"group 1: pulmonary arterial hypertension (disorders of the pulmonary arteries themselves)"
"1.1: idiopathic pulmonary arterial hypertension"
"1.2: heritable pulmonary hypertension"
"1.3: drug- and toxin-induced pulmonary hypertension"
"1.4: pulmonary hypertension associated with"
"group 2: pulmonary hypertension due to left-sided heart disease"
"2.1: systolic dysfunction"
"2.2: diastolic dysfunction"
"2.3: valvular disease"
"2.4: congenital/acquired left heart inflow/outflow tract obstruction and congenital cardiomyopathies"
"group 3: pulmonary hypertension due to lung diseases and/or hypoxia"
"group 4: pulmonary hypertension due to chronic pulmonary thromboembolism"
"group 5: pulmonary hypertension due to unclear multifactorial mechanisms"
Expected headings
"Classification"
"2013 5th World Symposium on Pulmonary Hypertension classification has been superseded a few times since its publication. The symposium was held in Nice, France; hence, it is sometimes called the Nice classification system."