Flashcards in Week 238 - Heart Failure Deck (28)
Describe the key features of left-sided heart failure
Dyspnoea / Orthopnoea / PND (pulmonary congestion / oedema)
Signs of decreased tissue perfusion (decreased CO)
Signs of cyanosis or hypoxia
Describe features of right-sided heart failure
(Congestion of peripheral tissues)
Reduced liver function / hepatomegaly
Reduced GI function (anorexia, GI distress, weight loss)
Ascites / oedema
What is the overarching pathology with right-sided HF?
Systemic venous congestion
Which organ commonly causes right-sided HF?
Lungs / lung diesease e.g. COPD and PE
What is the term used when HF is a mixed picture of left and right-sided pathology?
Congestive Cardiac Failure
List 3 common causes of left-sided heart failure
What is paroxysmal nocturnal dyspnoea?
What someone awakens in the night feeling horribly short of breath the the point that they might need to stick their head out of a window to get fresh air in their lungs
What are the key investigations to be done in the suspected heart failure?
Blood tests - renal function, anaemia, Trop T, thyroid function, brain natriuretic peptide (BNP)
CXR - if congested yes; in not no!
ECHO - stiff walls (diastolic), poor/weak contraction (systolic), regional wall abnormality (e.g. Post MI)
Why might you also want to perform a profusion scan / angiogram?
To check coronary perfusion
What two overarching pathophysiology types cause systolic heart failure? Is the ejection fraction preserved or reduced?
Ejection fraction is reduced
Give 3 causes of impaired contractility
Coronary artery disease (MI, transient myocardial ischaemia)
Chronic volume overload (aortic or mitral regurgitation)
Give 2 causes of increased afterload leading to systolic heart failure
Uncontrolled severe HTN
Advanced aortic stenosis
What type of heart failure results in preserved ejection fraction?
Impaired Diastolic Filling
List 5 causes of impaired diastolic filling
Pericardial tamponade or constriction
Transient myocardial ischaemia
List the three compensatory mechanisms that occur in response to early stage heart failure
Hypertrophy and remodelling
How does the Frank-Starling compensatory mechanism work?
Acts to preserve forward cardiac output by increasing contractility and therefore stroke volume in response to incomplete ventricular emptying
How does hypertrophy and remodelling compensate for heart failure?
Increased wall stress leads to myocardial hypertrophy and extra cellular matrix deposition. Helps to preserve cardiac output
How does an eccentric and concentric hypertrophy pattern result?
Eccentric - response to volume overload (mitral/aortic regurgitation)
Radius enlargement in proportion to wall thickening
Concentric - response to pressure overload
Wall thickness increases without proportional chamber dilatation reducing wall stress substantially
How does the neurohumoral activation mechanism initially compensate for heart failure?
- Sympathetic NS (adrenergic stimulation)
- ADH secretion
- RAAS stimulation
(Enhances release of vasoconstricting / sodium-retaining neurohorones e.g. Ang. II, noradrenaline, endothelin1 and ADH (arginine vasopressin) - serve to increase TPR and improve systemic perfusion)
What signs on CXR are typical of heart failure?
- bilateral perihilar shadowing "bat wing appearance" (pulm. oedema)
- upper zone dilated pulmonary vessels (pulmonary venous HTN)
- Kerley B lines (septal lines - specific sign of pulmonary oedema)
- costophrenic blunting (pleural effusion)
What does BNP stand for and when is it released?
BNP = Brain Natriuretic Peptide
It is released from the ventricles in response to excessive stretching of cardiomyocytes
N.B. Recombinant BNP (Nesiritide) is not used in Mx in UK pts
What is meant by the term Orthopnoea?
Difficulty breathing when lying flat
What is Paroxysmal Nocturnal Dyspnoea (PND)?
Waking at night gasping for breath - may feel need to stick head out of a window to get air into lungs
What are the key investigations for suspected heart failure?
What bloods should you request in a patient with suspected HF?
BNP (brain natriuretic peptide)
What might an ECHO tell you?
Whether there is wall stiffening (diastolic failure)
Weakness in contractility (systolic)
Valvular dysfunction (systolic)
Regional wall abnormalities
Why might a cardiac perfusion scan / scintigraphy be useful in the investigation of HF?
It illustrates the blood supply to the myocardium highlighting areas of ischaemia or infarction, may help decide whether or not a bypass or stent will be necessary or beneficial. Might give an idea of the type / cause of HF being dealt with and direct your management