S1W10 Pericarditis AM

What is the pericardium and what are its functions?

  • The pericardium is a thin sac surrounding the heart.

  • It consists of three layers and has several roles as defined by the European Society of Cardiology (ESC) in 2015:

  • Fixes the heart to the mediastinum

  • Provides protection against infection

  • Lubricates the heart’s movement

What are the layers of the pericardium?

The pericardium has two main layers:

  • Fibrous Pericardium: This is the outer fibrous sac covering the heart, attached to the sternum via sterno-pericardial ligaments.

  • Serous Pericardium: This comprises two layers and contains the pericardial cavity:

    • Parietal Pericardium: Continues with the fibrous pericardium and adds insulation.

    • Visceral Pericardium: The inner layer forming the epicardium, which protects heart layers and produces pericardial fluid.

What is pericarditis and its types?

Pericarditis is defined as the inflammation of the pericardial layers and is the most common form of pericardial disease. It may present with pericardial effusion and can manifest in various types:

  • Acute

  • Incessant

  • Recurrent

  • Chronic Additionally, myocarditis (permyocarditis) may occur.

What causes pericarditis?

Several factors may lead to pericarditis, including:

  • Infection (viral and bacterial)

  • Post-cardiac injury, for instance, following surgical procedures

  • Autoimmune diseases

  • Cancer/radiotherapy

  • Idiopathic causes, where the source is unknown.

How do patients present with pericarditis?

Patients often exhibit the following symptoms:

  • Sharp chest pain present in 85-90% of cases, described as pleuritic, worsens with inspiration or lying flat, and is alleviated by sitting or leaning forward.

  • Anxious appearance and discomfort

  • Low-grade fever

  • Dyspnea (shortness of breath)

  • Sinus tachycardia.

How is pericarditis diagnosed?

Diagnosis is based on ESC guidelines (2015) which state that at least two of the following four criteria must be met for acute pericarditis:

  • Chest pain

  • Pericardial rub

  • ECG changes

  • New or worsening pericardial effusion Additional tools for diagnosis include inflammatory markers and imaging techniques like X-ray, echocardiogram (ECHO), cardiac magnetic resonance (CMR), or CT scans.

What ECG changes are indicative of pericarditis?

ECG changes occur due to inflammation of the epicardium and adjacent myocardium, observed in about 60% of patients with acute pericarditis:

  • Widespread concave ST elevation

  • PR depression

  • Reciprocal ST depression and PR elevation in lead aVR (± V1)

  • Sinus tachycardia.

What are the stages of ECG changes in acute pericarditis?

The stages of ECG changes include:

  • Stage 1: PR-segment depression and ST-segment elevation

  • Stage 2: Normalization of initial findings

  • Stage 3: T-wave inversion

  • Stage 4: Normalization of ECG changes.

How does pericarditis differ from early repolarization?

Key differences include:

  • Pericarditis demonstrates widespread ST-segment changes with PR depression.

  • The ST/T wave amplitude ratio in lead V6 can indicate the condition:

    • 0.25 or greater suggests pericarditis

    • Less than 0.25 indicates Benign Early Repolarization (BER).

How does pericarditis compare to myocardial infarction (MI)?

MI typically presents as crushing chest pain which may radiate. While symptoms can be similar to pericarditis, there are ECG differences:

  • Only STEMI shows convex ST elevation.

  • Reciprocal ST depression is specific to STEMI.

  • Significant ST elevation in lead III compared to II may suggest STEMI.

What echocardiographic features are relevant in pericarditis?

Echocardiograms are useful for assessing complications of pericarditis, such as:

  • Constriction

  • Pericardial effusions

  • Cardiac tamponade

  • Myocardial impairment.

How is pericarditis treated?

Treatment usually involves:

  • Addressing the underlying cause, often with NSAIDs.

  • Pain relief methods.

  • Corticosteroids for recurrent cases.

  • Pericardiocentesis for significant effusions.

  • Pericardiectomy for constrictive pericarditis.

What is the prognosis for pericarditis?

The in-hospital mortality rate for pericarditis is approximately 1.1%, increasing with age and severe co-infections. Post-acute episode outcomes may include:

  • Complete resolution

  • Development of thick calcific plaques or adhesions

  • Risk of developing constrictive pericarditis.

What is pericardial constriction and its consequences?

Pericardial constriction refers to the heart being constricted by the surrounding pericardium, leading to:

  • Impaired filling in diastole

  • Reduced cardiac output

  • Interdependent ventricles. There are different types including transient, effusive-constrictive, and chronic constriction, with common causes being bacterial pericarditis (tuberculosis), cardiac surgery, and radiotherapy.

What are the symptoms and diagnosis methods for pericardial constriction?

Symptoms may include:

  • Fatigue

  • Shortness of breath (SOB)

  • Abdominal swelling and discomfort

  • Elevated jugular venous pressure (JVP)

  • Hypotension

  • Distant heart sounds

  • Ascites

  • Pleural effusions.

Diagnosis methods include:

  • Echocardiography

  • Other imaging modalities (CT/MRI)

  • Cardiac catheterization.

What are the treatment options for pericardial constriction?

Treatment options can include:

  • Anti-inflammatory drugs

  • Medical therapy for congestion

  • Pericardial drainage

  • Surgical intervention (pericardiectomy).

What is pericardial effusion and what are its causes?

Pericardial effusion is defined as excess fluid in the pericardial space (normal volume is 15-50 mL). Causes may include:

  • Viral infections

  • Pericarditis

  • Heart attack

  • Bacterial infection

  • Cancer

  • Post-cardiac surgery.

Symptoms can range from asymptomatic to including SOB, fatigue, and palpitations. Diagnosis is typically via ECG, chest X-ray, and echocardiogram. Treatment focuses on managing the underlying cause (steroids, antibiotics) and may involve pericardial drainage (pericardiocentesis).

What are the indicators indicative of large pericardial effusion on ECG?

Indicators of large pericardial effusion may include:

  • Low voltage QRS complexes

  • Tachycardia

  • Electrical alternans.

How is low voltage defined in ECG terms and what are its causes?

Low voltage is defined as QRS complex amplitudes of < 5 mm in limb leads or < 10 mm in precordial leads. Causes may include:

  • The damping effect from effusion, emphysema, pneumothorax, or obesity

  • Infiltrative/connective tissue diseases (e.g. amiloidosis, scleroderma)

  • Loss of viable myocardium (e.g. myocardial infarction).

What is cardiac tamponade and its causes?

Cardiac tamponade is a clinical syndrome resulting from fluid accumulation in the pericardial space, leading to reduced ventricular filling and hemodynamic compromise. Untreated, it can result in cardiac arrest, with the severity not always correlating to effusion size. Causes may include:

  • Pericarditis

  • Tuberculosis

  • Surgical or invasive procedures

  • Trauma

  • Malignancy.

What are the signs and symptoms of cardiac tamponade?

Signs and symptoms include:

  • Beck’s Triad:

    • Elevated JVP

    • Hypotension

    • Distant heart sounds

  • Additional symptoms: SOB, tachycardia, and pulsus paradoxus.

How is echocardiography used in cardiac tamponade diagnosis?

Echocardiography is crucial for diagnosing cardiac tamponade and assessing the size and location of effusion to facilitate pericardiocentesis. Likely findings include:

  • Swinging heart

  • Exaggerated inflow

  • Septal bounce

  • Dilated inferior vena cava (IVC)

  • Wall collapse of chambers.

What is pericardiocentesis and why is it performed?

Pericardiocentesis is a procedure involving the insertion of a needle into the pericardial space to drain fluid. It is typically guided by echocardiography to increase accuracy, and analyzing the fluid content helps categorize potential causes.