Shortness of Breath - Johns Flashcards
What is Dyspnea?
“Abnormally uncomfortable awareness of breathing”
-Can be related to exertion or not related to exertion
What is in the differential for dyspnea on exertion (DOE)?
- CHF
- Angina (anginal equivalent)
- Obstructive airway disease
- Anemia
- Hypothyroid
- Metabolic acidosis
- Anxiety and hyperventilation
What is in the differential for dyspnea not related to exertion?
Sudden episodes at rest - pulmonary emboli, pneumothorax, anxiety
What is orthopnea?
Dyspnea when supine
-CHF, asthma, COPD
What is paroxysmal nocturnal dyspnea (PND)?
Waking at night short of breath (CHF, COPD)
What is Trepopnea?
Dyspnea when lying on side (CHF)
What is the pathophysiology of dyspnea?
- Exact mechanisms not known
- Stimulation of brainstem respiratory centers
- Receptors:
- -chemoreceptors
- -stretch receptors
- -intrathoracic receptors
What do chemoreceptors detect?
Peripheral afferents sense:
- -Inc. PaCO2
- -Dec. PaO2
- -Dec. pH
What is a Grade II/VI holosystolic murmur heard best at the apex that radiates to the axilla?
Mitral regurgitation
Why would someone with CHF have mitral regurgitation?
Chronic left ventricular dilation stretches annulus and causes dilation of the valve hole
What symptom does Left heart failure usually cause?
Lung edema
What symptom does right heart failure usually cause?
Extremity edema
What is CHF?
A syndrome of dyspnea on exertion, edema of the lungs or extremities and fluid retention resulting from cardiac dysfunction.
What causes left ventricular (LV) failure?
Coronary artery disease, valvular heart disease, hypertension, and congenital defects (e.g. ventricular septal defect, patent ductus arteriosus with large shunts)
Where is cardiogenic shock on the cardiac output curve?
Below heart failure
What is right ventricular (RV) failure caused by?
Most commonly caused by prior LV failure or tricuspid regurgitation.
-Other causes - mitral stenosis, primary pulmonary hypertension, multiple pulmonary emboli, pulmonary valve stenosis, RV infarction
What is High Output Failure?
A persistent high CO that eventually results in ventricular dysfunction.
What is the cause of high output failure?
Anemia, beriberi, thyrotoxicosis, pregnancy and A-V fistulas (from dialysis)
What is an AV fistula?
Connection between artery and vein – makes pressure between artery and vein pressure for dialysis
What is systolic function?
Ventricular contractile function
What causes systolic dysfunction?
Coronary artery disease, HTN, dilated congestive cardiomyopathy (viral, alcohol, beta-blockers, Ca blockers)
What is diastolic function?
Prolonged ventricular relaxation time and resistance to filling (ventricular stiffness)
What causes diastolic dysfunction?
HTN, age related
What is BNP?
B-type (brain) natriuretic peptide
-Neurohormone secreted from the cardiac ventricles in response to volume expansion and pressure overload
What is BNP used for?
Differentiates CHF (BNP should be increased due to ventricular stretching) from other causes of dyspnea
What are symptoms of left heart failure?
Dyspnea, Orthopnea, PND (paroxymal nocturnal dyspnea), Fatigue, Weakness
What are symptoms of right heart failure?
Fatigue, Weakness, Leg edema, Abdominal fullness
What are physical findings of CHF?
- Lung crackles
- Dullness to percussion of lung bases
- Elevated JVD
- Positive hepatojugular reflex
- S3, mitral insufficiency
- Ankle edema
- Hepatomegaly, ascites
What is NYHA functional classification Class I?
No limitation of physical activity.
What is NYHA functional classification Class II?
Slight limitation. Comfortable at rest, dyspnea or fatigue with activity.
What is NYHA functional classification Class III?
Marked limitation with physical activity, comfortable at rest.
What is NYHA functional classification Class IV?
Symptoms at rest, unable to carry on any physical activity without symptoms
How do diagnose CHF with chest x-ray?
- Cardiomegaly
- Pulmonary venous congestion
- Pleural effusions
How do you diagnose CHF with ECG?
- r/o MI
- Look for a-fib
How do you diagnose CHF with ECHO?
-Decreased LV function, diastolic dysfunction
What are other ways to diagnose CHF?
- Physical Exam
- Stress testing or coronary angiography (if coronary artery disease is suspected!!)
What does an irregular rhythm and no p waves indicate on ECG?
Atrial fibrillation
What happens on an ECG with lateral ischemia?
Inverted T waves at Lead I, aVL and V6.
What shows ischemia on ECG?
ST depression (subendocardial), T wave inversion
What shows MI on ECG?
ST elevation (transmural)
What shows on ECG for old MI?
ST elevation with Q waves!!
What are the inferior leads?
Leads II, III, aVF
What is the normal size of the heart on chest X-ray?
Less than half or half of the diameter of one lung field
What might you see on a CHF X-ray?
- No costophrenic angles
- Bilateral pleural effusion
- Increased vasculature of lungs
- Cardiomegaly
What is LV ejection fraction in a normal person?
50-60%
What might a CHF cardiac echo show?
Severe LV dysfunction - ejection fraction 20%
What factors determine stroke volume?
- Preload
- Myocardial contractility
- Afterload
- Neurohumoral factors also play a role
- -> increased catecholamines and Na+ and water cause activation of sympathetic and neurohormonal systems (vicious cycle)
What drugs can you use to decrease preload on the heart?
- Diuretics (Furosemide, Ethacrynic Acid)
- Vasodialators (venoselective - Isosorbide Dinitrate, Nitroglycerine - used for angina!!)
- -> By themselves these do not increase survival!
What drugs can you give to increase myocardial contractility?
- Digoxin - only commonly used oral med. –> reduces morbidity in patients also on diuretics and ACE inhibitors
- Dobutamine - give IV only - used in acute CHF in hospital
What drugs can you give to decrease after load in CHF?
- Arterial vasodilators - Apresoline
- ACE inhibitors - dilate arteries and veins - Major Advance! Improves mortality (Captopril, Enalapril)
- Angiotensin II receptor blockers - Also reduce mortality (Losartan)
What do the drugs that decrease after load in CHF do?
Make people LIVE LONGER!
What are neurohumeral treatments?
- Spironolactone
2. Carvedilol
What is Spironolactone?
Aldosterone antagonist - improves survival in severe CHF
What is Carvedilol?
Selective beta blocker, decreases catecholamines, improves survival
What drug can be used to affect brain natriuretic peptide?
Nesiritide (Natrecor)
- Needs to be infused IV for Stage IV heart failure
- Improved dyspnea
- Major side effect of hypotension
- COST: $380/day
What about patients with diastolic dysfunction? What is contraindicated?
Diuretics & vasodilators
-Patients do not tolerate decrease in plasma volume or BP
What are of value for patients with diastolic dysfunction?
ACE Inhibitors
-Use beta blockers to slow heart and allow more time for ventricular filling!!!
What do you think of with leg edema?
- Right sided heart failure
- Obstruction by clot
- Pregnancy putting pressure on vena cava
- Lymphatic tumors
What medication should be given with diastolic dysfunction?
CHF diastolic dysfunction –> beta blocker!
sometimes ACE inhibitors are valuable
Hepatomegaly can be a sign of?
Right heart failure
Enalapril is:
ACE inhibitor –> reduces after load
