Pericardial disease Flashcards
Describe the anatomy/layers of the pericardium
Outer = fibrous pericardium
Inner = serous pericardium - contains two layers (parietal and visceral) and the pericardial fluid between them
The main innervation of the pericardium comes from which nerves?
Vagus nerve (X)
Laryngeal recurrent nerve (XI)
Sympathetic nerve fibres
Phrenic nerves course over lateral surfaces of pericardium
Blood supply to the pericardium comes from branches of which arteries?
Aorta
Internal thoracic artery
Musculophrenic arteries
What are the functions of the pericardium?
- Pericardial fluid – 0.25 mL/kg lubricant
- Prevents over dilation
- Systolic function (torsion)
- Co-ordinates LV-RV interaction
- Protects heart
- Maintains position
- IS NOT A VITAL ORGAN
List the different types of acquired pericardial disease
- Pericardial effusion: haemorrhagic, transudate, exudate
- Constrictive or effusive-constrictive pericarditis
List some causes of a haemorrhagic pericardial effusion
Idiopathic
Neoplasia
Coagulopathy
Rupture of the LA
Trauma
List some causes of a transudate pericardial effusion
CHF
Hypoproteinaemia
Neoplasia
Peritoneopericardial diaphragmatic hernia (PPDH)
Renal failure
List some causes of an exudate pericardial effusion
FIP
Infection
Foreign body
What are the two most common causes of pericardial effusions in dogs?
Idiopathic
Neoplasia
What are the most common causes of pericardial effusions in cats
CHF
FIP
Infectious, lymphoma, mesothelioma, rhabdomyosarcoma, coagulation, thickening
Pericardial effusions are most commonly seen in which dogs?
Older, large breed
Describe the features of idiopathic pericardial effusions in dogs
- Exclusion diagnosis: No mass on echo, cytology negative for neoplasia
- St. Bernard, GR, Labrador,..
- Can recur
- Pericardectomy if recurrence
Name three neoplastic causes of pericardial effusions
Haemangiosarcoma
Chemodectoma/aortic body tumours
Mesothelioma
Haemangiosarcomas are most commonly seen in which dogs?
Older
GSD, golden retriever
Where is a haemangiosarcoma mass found in the heart/body?
- Mass associated with right atrium or right auricular appendage
- Commonly spleen +/- liver affected (if atrial mass then 30% chance of splenic involvement, if splenic mass then 10% chance of atrial involvement)
How does a haemangiosarcoma cause a pericardial effusion?
Bleed from the tumour into the pericardial space – has a compressive effect on the heart
How does a dog with a haemangiosarcoma present?
Acutely – collapse, pallor, rapid HR, signs of shock
How is a haemangiosarcoma treated?
Palliative
- Pericardiocentesis
- Pericardectomy
- Balloon pericardiotomy
Chemotherapy +/- surgery
Grave prognosis
How does a dog with a pericardial effusion die to a haemangiosarcoma appear on an echo?
Fluid (black) can be seen surrounding the heart
A mass can be seen on the right side of the heart – blood filled (need a sample)
Chemodectoma/aortic body tumours are most commonly seen in which dogs?
Older dogs, especially brachycephalic breeds (Boxer, English Bulldog, Boston Terrier)
Describe the pathogenesis of a Chemodectoma
Benign, slow-growing and locally invasive (around Ao and PA) – low metastatic rate (lungs, liver)
Can grow to be very large
How is a Chemodectoma treated?
Palliative pericardiectomy
Why are mesotheliomas challenging tumours?
Challenging to diagnose – reactive mesothelial cells show cytological features of malignancy.
Difficult to treat
Poor prognosis
What are the impacts of a pericardia effusion on the heart?
Fluid surrounding the heart increases the pressure on the heart
Impeded ventricular filling during diastole
This is exerted on the chambers differently = Cardiac tamponade
What are the consequences of reduced right ventricular filling during diastole?
- Reduced stroke volume -> reduced LV filling -> reduced LV stroke volume -> RAAS, tachycardia, weak pulses, collapse
- Reduced venous return to the right side -> R-CHF -> ascites, pleural effusion
Describe cardiac tamponade
- Intrapericardial pressure > RA (RV) pressure (pressure on the outside is bigger than the pressure on the inside)
- RA collapses during diastole
- Cardiac filling is severely impaired
- Reduced right sided cardiac output
- RAAS activation
- Results in RIGHT sided CHF
Describe acute pericardial effusions
- Relatively small amounts of pericardial effusion can result in profound haemodynamic compromise.
- Typically this is haemorrhage, therefore signs of forward failure in combination with haemorrhagic shock present
- If the accumulation of effusion within the pericardial sac is gradual, it can stretch and tolerate larger volumes, signs of R-CHF predominate
List the 3 non-specific signs of pericardial effusions in dogs
Decreased appetite
Lethargy
Gastrointestinal upset – diarrhoea due to malabsorption
List the 4 specific signs of pericardial effusions in dogs
- Abdominal enlargement
- Decreased exercise tolerance
- Mild coughing
- Syncope/collapse
Describe the clinical signs of right sided CHF in chronic pericardial effusion dogs
- Organomegaly
- Abdominal effusion
- Positive hepatojugular reflux
- Jugular distension/pulsation
- Tachycardia
- Muffled heart sounds
- Weak femoral pulses
Describe the clinical signs of acute pericardial effusions in dogs
- Weak
- Collapsed
- Tachycardic
- Pale MM
- Arrhythmic potentially
- Signs of haemorrhagic shock
- Signs of forward failure
- Weak pulses
Describe the findings on a routine haematology and serum biochemistry in dogs with pericardial effusions
- Pre-renal azotaemia is commonly found
- Increased liver enzymes due to liver congestion.
- The presence of anaemia and abnormalities in the RBC on the smear analysis should raise the suspicion of haemangiosarcoma
- In cats, hypergammaglobulinemia can be seen in FIP and azotaemia in uremic pericarditis
Describe the findings on a routine haematology and serum biochemistry in dogs with pericardial effusions
- Pre-renal azotaemia is commonly found
- Increased liver enzymes due to liver congestion.
- The presence of anaemia and abnormalities in the RBC on the smear analysis should raise the suspicion of haemangiosarcoma
- In cats, hypergammaglobulinemia can be seen in FIP and azotaemia in uremic pericarditis
Describe the ECG in a patient with a pericardial effusion
- Sinus tachycardia
- Small complexes
- Electrical alternans: rhythmic variation of the QRS amplitude due to changes in position of the heart swinging in the fluid
How does a pericardial effusion present on radiography?
- Globoid and enlarged cardiac silhouette
- Very distinct cardiac silhouette (defined edges)– minimal movement during the cardiac cycle
- Dorsal deviation of the trachea
- Loss of divergent angle between trachea - spine
- Dilated caudal vena cava
- Abdominal effusion
- Small pulmonary vessels – despite cardiomegaly
- Clear lung fields
Describe the features of a pericardial effusion seen on echocardiography
- Presence of hypoechoic (black) fluid around the heart
- Hyperechoic (white) pericardial line surrounding the fluid
- Collapse of the right atrium (tamponade)
- Swinging of the heart within the fluid
- Pleural effusion might also be present
Describe the drugs you could use to treat a pericardial effusion
Do NOT use Furosemide in dogs with PE
Note: cats can have PE from CHF therefore furosemide is indicated
If tamponade is present PERICARDIOCENTESIS should be performed promptly and is the only treatment option
When would/wouldn’t you give fluids to a patient with a pericardial effusion?
In dogs to increase cardiac preload high-rate fluids can be given intravenously (during preparation of pericardiocentesis)
NOT in cats with a pericardial effusion secondary to CHF
Describe preparation of a patient for a pericardiocentesis
- DO NOT USE DIURETIC!
- Check patient PCV
- Mild sedation - Opiates ideal – butorphanol
- Left lateral recumbency: Right lateral access 5th-6th ICS
- Prepare area 3rd-8th ICS
- Echo to check incision point
- Local anaesthetic: skin & pleura
Describe how a pericardiocentesis is carried out
- Stab incision in skin approx. 1/3 of chest diameter up from sternum
- Advance catheter + syringe AIM FOR OPPOSITE SHOULDER (left shoulder) – maintain gentle syringe suction until dark-red fluid
- Advance catheter and withdraw needle
- Attach to extension/three way tap
- Take a sample of the fluid
- Check PCV of sample! IF PCV IS THE SAME AS PATIENT BLOOD PCV STOP!!!!! Consider haemorrhagic effusion.
Describe what is seen on cytology of pericardial fluid
- Reactive mesothelial cells
- RBC
- Phagocytic cells, bacteria
- Neoplastic cells
During pericardiocentesis what changes should be seen in the patient?
Improvement of cardiovascular parameters:
- Reduction in HR
- Improvement in pallor
- Improved pulses
- Taller QRS on ECG
What should you do if cardiovascular parameters are not improving during pericardiocentesis?
Check fluid PCV vs dog PCV as may be draining whole blood
- Iatrogenic cardiac puncture
- Bleeding cardiac neoplasia causing haemorrhagic effusion
In this case STOP draining otherwise EXSANGUINATION
Describe post-op care following pericardiocentesis
Natural diuresis (ascites will resolve) via natriuretic peptide release – dog WILL need to pee!
Hospitalise 12-24 hours
- Atrial fibrillation
- Ventricular arrhythmias
- Weigh twice per day
What is indicated if there is recurrence following Pericardiocentesis
If quick, or no marked improvement: neoplasia = poor prognosis
Describe the features of constrictive pericarditis
- Rare! And hard to diagnose
- Thickened, fibrotic pericardium
- Idiopathic
- OR secondary to: recurrent pericardial effusions, neoplasia, FB/infection
- R-CHF, cardiac tamponade with little fluid
- Guarded prognosis without pericardiectomy
- Difficult to diagnose: diagnosis of exclusion
- Specialist Cardiology needed
PPDH stands for?
Peritoneopericardial diaphragmatic hernia
What is a Peritoneopericardial diaphragmatic hernia?
Defect in ventral diaphragm and pericardium → abdominal organs within pericardial sac
Often incidental finding
Which breeds are predisposed to Peritoneopericardial diaphragmatic hernia?
Weimaraner’s and Persian cats
What other malformations are seen with PPDH?
Sternal abnormalities
Ventral abdominal hernias
Congenital heart disease (PS, VSD)
Describe the aetiology of infectious pericarditis
Foreign body, penetrating wound, infectious agent
FIP in cats
