FIG 57.1 Pressure volume loop of the pericardium (Courtesy Dr Preetam Krishnamurthy, Cardiology Fellow, AIIMS, New Delhi.) The pericardium is afflicted in variety of diseases, both localized to the heart and as part of systemic illnesses Pericardial diseases cause distinctive hemodynamic changes and some of the classic physical findings in cardiology.2,3,5 Although clinical overlap is common, most of the cases can be categorized as having pericarditis, pericardial effusion with or without tamponade, and pericardial constriction Other structural abnormalities such as congenital absence of pericardium and pericardial cysts are rare (Table 57.1).3,4 This chapter provides an overview of common pericardial diseases in children Table 57.1 Common Causes of Pericardial Diseases in Children Pericarditis and Pericardial Effusion Infectious Viral Bacterial Mycobacterial HIV associated Fungal Noninfectious Inflammatory Connective tissue disorder Postpericardiotomy Autoinflammatory disorders Drug induced Neoplastic Primary Secondary Pericardial Constriction Tubercular pericarditis Bacterial pericarditis Radiation induced Postcardiac surgery Autoimmune disorder Idiopathic Congenital Pericardial cyst Absent pericardium Radiation induced Traumatic Iatrogenic Postcardiac intervention Postradiofrequency ablation Miscellaneous Chronic renal failure Hypothyroidism Pericarditis Pericarditis is the most common pericardial pathology encountered in clinical practice Based on the duration of illness, it can be classified as acute, recurrent, or chronic Acute pericarditis is usually self-limiting, lasting less than 2 weeks In some cases, the inflammation may continue up to 3 months beyond which it is labelled as chronic pericarditis.3,4,6 Concomitant involvement of the myocardium is referred to as “myopericarditis.”4 Acute Pericarditis Acute pericarditis is an acute inflammation of the pericardium The exact incidence of acute pericarditis in childhood is not known Most cases of acute pericarditis are idiopathic or due to viral infections Some cases labeled as idiopathic pericarditis may actually be due to viral infections Older children and adolescents present with acute onset of sharp, substernal chest pain radiating to the trapezius ridge.3,5,7 The pain worsens with inspiration and on lying down and subsides with leaning forward The pain in young children is variable though postural and respiratory variation is preserved.4 Pericardial friction rub is the most characteristic physical finding This high frequency, superficial scratching sound is similar to the sound made when walking on crunchy snow It results from the friction between inflamed pericardial layers and typically consists of three components corresponding to ventricular systole and early and late diastolic filling.2,7–9 It is best heard during inspiration, along the left sternal border with the patient leaning forward.8,9 The rub is often intermittent necessitating frequent auscultation It disappears with the accumulation of significant pericardial fluid.4 Nonspecific symptoms and obvious difficulties in eliciting clinical signs make the diagnosis challenging in infants and young children Diagnostic Evaluation Electrocardiography (ECG) is perhaps the most important diagnostic tool It is useful in the diagnosis at an early stage of the disease ECG shows sequential changes in ST and PR segments The ST-segment elevation is usually concave