Heart failure Flashcards
definition
cardiac output is inadequate for the body’s requirements
systolic failure
inability of the ventricle to contract normally, resulting in decreased cardiac output
ejection fraction <40%
causes:
IHD, MI, cardiomyopathy
NB systolic and diastolic failure usually coexist
diastolic failure
inability of the ventricle to relax and fill normally, resulting in increased filling pressures
ejection fraction is >50%
causes:
constrictive pericarditis, tamponade, restrictive cardiomyopathy, HTN
NB systolic and diastolic failure usually coexist
left vs right sided failure
may occur independently, or together as congestive cardiac failure
LVF:
Sx: dyspnoea, poor exercise tolerance, fatigue, orthopnoea, PND, nocturnal cough +/- pink frothy sputum, wheeze (cardiac asthma), nocturia, cold peripheries, weight loss, muscle wasting
RVF:
Causes: LVF, pulmonary stenosis, lung disease
Sx: peripheral oedema, ascites, nausea, anorexia, facial engorgement, pulsation in neck and face (tricuspid regurg), epistaxis
acute heart failure
often exclusively used to mean new onset acute or decompensated chronic HF characterised by pulmonary and/or peripheral oedema with or without signs of peripheral hypoperfusion
chronic heart failue
develops or progresses slowly
venous congestion is common but arterial pressure is well maintained until late
low output HF
CO is reduced and fails to increase normally with exertion
causes:
pump failure: systolic and diastolic HF, decreased HR (eg b-blockers, heart block, post MI), negatively inotropic drugs (most antiarrhythmic agents)
excessive preload:
eg mitral regurg or fluid overload (eg NSAID causing fluid retention). fluid retention may cause LVF in a normal heart if renal excretion is impaired or large volumes are involved (eg IVI too fast). more common if there is simultaneous compromise of cardiac function and in the elderly
chronic excessive afterload: eg aortic stenosis, HTN
high output HF
this is rare
output is normal or increased in the face of very high needs
failure occurs when CO fails to meet those needs
it will occur with a normal heart, or even sooner if there is heart disease
causes:
anaemia, pregnancy, hyperthyroidism, Paget’s disease, arteriovenous malformation, beri beri
consequences:
initially features of RVF, later LVF becomes evident
investigations
if ECG and B-type natriuretic peptide are normal, unlikely to be heart failure. if either is abnormal, perform echo
framingham criteria for congestive heart failure
2 major or 1 major + 2 minor
major: PND crepitations S3 gallop cardiomegaly increased central venous pressure weight loss (>4.5kg in 5 days) neck vein distension acute pulmonary oedema hepatojugular reflux
minor: bilateral ankel oedema dyspnoea on normal exertion HR >120BPM decrease in vital capacity nocturnal cough hepoatomegaly pleural effusion
treatment of chronic heart failure
diuretics: loop diuretics (eg furosemide). add K sparing diuretic (spironolactone) if K drops
ACEi: consider in all with left ventricular systolic dysfunction. switch to ARB if persistent cough
B-blockers: decrease mortality. benefits additional to ACEi in patients with HF due to LV dysfunction. initiate after diuretic and ACEi. start low and go slow with dose
spironolactone: decreases mortality by 30% when used with conventional therapy. use if symptomatic despite optimal therapy listed above
digoxin: helps symptoms even in those with sinus rhythm
vasodilators: used if intolerant of ACEi and ARBs , and also reduce mortality in conjunction with regular treatment
acute heart failure treatment
MEDICAL EMERGENCY
sit patient upright
100% O2 if no pre-existing lung condition
IV access and monitor ECG - treat any arrhythmias eg AF
investigations whilst continuing treatment - CXR, ECG, U+Es, troponin, ABG, consider echo, plasma BNP
diamorphine 1.25-5mg IV slowly - caution in liver failure and COPD
furosemide IV 40-80mg slowly - increase dose in renal failure
GTN spray 2 puffs SL - don’t give if systolic BP<90mmHg
necessary investigations, examination and history
if systolic BP>100, start nitrate infusion eg isosorbide dinitrate 2-10mg/h IVI, keep systolic BP >90
if the patient is worsening:
further dose furosemide, 40-80mg
consider CPAP - improves ventilation and recruiting more alveoli, driving fluid out of alveolar spaces and into vasculature
increase nitrate infusion (vasodilator) if able to do so without dropping BP <100
if systolic BP<100mmHg, treat as cardiogenic shock and refer to ICU
