Cardiology

Pericardial disease

Pericarditis

Introduction
  • Pericarditis is inflammation of the pericardium.
  • There are a variety of self limiting causes most of which are benign and settle with conservative measures
  • Important causes to consider are malignancy, drugs and TB

Causes include

  • Idiopathic/Post viral
  • MI or Post MI - Dressler's syndrome
  • Post pericardiotomy
  • Infectious - bacterial (TB), viral, fungal
  • Malignancy
  • Metabolic - uraemia, dialysis
  • Autoimmune - Dressler's, SLE
  • Familial Mediterranean Fever
  • Trauma/Radiation
  • Drugs

Clinical

  • Classically a pleuritic chest pain worse with inspiration and cough
  • Pain may be positional - improves sitting up and forwards
  • May be an audible friction rub with three components - atrial systole and ventricular systole and diastole.
  • There is a squeaky sound at left sternal border

Investigations

  • FBC: anaemia and raised WCC may be useful for infection/inflammation
  • ESR and CRP may be elevated and suggests an underlying inflammatory process
  • ECG : Widespread saddle shaped ST elevation and PR depression. May proceed to widespread T wave inversion and then normalisation. In IHD one would see reciprocal ST depression but this is not seen with acute pericarditis. ST depression only in cavity facing lead aVr
  • Troponin and CK may be slightly elevated suggesting an associated mild myocarditis
  • CXR often normal but may show a globular heart and echo required to differentiate cardiomegaly from effusion
  • Echo may show a pericardial effusion or even tamponade. Can also help check myocardial function
  • CT chest where extracardiac masses seen or when further imaging indicated

Management

  • Most cases are idiopathic or viral and self limiting and settle in 2-6 weeks.
  • Some may require treatment with NSAIDs as an analgesic and anti-inflammatory.
  • More severe cases may need Steroids.
  • Traditionally care must be taken with anticoagulants which may be required for other coexisting pathologies as there is a potential risk of bleeding into pericardial space

Constrictive Pericarditis

About

  • A cause of mainly right heart failure due to pericardial fibrosis

Causes

  • Idiopathic, Tuberculous, Radiation treatment,
  • Rheumatoid disease, Post surgical, Uraemia, Autoimmune,
  • Drug-induced:Procainamide, hydralazine, methysergide.

Differential Diagnosis

  • Restrictive cardiomyopathy
  • Cardiac tamponade

Aetiology

  • A useful concept is to consider a heart within a constricted pericardium much as a heart contained within a small rigid box which impairs expansion and so diastolic filling.
  • There is Impaired ventricular filling during diastole and all cardiac diastolic pressures become nearly equal.
  • On catheterisation of the heart pressures show a dip and plateau waveform "square root sign - early rapid filling and sudden stop.
  • The JVP rises with inspiration as insulated from normal intrathoracic pressures (Kussmaul's sign)

Clinical

  • The patient may be breathlessness with orthopnea and pleural effusions and symptoms and signs of right heart failure with ascites, lower limb oedema and hepatic congestion.
  • There may be poor cardiac output. Pleural effusion and hepatomegaly may be found. Can sometimes lead to liver investigations when the problem is cardiac.
  • Other findings include elevated JVP, X and Y descent visible. Pericardial knock (may be confused with S3) - sudden cessation of filling of ventricle within the rigid box of pericardium. Kussmaul's sign (elevation of jugular venous pressures with inspiration). No pulsus paradoxus

Investigations

  • CXR - Pleural effusions common, signs of TB, calcified pericardial outline.
  • ECG - low QRS voltage, generalised T wave inversion or flattening, and P mitrale.
  • Echocardiography and CT chest give detailed imaging
  • Cardiac MRI may show pericardial changes.
  • Cardiac catheterisation to look for coronary artery disease

Management

  • Complete pericardiectomy removes pericardium.
  • Do not use beta blockers or calcium antagonist that dampen the very necessary sinus tachycardia needed to maintain cardiac output (SV cannot be increased)

Pericardial effusion

Introduction
  • Filling of the pericardial space without compromised cardiac function. May be related to pericarditis

Aetiology

  • If pressure rises and impairs diastolic filling then this is compromised this is cardiac tamponade.

Causes

  • Causes include trauma - bleeding, Post surgical, Tuberculosis, HIV,
  • Malignancy, Connective tissue disease, Uraemia, Pericarditis, Myxoedema

Clinical

  • There may be a sinus tachycardia. Blood pressure is normal
  • Mild Raised JVP with absent Y descent. Muffled heart sounds and impalpable apex beat.

Investigations

  • ECG - Low voltage ECG , tachycardia and even electrical alternans
  • CXR - large globular heart suggests a pericardial effusion. (Needs 250 mls to be detectable on plain CXR).
  • Echocardiography - An effusion is seen and there is no diastolic collapse of Right Atrium.
  • Pericardial fluid for Gram stain, bacterial cultures, acid-fast bacilli stain and culture, PCR, Cytology, and carcinoembryonic antigen.

Management

  • Conservative "wait and see management may be reasonable if patient stable.
  • Pericardiocentesis to get fluid for examination.
  • Surgical treatment with pericardiectomy may be indicated

Pericardial tamponade

About

  • It just takes pressures round the heart to exceed diastolic filling pressures for cardiac output to fall and cause shock.
  • Slowly accumulating fluid is better accommodated for than sudden collections.

Aetiology

  • Collection of fluid or blood in the pericardial space can reduce cardiac filling.
  • Can be acute or chronic in presentation and build up of fluid. Pressure build can compress cardiac chambers and as soon as diastolic pressures are exceeded there is impaired diastolic filling and reduced cardiac output.

Causes

  • Trauma - bleeding
  • Post surgical
  • Tuberculosis
  • Malignancy - breast, lung, melanoma, Hodgkin disease
  • Aortic dissection
  • Post MI with wall rupture usually day 3-10
  • Connective tissue disease
  • Uraemia
  • Pericarditis

Clinical

  • Findings include Beck's triad - Distended Jugular veins, Arterial Hypotension, Diminished heart sounds. The patient may be shocked, periarrest or even in cardiac arrest.
  • In less acute cases there may be sinus Tachycardia and Hypotension, a raised JVP with absent Y descent, pulsus paradoxus - systolic BP falls greater than 10 mmHg during inspiration
  • Muffled heart sounds. Bronchial breath sounds may be heard in the left axilla or left base because of bronchial compression which leads to lower lung atelectasis. [Ewart's sign].
  • Kussmaul's sign is not typically seen (it is seen in Constrictive pericarditis)

Comparison with Constrictive pericarditis

  • With tamponade the heart is still affected by changes in thoracic pressures from respiration. Increased right sided filling with inspiration can compromise left sided function
  • Loss of the y descent can be difficult to discern at the bedside, especially in sick patients with tachycardia, it can easily be appreciated in recordings of systemic venous or right atrial pressure and provides a useful clue to the presence of significant tamponade"

Investigations

  • FBC - anaemia. U&E - renal failure is a cause. CRP/ESR - infection, autoimmune disease
  • TFT - hypothyroid
  • ECG - Low voltage ECG , tachycardia and even electrical alternans
  • CXR - pericardial effusion or may even be normal
  • Echocardiography - An effusion is seen and there is diastolic collapse of the lower pressure right atria and ventricle. The right ventricle may be slit like. Left atrial collapse may also be seen and is specific. Poor stroke volume.
  • Pericardial fluid for Gram stain, bacterial cultures, acid-fast bacilli stain and culture, PCR, Cytology, and carcinoembryonic antigen.

Management

  • Volume expanders may be used carefully and a conservative "wait and see" management may be reasonable if patient stable.
  • Patient should be moved to a centre where there is access to needle pericardiocentesis to treat or prevent tamponade. Surgical treatment with pericardiectomy may be indicated
  • Management then depends on underlying cause