteria, neoplastic cells

• Check for coag

• Culture

What should improve during pericardiocentesis?

• Reduction in HR

• Improvement in pallor

• Improved pulses

• Taller QTS on ECG

What could be the reason if the paramotors aren't improving after draining?

• Iatrogenic cardiac puncture —> get to correct place

• Bleeding cardiac neoplasia causing hemorrhagic effusion - STOP DRAINING otherwise will bleed out

What do you do after pericardiocentesis

• Natural diuresis i.e. ascites will resolve via natriuretic peptide release —> dog will need to pee

• Hospitalise for 12-24 hours to check for atrial fibrillation / ventricular arrhythmias

• Weigh twice per day to see if its lost fluid

• If recurrence suspect neoplasia (poor prog)

How will constrictive pericarditis present?

How is this treated and what is the prognosis?

• Rare

• R-CHF, cardiac tamponade with little fluid

• Pericardectomy, pericardial stripping

• Guarded prognosis without pericardiectomy

• Difficult to diagnose

• Specialist Cardiology needed

Which animals are predisposed to PPDH (peritoneopericardial diaphragmatic hernia)?

Weimaraners & Persian cats

What is PPDH?

• Defect of closure

  • Ventral diaphragm

  • Pericardium

• Abdominal organs within pericadial sac

often incidental finding

When would you get left atrial rupture?

• Advanced MDVD —> jet lesions

• Severe LA enlargement

• Atrial tears

If there is left atrial rupture what do you do?

If tamponade:

• Pericardiocentesis

• Blood transfusion

• Thoracotomy

• Guarded prognosis

What are the causes of infectious pericarditis?

• FB

• Penetrating wound

• Infectious agent e.g. FIP in cats

What would you do with infectious pericarditis?

• Aggressive antibiosis

• Fluid Culture

• Exploratory thoracotomy

• Pericardiectomy