Cardiology Flashcards
What is chronic heart failure?
A clinical syndrome involving reduced cardiac output because of impaired cardiac contraction
What are typical clinical symptoms of CHF?
Shortness of breath, fatigue and ankle swelling.
What is the prevalence of CHF?
1-2%, rising to 10% in over 70 year olds
What are three factors stroke volume requires?
- adequate preload
- optimal myocardial contractility (Frank-Starling mechanism)
- decreased afterload
Cardiac output =
stroke volume x heart rate
Which factors reduce cardiac output, potentially causing CHF?
- Decreased heart rate
- Decreased preload
- Decreased contractility
- Increased afterload
(cardiac output = heart rate [1] x stroke volume [2,3,4])
How is CCF diagnosed using the Framingham criteria?
2 major criteria or 1 major + 1 minor
What is the major criteria for the Framingham criteria for CCF?
- PND
- +ve abdominojugular reflux
- Neck vein distension
- S3
- Basal creps
- Cardiomegaly
- Acute pulmonary oedema
- ↑ CVP (>16cmH2O)
- Wt. loss >4.5kg in 5d 2O to Rx
What is the minor criteria for the Framingham criteria for CCF?
- Bilat ankle oedema
- SOBOE
- ↑HR >120
- Nocturnal cough
- Hepatomegaly
- Pleural effusion
- 30% ↓ vital capacity
Most common causes of HF in the UK?
Coronary heart disease (MI), atrial fibrillation, valvular heart disease and hypertension
Other causes of HF?
Endocrine or medications
What are endocrine causes of HF?
Hypothyroidism, hyperthyroidism, diabetes, adrenal insufficiency, Cushing’s syndrome
What medications can cause HF?
Calcium antagonists, anti-arrhythmics, cytotoxic medication, beta-blockers
When does high-output cardiac failure occur?
In states where demand exceeds normal cardiac output such as pregnancy, anaemia and sepsis.
A useful acronym to remember some of the causes of CHF:
HIGH-VIS: hypertension, infection/immune, genetic, heart attack, volume overload, infiltration, structural
What are some infective/immune causes of CHF?
Viral (e.g. HIV), bacterial (e.g. sepsis), autoimmune (e.g. lupus, rheumatoid arthritis)
What are genetic causes of CHF?
Hypertrophic obstructive cardiomyopathy (HOCM), dilated cardiomyopathy (DCM)
What are causes of volume overload that lead to CHF?
Renal failure, nephrotic syndrome, hepatic failure
What are causes of infiltration that lead to CHF?
Sarcoidosis, amyloidosis, haemochromatosis
What are structural causes of CHF?
Valvular heart disease, septal defects
Typical symptoms of CHF?
- Dyspnoea on exertion
- Fatigue limiting exercise tolerance
- Orthopnoea: the patient may be using several pillows to reduce this symptom.
- Paroxysmal nocturnal dyspnoea (PND): attacks of severe shortness of breath in the night that are relieved by sitting up (pathognomonic for CHF).
- Nocturnal cough with or without the characteristic ‘pink frothy sputum’.
- Pre-syncope/syncope
- Reduced appetite
Relevant past medical history for CHF?
Hypertension, coronary artery disease and valvular heart disease (common causes of CHF)
Relevant medication history for CHF?
Calcium antagonists, antiarrhythmics, cytotoxic medication and beta-blockers (in the acute phase, but long term provide prognostic benefit).
Relevant family history for CHF?
Cardiomyopathy (e.g. HOCM) or coronary artery disease
Relevant social history for CHF?
Smoking, excess alcohol intake and recreational drug use
Clinical findings of CHF in cardio exam?
- Tachycardia at rest
- Hypotension
- Narrow pulse pressure
- Raised jugular venous pressure
- Displaced apex beat (due to left ventricular dilatation)
- Right ventricular heave
- Gallop rhythm on auscultation (pathognomic for CHF)
- Murmurs associated with valvular heart disease (e.g. an ejection systolic murmur in aortic stenosis)
- Pedal and ankle oedema
Clinical findings of CHF in resp exam?
- Tachypnoea
- Bibasal end-inspiratory crackles and wheeze on auscultation of the lung fields
- Reduced air entry on auscultation with stony dullness on percussion (pleural effusion)
Clinical findings of CHF in abdo exam?
Hepatomegaly, ascites
What bedside investigations should be done in CHF?
Full history, cardio/resp/cardio exams, urinalysis and ECG
What would an ECG show in CHF?
- Tachycardia
- Atrial fibrillation (due to enlarged atria)
- Left-axis deviation (due to left ventricular hypertrophy)
- P wave abnormalities (e.g. P.mitrale/P.pulmonale due to atrial enlargement)
- Prolonged PR interval (due to AV block)
- Wide QRS complexes (due to ventricular dyssynchrony)
Why is there AF in CHF?
Due to enlarged atria
Why is there left-axis deviation in CHF?
Due to left ventricular hypertrophy
Why are there P wave abnormalities in CHF?
P.mitrale or P.pulmonale due to atrial enlargement
Why is there a prolonged PR interval in CHF?
Due to AV block
Why are there wide QRS complexes in CHF?
Due to ventricular dyssynchrony
What bloods do you want to do in CHF?
- FBC (anaemia)
- U&E (renal failure, electrolyte abnormalities due to fluid overload (e.g. hyponatraemia))
- LFTs (hepatic congestion)
- Glucose/HbA1c (ischaemic risk profile)
- Lipids (ischaemic risk profile)
- Troponin (if considering recent myocardial infarction)
- BNP/NT-proBNP (heart failure)
- TFTs
- cardiomyopathy screen
Screening for cardiomyopathy includes which blood tests?
- Serum iron and copper studies (to rule out haemochromatosis and Wilson’s disease)
- Rheumatoid factor, ANCA/ANA, ENA, dsDNA (to rule out autoimmune disease)
- Serum ACE (to rule out sarcoidosis)
- Serum-free light chains (to rule out amyloidosis)
NT-proBNP level >2000 ng/L significance:
refer urgently for specialist assessment and transthoracic echocardiography within 2 weeks
NT-proBNP level 400-2000ng/L significance:
refer routinely for specialist assessment and transthoracic echocardiography within 6 weeks
NT-proBNP level <400 ng/L significance:
heart failure unlikely
What are other conditions in which NT-proBNP may be raised other than CHF?
- Left ventricular hypertrophy
- Tachycardia
- Liver cirrhosis
- Diabetes
- Acute or chronic renal disease
What imaging can be done in CHF?
Transthoracic echocardiography, CXR, cardiac MRI
What are typical CXR findings associated with CHF?
- Alveolar oedema (perihilar/bat-wing opacification)
- Kerley B lines (interstitial oedema)
- Cardiomegaly (cardiothoracic ratio >50%)
- Dilated upper lobe vessels
- Effusions (e.g. pleural effusions – blunted costophrenic angles)
What is is the gold standard investigation for assessing ventricular mass, volume and wall motion?
Cardiac MRI
What is a cardiac MRI used for and why is it used?
To assess ventricular mass, volume and wall motion. It can also be used with contrast to identify infiltration (e.g. amyloidosis), inflammation (e.g. myocarditis) or scarring (e.g. myocardial infarction). It is typically used when echocardiography has provided inadequate views.
What can an echo show in relation to CHF?
- Global systolic and diastolic function (Ejection fraction normally ~60%)
- Focal / global hypokinesia
- Hypertrophy
- Valve lesions
- Intracardiac shunts
What is LVEF?
LVEF is the percentage of blood that enters the left ventricle in diastole that is subsequently pumped out in systole.
How is LVEF measured?
LVEF is usually measured using transthoracic echocardiography, however, MRI, nuclear medicine scans and transoesophageal echocardiography can also be used.
New York Heart Association’s (NYHA) classification system:
Class I: no symptoms during ordinary physical activity
Class II: slight limitation of physical activity by symptoms
Class III: less than ordinary activity leads to symptoms
Class IV: inability to carry out any activity without symptoms
BNP is secreted from ventricles in response to:
↑ pressure → stretch, tachycardia, glucocorticoids, and
thyroid hormones
What are actions of BNP?
↑ GFR and ↓ renal Na reabsorption, ↓ preload by relaxing smooth muscle
What is the general management for CHF?
Lifestyle, vaccinations, medication review, monitoring
Describe lifestyle management for CHF?
- Fluid and salt restriction
- Regular exercise
- Smoking cessation
- Reduced alcohol intake
What vaccinations should you give in CHF?
Influenza and pneumococcal disease
Which medications may be harmful in the context of heart failure?
- Calcium channel blockers (e.g. verapamil, diltiazem)
- Tricyclic antidepressants
- Lithium
- NSAIDs and COX-2 inhibitors
- Corticosteroids
- QT-prolonging medications