bubble_chart Overview

Acute pericarditis is broadly categorized into infectious and non-infectious types and is often part of a systemic disease. In the neonatal period, it primarily arises from sepsis; in infants and young children, it is frequently associated with pneumonia or sepsis. In children aged 4–5 years and older, it is mostly caused by wind-dampness heat, subcutaneous node disease, or purulent/viral infections. Occasionally, it may complicate Bi disease or other connective tissue disorders, and rarely occurs in uremia or local trauma. Since acute pericarditis is often a manifestation of systemic illness or the extension of adjacent tissue lesions, clinical presentations usually focus on the primary disease, sometimes even masking the signs of pericarditis, leading to a misdiagnosis of fistula disease.

bubble_chart Diagnosis

[Auxiliary Examination]

1. X-ray examination The cardiac shadow appears pear-shaped or flask-like, with the disappearance of the arches on both the left and right cardiac borders, widening of the caval veins, and significant differences in the cardiac shadow between supine and upright positions. In the supine position, the base of the heart widens, and under fluoroscopy, cardiac pulsation weakens or disappears. 2. Electrocardiogram (ECG) examination Due to pericardial effusion and myocardial injury beneath the epicardium, the former may result in low QRS voltage, while the latter causes ST-segment and T-wave changes. In the initial stages of the disease, ST-segment elevation with a downward convexity can be observed in all leads, lasting for several days before the ST segments return to baseline. The T waves become generally flat and then invert, which may persist for weeks or longer. 3. Echocardiography Even a small amount of effusion can produce an echo-free space between the left ventricular posterior wall and the pericardium. With increasing effusion, an echo-free space also appears between the right ventricular anterior wall and the chest wall. It can estimate the volume of effusion and assist in locating the site for pericardiocentesis.

Symptoms and signs

1. Precordial stabbing pain or pressure sensation May worsen with deep inspiration and supine position, with significant variability in the nature and intensity of the pain.
2. Dyspnea In most children, so-called dyspnea is often shallow, rapid breathing adopted to alleviate pain. True dyspnea only occurs with large effusions compressing lung tissue.
3. Pericardial friction rub Most pronounced at the lower left sternal border, characterized by a rough, leather-rubbing sound near the ear, synchronous with heart sounds and unrelated to respiratory rhythm. The friction rub is transient and often appears in the early stages of the disease, usually disappearing as pericardial effusion increases.
4. Jugular vein distension and pulsus paradoxus With significant pericardial effusion, especially when it develops rapidly, children often experience dyspnea, tachycardia, dysphoria, and tend to assume a sitting position. Depending on the degree of cardiac compression, the pulse may be normal, weak, or paradoxical, and the jugular veins may appear normal or distended.
5. Cardiac border enlargement Expands bilaterally and changes with body position. The lower border widens in the sitting position, while the base of the heart widens in the supine position. The apical impulse is indistinct, and heart sounds are distant.
6. Positive Ewart's sign Large effusions compressing the lungs and bronchi may produce dullness and bronchial breath sounds below the left scapula, indicating a positive Ewart's sign.

bubble_chart Treatment Measures

﹝Treatment﹞

The primary approach is to treat the underlying disease, supplemented by symptomatic treatment.

(1) **Non-specific pericarditis** In recent years, this has become one of the main causes of acute pericarditis, with some cases possibly being viral pericarditis. Corticosteroids have shown good efficacy in promoting the absorption of effusions. For patients with significant effusion, prednisone may be administered at 1–2 mg/kg per day, divided into three oral doses. After 2–3 weeks, the dose should be reduced by 5–10 mg per day each week, with a total treatment duration of 6–8 weeks.

(2) **Purulent pericarditis** Early blood cultures and pericardial fluid cultures can often identify the pathogen, allowing for the use of high-dose antibiotics tailored to the infection. Clinically, *Staphylococcus aureus* infections are the most common, and high-dose oxacillin (200 mg/kg per day, administered intravenously) may be used, optionally combined with gentamicin (3–6 mg/kg per day). Alternatively, cefazolin (50–100 mg/kg per day, administered intravenously every 8 hours) may be chosen. The treatment course should be relatively long (1–2 months). Pericardial puncture for pus drainage should be performed every 1–2 days. Currently, early open surgical drainage is often recommended to reduce the risk of subsequent pericardial constriction.

(3) **Tuberculous pericarditis** Standard anti-tuberculosis therapy should be adopted, including isoniazid, streptomycin, and sodium para-aminosalicylate. The latter may also be replaced with rifampin (refer to the tuberculosis chapter). For cases with significant effusion, prednisone (1–2 mg/kg per day) may be added for 6–8 weeks to accelerate fluid absorption and reduce adhesions.

(4) **Rheumatic pericarditis** Rheumatic pericardial effusion often resolves spontaneously. Symptoms are primarily caused by myocarditis and endocarditis, and treatment should follow the principles of anti-rheumatic fever therapy (see the rheumatic fever chapter for details).

(5) **Management of cardiac tamponade** When pericardial effusion accumulates rapidly or excessively, tamponade may occur. The child presents with an acutely ill appearance, dyspnea, tachycardia, cyanosis, hypotension, narrowed pulse pressure, jugular vein distension, enlarged cardiac borders, absent cardiac impulse, distant heart sounds, and pulsus paradoxus. Emergency pericardiocentesis should be performed to drain fluid and relieve pressure.