Cardiac failure (acute & chronic) Flashcards
Define cardiac failure
Inability of cardiac output to meet body’s demands despite normal venous pressures
Aetiology of cardiac failure
2 types of cardiac failure
Low output cardiac failure - reduced CO
High output cardiac failure - increased demand
Aetiology of low output cardiac failure
3 types
Left heart failure
Right heart failure
Biventricular failure
Aetiology of low output cardiac failure - left heart failure
5
Ischaemic heart disease Hypertension Cardiomyopathy Aortic valve disease Mitral regurgitation
Aetiology of low output cardiac failure - right heart failure
(7)
Secondary to left heart failure (= congestive cardiac failure)
Infarction
Cardiomyopathy
Pulmonary hypertension/embolus/valve disease
Chronic lung disease
Tricuspid regurgitation
Constrictive pericarditis/pericardial tamponade
Aetiology of low output cardiac failure - biventricular failure
(4)
Arrhythmia
Cardiomyopathy (dilated or restrictive)
Myocarditis
Drug toxicity
Aetiology of high output cardiac failure
6
Anaemia Beri beri Pregnancy Paget's disease Hyperthyroidism Arteriovenous malformation
Epidemiology of cardiac failure
10% >65 yrs old
Presenting symptoms of left heart failure
4
(symptoms caused by pulmonary congestion) Dyspnoea Orthopnoea Paroxysmal nocturnal dyspnoea Fatigue
Presenting symptoms of acute left ventricular failure
4
Dyspnoea
Wheeze
Cough
Pink frothy sputum
Presenting symptoms of right heart failure
6
Swollen ankles Fatigue Increased weight (due to oedema) Reduced exercise tolerance Anorexia Nausea
New York Heart Association classification of dyspnoea
4
1 - no dyspnoea
2 - dyspnoea on ordinary activities
3 - dyspnoea on less than ordinary activities
4 - dyspnoea at rest
Signs of left heart failure on physical examination
6
Tachycardia
Tachypnoea
Displaced apex beat
Bilateral basal crackles
S3 gallop (caused by rapid ventricular filling)
Pansystolic murmur (due to functional mitral regurgitation)
Signs of acute left ventricular failure on physical examination
(8)
Tachypnoea Cyanosis Tachycardia Peripheral shutdown Pulsus alternans Gallop rhythm Wheeze (cardiac asthma) Fine crackles throughout lung
Signs of right heart failure on physical examination
5
Raised JVP Hepatomegaly Ascites Ankle/sacral pitting oedema Signs of functional tricuspid regurgitation
Definition & aetiology of pulses alternans
1 +4
Arterial pulse waveforms showing alternating strong & weak beats
Sign of left ventricular systolic impairment
In left ventricular dysfunction, ejection fraction significantly decreases —> reduced stroke volume
Left ventricle is stretched more for next contraction due to increased end-diastolic volume of previous beat —> increased strength of myocardial contraction (Starling’s law)
Results in stronger systolic pulse
Investigations for cardiac failure
5 groups
Bloods CXR ECG Echocardiogram Swan-Ganz catheter
Investigations for cardiac failure - bloods
7 + 3 acute ventricular
FBC U&Es LFTs CRP Glucose Lipids TFTs
ABG
Troponin
BNP -
Raised plasma BNP suggest diagnosis of cardiac failure
Low plasma BNP rules out cardiac failure (90% sensitivity)
Investigations for cardiac failure - CXR
5
ABCDE Alveolar shadowing Kerley B lines Cardiomegaly Upper lobe diversion Pleural effusion
Investigations for cardiac failure - ECG
3
May be normal
May show ischaemic changes (pathological q waves, t wave inversion)
May show arrhythmia or left ventricular hypertrophy
Investigations for cardiac failure - echocardiogram
3
Assess ventricular contraction
Systolic dysfunction = LV ejection fraction <40%
Diastolic dysfunction = decreased compliance of myocardium leads to restrictive filling defect
Investigations for cardiac failure - Swan-Ganz catheter
Allows measurement of right atrial, right ventricular, pulmonary artery, pulmonary wedge & left ventricular end-diastolic pressures
Management of acute left ventricular failure
2 groups
Treating cardiogenic shock
Treating pulmonary oedema
Management of acute left ventricular failure - cardiogenic shock
(3)
Severe cardiac failure w/ low BP
Requires use of inotropes (e.g. dobutamine)
Managed in ITU
Management of acute left ventricular failure - pulmonary oedema
(7)
Sit patient up
60-100% oxygen (consider CPAP)
Diamorphine (venodilator + anxiolytic)
GTN infusion (venodilator —> reduced preload)
IV furosemide (venodilator + later diuretic effect)
Monitor BP resp rate oxygen saturation urine output ECG
Treat the cause (e.g. MI, arrhythmia)
Management of chronic left ventricular failure
2 general + 9
Treat the cause (e.g. hypertension)
Treat the exacerbating factors (e.g. anaemia)
ACE inhibitors
β-blockers
Loop diuretics
Aldosterone antagonists
Angiotensin receptor blockers
Hydralazine & a nitrate
Digoxin
N-3 polyunsaturated fatty acids
Cardiac resynchronisation therapy
(Avoid drugs that could adversely affect patient w/ heart failure due to systole dysfunction - e.g. NSAIDS, non-dihydropyridine CCBs)
Management of chronic left ventricular failure - ACE inhibitors
(2)
Inhibit renin-angiotensin systen & inhibit adverse cardiac remodelling
Slow down progression of heart failure & improve survival
Management of chronic left ventricular failure - β blockers
3
Block effects of chronically activated sympathetic system
Slow progression of heart failure & improve survival
Benefits of ACE inhibitors & β-blockers are additive
Management of chronic left ventricular failure - loop diuretics
Alongside dietary salt restriction, can correct fluid overload
Management of chronic left ventricular failure - aldosterone antagonists
(2)
Improve survival in patients w/ NYHA class III/IV symptoms on standard therapy Monitor K+ (these drugs may cause hyperkalaemia)
Management of chronic left ventricular failure - angiotensin receptor blockers
(2)
May be added in patients w/ persistent symptoms despite use of ACE inhibitors & β-blockers
Monitor K+ (these drugs may cause hyperkalaemia)
Management of chronic left ventricular failure - hydralazine & a nitrate
May be added in patients (particularly Afro-Caribbeans) w/ persistent symptoms despite use of ACE inhibitors & β-blockers
Management of chronic left ventricular failure - digoxin
2
Positive inotrope
Reduces hospitalisation but does NOT improve survival
Management of chronic left ventricular failure - N-3 polyunsaturated fatty acids
Provide small beneficial advantage in survival
Management of chronic left ventricular failure - cardiac resynchronisation therapy
(3)
Biventricular pacing improves symptoms & survival in patients w/ left ventricular ejection fraction <35%, cardiac desynchrony (GRS >120 ms) & moderate severe symptoms
Also candidates for implantable cardioverter defibrillator (ICD)
May receive a combined device
