PBL 6: Gerald Williams Flashcards
What is heart failure?
When the heart fails to supply enough blood to meet the body’s metabolic needs
What is orthopnea?
Difficulty sleeping and coughing when sleeping and lying flat
What is paroxysmal nocturnal dyspnea?
Waking up suddenly with severe anxiety and breathlessness
What is pulsus alternans?
Alternating strong and weak pulse indicative of left ventricular systolic impairment
What are the causes of heart failure?
Cardiac: hypertension, bicuspid aortic valve, valvular heart disease, ischemic heart disease
Non-cardiac: infection, over-reactive thyroid, anaemia, renal failure, medications
What are the main symptoms of heart failure?
Tiredness/Fatigue Pulmonary Oedema Paroxysmal Nocturnal Dyspnoea Ankle Swelling Pulsus Alternans Tachycardia Breathlessness Hepatojugular Reflex
Why do you tachycardia?
Reduction in stroke volume so there is compensation by the SNS acting on the SAN and AVN to increase heart rate to therefore increase SV and CO
Why do you get tiredness/fatigue?
LV cannot pump enough oxygen in the blood when demands are high on exertion so metabolic demands not met
Chemical factors also released from hypoxic skeletal muscle and nerve impulses leading to dilation of heart muscle
Why do you get pulmonary oedema?
LV failure = EDV increases = LA pressure increases = pulmonary venous pressure increases = becomes greater than oncotic pressure so according to Starling’s law fluid moves out into the alveolar air spaces
Why do you get breathless?
Pulmonary oedema means fluid in the lungs results in poor gas transfer and diffusion
When lying down it is increased as sympathetic nervous system activity is reduced = reduced respiratory drive and reduced bronchodilation
Why do you get paroxysmal nocturnal dyspnoea?
Pulmonary oedema and hypoxia triggers nerve endings at night causing you to wake up suddenly
Why do you get ankle swelling?
Pulmonary oedema = hypoxia = shunting (pulmonary arterial constriction = pulmonary hypertension = right ventricle increased to pump blood to the lungs = right ventricle may enlarge = Due to such high pressures in the pulmonary arteries the central venous pressure can also increase = Back-flow of blood disrupts Starling’s Law in capillaries where hydrostatic pressure is now increased resulting in fluid leakage out of the vessels.
indicative of CHF where there is right and left sided heart failure
Why do you get hepatojugular reflex?
Increase in central venous pressure
Right sided heart failure
Why do you get pulsus alternans?
Left systolic impairment = aortic stenosis/valve disease
How is heart failure diagnosed?
- Framingham criteria (need 2 major and 1 minor or 1 major and 2 minor)
- BNP!!! >100
- Clinical exam - S3 gallop, small pulse volume, LV enlargement as apex displaces, S4 sound, other heart murmurs if mitral regurg (systolic murmur)
- CXR - pulmonary oedema (bat wing sign, consolidation), kerley B lines, pleural effusion, cardiomegaly
- Echocardiogram - dilated ventricles and left atrium
- ECG - not that useful but will never be normal
- Doppler ultrasound - mitral regurgitation, dilated left ventricle
