cardiac failure Flashcards
definitoon of cardiac failure
Inability of the cardiac output to meet the body’s demands despite normal venous pressures.
defintion of acute cardiac failure
new onset acute/decompensation of HF,
characterized by pulmonary and/or peripheral oedema
with or without signs of peripheral hypoperfusion.
definition of chronic cardiac failure
Develops or progresses slowly. Venous congestion is common but arterial pressure is well maintained until very late.
systolic HF
inability of the ventricle to contract normally = reduced CO, EF <40%
diastolic HF
inability of ventricle to relax and fill normally = increased filling pressures.
Typically EF is >50% – HFpEF (heart failure with preserved EF).
low output HF
Cardiac output is low and fails to raise normally with exertion.
high output HF
rare.
output is normal or increased in the face of increased needs.
Failure occurs when cardiac output fails to meet these needs.
will occur with a normal heart, but earlier in heart disease
aetiology of low output LHF
- ischemic heart disease,
- HTN,
- cardiomyopathy,
- aortic valve disease,
- mitral regurg,
- fluid overload
aetiology of low output RHF
- secondary to LHF,
- infarction,
- cardiomyopathy,
- pul HTN/embolus/valve disease,
- chronic lung disease (cor pulmonale),
- tricuspid regurg,
- constrictive pericarditis/pericardial tamponade,
- pul stensosis
aetiology of low output biventricular failure
arrthmia,
cardiomyopathy (dilated/restrictive),
myocarditis,
drug toxicity
aetiology of low output pump failure
systolic +/ diastolic HF,
reduced HR (B blockers, heart block, post MI),
negatively inotropic drugs (eg most antiarrhythmic agents).
aetiology of high output HF
anaemia
beriberi
pregnancy
Paget’s disease
hyperthyroidism
arteriovenous malformation
aetiology of systolic HF
IHD, MI, cardiomyopathy
aetiology of diastolic HF
ventricular hypertrophy, constrictive pericarditis, tamponade, restrictive cardio myopathy, obesity
what is congestive cardiac failure
when R and L ventricular failure occur together
effect of preload and afterload on HF
Excessive preload = ventricular dilatation - exacerbates pump failure.
Excessive afterload = ventricular muscle thickening (ventricular hypertrophy), = stiff walls and diastolic dysfunction.
epidemiology of HF
1–3% of the general population;
~10% among elderly patients (>65)
sx of LHF
symptoms caused by pulmonary congestion
Dyspnoea (New York Heart Associationclassification):
- none
- on ordinary activities
- on less than ordinary activities
- at rest
poor exercise tolerance
orthopnoea
paroxysmal nocturnal dyspnoea
fatigue
nocturia
cold peripheries
weight loss
sx of acute LVF
Dyspnoea,
wheeze,
cough
pink frothy sputum
sx of RHF
- swollen ankles
- ascites
- fatigue
- increased weight (from oedema)
- reduced exercise tolerance
- anorexia
- nausea
- facial engorgement
- epistaxis
sx of high output HF
initially features of RVF;
later LV F becomes evident.
signs of LHF
tachycardia
tachypnoea
displaced apex beat (LV dilatation)
bilateral basal crackles
3rd heart sound - gallop rhythm: rapid ventricular filling
pansystolic murmur (functional mitral regurg)
signs of acute LVF
tachypnoea
cyanosis
tachycardia
peripheral shut down
pulsus alternans
gallop rhythm
wheeze ‘cardiac asthma’
fine crackles throughout the lung
signs of RHF
raised JVP
hepatomegaly
ascites
anklesacral pitting
oedema
signs of functional tricuspid regurg
general signs of HF
cyanosis
low BP
narrow pulse pressure
RV heave - pul hypertension
severity graded by New York Classification
Ix for HF
bloods
CXR
ECG
echo
Swan-Ganz catheter
if BNP and ECG normal - unlikely HF, if either not normal - need echo
bloods for HF
FBC, UE, LFT, CRP, glucose, lipid, TFT
in acute LVF - ABG, troponin, BNP
- raised Plasma BNP suggests the diagnosis of cardiac failure.
- A low plasma BNP rules out cardiac failure (90% sensitivity).
CXR in acute LVF
cardiomegaly (heart >50% of thoracic width)
prominent upper lobe vessels
pleural effusion
interstitial oedema - kerley B lines
perihilar shadowing - Bat’s wings
fluid in fissures
ECG in HF
may be normal
ischemic changes
arrhythmia
MI
LVH - seen in hypertension
echo for HF
assess ventricular contraction
MI
If left ventricular ejection fraction (LVEF)<40%: systolic dysfunction.
Diastolic dysfunction: reduced compliance leading to a restrictive filling defect.
Swan-Ganz catheter
Allows measurements of right atrial, right ventricular, pulmonary artery, pulmonary wedge and left ventricular end-diastolic pressures.
complications of HF
resp failure
cardiogenic shock
death
Px of HF
Fifty per cent of patients with severe heart failure die within 2 years.
Mx of acute LVF
medical emergency
cardiogenic shock - severe cardiac failure, low BP = need inotropes eg dopamine, dobutamine and should be managed in ITU
pul oedema
- Sit up patient, 60–100% O2 and consider CPAP
- diamorphine (venodilator and anxiolytic effect)
- GTN infusion - reduce preload
- IV furosemide if fluid overloaded (venodilator and later diuretic effect)
- monitor BP, RR, sats, urine output, ECG
- treat cause
Mx of chronic LVF
- treat cause - eg HTN
- treat exacerbating factors eg anaemia, thyroid disease, infection, raised BP
- stop smoking, drinking, eat less salt, optimise weight
- Annual ’flu vaccine, one-off pneumococcal vaccine.
- ACEi
- B blocker
- loop diuretic eg furosemide and salt restriction to treat fluid overload
- aldosterone antagonists
- angiotensin receptor blockers
- hydralazine and a nitrate (visodilators) - reduce mortality
- digoxin - positive inotrope - reduces hospitalisation, doesnt improve survival
- n-3 polyunsaturated fatty acids - benefit mortality
- cardiac resynchronisation therapy
- Avoid drugs that can adversely affect patients with heart failure due to systolic dysfunction,e.g. NSAIDs, non-dihydropyridine calcium channel blockers (i.e. diltiazem and verapamil).
why ACEi for HF
e.g. enalapril, perindopril, ramipril:
Inhibit intracardiac renin-angiotensin system which may contribute to myocardial hypertrophy and remodelling.
slow progression of the heart failure and improve survival, improve sx
if LV systolic dysfunction
SE - high K
why B blocker for HF
bisprolol or carvedilol
Block the effects of chronically activated sympathetic system
slow progression of the heart failure and improve survival
The benefits of ACEinhibitors and b-blockers are additive.
why loop diuretics for HF
reduce Sx
SE - reduce K, renal impairment
Monitor U&E and add K+-sparing diuretic (eg spironolactone)
if K+<3.2mmol/L = predisposition to arrhythmias, concurrent digoxin therapy, or pre-existing K+-losing conditions.
if refractory oedema - consider adding thiazide eg metolazone
aldosterone antagonists in HF
spirinolactone/eplerenone
improve survival in pts with classification 3 or 4
use if still Sx, or post MI with LV systolic dysfunction
Monitor K+ (may cause hyperkalaemia).
- May be used to assist in the management of diuretic-induced hypokalaemia.
ARB in HF
candesartan
added in pts with persistent symptoms despite ACE inhibitors and B blockers
monitor K+ may cause hyperkalaemia
hydralazine and a nitrate in HF
May be added in patients (particularly in Afro-Caribbeans) with persistent symptoms despite therapy with an ACE inhibitor and b-blocker
cardiac resynchronisation therapy in HF
Biventricular pacing improves symptoms and survival in patients with LVEF <=35%, cardiac dyssynchrony (QRS>120msec) and moderate to severe symptoms despite optimal medical therapy.
Most patients who meet these criteria are also candidates for an implantable cardiac defibrillator (ICD) and receive a combined device.
digoxin in HF
helps sx even if in sinus rhythm
give in pts with LV systolic dysfunction of still sx or signs when have standard therapy (inc ACEi or B blocker) or AF
monitor UE - low K = risk toxicity
Mx of intractable HF
- reassess cause
- switch furosemide to butmetanide
- minimal exertion
- Na and fluid restriction
- metolazone and IV furosemide
- opiates and IV nitrates - relieve sx
- weigh daily
- frequent UE - beware low K
in extremis - IV ionotropes
consider cardiac resynchronisation, LV assist device or transplant
palliative care for HF
treat/prevent co-morbidities eg flu vaccine
good nutrition
tackly dyspnoiea, nausea, constipation, and low mood
opiates - pain and dyspnoea
ox
L ventricular assist devices
bridging therapy while waiting for heart transplant
pump force blood through tubing from LV to aorta
