PH - Types and classes

Q: 34 years old female with a known history of pulmonary Arterial Hypertension (PAH), group 1, is admitted to ICU with severe shortness of breath. Medical Record shows that she is classified as class 1V of functional classification. What is the difference between types and functional groups of pulmonary hypertension (PH)?

Answer: Patients with pulmonary hypertension are classified into two classifications.

1. They are classified among 5 types depending on the etiology.

2. They are classified among 4 classes depending on their functional capacity.

Types depending on etiology: Clinical classification of pulmonary hypertension per 6th World Symposium on Pulmonary Hypertension.

1 Pulmonary Arterial Hypertension (PAH)

2 PH due to left heart disease

3 PH due to lung disease and/or hypoxia

4 PH due to pulmonary artery obstructions

5 PH with unclear and/or multifactorial mechanisms 

These groups have further subclassifications depending on further underlying etiologies. Classification under types is extremely vital as managements are different for different groups.

Classes depending on functional capacity: World Health Organization's (WHO) functional classification for pulmonary hypertension divides patients into 4 classes.

I PH without resulting limitations of physical activity

II PH resulting in slight limitation of physical activity

III PH resulting in marked limitation of physical activity

IV PH resulting in an inability to carry on any physical activity without symptoms

#pulmonary

References:

1. European Respiratory Journal 53 (1) 1801913; DOI: 10.1183/13993003.01913-2018. Published 24 January 2019.

2. Rich S. Primary pulmonary hypertension: executive summary. Evian, France. World Health Organization, 1998.