Differential Diagnosis of Dyspnea Flashcards
1
Q
Dyspnea due endocardial heart diseases
A
- Valvular disease (AS, AR, MR, MS)
2
Q
Dyspnea due to conduction system diseases
A
- Bradycardia
- Sinus Sick Syndrome
- Atrioventricular block
- Tachycardia
- Atrial fibrillation and other SVTs
- Ventricular tachycardia
3
Q
Dyspnea due to myocardial heart diseases
A
- Systolic failure
- CAD and non-ischemic CMs
- Result ⇡ LEDV, LEDP, and capillary pressures
- ⇡ capillary Ps → interstitial edema → stimulation of pulmonary receptors → dyspnea
- HTN
- Alcohol abuse
- CAD and non-ischemic CMs
- Diastolic failure
- Diastolic dysfunction occurs when LV wall thickness increases and LV compliance decreases
- → impaired LV filling → ⇣CO → stimulates metaboreceptors → dyspnea
- → ⇡ LVP → ⇡ LAP → ⇡ pulmonary vv. and capillary pressures → stimulates mechanoreceptors → dyspnea
- HTN
- AS
- HCM
- Diastolic dysfunction occurs when LV wall thickness increases and LV compliance decreases
4
Q
Dyspnea due to pathology within other heart structures
A
- Coronary arteries
- Ischemia
- Pericardium
- Tamponade
- Constrictive pericarditis
- These both lead to ⇡ intracardiac and pulmonary vascular pressures → stimulation of pulmonary receptors → dyspnea
- If CO is limited, at rest or during exercise, → stimulation of metaboreceptors and chemoreceptors → dyspnea
5
Q
Dyspnea due to alveolar pathology
A
- Pulmonary edema
- secondary to heart failure
- ARDS
- Pneumonia
6
Q
Dyspnea due to airway diseases
A
- Suprathoracic airways
- laryngeal edema
- Intrathoracic airways
- Asthma
- COPD
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7
Q
Dyspnea due to pathology of pulmonary blood vessels
A
- Pulmonary emboli
- Primary pulmonary HTN
- These diseases both → ⇡ pulmonary a. P → stimulation of pulmonary receptors
8
Q
Dyspnea due to pleural pathology
A
- PTX
- Pleural effusions
- Transudative
- Heart failure
- Cirrhosis
- Nephrotic syndrome
- Pulmonary embolism (PE)
- Exudative
- Tuberculosis
- Cancer
- Parapneumonic effusions
- Connective tissue diseases
- PE
- Transudative
9
Q
Dyspnea due to interstitial pathologies
A
- Edema
- Inflammatory
- Organic exposures (e.g, hay, cotton, grain)
- Mineral exposures (e.g., asbestos, silicon, coal)
- Idiopathic diseases (e.g., sarcoidosis, scleroderma, SLE, Wegener granulomatosis)
- Infectious
10
Q
Anemia
A
- Mild to moderate anemia is associated with breathing discomfort during exercise
- Related to stimulation of metaboreceptors
- Oxygen saturation is normal in patients with dyspnea due to anemia
11
Q
Inputs in production of dyspnea
A
- Receptors throughout the respiratory system (chemo-, mechano-, metabo-) project:
- directly to the sensory cortex to provide qualitative sensory experiences and feedback to the respiratory pump
- to areas of the brain responsible for the control of ventilation
- these areas send signals to the motor cortex, which then directs motor output to the ventilatory mm. and at the same time sends a neural signal to the sensory cortex via a corollary discharge (feedforward)
- A discrepancy or mismatch between the feedforward message to the ventilatory muscles and the feedback from receptors that monitor the response of the ventilatory pump → error signal generation → increased intensity of dyspnea
12
Q
Respiratory Chemoreceptors
A
- Are in the carotid bodies and medulla
- Are activated by:
- hypoxemia (low [O2] in the blood)
- acute hypercapnia (excessive CO2 in the blood)
- acidemia (excessive acid in the blood)
- Stimulation of chemoreceptors → sensation of air hunger → ⇡ in ventilation
13
Q
Respiratory Mechanoreceptors
A
- In the lungs
- Stimulated by bronchospasm → sensation of chest tightness
14
Q
Pulmonary Vascular Receptors
A
- Activated by changes in pulmonary artery pressure → air hunger → ⇡ in ventilation
15
Q
Pulmonary Metaboreceptors
A
- In skeletal muscle
- Activated by chemical changes in the local biochemical milieu of the tissue active during exercise
- When stimulated, they contribute to breathing discomfort
