Cardiac Failure (acute and chronic)

Question 1

Definition

Answer 1

Inability of the cardiac output to meet the body’s demands despite normal venous pressures

Question 2

Aetiology/Risk factors (low output, left cardiac failure)

Answer 2

· Ischaemic heart disease

· Hypertension

· Cardiomyopathy

· Aortic valve disease

· Mitral regurgitation

Question 3

Aetiology/Risk factors (low output, right cardiac failure)

Answer 3

· Secondary to left heart failure (in which case it is called congestive cardiac failure)

· Infarction

· Cardiomyopathy

· Pulmonary hypertension/embolus/valve disease

· Chronic lung disease

· Tricuspid regurgitation

· Constrictive pericarditis/pericardial tamponade

Question 4

Aetiology/Risk factors (low output, biventricular failure)

Answer 4

· Arrhythmia

· Cardiomyopathy (dilated or restrictive)

· Myocarditis

· Drug toxicity

Question 5

Aetiology/Risk factors (high output cardiac failure)

Answer 5

o Anaemia

o Beri beri

o Pregnancy

o Paget’s disease

o Hyperthyroidism

o Arteriovenous malformation

Question 6

Epidemiology

Answer 6

10% > 65 yrs old

Question 7

Presenting symptoms (left heart failure)

Answer 7

Symptoms caused by pulmonary congestion

o Dyspnoea - divided based on the New York Heart Association classification:
· 1 - no dyspnoea
· 2 - dyspnoea on ordinary activities
· 3 - dyspnoea on less than ordinary activities
· 4 - dyspnoea at rest

o Orthopnoea
o Paroxysmal nocturnal dyspnoea
o Fatigue

Question 8

Presenting symptoms (acute left ventricular failure)

Answer 8

o Dyspnoea

o Wheeze

o Cough

o Pink frothy sputum

Question 9

Presenting symptoms (right heart failure)

Answer 9

o Swollen ankles

o Fatigue

o Increased weight (due to oedema)

o Reduced exercise tolerance

o Anorexia

o Nausea

Question 10

Signs on physical examination (left heart failure)

Answer 10

o Tachycardia

o Tachypnoea

o Displaced apex beat

o Bilateral basal crackles

o S3 gallop (caused by rapid ventricular filling)

o Pansystolic murmur (due to functional mitral regurgitation)

Question 11

Signs on physical examination (acute left ventricular failure)

Answer 11

o Tachypnoea
o Cyanosis
o Tachycardia
o Peripheral shutdown

o Pulsus alternans
· Arterial pulse waveforms showing alternating strong and weak beats
· Sign of left ventricular systolic impairment
(Explanation:
§ In left ventricular dysfunction, ejection fraction significantly decreases leading to a reduction in stroke volume
§ This causes an increase in end-diastolic volume
§ This means that the left ventricle is stretched more for the next contraction
§ Due to Starling’s Law, the increased stretch of the left ventricle caused by the increased end-diastolic volume following the previous beat leads to an increase in the strength of the myocardial contraction
§ This results in a stronger systolic pulse

o Gallop rhythm
o Wheeze (cardiac asthma)
o Fine crackles throughout lung

Question 12

Signs on physical examination (right heart failure)

Answer 12

o Raised JVP

o Hepatomegaly

o Ascites

o Ankle/sacral pitting oedema

o Signs of functional tricuspid regurgitation

Question 13

Investigations (bloods)

Answer 13

o FBC
o U&E
o LFTs
o CRP
o Glucose
o Lipids
o TFTs

In acute left ventricular failure:
o ABG
o Troponin
o BNP
· Raised plasma BNP suggests diagnosis of cardiac failure
· Low plasma BNP rules out cardiac failure (90% sensitivity)

Question 14

Investigations (other)

Answer 14

· CXR (abcde)
o Alveolar shadowing
o Kerley B lines
o Cardiomegaly
o Upper Lobe Diversion
o Pleural Effusion

· ECG
o May be normal
o May show ischaemic changes (pathological q waves, t wave inversion)
o May show arrhythmia or left ventricular hypertrophy

· Echocardiogram
o Assess ventricular contraction
o Systolic dysfunction = LV ejection fraction < 40%
o Diastolic dysfunction = decreased compliance of the myocardium leads to restrictive filling defect

· Swan-Ganz Catheter
o Allows measurement of right atrial, right ventricular, pulmonary artery, pulmonary wedge and left ventricular end-diastolic pressures

Question 15

Management plan (acute left ventricular failure)

Answer 15

o Treating Cardiogenic Shock:
· This is severe cardiac failure with low blood pressure
· Requires the use of inotropes (e.g. dobutamine)
· Managed in ITU

o Treating Pulmonary Oedema:
· Sit the patient up
· 60-100% Oxygen (and consider CPAP)
· Diamorphine (venodilator + anxiolytic)
· GTN infusion (venodilator –> reduced preload)
· IV furosemide (venodilator and later diuretic effect)

· Monitor:
§ BP
§ Respiratory rate
§ Oxygen saturation
§ Urine output
§ ECG

· TREAT THE CAUSE! (e.g. MI, arrhythmia)

Question 16

Management plan (chronic left ventricular failure)

Answer 16

o TREAT THE CAUSE (e.g. hypertension)
o TREAT EXACERBATING FACTORS (e.g. anaemia)

ACE inhibitors
Beta-blockers
Loop diuretics
Aldosterone antagonists
Angiotensin receptor blockers
Hydralazine and a Nitrate
Digoxin
N-3 polyunsaturated fatty acids
Cardiac resynchronisation therapy

o CAUTION: avoid drugs that could adversely affect a patient with heart failure due to systolic dysfunction (e.g. NSAIDs, non-dihydropyridine CCBs)

Question 17

Possible complications

Answer 17

· Respiratory failure

· Cardiogenic shock

· Death

Question 18

Prognosis

Answer 18

· 50% with cardiac failure die within 2 years