Pulmonary Hypertension Flashcards
Types of PH
1- aterial
2- venous
3- hypoxia/ lung disease
4- clot
5- hematology/metabolic
Pulmonary hypertension (PH) is classified into five groups based on its cause. Group 1 (Pulmonary Arterial Hypertension, PAH) involves high pressure in the pulmonary arteries due to narrowing or stiffness of these arteries, often resulting from conditions like idiopathic PAH or connective tissue diseases or hiv cocaine
Group 2 (Pulmonary Venous Hypertension) is caused by left-sided heart failure or mitral valve disease, leading to high pressure in the pulmonary veins. Group 3 (Pulmonary Hypertension due to Lung Diseases) includes conditions like chronic obstructive pulmonary disease (COPD), interstitial lung disease, or sleep apnea that cause chronic low oxygen levels, leading to pulmonary vasoconstriction and increased pressure in the pulmonary arteries. Group 4 (Chronic Thromboembolic Pulmonary Hypertension, CTEPH) is caused by long-term blood clots obstructing pulmonary vessels. Group 5 (Miscellaneous causes) includes conditions like hematologic disorders, metabolic diseases, or tumors that contribute to pulmonary hypertension. Each group has different causes and treatment approaches, with the focus being on managing the underlying condition to alleviate the high pulmonary pressure.
Group 3 type PH
Group 3 Pulmonary Hypertension is associated with hypoxia or lung diseases (HUMOTS can help you remember the main causes):
• H: Hypoxia (chronic low oxygen levels, like living at high altitudes).
• U: Underlying lung diseases (especially COPD or interstitial lung disease).
• M: Mixed restrictive and obstructive lung disease.
• O: Obesity-related conditions (like obesity hypoventilation syndrome).
• T: Thoracic deformities (like kyphoscoliosis).
• S: Sleep-disordered breathing (e.g., obstructive sleep apnea).
These conditions cause chronic low oxygen, which leads to pulmonary vasoconstriction and remodeling of the pulmonary arteries, resulting in increased pressure. The treatment focuses on managing the underlying lung disease and improving oxygenation, as treating hypoxia can help lower the pulmonary pressures.
Treatment of Group 1 PH : PAH
1- endothelin receptor antagonists have been studied and have moderate evidence of improving exercise capacity and decreasing symptom severity. Examples of endothelin receptor antagonists approved for use in certain countries include bosentan and ambrisentan.
2- phosphodiesterase inhibitors, such as sildenafil .
3- Prostacyclin analogues - treprostinil , iloprost
Treatment of Group 1 PH : PAH
1- endothelin receptor antagonists have been studied and have moderate evidence of improving exercise capacity and decreasing symptom severity. Examples of endothelin receptor antagonists approved for use in certain countries include bosentan and ambrisentan.
2- phosphodiesterase inhibitors, such as sildenafil .
3- Prostacyclin analogues - treprostinil , iloprost
Definition of PAH
Pulmonary arterial hypertension (PAH) may be defined as a resting mean pulmonary artery pressure of >= 20 mmHg
PAH is diagnosed in the absence of COPD although certain factors increase the risk, including HIV, cocaine and anorexigens (e.g. fenfluramine) and genes - inherited in an autosomal dominant
Clinical signs of PAH
1- progressive exertional dyspnoea is the classical presentation
2- other possible features include exertional syncope, exertional chest pain and peripheral oedema
3- cyanosis
4- right sided heart failure
clinical signs:
1- right ventricular heave: indicating right ventricular hypertrophy or dilatation
2- loud P2: early in the disease reflects increased pulmonary artery pressure and may be accompanied by a palpable P2 in severe cases. With advanced PAH there may be right ventricular failure leading to a soft S2
3- raised JVP with prominent ‘a’ waves: reflects increased resistance to right atrial emptying due to elevated right ventricular end-diastolic pressure
4- tricuspid regurgitation
Explained clinical signs
These signs of pulmonary arterial hypertension (PAH) reflect the physiological consequences of increased pressure in the pulmonary arteries and the strain it puts on the right side of the heart:
1. Right Ventricular Heave:
• This is a palpable forceful thrust of the right ventricle against the chest wall, typically felt at the lower sternum or right side of the chest.
• It occurs due to right ventricular hypertrophy (thickening) or dilatation (enlargement), which develops as the right ventricle works harder to overcome the elevated pressures in the pulmonary arteries.
2. Loud P2:
• The “P2” sound is the second heart sound (S2), caused by the closure of the pulmonary valve. In PAH, increased pulmonary artery pressure means the pulmonary valve closes more forcefully, producing a loud P2.
• In the early stages, this may simply result in a louder sound. In more severe PAH, you may even feel a palpable P2 (a vibration you can feel on the chest), reflecting the increased force with which the valve closes.
• In advanced PAH, if the right side of the heart becomes severely overloaded and fails, S2 may become softer due to reduced ability of the right ventricle to generate the force needed for proper pulmonary valve closure.
3. Raised JVP with Prominent ‘a’ Waves:
• The jugular venous pressure (JVP) is an indicator of the pressure in the right atrium. In PAH, the right ventricular end-diastolic pressure increases due to the heart’s difficulty in pumping blood against the high pulmonary artery pressure.
• This leads to increased resistance to right atrial emptying, and you may observe prominent ‘a’ waves in the JVP. The ‘a’ wave represents the atrial contraction, which is more pronounced when there’s resistance (due to right ventricular dysfunction).
4. Tricuspid Regurgitation:
• As the right ventricle dilates and hypertrophies in response to increased pulmonary pressures, the tricuspid valve (between the right atrium and right ventricle) may become distorted or unable to close properly.
• This results in tricuspid regurgitation, where blood leaks backward from the right ventricle into the right atrium during systole. The regurgitation further contributes to right atrial pressure and worsens the overall circulation problems associated with PAH.
All these signs reflect the right-sided heart failure that can develop in PAH, where the right ventricle is unable to efficiently pump blood through the pulmonary circulation due to the increased resistance in the pulmonary arteries.
Range of Pulmonary Hypertension
This patient has confirmed pulmonary hypertension as her mean resting pulmonary arterial pressure is > 25 mmHg
