The modern conception of Asperger syndrome came into existence in 1981, and went through a period of popularization. It became a standardized diagnosis in the 1990s, and was retired as a diagnosis in 2013. Many questions and controversies about the condition remain. Classification
The extent of the overlap between Asperger syndrome and high-functioning autism (HFA – autism unaccompanied by intellectual disability) is unclear. The ASD classification is to some extent an artifact of how autism was discovered, and may not reflect the true nature of the spectrum; methodological problems have beset Asperger syndrome as a valid diagnosis from the outset. In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published in May 2013, Asperger syndrome, as a separate diagnosis, was eliminated and folded into autism spectrum disorder. Like the diagnosis of Asperger syndrome, the change was controversial and thus Asperger syndrome was subsequently not removed from the WHOs ICD-10; however, it was removed from the ICD-11.The World Health Organization (WHO) previously defined Asperger syndrome (AS) as one of the autism spectrum disorders (ASD) or pervasive developmental disorders (PDD), which are a spectrum of psychological conditions that are characterized by abnormalities of social interaction and communication that pervade the individuals functioning, and by restricted and repetitive interests and behavior. Like other neurodevelopment disorders, ASD begins in infancy or childhood, has a steady course without remission or relapse, and has impairments that result from maturation-related changes in various systems of the brain.
The pain is usually relieved by sitting up or bending forward, and worsened by lying down (both recumbent and supine positions) or by inspiration (taking a breath in). The pain may resemble that of angina but differs in that pericarditis pain changes with body position, where heart attack pain is generally constant and pressure-like. Other symptoms of pericarditis may include dry cough, fever, fatigue, and anxiety.Due to its similarity to the pain of myocardial infarction (heart attack), pericarditis can be misdiagnosed as a heart attack. Acute myocardial infarction can also cause pericarditis, but the presenting symptoms often differ enough to warrant diagnosis. The following table organizes the clinical presentation of pericarditis differential to myocardial infarction:

Physical examinations
The classic sign of pericarditis is a friction rub heard with a stethoscope on the cardiovascular examination, usually on the lower left sternal border. Other physical signs include a person in distress, positional chest pain, diaphoresis (excessive sweating); possibility of heart failure in form of pericardial tamponade causing pulsus paradoxus, and the Becks triad of low blood pressure (due to decreased cardiac output), distant (muffled) heart sounds, and distension of the jugular vein (JVD). Complications
Pericarditis can progress to pericardial effusion and eventually cardiac tamponade.