Pericardial disease in SA Flashcards
What is the pericardium?
Sac surrounding heart
- Inner –“visceral” layer –closely applied to surface of heart
- Outer –“parietal” layer
- No significant lumen
Look at this diagram of the heart?
What can be seen here?
Pericardium peeled back from heart
Discuss components of pericardium?
- Visceral layer = epicardium
- Parietal layer contiguous with BV adventitial layer
- Sterno-pericardial ligament
- Phrenico-pericardial ligament
- Prevents distension
What is the function of the pericardium?
- Not essential/can take it off don’t need it
- Fixes the heart anatomically
- Reduce friction
- Equalizes gravitational forces (pericardial fluid)
- Prevention of overdilation (pericardial restraint)
- Regulation between stroke volumes of both ventricles (ventricular coupling)
What can go wrong with the pericardium?
Pericardial sac can fill with fluid:
- Blood (most common presentation)
- Transduate
- Exudate
Mass can be present within the pericardial space, heart or the pericardium. Particularly tumours which grow from cardiac structures.
- Neoplasia
- Haemangiosarcoma, mesothelioma, chemodectoma, metastatic tumours–thyroid, osteosarcoma, mast cell tumoursetc
- Pericardial peritoneal diaphragmatic hernias –cats (often not symptomatic)
- Pericardial cysts –congential
The pericardium can become stiff –‘ constrictive’ usually a consequence of recurrent intracranial problems
Occasional traumatic case particularly animals which get bitten across base of tress (may see pus in pericardium)
Discuss pericardial disease?
Impaired ventricular filling as a consequence of increased intrapericardialpressures (not volume)
- fluid accumulation
- presence of a mass
- pericardial constriction
- Typically means the ventricle can’t fill
What is cardiac tamponade?
Cardiac tamponade
- Intrapericardial pressure equilibrates with the right atrial and right ventricular filling pressures
- Patient presents with ascites with chronic tamponade
- Then get clinical signs of RCHF
- Continuum that ranges from subclinical to fulminant heart failure
Chronic tamponade –> Congestive right heart failure (common) slow build up of pressure in pericardium which allows animal to compensate until animal collapses
Acute tamponade –> Low cardiac output and shock (forward failure) this is rare
What is constrictive pericardial disease?
Restriction of pericardial filling secondary to reduced pericardial compliance
What is the typical history of pericardial disease?
Typical History
Depends on the pathophysiology but two common types of presentation:
Acute cases –Sudden onset exercise intolerance, weakness, collapse, shock, rapid death if untreated
Chronic cases –more common - 2 week history of ascites, progressive exercise intolerance, lethargy, GIT signs, collapse
What are the clinical signs of pericardial disease?
Clinical signs (similar to RCHF)
- Jugular distension
- Positive hepatojugularreflex (squeeze liver and see the jugular bulge)
- Ascites (due to RCHF)
- Tachycardia
- Muffled heart sounds
- Weak femoral pulses (+/-pulsusparadoxus) Due to underfillingof left side
- Pale mucous membranes
- Tachypnoea/ dyspnoea
- GIT signs
- Typical presentation dull, ascitic dog.
What are the Pericardial disease Clinical presentation Triad of clinical signs?
1.Muffled heart sounds
2.Right sided heart failure
- Ascites
- Distended jugular veins
- Positive hepatojugular reflex
3.Forward failure
- Poor peripheral pulses
- Paradoxical pulse or pulsusparadoxus(pulse quality varies from beat to beat)
Discuss pulsus paradoxus?
- Not “paradoxus” and not pathognomonicof cardiac tamponade.
- Exaggeration of a normal process –During inspiration there is a decrease in intrathoracic pressure leading to preferential blood flow into the RA, RV and pulmonary veins (these are the most compliant blood vessels and cardiac chambers) this leads to reduced pre load to the left side of the heart.
- Due to ventricular interdependence
- A difference of more than 10mmHg in the systemic blood between inspiration (lower) and expiration (higher).
Discuss pericardial disease diagnosis?
Diagnostically should have high index of suspicion from clinical POV
- Triad of clinical signs: Jugular distension, poor pulses, right sided heart failure
- ECG
- Tachycardia –Small complexes (as pressure from fluid impacts on electrical conductivity)
- Electrical alternans
Discuss echocardiograhy and pericardial disease?
- Gold standard
- Effusion, mass, hernia, cyst
- Important to perform echo prior to drainage IF patient is stable enough
- ECHO ANY DOG WITH ASCITES (because pericardial effusion is a common cause of ascites)
Discuss this echocardiogram of pericardial disease?
Can see echo free gap surrounding the heart
Heart bounding around in fluid fill sac
Free wall or RV and atrium will be collapsing
Look out for a mass lesion in this * region right atrial haemangiosarcomas
How does pericardial disease appear on radiograph?
Radiography
- Globoid enlargement of the cardiac silhouette with a sharp outline differentiate that from generalised cardiac enlargement
- Herniation of intestinal organs or cystic lesion
Discuss pericardial disease treatment?
Treatment
“Drugs don’t work” these animals already have low CO due to poor filling so diuresis would make it worse
Emergency care
- Oxygen
- i/v fluid (shock rate) if their CO is very poor
Pericardiocentesis/ pericardial strip
What are the common causes of pericardial effusion?
Discuss acquired disorders pericardial disease?
Pericardial effusion in dogs
Cardiac neoplasia (most common)
- Haemangiosarcomas (most common)
- Heart base tumors(tumours of the cells in aortic arch chemdectomas)
- Mesotheliomas
- Lymphosarcoma
Idiopathic pericardial haemorrhagic
Left atrial rupture
Coagulopathies, uremic, infection (bacterial and fungal)
Cats in heart failure often have a degree of pericardial effusion secondary to the heart failure so don’t need to drain in cats as it will go away when you treat the heart failure –CHF, FIP
Discuss cardiac neoplasia and pericardial effusion?
Haemangiosarcomas (typically effect RA region)
- Older GSD and Golden Retrievers
- Right atrial/right auricular appendage
- Metastatic disease is common by time detected
- Acute tamponade(haemorrhage)
- can be a small volume if an acute bleed
- Can present with forward failure
- Surgical resection (difficult)
Discuss cardiac neoplasia?
Heart base tumours
- Chemodectomas
- Ectopic thyroid carcinoma
- Older brachycephalic
- Form around the aortic arch
- Rarely metastasise
- Present with Chronic tamponade
- Presented in RHF
- No surgical treatment
Discuss mesotheliomas?
Mesotheliomas
Arise from any serous membranes:
- Pericardium
- Pleura
- Peritoneum
- Tunica vaginalis of the testes
Severe pleural & pericardial effusion
Histopathological diagnosis
Chronic tamponade
Presented in RHF
Not particularly common more like to see pleural form
Pericardiectomy
