Flashcards in Diseases Of The Heart Deck (11):
What is left ventricular heart failure?
Left ventricle loses ability to contract normally - can't pump with enough force to push enough blood into circulation.
What causes LVF?
1. Myocardial infarction
2. Hypertrophic or dilated cardiomyopathy
4. Mitral stenosis or aortic insufficiency
What is mitral stenosis?
- Narrowing of mitral valve
- Restricts blood flow from left atrium to left ventricle
- Decreased volume of blood pumped into systemic circulation.
What is aortic insufficiency?
- Leaking aortic valve
- Blood flow from aorta to left ventricle
Why is LVF worse when lying down?
1. Redistribution of blood from lower extremities to lungs - additional volume cannot be pumped out by LV.
2. May also be reabsorption of oedema fluid from other parts of the body.
What happens to plasma brain natriuretic peptide in heart failure?
- BNP = biologically active peptide with vasodilator and natriuretic properties. Cleaved from pro-BNP released from cardiac ventricles in response to myocyte stretching.
- BNP levels increase markedly in LVF and level in heart failure correlates with symptom severity - important clinical marker for diagnosis of heart failure in patients with unexplained dyspnoea.
What are the symptoms of LVF?
6. Elevated pulmonary wedge pressure
7. Exertional dyspnea
9. Paroxysmal nocturnal dyspnea
10. Pulmonary congestion
- blood-tinged sputum
What is tachypnea?
Increase in respiratory rate above normal.
What is dyspnea?
Subjective sensation of difficult/uncomfortable breathing.
What is orthopnea?
Sensation of breathlessness in the recumbent position.