Other than PAH, various pathologies including lung diseases, chronic hypoxia, and chronic thromboembolic diseases may also cause occurrence of precapillary
subgroup of PH.
The presence of luminal constrictions before irregularly dilated capillaries in the anterior ciliary processes suggests precapillary
The term "multicompartment involvement" refers to changes characterized by unexplained intrinsic airways disease (airflow obstruction, bronchiolitis, or bronchiectasis; Figure 6) evidenced by pulmonary function tests, HRCT, or histopathologic findings; unexplained pulmonary vasculopathy (precapillary
pulmonary hypertension: group 1, pulmonary arterial hypertension; group 10, pulmonary venoocclusive disease; and group 3, pulmonary hypertension due to chronic lung disease and/or hypoxia; Figure 7) demonstrated mainly by cardiac hemodynamic assessment; and unexplained pleural or pericardial effusion or thickening detected by HRCT or ultrasound imaging or pleuritis on lung biopsy (Figure 8).
(2004) shows that Allium sativum (garlic oil) also reduces precapillary
vessel resistance of the microvascular bed by increasing IL-6 secretion from the vascular endothelium during a hypoxic state.
Using clinically defined cut-offs for transpulmonary gradient (>12 mm Hg), pulmonary vascular resistance (3 Woods units), and diastolic pulmonary gradient (≥7 mm Hg), the frequency of precapillary
PH was 12.6, 8.8, and 3.5 percent, respectively.
Pulmonary Arterial Hypertension (PAH) (also termed precapillary
PH) is diagnosed when, in addition, PAWP is [less than or equal to]15 mmHg .
 revealed that, in hypertensive patients with HFpEF, the increased pulmonary artery pressure may not be attributable to the passive venous PH and there may be an additional precapillary
pulmonary artery hypertension mediated by functional or organic arteriolar disorders, which may need a novel therapeutic strategy for PH-HFpEF.
In such patients, other pulmonary blood vessels may not be able to compensate for the increase in pulmonary blood flow by an expansion of the pulmonary artery at the level of the precapillary
Amlodipine causes mainly precapillary
vasodilatation without proportional increase of postcapillary blood flow, which leads to peripheral edema.
Avouac et al., "High N-terminal pro-brain natriuretic peptide levels and low diffusing capacity for carbon monoxide as independent predictors of the occurrence of precapillary
pulmonary arterial hypertension in patients with systemic sclerosis," Arthritis & Rheumatism, vol.
Primary etiologies of PH include left congestive heart failure, (postcapillary PH), thromboembolism, chronic respiratory disease, heartworm or right to left shunting (precapillary
PH) (JOHNSON, 2016).
(2) The generally accepted pathophysiology of Purtscher-like retinopathy is vascular endothelial damage and arteriolar precapillary
occlusion by emboli of leucocytes, fibrin, fat, and complement aggregates.