T4 - Heart Failure Flashcards
1
Q
How many people in the US will be treated for HF by 2030?
A
8 million
2
Q
HF is defined as a complex syndrome that results from any structural or functional impairment of ______ ______ or blood _______.
A
ventricular filling
blood ejection
3
Q
HF leads to tissue-hypoperfusion, which causes what?
A
Fatigue, dyspnea, weakness, edema, and weight gain
4
Q
HF may be caused by structural abnormalities of what?
A
pericardium, myocardium, endocardium, valves, or great vessels
5
Q
What is the classification of HF with reduced EF (HFrEF)?
A
HF with EF ≤ 40%
6
Q
How is HF with preserved EF (HFpEF) diagnosed?
A
HF with EF ≥ 50%
7
Q
What is considered borderline HFpEF?
A
HF symptoms with an EF between 40-49%
8
Q
What is a common feature present in both HFpEF and HFpEF?
A
Diastolic dysfunction
9
Q
What are the distinguishing features between HFrEF and HFpEF?
A
LV dilation patterns and remodeling, along with different responses to medical treatment
10
Q
Why is EF considered a useful tool in HF diagnosis and management?
A
It is easily measured on echo and serves as the main marker for determining HF risk factors, treatment and outcomes
11
Q
What proportion of HF pts have a normal (>50%) EF?
A
Half of HF pts have a normal EF
12
Q
The proportion of pts with HFpEF is increasing d/t it’s relationship to what kind of conditions?
A
co-morbidities: HTN, DM, AFib, obesity, metabolic syndrome, COPD, RI anemia
13
Q
Pts with HFrEF are more likely to have modifiable risk factors as well as a higher incidence of what cardiovascular issues?
A
myocardial ischemia and infarction, previous coronary intervention, CABG, and PVD
14
Q
What percentage of HF cases are HFpEF?
A
52%
15
Q
What percentage of HF cases are HFrEF?
A
33%
16
Q
___% are borderline HFpEF (40-49%)
A
16%
17
Q
Women are more likely to be affected by _______, and men are more likely to be affected by ________.
A
Women = HFpEF
Men = HFrEF
18
Q
LV diastolic dysfunction (LVDD) is the primary determinant of ______, whereas contractile dysfunction is the primary determinant for ______.
A
LVDD = HFpEF
contractile dysfunction = HFrEF
19
Q
The LV’s ability to fill is determined by what 5 factors?
A
- Pulmonary venous blood flow
- LA function
- MV dynamics
- Pericardial restraint
- Active and passive elastic properties of the LV
20
Q
When is LV diastolic function considered normal?
A
When filling factors provide a LVEDV (preload) that provides sufficient CO for cellular metabolism without elevating pulm venous and LA pressures
21
Q
The majority of LVDD measurements depend on what 3 factors?
A
HR, loading conditions, and myocardial contractility
22
Q
In _____, higher LV filling pressures are required to achieve normal EDV.
A
HFpEF
23
Q
What does a steeper rise of the end-diastolic pressure-volume curve indicate?
A
Delayed LV relaxation and increased myocardial stiffness
24
Q
What does LV relaxation and increased myocardial stiffness lead to?
A
reduced LV compliance, LA hypertension, LA systolic/diastolic dysfunction, pulm venous congestion and exercise intolerance
25
Left: decreased contractility is indicated by a decrease in the slope of the end-systolic pressure-volume relation (HFrEF)
Right: decreased in LV compliance is indicated by an increase in the end-diastolic pressure-volume relation slope (HFpEF)
*These diagrams emphasize that heart failure may result from LV systolic or diastolic dysfunction independently
26
Common Causes of LV diastolic dysfunction (chart)
27
What causes delays in relaxation in the LV?
"active stiffening" caused by failure of the actin-myosin disassociation, which occurs due to inadequate perfusion or dysfunctional intracellular calcium homeostasis
28
LV relaxation is dependent on _______, which is typically elevated in hypertensive patients.
afterload
29
______ exacerbates the failure of LV relaxation.
Tachycardia
30
What is a characteristic feature of profound exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF)?
Profound exercise intolerance is observed despite having only a modestly depressed left ventricular systolic function.
31
What is the consequence of prolonged compression of the coronary arteries in heart failure?
Prolonged compression of the coronary arteries restricts diastolic coronary blood flow, contributing to subendocardial ischemia and a further reduction in exercise tolerance.
32
What are some of the most common symptoms of heart failure? (x10)
- Fatigue
- Tachypnea
- Dyspnea
- Paroxysmal nocturnal dyspnea
- Orthopnea
- S3 gallop
- JVD
- Peripheral edema
- Exercise intolerance
- Reduced tissue perfusion
33
Symptoms that are more common with HFpEF? (x3)
- Paroxysmal nocturnal dyspnea
- Pulmonary edema
- dependent edema
34
Symptom more common with HFrEF? (x1)
S3 gallop
35
When EF is reduced, what establishes the diagnosis of HFrEF?
the presence of HF symptoms
36
In contrast to HFrEF, the initial diagnosis of HFpEF is often ____ ________, especially when the pt has little/no symptoms at rest.
more difficult
37
What procedure defines elevated LV systolic and diastolic stiffness using pressure-volume analysis or provocative testing (e.g. exercise and rapid IV volume expansion)?
cardiac catheterization
38
Direct measurement of RV filling pressures offers further info on severity of _____.
HFpEF
39
Mean PCWP _____ mmHg at rest or ____mmHg during exercise provides strong evidence of HFpEF and is a predictor of ______.
>15mmHg
25mmHg
mortality
40
What findings may be detected on chest X-ray (CXR) in patients with heart failure?
- Pulmonary disease
- Cardiomegaly
- Pulmonary venous congestion
- Interstitial or alveolar pulmonary edema.
41
What is an early radiographic sign of LV failure and pulmonary venous hypertension?
distention of the pulmonary veins in upper lobes of the lungs
42
Perivascular edema appears as a ____ or a _____ haze with ill-defined margins.
hilar or perihilar
43
What radiographic findings reflect interlobular edema and may be present in HF?
Kerley lines
44
In a CXR, alveolar edema produces homogenous densities, typically in a ________ pattern.
butterfly
45
What two types of effusions might be present on an CXR in a pt with HF?
Pleural effusion
Pericardial effusion
46
Radiographic evidence of pulmonary edema may lag behind clinical evidence by how long?
Up to 12 hours.
47
Diagnosis of HFpEF includes what important diagnostic study?
Echocardiogram
48
The ACC/AHA diagnostic criteria depends on what 3 factors?
- HF symptoms
- EF >50%
- evidence of LVDD
This approach is useful for pts with clear symptomatology, but may be too simplistic for subclinical HFpEF
49
ESC guidelines rely entirely on _____ ___________; and are limited bc they do not incorporate provocative testing
resting echocardiogram
The ESC criteria is more specific and incorporates several echo indexes based on 2D measurements
50
EKG abnormalities are common in HF pts and are typically r/t underlying pathology such as? (x3)
- LV hypertrophy
- Previous MI
- arrhythmias and conduction abnormalities
51
EKG alone has a ___ predictive value for diagnosis or risk-prediction of HF
low
52
What are important biomarkers used in the evaluation of HF?
Brain natriuretic peptide (BNP) and N-terminal pro-BNP.
53
Natriuretic peptide concentrations are related to what?
LV end-diastolic wall stress
54
LV end-diastolic wall stress is higher in _______ due to what 2 things?
HFrEF
LV dilation and eccentric remodeling
55
HFpEF is associated w/ _______ hypertrophy, relatively ______ LV chamber size, and ______ LV end-diastolic wall stress, allowing for lower BNP or NT-proBNP levels.
concentric hypertrophy
normal LV chamber size
lower LV end-diastolic wall stress
56
_______ are systemically released d/t myocardial damage, and serve as a measure of risk prediction.
Troponins
57
What 2 labs represent the inflammatory component of HF?
C-reactive protein (CRP)
Grown differentiation factor-15 (GDF15)
58
Classification of HF:
The NYHA system focuses primarily on what?
the degree of physical limitation
59
Classification of HF:
The ACC/AHA focus on what?
the presence and severity of HF
pts are often classified using a combination of both scoring systems
60
Since progression of HF is linked to reduced 5-year survival, it is important to note that these stages are _____.
progressive
61
Survival of pts w/ _____ has improved during the past 3 decades, but the mortality in those with _____ remains unchanged.
HFrEF
HFpEF
62
Medication treatments are ______ for HFpEF, although benefit is seen in those with HFrEF.
ineffective
63
HFpEF treatment?
- mitigation of symptoms
- treat associated conditions
- exercise
- weight loss
64
HFrEF treatment?
- BBs
- ACE-inhibitors
65
Treatment algorithm for HFpEF (chart)
66
Loop diuretics are recommended for chronic HF treatment because they do what 3 things?
- reduce LV filling pressures
- decrease pulmonary venous congestion
- improve HF symptoms
67
What other class of diuretics may be useful in pts with poorly controlled HTN to prevent the onset of HFpEF?
Thiazide diuretics
68
What class of medication is strongly recommended for HFrEF, though benefit is not clearly established for HFpEF?
beta-blockers
Benefit not clearly established for HFpEF, although BB's are often prescribed for other indications (HTN, MI, HR control w/Afib)
69
What 2 classes of meds are mainstay treatment for HFrEF though no benefit shown for HFpEF?
ACE-inhibitors and ARBs
70
What lifestyle changes are encouraged in chronic HF treatment?
- Aerobic fitness reduces symptoms and improves QOL
- Weight loss significantly reduces major risk factors
- Salt-restricted Dietary Approaches to Stop Hypertension (DASH) diet
- Control of HTN and blood glucose
71
What is the goal of surgical treatment for chronic HF?
to prevent ventricular remodeling and retain natural geometry of the heart
72
Coronary revascularization surgical procedures?
coronary revascularization via CABG or PCI can reverse LV dysfunction following MI
Successful early revascularization may prevent permanent EF reductions
73
CABG has been shown to reduce 10-year mortality by __%.
7%
74
Treatment for HR with a ventricular conduction delay (prolonged QRS)
AKA "biventricular pacing"
cardiac resynchronization therapy (CRT)
75
CRT: placement of a dual-chamber cardiac pacemaker, an additional lead is introduced through the _____ _____ and advanced until it reaches the lateral wall of the ____.
coronary sinus
LV
76
CRT or biventricular pacing stimulates the heart to contract more _______ and ______ to improve CO.
synchronously and efficiently
77
CRT is recommended for pts with NYHA class III or IV with EF ____% and a QRS duration ___-___milliseconds.
EF <5%
QRS duration 120-150ms.
78
CRT outcomes? (x5)
1. fewer HF symptoms
2. better exercise tolerance
3. improved ventricular function
4. less hospitalizations
5. decreased mortality
79
CRT risks? (x3)
1. infection
2. misplacement
3. device failure
80
Allows remote observation of intracardiac pressure to guide treatment and prevent decompensation?
implantable hemodynamic monitoring
81
Used for prevention of sudden death in pts with advanced HF?
implantable cardioverting-defibrillators (ICDs)
82
What percentage of HF deaths are due to sudden cardiac dysrhythmias?
50%
83
In what stage of HF may patients benefit from MCS by a VAD?
pts in terminal stages of HF
- studies show increased survival and improved QOL in HF pts treated w/ VADs compared to medical therapy alone
- VADs can take over partial or total function of the damaged ventricle
84
LVAD used for: (x4)
1. temporary ventricular assistance while heart is recovering its function
2. pts awaiting cardiac transplant
3. pts are on inotropes or IABP with reversible medical conditions
4. Pts with advanced HF who aren't transplant candidates
85
____ heart failure is classified as long-standing HF disease.
chronic HF
86
____ heart failure: rapid onset, often presenting with life-threatening conditions.
acute HF
pts may require hospitalization, tx is aimed at decreasing volume and stabilizing hemodynamics
87
What does the term "acute heart failure" encompass?
applies to both patients who present with worsening preexisting heart failure (acute decompensated heart failure [ADHF]) and those who present for the first time with heart failure (de novo acute heart failure [de novo AHF]).
88
ADHF symptoms as a result of decompensation include: (x3)
fluid retention
weight gain
dyspnea
89
What characterizes de novo AHF?
sudden increasing in intracardiac filling pressures, or acute myocardial dysfunction, leading to decreased peripheral perfusion and pulm edema
90
What is the leading cause of de novo AHF?
cardiac ischemia d/t coronary occlusion
- management is focused on stabilizing hemodynamics, restoring myocardial perfusion, and improving myocardial contractility
91
Less common causes of de novo AHF?
- viral
- drug-induced (toxic)
- peripartum cardiomyopathies
92
Management of underlying cause of de novo HF may allow for complete restoration: true or false?
True
93
What are the components of the hemodynamic profile in acute heart failure?
low cardiac output, high ventricular filling pressures, and hypertension or hypotension.
94
What is the first-line treatment for acute heart failure (AHF)?
Diuretics are the first-line treatment for AHF, and they should be given immediately in patients with fluid overload to mitigate symptoms and decrease mortality.
95
What are some examples of diuretics commonly used in the treatment of acute heart failure?
Furosemide, bumetanide, and torsemide can be given as bolus or continuous infusions in the treatment of acute heart failure.
96
How does reducing intravascular volume impact pulmonary congestion in acute HF?
- decreased CVP and PCWP thereby reducing pulmonary congestion
97
Which vasodilator is effective in rapidly decreasing afterload, and which one is commonly used as an adjunct to diuretic therapy?
SNP is effective in rapidly decreasing afterload, whereas NTG is commonly used as an adjunct to diuretic therapy.
- routine use of vasodilators is not shown to improve outcomes
98
Vasopressin receptor antagonists such as _____ can reduce arterial constriction, hyponatremia and volume overload associated with AHF.
Tolvaptan
99
Classification of drugs that is mainstay treatment for pts with acute reduced contractility or cardiogenic shock
Positive inotropes
100
Several inotropes _____ cAMP, which increases intracellular _____ and excitation-contraction coupling.
increase
calcium
101
Catecholamines stimulate __-receptors on the myocardium to activate ____ ____ to increase cAMP.
β-receptors
adenylyl cyclase
*catecholamines = epi, norepi, dopamine, dobutamine
102
Class of drugs that indirectly increase cAMP by inhibiting its degradation.
PDE-inhibitors (milrinone)
103
What is exogenous BNP? Give an example.
Nesiritide, a recombinant BNP that binds to A- and B-type natriuretic receptors, inhibiting the RAAS and promoting arterial, venous, and coronary vasodilation, decreasing LVEDP and improving dyspnea
-However, Nesiritide has not shown advantage over traditional vasodilators such as NTG & SNP
104
When medical management fails and organ dysfunction occurs, what is indicated?
mechanical circ support (MCS)
105
What is the INTERMACS?
Interagency Registry of Mechanically Assisted Circulatory Support is a MCS decision-making tool developed by the Society of Thoracic Surgeons (STS) based on patient clinical profiles.
106
This MCS device functions by cyclic helium ballon inflation after Ao valve closure, followed by deflation during systole
IABP (intraaortic balloon pump)
107
IABP improve LV coronary perfusion by reducing _____.
LVEDP.
108
What two diagnostic tests are the primary modes for IABP placement evaluation?
TEE and x-ray
109
IABP degree of support varies based on what?
set volume
size of balloon
ratio of supported beats
- Full support would be 1:1 (one inflation for every heartbeat)
110
What IABP ratio is appropriate for a tachycardic patient?
1:2 (one inflation per every two beats)
111
IABP provides only modest improvements in CO by _____L/min (range) and render pts immobile, limiting its long term use.
0.5-1 L/min
112
This MCS device can be placed percutaneously to reduce LV strain and myocardial work in the setting of AHF.
impella
- Can be utilized for up to 14 days and serve as a transition to recovery or a bridge to cardiac procedure (CABG, PCI, VAD, transplant)
113
Structure and placement of the impella device?
rotary pump inserted thru femoral artery, advanced thru the Ao valve and situated in LV
114
How does the impella pump work?
draws blood continuously from the LV through the distal port and ejects it into the ascending aorta through its proximal port
115
This device consists of a small pump and controller, but generates heat, causing hemolysis and lower flows
Peripheral VAD
116
Central ECMO for cardiorespiratory support include cannulas placed in what cardiac structures?
RA and Aorta
- require invasive maneuvers or sternotomy/thoracotomy for placement
117
Benefits of central ECMO?
- complete ventricular decompression
- avoidance of limb impairment
- avoidance of SVC syndrome
118
Pts on ECMO likely have ______ lung perfusion as blood bypasses the lungs before returning to aorta
reduced
119
INH anesthetics may be significantly limited by functional ______ around the lungs.
shunting
120
What anesthetic plan should be considered for pts on ECMO?
TIVA
121
CRNA must recognize that the ECMO membrane is ______, causing many agents, including fentanyl, to become sequestered within the circuit
lipophilic
122
Benefits of BiVAD (biventricular assist device)
- two independent circuits to allow for weaning of either the left- or right-sided support
- separate circuit for each side or can be centrally cannulated individually
123
HF pts have an increased risk of developing these complications: (x6)
- renal failure
- sepsis
- pneumonia
- cardiac arrest
- longer periods of mechanical ventilation
- increased 30 day mortality
124
Surgery should be postponed in pts with these complications: x3
- pts experiencing decompensation
- a recent change in clinical status
- de novo AHF
125
______ are generally held on day of surgery. ____ ____ maintenance is essential, as studies show they reduce perioperative M&M.
Diuretics
Beta-blockers
126
____ and _____ should be interrogated prior to surgery.
ICDs and pacemakers
127
________ are a group of myocardial diseases associated with mechanical and/or electrical dysfunction that usually exhibit _____ ______ or _____.
Cardiomyopathies
ventricular hypertrophy
dilation
128
This type of cardiomyopathy is confined to the heart muscle
Primary cardiomyopathy
129
This type of cardiomyopathy includes pathophysiologic cardiac involvement in the context of multiorgan disorder.
Secondary cardiomyopathy
130
Key features of hypertrophic cardiomyopathy:
- Complex primary CM
- can affect all ages, prevalence of 2-5 per 1000 people
- most common genetic CV disease
131
How is HCM characterized?
LV hypertrophy in the absence of other disease capable of inducing ventricular hypertrophy
132
HCM usually presents with hypertrophy of the ______ septum and the __________ free wall.
interventricular
anterolateral
- histological features include hypertrophied myocardial cells and patchy scarring
133
Hypertrophic CM pathophysiology is related to: (x6)
- myocardial hypertrophy
- dynamic LVOT obstruction
- mitral regurgitation
- diastolic dysfunction
- myocardial ischemia
- dysrhythmias
134
Hypertrophied myocardium has a _______ relaxation time and _______ compliance.
prolonged relaxation time
decreased compliance
135
What is present in HCM pts whether or not they have CAD?
myocardial ischemia
136
Cause of sudden death in young adults with HCM?
dysrhythmias
- caused by disorganized cellular architecture, myocardial scarring, and an expanded interstitial matrix
137
In asymptomatic HCM pts, unexplained ____ may be the only sign. EKG abnormalities are seen in __-__% of pts (range).
LVH
75-90% (include high QRS voltage, ST-segment and T-wave alterations, abnormal Q waves, LA enlargement)
138
Diagnostic findings of HCM:
- echo may show myocardial wall thickness >15mm
- EF usually >80%, reflecting hypercontractility
- EF severely depressed in terminal states
- cardiac cath shows increased LVEDP
139
HCM medical treatment includes:
Beta blockers and CCBs
- Pts who develop HF despite BB & CCBs may show improvement with diuretics
140
This drug has negative inotropic effect, improves LVOT obstruction and HF symptoms in pts with HCM.
Disopyramide - considered as add-on therapy in pts who remain symptomatic
141
Type of dysrhythmia that often develops in HCM and is assoc w/ increased risk of thromboembolism, HF and sudden death
Afib
- Long-term anticoagulation is indicated for recurrent or chronic Afib
142
Most effective antidysrhythmic drug in patients with HCM
Amiodarone
(ICD placement is the primary tx for pts at risk of sudden cardiac death d/t dysrhythmias)
143
When is surgery typically considered in a patient with HCM?
Surgery is reserved for the subgroup of pts w/ large outflow tract gradients and severe sx despite medical tx
144
3 surgical procedures for pts with HCM
- septal myomectomy
- cardiac cath w/injection to induce ischemia of septal perforator arteries
- echo-guided perc septal ablation
(If pts remain symptomatic, a prosthetic MV can be inserted to counteract the systolic anterior motion of the mitral leaflet)
145
Dilated Cardiomyopathy (DCM) is a primary myocardial disease characterized by what? (x4)
- LV or biventricular dilation
- biatrial dilation
- decreased ventricular wall thickness
- systolic dysfunction without abnormal loading conditions or CAD
146
Initial symptom(s) of DCM?
heart failure
- chest pain may also occur
147
In patients with DCM, ventricular ______ may lead to mitral and/or tricuspid _______.
dilatation
regurgitation
(Dysrhythmias, conduction abnormalities, emboli and sudden death are common)
148
Typical DCM echo findings?
dilation of all 4 chambers, predominantly the LV as well as global hypokinesis
149
Treatment for DCM?
Similar to HF
- Anticoags often initiated as well
- Prophylactic ICD placement decreases risk of sudden death by 50%
150
Common dysrhythmias and EKG findings in pts with DCM?
PVCs and Afib
- EKG often shows ST-segment and T-wave abnormalities, LBBB
151
DCM remains the principal indication for _____ ______.
cardiac transplant
152
Stress cardiomyopathy is also known as...?
Apical ballooning syndrome
153
Stress cardiomyopathy is characterized by:
- LV apical hypokinesis w/ ischemic EKG changes, however coronary arteries remain patent
- temporary disruption of contractility of LV apex (rest of heart normal)
154
Common symptoms of stress cardiomyopathy?
Main causative factor?
Chest pain and dyspnea
Stress is main causative factor
(affects women > men)
155
Form of dilated cardiomyopathy of unknown cause that arises during the peripartum period (3rd trimester-5 months postpartum)
Peripartum Cardiomyopathy
- rare primary cardiomyopathy
156
Peripartum cardiomyopathy is diagnosed based on 3 criteria:
1. development of HF in the period surrounding delivery
2. absence of another explainable cause
3. LV systolic dysfunction with LVEF >45%
(Dx studies include: EKG, Echocardiogram, CXR, cardiac MRI, cardiac cath, endomyocardial biopsy & BMP levels)
157
Secondary cardiomyopathies are due to:
systemic diseases that produce myocardial infiltration and severe diastolic dysfunction
158
The most common cause of secondary cardiomyopathy?
Other causes?
amyloidosis
- hemochromatosis, sarcoidosis, carcinoid tumors
159
Diagnosis of secondary cardiomyopathy should be considered in pts who have HF but no evidence of ______ or _____ dysfunction.
cardiomegaly or systolic dysfunction
(pts have a low to normal BP and can develop orthostatic hypotension)
160
Classification of primary cardiomyopathies (chart)
161
Classification of secondary cardiomyopathies (Chart)
162
What is Cor Pulmonale?
Cor pulmonale is RV enlargement (hypertrophy and/or dilatation) that may progress to right-sided heart failure
163
Causes of cor pulmonale?
- pulmonary htn
- myocardial disease
- congenital heart disease
- any significant respiratory, connective tissue or chronic thromboembolic disease
164
What is the most common cause of cor pulmonale?
COPD is most common cause
(more prevalent in males >50 years old)
165
EKG findings of cor pulmonale:
- signs of RA and RV hypertrophy
- RA hypertrophy suggested by peaked P waves in leads II, III, and aVF
- RAD and RBBB also seen
(other dx tests include: TEE, RHC, CXR)
166
A complex state in which the heart is unable to fill with or eject blood at a rate appropriate to meet tissue requirements?
Heart Failure
167
This type of HF is commonly d/t obstructive ischemic heart disease:
HFrEF (HF w/ reduced EF)
168
This type of HF is commonly d/t the result of poor lifestyle choices and comorbidities, and is increasing in prevalence?
HFpEF (HF w/ preserved EF)
169
Management of AHF includes what types of meds and interventions?
Loop diuretics in combination with vasodilators, positive inotropes and/or mechanical devices
170
What is the most common genetic cardiac disorder? It's pathophys is r/t to the development of LVOT obstruction and ventricular dysrhythmias that can cause sudden death
Hypertrophic Cardiomyopathy (HCM)
171
Factors that induce LVOT obstruction in HCM pts include: (x4)
- hypovolemia
- tachycardia
- increased myocardial contractility
- decreased afterload
172
The most common form of cardiomyopathy and the second most common cause of HF
Dilated cardiomyopathy (principal indication for cardiac transplant)
173
This type of cardiomyopathy includes RV enlargement that may progress to right HF; caused by diseases that promote pulmonary htn
cor pulmonale
174
The most important determinant of pulmonary htn and cor pulmonale in patients with chronic lung disease is _____ _____.
alveolar hypoxia
(the best treatment is long-term oxygen therapy)
