Pericardial disease questions Flashcards
What is pulsus paradoxus
abnormally excessive fall in systolic blood pressure on inspiration > 10 mmHg
Normally on inspiration there is a slight fall in systolic blood pressure (< 5mmHg).
In cardiac tamponade, the increased venous return that occurs on inspiration causes filling of the right heart, thereby displacing the interventricular septum to the left (rigid box with tamponade) resulting in less filling possible in the left heart producing a reduced cardiac output and systemic blood pressure
Other causes of PP include constrictive pericarditis and status asthmaticus
What are clinical features of pericardial tamponade
Hemodynamic compromise with acute dyspnea and tachypnea
low pulse volume with pulsus paradoxus
Low and undetectable blood pressure
Raised jugular venous pulse (JVP) with a prominent x descent but no y descent
Muffled heart sounds
Oilguria or anuria
What are the typical findings on investigations with pericardial tamponade
1) ECG–low voltage QRS complexes, electric alternans (due to the heart moving within a fluid-filled sac)
2) CXR–symmetrical globular enlargement of the heart
3) Echocardiography
a) large pericardial collection
b) heart swinging freely within the pericardial sac
c) early diastolic collapse of the right ventricle
d) late diastolic collapse of the right atrium
e) marked respiratory tricuspid valve (>40%) and and mitral valve (>25%) inflow variation
What are the causes of constrictive pericarditis
Idiopathic, which is the major cause in the developed world
Infection—tuberculosis, viral (coxsackie), fungal (hisotplasma)
Mediastinal radiotherapy, which is dose-dependent (lymphoma)
Post Cardiac surgery
tumor, drugs (procainamide),
Sarcoidosis, amyloidosis,
carcinoid syndrome,
myocardial infarction,
uremia,
trauma
Clinical features of constrictive pericarditis
symptoms of left and right heart failure (anorexia, ascites, peripheral edma, fatigue, weakness Raised jugular venous pressure Ascites Peripheral edema Heptosplenomegaly displaced apex beat muffled heart sounds Narrowed pulse pressure Kussmaul's sign palsus paradoxus
what are features of cxr and echo of constrictive pericarditis
CXR- pericardial calcification and bilateral pleural effusions
Echocardiogram
impaired diastolic ventricularfilling, thickened echo bright pericardiaum,and dilated right atrium, inferior vena cava and hepatic veins
Doppler echocardiography
increased E:A ratio (rapid early filling and diastasis) and decreased inspiratory flow reduction in the hepatic veins.
Role of Cardiac Cath in constrictive cardiac cath
Cardiac Catheterisation (important for differentiation of constrictive pericarditis from restrictive cardiomyopathy)
a) equalisation (within 5mmHg) of raised left and right ventricular end-diastolic pressures at any phase of respiration
b) Equalisation of raised (>10mmHg) left and right atrial pressures with prominent x and y descents
c) square root sign—dip and plateau pattern of ventricular pressure with most of the diastolic filling occurring in early diastole, due to raised venous pressure, which then halts abruptly in mid-diastole.
d) left ventricular systolic function is usually normal but may be impaired in severe cases
e) pulmonary artery systolic pressure <50mmHg
f) right ventricular end-diastolic pressure ratio >1:3
How is constrictive pericarditis differentiated from restrictive cardiomyopathy(RCM)
Features for RCM and CP
1) increased EA ratio on the mitral valve inflow pattern
2) dip and plateau ventricular waveform
3) Prominent x and y descents on the atrial waveform
Patients with RCM more likely to have
1) Pulmonary hypertension (PASP > 50mmHg)
2) Reduced left ventricular function
3) endomocardial biopsy evidence of an infiltrative process
Patients with CP are more likely to have
1) Equalization of left and right ventricular end-diastolic pressure (<5mmH)
2) Kussmaul’s sign
3) Right ventricular end-diastolic to systolic ressure > 1:3
4) CT or echocardiographic evidence of a thickened pericardium
What are the principles of pericardiectomy
Aim to achieve complete removal of all thickened pericardium and epicardium from the left and right ventricle and diaphragm whilst preserving both phrenic nerves
CPB and cardioplegia arrest is usually required for posterior pericardium
Operative mortality is 10- 15% with a 5 year survival of 70% following pericardiectomy
What are the causes of restrictive cardiomyopathy
Scleroderma Amyloidosis Iron storage disease Loeffler's eosinophilic/endomyocaridal fibrosis Sarcoidosis
List 5 cardiac catheterization findings of a patient with constrictive pericarditis
Equalization of filling pressure Elevation of mean atrial pressure square root sign prominent Y decent on the right atrial pressure tracing elevated RV end diastolic pressure LV ejection fraction must be > 40%
List 5 criteria for distinguishing restrictive cardiomyopathy from constrictive pericarditis
- Early diastolic filling–decreased in restrictive–normal in CP
- Left and right ventricular end-diastolic pressures after fluid challenge–diverge in restrictive cardiomyopathy, parallel in CP
- endomyocardial biopsy–may show fibrosis in restrictive cardiomyopathy (normal in CP)
- systolic contraction velocity–may be slow in restrictive cardiomyopathy (normal in CP)
- CT Scan/MRT/Echocardiography—may demonstrate thickened pericardium with pericarditis
Name 5 important issues with surgery for constrictive pericarditis
- Median sternotomy with full cardiopulmonary bypass
- pericardium needs to be removed from phrenic to phrenic and posterior to left phrenic nerve (best done on CPB)
- Areas of grafts have to be protected
- likley to be bloody
- in general a high risk procedure
- Usually want to remove the pericardium from the left ventricle first, then the right ventricle and then both atria
strip it off the vena cavae
How is diagnosis of Cardiac Tamponade
Intrapericardial fluid causing hemodynamic compromise
Echo Hallmark: RA and RV compression
Equalization of RA, LA, LVEDP, RVEDP, wedge pressures
What is Becks triad
Distended neck veins
Hypotension
reduced heart sounds
