Pulmonary hypertension in hereditary haemorrhagic telangiectasia

Table 1 Updated classification of pulmonary hypertension

Pulmonary arterial hypertension

Idiopathic PAH

Hereditable PAH

BMPR2

ALK1, endoglin (with or without hereditary haemorrhagic telangiectasia), SMAD9, CAV1, KCNK3

Unknown

Drug and toxin induced

Associated with:

Connective tissue diseases

HIV infection

Portal hypertension

Congenital heart diseases

Schistosomiasis

Pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis

Persistent pulmonary hypertension of the newborn

Pulmonary hypertension due to left heart disease

Left ventricular systolic dysfunction

Left ventricular diastolic dysfunction

Valvular disease

Congenital/acquired left heart inflow/outflow tract obstruction and congenital cardiomyopathies

Pulmonary hypertension due to lung diseases and/or hypoxia

Chronic obstructive pulmonary disease

Interstitial lung disease

Other pulmonary diseases with mixed restrictive and obstructive pattern

Sleep-disordered breathing

Alveolar hypoventilation disorders

Chronic exposure to high altitude

Developmental abnormalities

Chronic thromboembolic pulmonary hypertension

PH with unclear and/or multifactorial mechanisms

Haematological disorders: chronic haemolytic anaemia, myeloproliferative disorders, splenectomy

Systemic disorders: sarcoidosis, pulmonary histiocytosis, lymphangioleiomyomatosis

Metabolic disorders: glycogen storage disease, Gaucher disease, thyroid disorders

Others: tumoural obstruction, fibrosing mediastinitis, chronic renal failure, segmental PH

PH: Pulmonary hypertension; BMPR2: Bone morphogenetic protein receptor, type 2; CAV1: Caveolin-1; HIV: Human immunodeficiency virus. Adapted from Simonneau et al[46], with permission of the publisher.

Table 2 Haemodynamics in pulmonary hypertension associated with hereditary haemorrhagic telangiectasia

	High output PH	PAH
mPAP (mmHg)	+	++
PAWP (mmHg)	=/+	=
PVR (Wood units)	=	++
CO (L/min)	++	-

PH: Pulmonary hypertension; PAH: Pulmonary arterial hypertension; mPAP: Mean pulmonary artery pressure; PAWP: Pulmonary artery wedge pressure; PVR: Pulmonary vascular resistance; CO: Cardiac output. +: Increase; =: Normal; -: Decrease. Adapted from Faughnan et al[17], with permission of the publisher.