MKSAP 6: Pulmonary Vascular Disease Flashcards
What is normal mean pulmonary artery pressure and what constitutes pulmonary HTN?
Normal: 15mmHg
PH: 25 mmHg
Define the different groups of pulm HTN
Group 1: Pulmonary arterial HTN
- idiopathic, heritable, drug and toxin induced, connective tissue diseases, HIV infection, portal HTN and congenital heart disease
Group 2: Pulm HTN due left sided heart disease
Group 3: Pulm HTN due to lung disease and/or hypoxia
Group 4: CTEPH
Group 5: Pulm HTN with unclear or multifactorial causes
- hematologic disorders, systemic disorders, metabolic disorders
The is the pathophysiologic basis for Group 2 Pulm HTN and Group 3 Pulm HTN?
What is the underlying issue for all causes of Pulm HTN?
Group 2: LV dysfunction and valvular disease lead to PH by volume and pressure overload
Group 3: Vasoconstriction brought on by alveolar hypoxia leading to pulmonary vascular remodeling
all causes: RV hypertrophy and dilatation develop over time in response to pulmonary artery pressure overload and mismatch of myocardial oxygen supply and demand resulting in ischemia, arrythmias and RV failure
How does Pulm HTN initially present and then how does it present as it progresses?
What are some cardiovascular exam findings?
Initially: exertional dyspnea and fatigue
Progression: exertional chest pain, syncope and peripheral edema
JVD, a prominent jugular venous a wave, parasternal heave, a widened split S2 with a prominent pulmonic component or R sided regurgitant murmurs as RV dilates
What is an initial helpful test and what is the confirmatory test?
TTE then RHC
**Remember that if you suspect lung disease as a cause, get tests to confirm that first before a RHC.
RHC should be considered after a normal TTE if the index of suspicion for Pulm HTN is high
What are the general treatment guidelines for pulm HTN groups 2-5 and group 1?
Groups 2-5 treat the underlying condition
Group 1 can have advanced therapy with vasodilators
What is the underlying pathophysiology in CTEPH?
The organized thrombus incorporates into the pulmonary artery endothelium thereby increasing pulmonary vascular resistance and pressures and eventually leading to right sided heart failure
What are the diagnostic criteria for CTEPH?
1) Documentation of PH (pulm HTN - pulm art pressure > 25 mmHg by RHC in the absence of L heart pressure overload) and
2) compatible imaging evidence of chronic thromboembolism
What are the imaging findings on CTPA compatible with CTEPH?
Vascular webs, intimal irregularities, and luminal narrowing
What is the more sensitive testing modality for CTEPH?
V/Q scan
What is the next diagnostic approach after imaging evidence of CTEPH?
Conventional pulmonary angiography to best characterize the extent and distribution of organized thrombus and to determine suitability for surgical intervention
What is the medical treatment for CTEPH?
Anticoagulant therapy that is generally lifelong.
What are the mechanical/surgical considerations for CTEPH?
IVC filter can be considered although its role in long term outcomes is not known.
Surgery in the form of pulmonary thromboendarterectomy is the only definitive therapy for CTEPH and evaluation even in mild disease is warranted.
Define Group 1 PAH
Defined by a proliferative vasculopathy originating in the pulmonary artery endothelium, driven by imbalances in substances that affect vascular tone and endothelial/smooth muscle cellular growth (NO, prostacyclin, and endothelin)
What are the 3 classifications of PAH
1) idiopathic
2) heritable
3) associated with other conditions
What gene is involved in heritable form of Pulm HTN?
TGF-beta signaling system with most in BMPR2 which normally contributes to the apoptotic process
What are the other conditions are encountered with and associated with PAH?
connective tissue diseases, portal HTN, HIV infection, illicit drug use, toxin exposure and congenital heart disease
What is the diagnostic testing indicated for diagnosis of PAH?
RHC
What are the goals of therapy for PAH?
Reduce vascular pressures
control symptoms
improve or maintain quality of life
What supportive therapies can be considered in PAH?
Diuretic therapy Supplemental oxygen Anticoagulation is recommended Digoxin improves RV function Exercise training
What is the indication for calcium channel blockers in PAH?
Only prescribed for patients demonstrating a vasodilator response on RHC
Sildenafil for PAH
phosphodiesterase 5 inhibitor - prolongs effect of intrinsic vasodilator cyclic GMP
initial therapy for mild to moderate disease
tadalafil for PAH
phosphodiesterase 5 inhibitor - prolongs effect of intrinsic vasodilator cyclic GMP
initial therapy for mild to moderate disease
Bosentan
endothelin - 1 receptor antagonist: blocks action of endogenous vasoconstrictor and smooth muscle mitogen endothelin
initial therapy for mild to moderate disease
ambrisentan
endothelin - 1 receptor antagonist: blocks action of endogenous vasoconstrictor and smooth muscle mitogen endothelin
initial therapy for mild to moderate disease
What are the side effects of endothelin 1 receptor antagonists and what screening is recommended?
class wide risk of liver injury and teratogenicity; LFT and pregnancy testing for reproductive age women are required
Iloprost
an inhaled prostanoid: supplements endogenous levels of prostacyclin, a vasodilator with anti-smooth muscle proliferative properties
epoprostenol
a parenteral prostacyclin analogue: supplements endogenous levels of prostacyclin, a vasodilator with anti-smooth muscle proliferative properties
treprostinil
a parenteral prostacyclin analogue: supplements endogenous levels of prostacyclin, a vasodilator with anti-smooth muscle proliferative properties
