Pulmonary HTN Flashcards
Pulmonary Hypertension
Definition
Pathophysiological observation defined as a mean pulmonary arterial pressure (PAP) > 25 mmHg.
- Includes a wide spectrum of clinical conditions
- Complicates most CV and respiratory diseases
- Results in ↑ morbidity and mortality
Pulmonary HTN
Symptoms
Non-specific ⇒ delayed diagnosis
- Progressive dyspnea
- Fatigue
- CP
- Presyncope / syncope
- Lower extremity edema
- Palpitations
- Hoarseness from Ortner syndrome
- Enlargement of RA causing compression recurrent laryngeal nerve
Pulmonary HTN
Signs
- ↑ Intensity of pulmonary second heart sound
- Tricuspid regurgitation murmur
- Pulmonary insufficiency murmur
- Right ventricular S3 and S4
- Parasternal heave or sub-xiphoid thrust
- JVD
- Hepatomegaly
- Ascites
- Peripheral edema
Pulmonary HTN
Classification
WHO Classification
Largely based on underlying etiology
- Pulmonary Arterial HTN
- PH due to left heart disease
- PH due to lung disease and/or hypoxia
- Chronic thromboembolic pulmonary hypertension (CTEPH) and other pulmonary artery obstructions
- PH with unclear and/or multifactorial mechanisms
WHO Group 1:
Pulmonary Arterial Hypertension
(PAH)
Classic PH that includes all causes of pre-capillary PH.
Due to vasoconstriction & proliferation of SM in pulmonary vasculature.
Etiologies include:
-
Idiopathic PAH (IPAH)
- Uncommon ⇒ ~ 2/mil people
- Female predominance
- Usually presents in 4th-5th decade of life
-
Familial PAH
- Type 2 Bone Morphogenetic Receptor Protein (BMPR-2) mutation
-
Drug and toxin induced
- Diet pills such as Fenfluramine (Phen-Phen), aminorex, dexfenfluramine
- CT diseases ⇒ most commonly scleroderma, SLE, RA
- HIV
- Portal HTN
- Congenital heart disease with systemic to pulmonary shunt
- Pulmonary capillary hemangiomastosis & pulmonary veno-occlusive disease
- Persistent pulmonary HTN of the newborn
WHO Group 2:
Pulmonary Venous Hypertension
(PVH)
“Post-capillary pulmonary HTN”
Largest subset of patients.
Tend to develop from left heart failure with ↑ LV-EDP which reflects back into the pulmonary venous vasculature.
Etiologies include:
- LV systolic dysfunction
- LV diastolic dysfunction
- Vavlular heart disease
- Congenital/acquired left heart inflow/outflow tract obstruction
- Congenital cardiomyopathies
- Congenital/acquired pulmonary vein stenosis
WHO Group 3:
Pulmonary HTN due to Hypoxemia and Lung Disease
“Cor Pulmonale”
2nd largest subset of PH
Conditions include:
- Chronic obstructive pulmonary disease
- Interstitial lung disease
- Sleep disordered breathing (OSA)
- Alveolar hypoventilation disorders
- Chronic exposure to high altitude
- Developmental lung diseases
WHO Group 4:
Pulmonary Arterial Obstruction
Causes include:
- CTEPH: Chronic thromboembolic pulmonary HTN
-
Non-thrombotic obstruction
- Angiosarcoma
- Other intravascular tumors
- Arteritis
- Parasites ⇒ Hydatidosis
- Congenital pulmonary artery stenosis
WHO Group 5:
Unclear or Multifactorial Pulmonary HTN
Causes include:
- Hematologic disorders
-
Chronic hemolytic anemias
- Sickle cell disease is the classic example
- Myeloproliferative disorders
-
Chronic hemolytic anemias
- Systemic disorders
- Lymphangioleiomyomatosis (LAM)
- Neurofibromatosis
- Sarcoidosis
- Metabolic disorders
- Glycogen storage diseases
- Chronic renal failure
Sickle Cell Anemia
Sickle cell is the classic example of a multifactorial cause of pulmonary HTN.
- ↓ NO pathway ⇒ group 1 type
- Can affect left heart ⇒ PVH ⇒ group 2 type
- Can develop infarctions and hypoxemia in the lungs ⇒ group 3 type
- Prone to thromboembolism ⇒ group 4 type
Pulmonary HTN
Diagnosis
-
ECHO ⇒ screening tool of choice
- Estimate PA systolic pressure
- RV dilatation or hypertrophy
- ↓ RV systolic function
- Right atrial enlargement
- BNP or NT pro BNP
- EKG
- CXR & CT Chest
- On CT, PA can be larger than aorta ⇒ hallmark of PH
- PFTs
- Cardio-Pulmonary Exercise Test (CPET)
- Cardiac MRI
-
Right heart catherization ⇒ confirmatory test
- Direct PA pressure measurement
- Pulmonary capillary wedge pressure (PCWP)
- Surrogate for LA pressure & LVEDP
- Helps to ID PVH
- Cardiac output
- Confirm diagnosis, assess severity, and differentiate etiologies
Pulmonary HTN
Treatment
-
General measures
- Treat the underlying condition
- Oxygen therapy ⇒ maintain spO2 ≥ 90%
- Minimize fluid overload ⇒ diuretics, salt restriction
- Immunizations ⇒ Pneumococcal, Influenza
- Avoid pregnancy ⇒ dual method contraception
- Pulmonary rehabilitation
- Digoxin ⇒ may be helpful if RV failure is present
- Inflight O2
- High risk for anesthesia ⇒ general vs epidural
-
Advanced therapies
-
Pulmonary vasodilator therapy
- Approved for groups 1 and 4
- Not approved for groups 2, 3, 5
-
Pulmonary vasodilator therapy
-
Other specific therapies
- Anticoagulation
- Pulmonary thromboendarterectomy
- Balloon pulmonary angioplasty
- Lung transplant
- Group 3 with advanced lung disease
- Group 1 PAH ⇒ progressive despite parenteral therapy
- Heart/lung transplant ⇒ uncorrectable congenital heart lesions
