Features
Implications
- Myocardium less contractile
- Ventricle is less compliant and less able to generate tension during contraction
- Limits size of and changes in stroke volume
- Cardiac output becomes rate dependent
- Bradycardia associated with reduced cardiac output and in the neonate external compression should be started if the rate is <60 bpm
- Myocardium less contractile
- Ventricle is less compliant and less able to generate tension during contraction
- Limits size of and changes in stroke volume
- More prone to developing low cardiac output ('cold') shock during sepsis
- Vagal parasympathetic tone is most dominant
- Sinus arrhythmia is common
- Prone to bradycardia with hypoxia, which should should be treated with oxygen and ventilation initially
- Vagal parasympathetic tone is most dominant
- Sinus arrhythmia is common
- Prone to bradycardia with hypoxia, which should should be treated with oxygen and ventilation initially
- Resting and maximal heart rate values decrease spontaneously with age
- Age dependent parameters should be targeted during resuscitation
- Cardiac output is 300-400 ml/kg/min at birth and decreases to 200 ml/kg/min within a few months
- Age dependent parameters should be targeted during resuscitation
- Ductus arteriosus contracts in the first few days of life and fibroses within 2-4 weeks
- Closure is pressure dependent with neonatal pulmonary vasculature reacting to the rise in PaO2 and pH and the fall in PaCO2 at birth
- Alterations in pressure and in response to hypoxia and acidosis can lead to reversion to the transitional circulation in the first few weeks after birthv