Heart Failure Flashcards
Define Heart Failure
Inability of the heart to pump or supply enough blood. Either a SYSTOLIC (pump problem) or DIASTOLIC (filling problem) failure. Not a diagnosis, but a syndrome.
Define systolic heart failure
Contractility of the left ventricle is reduced, causing reduced stroke volume and reduced ejection fraction and high end diastolic pressure/volume
What is normal LVEF
> 50%
CO = HR X SV (~5L/min)
What are common causes of systolic heart failure?
Anything that causes poor contractility, such as:
- Ischemia (most common)
- Long standing hypertension
- Dilated cardiomyopathy (e.g. from alcohol, haemochromotosis)
Define diastolic heart failure
LV has reduced compliance so less blood returns to the heart, and end diastolic pressure is increased. However, ejection fraction is normal
What are the causes of diastolic heart failure?
Anything that reduces ventricular compliance or causes hypertrophy such as:
- Hypertension
- Aortic stenosis or other valvular disease
- Inherited hypertrophic cardiomyopathy
- Restrictive cardiomyopathies
- Left to right cardiac shunt (ASD/VSD)
- Tachycardias (e.g. AF, aneamia, thyrotoxicosis, steroid induced)
What are the common causes of RHF?
- Most commonly, LHF
- PAH
- Right to left cardiac shunt
- Pulmonary causes “Cor Pulmonale” such as COPD, emphysema, PE
What are the common symptoms of RHF ?
Venous congestion is the main issue causing peripheral odema, ascites, nausea and anorexia and facial engorgement.
What are the common symptoms of LHF?
Pulmonary odema is the main issue, and causes dyspnea (especially with exertion), poor exercise tolerance, orthopnea and PND. In advanced disease patients can have resting tachycardia, cool and pale extremities and unexplained fatigue due to poor tissue perfusion
What is cardiorenal syndrome?
- Reduced CO activates RAAS due to reduced blood flow to kidneys
- RASS causes retention of Na+ and H20 to help increase BV and increase end diastolic volume
- This leads to worsening pulmonary odema and peripheral pitting odema
What are some common exam findings in LEFT heart failure?
- Coarse crackles bibasally (not cleared by coughing)
- Peripheral odema
- Third heart sound S3 (“ventricular gallop”)
- In severe cases can develop pulsus alternans (alternating pulse pressures)
- Narrow pulse pressure
- Displaced apex beat
What are the common exam findings of RIGHT heart failure?
- Raised JVP
- Spleno/Hepatomegaly (from congestion)
- Pitting odema or ascites
What medications should be considered in HF patients?
TREAT UNDERLYING CAUSE FIRST! ACEi, ARB and aldosterone receptor antagonists (e.g. spironolactone) reduce mortality. Beta-blockers should be USED WITH CAUTION if decompensated as they are a negative ionotrope. Thiazide or loop diuretics only treat symptoms! Vasodilators (isosorbide) or inotropes (digoxin) used in severe cases.
What is the use of BNP in CHF?
- Hormone released from myocardium in response to stretch
- Diagnostic “rule out test” if <30pg/mL; very likely if >145pmol/L
- Can be used to assess response to treatment
What are the NYHA classifications?
Class 1: symptoms (SOB/angina/fatigue) with extreme exertion; does not limit physical activity
Class 2: symptoms with moderate exertion
Class 3: symptoms with minimal exertion
Class 4: symptoms at rest; greatly restricts physical activity
What other health conditions should be considered and well managed in CHF?
- Hypertension
- IHD
- Valvular heart disease
- Hyperthyroidism
- Diabetes
- AF and other tachyarrythmias
- Alcoholism
What lifestyle recommendations should be encouraged in CHF?
- Smoking cessation
- Minimal ETOH
- Low Na+ (<2g/day)
- Fluid restriction (<2L/day)
- Maintaining a healthy weight
- Daily weights to manage exacerbations
- Flu vaccine annually
Complication of poorly controlled HF
- Pulmonary odema or acute decompensated heart failure
- Recurrent ventricular tachycardias or malignant arryythmias which can cause sudden cardiac death; may require implanted defibrillator
How do you treat acute decompensated heart failure?
- ABCD support: sit up, oxygen, GTN
- IV loop diuretics
- IV vasodilators
- IV inotropic agents (e.g. dobutamine)
How does hypertension cause systolic HF?
Increase arterial pressures cause LV hypertrophy, which increases the oxygen demand and reduces coronary supply that is unsustainable, causing weaker ventricular contractions and systolic failure.
How does dilated cardiomyopathy cause systolic HF?
LV grows in size in an attempt to increase ventricular filling (preload) to increase contraction (Frank Starlings law). Ultimately this makes the myocardium thin and weak leading to systolic heart failure.
Describe spironolactone
- Often used for symptomatic heart failure alongside ACEi and b-blocker
- Risk of hyperkalemia and hypotension
- Start at 25mg OD
Describe digoxin
- Ionotrope used in systolic heart failure
- Toxicity can cause confusion, nausea and vision changes
- Interacts with many different meds
What are common DDx for CHF?
- Nephrotic syndrome
- Liver disease causing hypoalbuminemia
What investigations should be ordered in CHF?
- FBC (exclude anemia)
- UEC (K+, Na+ can be presipidants; renal function for meds)
- BNP
- TFTs
- CXR (signs of congestion; cardiomegaly)
- ECG (arrythmias, MI, LVH, LBBB)
- ECHO
- Angiography (IHD)
What is first line management for CHF?
1st line - Furosemide 20-40mg OD 2nd- ACEi (cilazipril 1-2.5mg) or Beta blocker (metoprolol 23.75mg) 3rd- add other 4th- spironolactone 5th- ARB/digoxin/anticoag
What drugs should be avoided in CHF?
- NSAIDs
- CCB e.g. verapamil (negative ionotropes)
- B-blockers in acute decompensation
