Congestive Cardiac Failure Flashcards
What is the most likely cause of heart failure?
Heart failure is the most likely cause due to the combination presence of dyspnoea, oedema, elevated JVP, basal crepitations and enlarged liver.
What is dyspnea?
Dyspnoea - by definition refers to a state where the subject is uncomfortably aware of his/her breathing. It is usually associated with either the increase in the work of breathing - associated with reduced lung compliance (stiff lungs) or increased respiratory rate. It is therefore a non-specific symptom and may occur in diseases pertaining to the cardiovascular, respiratory systems or in the presence of severe anaemia. Review the causes of dyspnoea in these systems.
What are the symptoms of R heart failure? L heart failure?
Ankle oedema, hepatomegaly and elevated JVP = right heart failure
Bibasal crepitations = left heart failure.
What’s the term used to describe breathlessness that is worse when lying down?
Orthopnoea is shortness of breath that occurs when lying flat causing the person to have to sleep propped up in bed or sitting in a chair. It is often a symptom of left ventricular failure and/or pulmonary oedema.
Why does orthopnea occur?
Orthopnoea occurs because the normal pooling of blood in the lungs in the supine position is added to a chronically congested pulmonary vasculature; the increased venous return cannot be compensated for by the left ventricle.
The components of the Jugular Venous Waves: the “A”, “C” and “V” waves. Why and where in the cardiac cycle do they occur?
Waves
a – pre-systolic: produced by right atrial contraction
c - bulging of the tricuspid valve into the right atrium during ventricular systole (isovolumic phase)
v – occurs in late systole; increased blood in the right atrium from venous return
The a and v waves can be identified by timing the double waveform with the opposite carotid pulse. The a wave will occur just before the pulse and the v wave occurs towards the end of the pulse.
Descents
x – a combination of atrial relaxation, downward movement of the tricuspid valve and ventricular systole
y – the tricuspid valve opens and blood flows into the right ventricle
What do you understand by the term “Grade 4 murmur”?
A Grade 4 murmur is a loud murmur with a palpable thrill. Based on the intensity of a murmur it may be classified into the four following grades:
Grade 1: The murmur is heard only on listening intently for some time.
Grade 2: A faint murmur that is heard immediately on auscultation.
Grade 3: A loud murmur with no palpable thrill.
Grade 4: A loud murmur with a palpable thrill.
What should you keep in mind when assessing the significance of a murmur note?
A soft ejection murmur may not signify organic pathology
A new murmur is always significant
A loud murmur associated with a thrill is always abnormal
Diastolic murmurs are always abnormal
What is the Frank-Starling curve?
Describes the relationship between the volume of blood in the heart at the end of diastole (known as the pre-load or end-diastolic volume) and the force of contraction of the ventricle. In the normal heart, if myocardial fibres are stretched by an increased volume of blood, there will be an increase in the force and velocity of the contraction.
A failing heart has reduced contractility. This increases the end diastolic volume. Initially the heart will try to respond by increasing the force of contraction. However a greater end diastolic volume is required to give the same force of contraction. The graph is shifted to the right. Eventually a critical point will be reached where the heart can no longer respond to increasing end diastolic volumes and it will decompensate- stroke volume will decrease with further increases in end diastolic volume. The increased venous pressure causes fluid to leak out of the blood into the alveolar interstitial fluid resulting in pulmonary oedema.
- Acidosis + anaesthetic agents = decreased contractibility
- Catecholamines + calcium = increased contractibility
Coronary heart disease and hypertension are the most common causes of heart failure in the UK. What other causes of heart failure do you know?
Ischaemic heart disease accounts for around 40% of all causes of heart failure in the UK. It is useful to categorise other causes of heart failure into the following:
- Structural causes: Valvular disease such as aortic regurgitation, aortic stenosis, mitral regurgitation and mitral stenosis.
- Congenital heart disease: ASD, VSD, inherited cardiomyopathies.
- Rate-related causes: uncontrolled atrial fibrillation, thyrotoxicosis and anaemia (causing a high output state), heart block (causing a low output state)
- Pulmonary causes: COPD, pulmonary fibrosis, recurrent pulmonary emboli, and primary pulmonary hypertension cause right sided heart failure which in turn can cause congestive cardiac failure.
- Alcohol and drugs: Some chemotherapy drugs are cardiotoxic
- Pericardial disease: chronic pericarditis (caused by tuberculosis, lupus, viruses).
- Autoimmune disease: such as amyloidosis and sarcoid.
- Miscellaneous: Pregnancy-induced cardiomyopathy, acute viral myocarditis
What are 4 causes of mitral regurgitation?
- Rheumatic heart disease
- Ischaemic heart disease - associated with papillary muscle rupture
- Valvular vegetations - as in patients with endocarditis
- Physiological mitral valve regurgitation due to dilated left atrium
What is “ejection fraction”?
A measurement of how much blood is being pumped out of the heart with each contraction. It is expressed as a percentage. (i.e. stroke volume/end diastolic volume). A normal ejection fraction is 50 – 70%.
Explore the statements “because the duration of atrial fibrillation is not clear, a rate control strategy using medical therapy would be preferred at this stage” and “never cardiovert someone who has been in AF for more than 48 hours unless it’s going to be life-saving” in greater detail.
In atrial fibrillation, blood flow will be turbulent, with possible areas of decreased flow or stasis of blood in the atria. This can cause clots to form, and the risk is significantly greater after a patient has been in atrial fibrillation for longer than 48 hours. Therefore, if normal sinus rhythm was restored by cardioverting the patient, the clots could be dislodged and there is a risk of causing an embolic stroke. Therefore, if the onset of atrial fibrillation is not known, or the patient has been in atrial fibrillation for longer than 48 hours, cardioversion (a “rhythm control” strategy) is not recommended. In these circumstances a safer approach would be to control the rate with appropriate medication and anti-coagulate the patient. If appropriate, cardioversion can be attempted at a later date once the patient is fully anti coagulated and an echocardiogram has excluded the presence of thrombi.
Who does cardiac failure affect and what is it likely preceded or associated with?
Usually affects > 75y (1:200 - 50-60y; 1:10 - 80+)
Preceeded or associated with AF (usually in elderly)
What does Reynold’s number represent?
The chance that blood flow will be turbulent
What is the physiology of how murmurs are produced?
- Decreased viscosity of blood
- Decreased radius of vessels/valve
- Increased velocity of blood through morphogenically normal structures
- Regurgitation across incompetent valve
Name an example for each murmur mechanism
Decreased viscosity of blood -> Anemia
Decreased radius of vessels/valve -> Valvular stenosis, coarctation of aorta, ventricular septal defect
Increased velocity of blood -> Hyperdynamic states (i.e. sepsis, hyperthyroidism)
Regurgitation across incompetent valve -> valvular regurgitation
How are murmurs graded?
Grade 1 - 6
1: Barely audible
2: Soft, but easily heard
3: Loud
4: Associated with thrill
5: Very loud, heard without full contact of stethoscope
6: Audible without stethoscope
What are the 3 basic shapes of murmurs?
- Crescendo-decrescendo (i.e. AS)
- Uniform (i.e. MR)
- Decrescendo (i.e. AR)
1 + 2 = systolic murmur
3 = diastolic murmur
Name the 2 most important diagnostics for acute heart failure
- Serum BNP
- normal if < 100ng/l or NT-proBNP < 300ng/l - Doppler 2D echo
- Looking for cardiac abnormalities
What is the treatment for acute heart failure?
- IV diuretics
- B-blocker (not atenolol!)
- ACE-i/ARB + aldosterone antagonist (LVEF < 45%)
- TAVI/surgical replacement if AS
- Surgical valve repair if MR
Outline the cardiovascular continuum
- Risk factors
- Atherosclerosis/LVH
- CAD
- Myocardial ischemia
- Coronary thrombosis
- MI
- Arrhythmia/loss of muscle
- Remodelling
- Ventricular enlargement
- CHF
- Death
HF prevalence increases > 55y
Name 12 causes of heart failure
- Ischemia (CAD, AMI) - 40%
- HTN
- Diabetes (diabetic cardiomyopathy)
- Valvular (AS, MR)
- Tachycardia induced (uncontrolled AF)
- Toxins/drugs (alcohol, doxorubicin - anticancer)
- Infective (viral myocarditis - affects young)
- Endocrine (thyrotoxicosis, phaeochromocytoma)
- Dilated cardiomyopathy (idiopathic, pregnancy)
- Genetic (hypertrophic obstructive cardiomyopathy)
- Pulmonary (COPD, pulmonary fibrosis, PE)
- Autoimmune (Sarcoidosis, amyloidosis)
What is the most common presenting symptom of HF?
SOB
- Exertion/rest
- Paroxysmal nocturnal dyspnea
- Orthopnea
Fatigue/loss of energy
Name 6 signs of heart failure
- Pulmonary oedema/pleural effusion
- Increased JVP
- Pitting oedema
- Ascites
- Tachycardia
- S3 gallop
How is a diagnosis of heart failure made?
- Symptoms of HF +
- Signs of HF +
- Objective structural/functional cardiac abnormality at rest (i.e. cardiomegaly, S3, ECG)
HF is always secondary to another cause
What investigations can diagnose HF?
- Bloods -> FBC, Hematinics (iron, B12, folate), U+E (CRF), TFTs, Glucose, LFTs (pulm. congestion), Troponin I
- ABGs
- Brain Natriuretic Peptide (BNP)
- Secreted by ventricles of heart in response to excessive stretching of heart muscle cells
- Increased levels = worse outcome - Chest xray
- ECHO (info relating to LVEF - normal ~60%)
- ECG (i.e. AF, arrhythmias)
What are the 2 categories of HF patients?
- HF presenting with preserved LV function (EF > 45%)
2. HF presenting with reduced LV function (EF < 45%)
What may LVH indicate?
- HTN
- Aortic stenosis
- HOCM - hypertrophic obstructive cardiomyopathy