Cardiology: Pericardial Diseases Flashcards
Describe the anatomy of the pericardium
Outer- fibrous pericardium:
* tough sac that continues with the adventia of the great vessels dorsally, with the sternopericardial ligament ventrally
Inner- serous pericardium:
* contains two laters with pericardial fluid between them- a thin layer of mesothelial cells is present
* Parietal layer- inner surface of fibrous pericardium
* Visceral layer: froms the epicardium
What innervates the pericardium?
- Vagus nerve
- Laryngeal recurrent nerve
- Sympathetic nerve fibres
- Phrenic nerves
What supplies blood to the pericardium?
- Aorta
- Internal thoracic artery
- Musculophrenic arteries
Cardiac, mediastinal and pre-sternal LNs recieve lymphatic draining
What are the functions of the pericardium?
- Contains fluid for lubrication
- Prevention of overdilation
- Systolic function
- Protection from infection
- Maintain heart in fixed position
- Co-ordinates function between LV and RV
How are pericardial diseases classified?
Congenital or Acquired
- What are the three congenital pericardial diseases?
- What are aquired diseases?
- Pericardioperitoneal diaphragmatic hernia, Intrapericardial cyst
pericardial defect - Pericardial effusion or constrictive pericarditis
What are the three types of pericardial effusions and what diseases can cause each?
Haemorrhagic:
* Idiopathic
* Neoplasia
* Coagulopathy
* Rupture of LA
* Trauma
Transudate:
* CHF
* Hypoproteinaemia
* Neoplasia
* PPDH
* Renal failure
Exudate:
* FIP
* Infection
* Foreign body
What is the most common pericardial disorder?
Pericardial effusion
Most common- idiopathic or neoplasia
- What types of dogs more commonly develop pericardial effusion?
- When is it frequently found in cats?
- What other casues are there?
- Older, large breed dogs
- Cats with CHF, FIP
- Lymphoma, rhabdomyosarcoma, bacterial pericarditis, coccidiomycocis, aspergillus, coagulation disorder, uraemia
- How is idiopathic PE diagnosed?
- What breeds are more affected?
- How can it be treated?
- Exclusion diagnosis
- Older, larger breeds- GR, Saint B, Lab, New FL
- May require pericardiectomy if recurrencte (3rd)
What neoplasias can cause pericardial effusions?
- Haemangiosarcoma
- Chemodectoma
- Mesothelioma
- Lymphoma
- Ectopic thyroid carcinoma
- Rhadomyosarcoma
- What breed is predisposed to haemangiosarcoma PE?
- Where is the mass usually associated?
- What should be checked?
- How can it be treated?
- Older dogs, especially GSD and golden retriever
- RA or right auricular appendage
- effusion PCV- actively bleeding
- Grave prognosis- pericardiocentesis/ectomy/ balloon pericardiotomy palliative, chemo (MST 6months)
- What breeds are predisposed to chemodectoma?
- What type of neoplasm is it?
- Older especially brachs dogs
- Benign- locally invasive, low metastasis
Palliation with pericardiectomy prolonged survival with good quality of life
- How can mesothelioma PE be diagnosed?
- How can it be treated?
- difficult- usually requires pericardial biopsy
- Difficult- intracavitary cisplatin, IV doxorubicin- poor prognosis
Explain the following signs of chronic effusion
* Cardiac tamponade
* Right congestive heat failure signs
* Left ventricle compression
* Pulsus paradoxus
- Effusion decreases stroke volume
- Activates RAAS and sympathetic
- Peripheral vasoconstriction, increased HR and fluid retention
- Compression on right side causes right atrial cardiac tamponade (collapse)
- Venous return compromised- systemic venous pressures- RCHF
- Greater filling of the right ventricle during inspiration- deviation of the IVS toward LV- compresses LV
- Pulsus paradoxus- no/reduced pulse during inspiration
What are the effects of acute effusion?
- Even small effusion causes large haemodynamic compromise
- Haemorrhage usually
- Combination of forward failure and haemorrhagic shock
What does constrictive pericarditis cause?
- Pericardium- thickened, fibrotic and non-distended
- Small effusion causes elevated pressures- cardiac tamponade
What are the clinical signs of pericardial effusions?
- Non-specific
- Organomegaly
- Abdominal enlargment
- Decreased excercise intolerance
- Syncope/collapse
- Respiratory distress
What is likely to be found on physical examination of pericardial effusion cases?
- R-CHF with muffled heart sounds, weak femoral pulses
- Ascites
- Jugular distension
- Positive hepatojugular reflex
- Hepatomegaly
- Muffled heart sounds
- Weak femoral pulses
- Tachycardia
What is commonly found on routine haematology?
- Pre-renal azotaemia
- Increased liver enzymes- liver congestion
- Anaemia
- Coagulation panel indicated if petechial haem found
- Cats- hyperhammaglobinaemia in FIP, azotaemia in uremic pericarditis
- Myocardial infiltrations- cardiac troponin I
What may routine blood pressure and an ECG show with a pericardial effusion?
BP
* Can be hypotensive to severe forward failure, haemorrhagic shock
* Can be normal
ECG
* Sinus tachycardia
* Small complexes
* Electrical alternans: rhythmic variation of the QRS amplitude due to changes in the position of the heart swinging in the fluid
How does pericardial effusion present on radiography?
- Globoid and enlarged cardiac silhouette
- Very destinct silhouette- minimal moving
- Dorsal deviation of the trachea
- Loss of divergent angle between trachea and spine
- Dilated caudal vena cava
- Abdominal effusion
- Small pulmonary vessels- despite cardiomegaly
- Clear lung fluids
Needs to be differentiated from cardiomegaly
What are the features of echocardiography on pericardial effusion?
Why is the abdomen also ultrasounded?
- Presence of hyperechoic fluid around the heart
- Hyperechoic pericardial line surrounding the fluid
- Collapse of the right atrium
- Swining of the heart within th efluid
- Pleural effusion may also be present
Abdominal ultrasound:
Assess for primary or metastatic neoplasia
Assess for any other concurrent disease
What can pericardial fluid show?
Usually serosangineous- port looking
* Always send for cytology ± culture
* Common to find reactive meothelial cells- difficult to differentiate between reactive and neoplastic
* Neoplasias might not shed cells
Why should diurectice not be used in managment of pericardial effusion in dogs?
Further decrease the cardiac preload and worsen tamponade
- What needs to be performed if tamponade?
- How can cardiac preload be increased ?
- Pericardiocentesis
- High-rate fluids IV
Describe the process of pericardiocentesis
- Check PCV
- Mild sedation- opioid or low dose ACP
- Left lateral or sternal recumbancy
- ECG monitoring- ventricular arrythmia if too close to the heart
- Prepare 3-8th IC space
- Check with ultrasound where to go
- Local anaesthetic infiltration 5-6th intercostal space- lidocaine
- Stab incision in skin 1/3 of chest diameter up from sternum
- 14G neegle catheter or pericardiocentesis catheter and attached 10-20ml syringe
- Advance catheter and syringe- aim for opposite shoulder- maintain gentle syringe suction
- Advance catheter with draw needle/three way tap
- Take sample of fluid
- Check PCV
- Meaure fluid
- Monitor for arrythmias
- Diuresis should follow
What complications can follow pericardiocentesis?
- Arrhythmias- usually self limiting
Atrial fibrillation
Ventricular arrhythmias - Pulmonary oedema due to rapid increase in left heart filling
- Coronary lacterations
- Intracardiac puncture
- Pneumothorax- rare
If improvement not as marked and quick recurrence- neoplasia likely
When is a pericardectomy recomended?
- If 3 or more pericardiocenteses
- Constrictive pericarditis might develop
What can cause constrictive pericarditis?
- Idiopathic
- Recurrent PE
- Neoplasia
- Foreign body
- Infectious pericarditis
- What clinical signs can occur with constrictive pericarditis?
- How is it treated?
- Signs of R-CHF and cardiac tamponade- despite small amounts of pericardial fluid
- Pericardectomy and surgical stripping of the fibrotic pericardium
Guarded prognosis
- What is peritonealpericardial diaphragmatic hernia?
- How is it often discovered?
- What breeds are predisposed?
- Why do clinical signs vary?
- How is it diagnosed?
- How is it treated?
- Defect in ventral diaphragm and pericardium
- Often incidental
- Weimaraners and persian cats
- Depends on herniated organs
- Apex beat apsent- radiography/echo
- Corrected surgically- not indicated in old asymptomatic
- What is a benign intrapericardial cyst?
- What is it associated with?
- How is it diagnosed?
- Encapsulted adipose tissue- organising cystic haematoma
- Associated with PPDH
- Echocardiography
Surgical removal- can be difficult
When uncommonly can left atrial ruptures/tears occur?
How is it treated?
- With advances mitral valve disease and severe LA enlargment
- Pericardiocentesis, blood transfucion, thoracotomy to remove clots and repair
Grave prognosis
What can cause infectious/inflammatory pericardititis?
- Foreign body
- Penetrating wound
- Infectious agent haematogenous spread
- FIP in cats
Treated with aggressive antibiosis
