Pericardial Disease

Question 1

What are 3 congenital disorders associated with the pericardium?

Answer 1

1. peritoneopericardial diaphragmatic hernia
2. pericardial cyst (rare, not reported in cats)
3. pericardial defects (rare, not reported in cats)

Question 2

What are the clinical signs of PPDH?

Answer 2

• about 50% = asymptomatic/ incidental
• c/s = respiratory or GI, such as dyspnea, respiratory distress, vomiting, anorexia

Question 3

What is PPDH?

Answer 3

Peritoneopercardial diaphragmatic hernia
- the pericardium fails to develop properly at the ventral edge, resulting in abdominal organs (ex. liver & gallbladder most commonly) herniating

Question 4

How is PPDH diagnosed>?

Answer 4

• On PE: muffled heart/lung sounds, thin, tachypnea, sternum malformation
• On CXR: gas opacity/ bowel loops in chest, cranial shift of gastric axis, increased size of heart silhouette and loss of distinction between heart and diaphragm
• Echo = confirmatory
  ddx = consolidation (hepatization) of the accessory lung lobe
• increased ALT in dogs, increased Ca2+ in cats

Question 5

How is PPDH treated?

Answer 5

surgery

Question 6

What are some ddx for pericardial defects?

Answer 6

can look like a right or left auricle bulge on CXR
ddx: neoplasia, AV disease leading to secondary dilation

Question 7

What are 2 acquired pericardial diseases?

Answer 7

1. pericardial effusion
2. restrictive pericarditis

Question 8

What’s the most common pericardial disease in dogs and cats?

Answer 8

pericardial effusion

Question 9

What’s cardiac tamponade?

Answer 9

impaired ventricular filling due to increased pericardial pressure, leading to a decreased stroke volume and cardiac output

Question 10

How does acute pericardial effusion cause cardiogenic shock?

Answer 10

• right side of the heart = more compliant = more affected by the pericardial effusion –> collapse of the R side of the heart
• decreased R diastolic filling –> decreased L ventricular filling –> decreased cardiac output –> cardiogenic shock

Question 11

What are the systemic signs related to chronic pericardial effusion?

Answer 11

right sided congestive heart failure predominates
- atrial natriuretic peptide is not activated in cardiac tamponade –> limit natriuresis, sustains volume overload and increased venous pressure

Question 12

What’s the pathophysiology of pulsus paradoxus?

Answer 12

• it’s an exaggerated change in left ventricular stroke volume
• upon inspiration, there is increased in intrathoracic pressure – the blood will flow to lower pressure area such as the cava, pulmonary vein, R atrium & ventricle
• this will decrease the L sided filling, thus a reduction in stroke volume
• with pericardial effusion, the outward expansion of the ventricle is limited –> ventricular interdependence
• the septum will bow towards the L during the R sided filling, further decreasing the L ventricular filling volume and thus stroke volume
• this plus the normal decrease in L ventricular stroke volume with inspiration = pulsus paradoxus

Question 13

What’s the most common cause of pericardial effusion in the dog?

Answer 13

neoplasia
followed by idiopathic
other uncommon causes = infectious, cardiovascular, metabolic and toxic (rare)

Question 14

What are the hallmark physical abnormalities associated with acute cardiac tamponade?

Answer 14

• pale MM
• tachypnea
• weak pulse
• muffle heart sound

Question 15

What are the typical signs of chronic cardiac tamponade?

Answer 15

• distended jugular vein/ pulsation
• positive hepatojugular reflux test
• hepatomegaly
• ascites

Question 16

Which imaging modality can provide definitive diagnosis for pericardial effusion?

Answer 16

Echo –> cannot ddx between idiopathic and mesothelioma
- CXR may not see the classic signs unless it’s chronic

Question 17

What are some possible neoplasia associated with the heart?

Answer 17

Right atrium/ auricle: hemangiosarcoma
Heart base: neuroendocrine (chemodectoma), thyroid carcinoma, mesothelioma
- lymphoma, sarcoma, etc also possible

Question 18

How is pericardial effusion treated?

Answer 18

Acute/ cardiogenic shock: pericardiocentesis, aggressive fluid therapy
Chronic cardiac tamponade: echo then do centesis
For idiopathic: subtotal pericardectomy
Hear base mass: partial pericardectomy
Infective pericarditis: subtotal pericardectomy, post-op chest tube, long term (min 6m) antibiotics

Question 19

What’s constrictive pericarditis?

Answer 19

it’s when either (or both) the parietal or the visceral pericardium develops fibrosis without sticking to each other.

Question 20

Can effusion be present with constrictive pericarditis?

Answer 20

Yes, sometimes there is a small volume of pericardial effusion - constrictive-effusive pericarditis

Question 21

What are some clinical signs associated with constrictive pericarditis?

Answer 21

• ascites = consistent feature
• jugular distension = common
• pulsus paradoxus = uncommon

Question 22

What are some causes of constrictive pericarditis?

Answer 22

• previous pericardial effusion
  - infectious pericardial effusion (ex. C immitis) or idiopathic
• intrapericardial foreign body
• osseous metaplasia
• idiopathic

Question 23

How is constrictive pericarditis diagnosed?

Answer 23

R heart catheterization –> looking at the filling pressure “dip & plateau”
- echo is not helpful
- will see hepatic vein distension

Question 24

How is constrictive pericarditis treated?

Answer 24

subtotal pericardiectomy and removal of constrictive pericardium
- parietal has better prognosis than visceral

Question 25

What’s the most common cause of feline pericardial effusion?

Answer 25

Pericardial effusion = most common pericardial disease in cats
- usually don’t result in cardiac tamponade
- most common cause = CHF, followed by neoplasia (rare), infective (rare)
- effusion = looks like pleural effusion, rarely hemorrhagic like dogs

Question 26

How is feline pericardial effusion treated?

Answer 26

Pericardiocentesis if echo evidence of cardiac tamponade is present