15.2.3 Cardiac Failure

Question 1

Define cardiac failure

Answer 1

• According to AHA: “complex clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood.”
• reduced ejection fraction (systolic ventricular dysfunction)
• preserved ejection fraction (diastolic ventricular dysfunction)
• Also defined as the inability of the heart to pump enough blood to meet the metabolic demand
• The clinical picture that we see is from the low output and the compensatory mechanisms

Question 2

Stroke vol and preload in failing heart vs normal heart

Answer 2

Slide 4

Normal heart - ⬆️ preload: ⬆️ stroke vol

Failing heart - ⬆️ preload : ↔️ stroke vol

Question 3

Heart failure results from

Answer 3

• vol overload
• pressure overload
• primary myocardial problem

Question 4

Physiological responses

Answer 4

• Renal retention of fluid
• Renin-angiotensin mediated vasoconstriction
• Sympathetic over activity
• Increasing cardiac output:
  • increasing end-diastolic volume (preload)
  • vasoconstriction (afterload)
  • increased heartrate
• children can go tachycardia to compensate

Question 5

Aetiology of cardiac failure in structurally normal heart

Answer 5

• Primary cardiomyopathies:
  • Idiopathic dilated cardiomyopathy
  • Hypertrophic cardiomyopathy
  • Left ventricular noncompaction cardiomyopathy (just non compaction)
  • Restrictive cardiomyopathy
  • Arrhythmogenic right ventricular dysplasia
• Myocarditis
• Toxic-related (chemo)
• Hypo-orhyperthyroidism
• Anthracyclinechemotherapy
• Radiationtoxicity
• Iron overload
• Ethanol
• Tachycardia-induced
• Rheumatic heart disease
• Metabolic disease (Inborn errors of metabolism; Mitochondrial disease)
• Kawasaki disease
• Muscular dystrophy
• Primary right ventricular failure (Pulmonary hypertension)

Question 6

Aetiology of cardiac failure in structurally abnormal heart

Answer 6

• Obstructive left heart lesions
• Regurgitant valvular lesions
• Large left-to-right shunts (most common)
• Postoperative ventricular dysfunction
• Anomalous left coronary artery from the pulmonary artery (always concerned about) {coronary artery not coming from aorta}
  ➡️ pressure in pulmonary artery that causes problem
  ➡️ 20mmHg diastolic pressure needed to fill coronary artery
  ➡️ pulmonary is only 10mmHg
• Primary right ventricular failure
  • Eisenmenger syndrome
  • Failure of systemic right ventricle

Question 7

Congenital heart disease

Answer 7

• cause HF through three general mechanisms
  • critical left sided obstructions
  • valvular regurgitation
  • left to right shunts

Question 8

Signs and symptoms of cardiac failure

Answer 8

Symptoms
- do no feed well (most common complaint) -> basically exercise that baby do
- poor weight gain
- failure to thrive
- irritability

Signs
- tachypnea
- tachycardia
- diaphoresis (during feeding)
- cyanosis
- murmurs
- resp distress
- BP abnormalities
- thrills or heaves

No oedema in children

Question 9

Ross classification of paediatric failure

Answer 9

Class I
- Asymptomatic

Class II
- Mild tachypnea or diaphoresis with feeding in infants; dyspnea on exertion in older children

Class III
- Marked tachypnea or diaphoresis with feeding in infants; prolonged feeding times with growth failure resulting from HF; marked dyspnea on exertion in older children

Class IV
- Symptoms such as tachypnea, retractions, grunting, or diaphoresis at rest