|
Headlines:
|
 |
Back to Cardiovascular Diseases
Constrictive pericarditis
In physiology, constrictive pericarditis is due to a thickened, fibrotic
pericardium, which prevents the heart from expanding during diastole
(relaxation).
Causes
In many cases, constrictive pericarditis is a late sequelae of an
inflammatory condition of the pericardium. The inflammatory condition is
usually an infection that involves the pericardium, but it may be after
a heart attack or after heart surgery.
Almost half the cases of constrictive pericarditis in the developing
world are idiopathic in origin. In regions where tuberculosis is common,
it is the cause in a large portion of cases.
Causes of constrictive pericarditis include:
- Idiopathic
- Post Viral Pericarditis
- Tuberculosis
- Postsurgical
- Prior Mediastinal Radiation Therapy
- Chronic Renal Failure
- Connective Tissue Disorders
- Neoplastic Pericardial Infiltration
- Incomplete Drainage of Purulent pericarditis
- Fungal and Parasitic Infections
- Following Pericarditis Associated with Acute Myocardial Infarction
- Following Postmyocardial Infarction (Dressler) Syndrome
- In Association with Pulmonary Asbestosis
Pathophysiology
Constrictive pericarditis is due to a thickened, fibrotic pericardium
that forms a non-compliant shell around the heart. This shell prevents
the heart from expanding when blood enters it. This results in
significant respiratory variation in blood flow in the chambers of the
heart.
During inspiration, the negative pressure in the thoracic cavity will
cause increased blood flow into the right ventricle. This increased
volume in the right ventricle will cause the interventricular septum to
bulge towards the left ventricle, leading to decreased filling of the
left ventricle. Due to the Frank-Starling law, this will cause decreased
pressure generated by the left ventricle during systole.
During expiration, the amount of blood entering the right ventricle will
decrease, allowing the interventricular septum to bulge towards the
right ventricle, and increased filling of the left ventricle and
subsequent increased pressure generated by the left ventricle during
systole.
This is known as ventricular interdependance, since the amount of blood
flow into one ventricle is dependent on the amount of blood flow into
the other ventricle.
Symptoms and signs
Right sided heart failure symptoms predominate with progressive
shortness of breath, palpitations, fatigue, lower limb edema and ascites.
Clinical signs, on examination, include tachycardia, Kussmaul's sign as
well as jugular venous distension with a characteristic rapid y-descent.
Auscaltation may reveal a "pericardial knock". The abdomen may show
ascites and congestive hepatosplenomegaly.
Diagnosis
The diagnosis of constrictive pericarditis often difficult to make. In
particular, restrictive cardiomyopathy has many similar clinical
features to constrictive pericarditis, and differentiating them in a
particular individual is often a diagnostic dilemma.
1. Chest x-ray may show pericardial calcification.
2. EKG may show low QRS voltage.
3. Echocardiography may show wall thickening
4. CT or MRI are more sensitive than echocardiography
5. Cardiac catheterization to measure pressure changes in the left and
right ventricles.
Treatment
1. Pericardial stripping
The definitive treatment for constrictive pericarditis is pericardial
stripping, which is a surgical procedure where the entire pericardium is
peeled away from the heart. This may be effective in up to 50% of
patients. This procedure has significant risk
involved, since the thickened pericardium is often adherant to the
myocardium and coronary arteries. In patients who have undergone
coronary artery bypass surgery with pericardial sparing, there is danger
of tearing a bypass graft while removing the pericardium.
If any pericardium is not removed, it is possible for bands of
pericardium to cause localized constriction which may cause symptoms and
signs consistent with constriction.
2. Diuretics
Due to the significant risks involved with pericardial stripping, many
patients are treated medically, with judicious use of diuretics.
|
|
|
|
Are you a doctor or a nurse?
Do you want to join the Doctors Lounge online medical community?
Participate in editorial activities (publish, peer review, edit) and
give a helping hand to the largest online community of patients.
Click on the link below to see the requirements:
Doctors Lounge Membership
Application |
|
|
send
to a friend
printer
friendly version
