TĂNG ÁP ĐỘNG MẠCH PHỔI, Đ H Y DƯỢC TP HCM

Bài giảng dành cho sinh viên y khoa, bác sĩ đa khoa, sau đại học. ĐH Y Dược TP Hồ Chí Minh. Definition Causes Pathogenesis Pathophysiology Clinical Manifestations Natural History Diagnosis Management

PULMONARY

HYPERTENSION

Vu Minh Phuc MD.

1. Definition

2. Causes

3. Pathogenesis

4. Pathophysiology

5. Clinical Manifestations

6. Natural History

7. Diagnosis

8. Management

1 DEFINITION

 The normal pulmonary arterial pressure (PAP)

of children and adults at sea level

 Systolic/diastolic PAP = 20/12 mm Hg

 Mean PAP (mPAP) = 15 mm Hg

 Pulmonary hypertension (PHTN)

 mPAP  25 mm Hg at rest

 mPAP  30 mm Hg during physical exercise

2 CAUSES

1. L-R shunt lesions (hyperkinetic PHTN)

ASD, VSD, PDA, ECD

2. Alveolar hypoxia

 Pulmonary parenchymal disease

 Extensive pneumonia

 Primary or secondary hypoplasia of lungs

 Bronchopulmonary dysplasia

 Interstitial lung disease (Hamman-Rich syndrome)

 Wilson-Mikity syndrome

 Upper and lower airway obstruction

 Inadequate ventilatory drive (central nervous system disease)

 Disorders of chest wall or respiratory muscles

 Kyphoscoliosis

 Weakening or paralysis of skeletal muscle

 High attitude (in certain hyperreactors)

2 CAUSES

3. Pulmonary venous hypertension

Mitral stenosis, cor triatriatum, TAPVR with obstruction,

chronic left heart failure, left-sided obstructive lesions (aortic stenosis, coarctation of the aorta)

4. Primary pulmonary vascular disease

pulmonary hypertension with obscure cause

hydrocephalus, sickle cell anemia, thrombophlebitis

connective tissue disease

3- PATHOGENESIS

Endothelial dysfunction in PHTN

3- PATHOGENESIS

Imbalance of vasoactive mediators acting on the pulmonary vessels

3- PATHOGENESIS

 P (pressure) = F (flow)  R (resistance)

F or R or both   PHTN

 PHTN  constriction of pulmonary arterioles  PVR 

 RV hypertrophy

 Normal RV cannot sustain sudden pressure loads over 40-50 mmHg  acute right-sided heart failure if PVR increases abruptly.

 Hypertrophied RV can tolerate mild PHTN (PAPs = 50 mmHg)

Superimposed lung disease, alveolar hypoxia, acidosis

 RV may fail

3- PATHOGENESIS

3.1 Hyperkinetic pulmonary hypertension

3- PATHOGENESIS

3.2 Alveolar hypoxia

3- PATHOGENESIS

3.3 Pulmonary venous hypertension

3- PATHOGENESIS

3.4.Primary pulmonary vascular disease

TREATMENT OF

PULMONARY

HYPERTENSION

SMOOTH CELL

Vasodilation

GTP cGMP inactive GMP

gc pde V

PG

B2

NOr

Vasoconstriction

Ca++

Milrinone

Sildenafil

Sixtasentan Bonsentan ET-1

Tolazoline

Calcium blockers

PGE 1

PGI 2

Dobuta

Isoprote

NO

Nitroprusside Nitroglycerin

Bonsentan

L-citrullin L-arginine

NO synthetase

Bonsentan

B2

ATP

 A 1 : alpha 1 receptors

 AMP: adenosine monophosphate

 cAMP: cyclic AMP

 ATP: adenosine triphosphate

 B 2 : beta 2 receptor

 ET A : ETA receptors on smooth cells

 ET B : ETB receptors on smooth cells

and endothelial cells

 ET-1: endothelial-1, an isopeptide

produced primarily in the vascular

endothelial cells

 GMP: guanosine monophosphate

 cGMP: cyclic GMP

 GTP: guanosine triphosphate

 NOr: nitric oxide receptors

 PDE III: phosphodiesterase III

 PDE V: phosphodiesterase V

 PG: prostaglandin receptors

 PGE 1 : prostaglandin E1

 PGI 2 : prostacyclin

PULMONARY VASODILATORS

diltiazem)

PULMONARY VASODILATOR

TREATMENT

- mPAP > ½ mSBP and/or

- Increasing PAP causes tachycardia and falling toe temperature

- NO

- Epoprostenol/ Ventavis

YES

- Sixtasentan

se