. 2018 Aug 12;2018(3):24. doi: 10.21542/gcsp.2018.24

Table 2. Summary of evidence for ‘Minor’ risk factors for sudden cardiac death in childhood hypertrophic cardiomyopathy.

Clinical risk factors	Summary of evidence
Gender	No studies have reported a significant association between SCD and gender
Age	Presentation in infancy is associated with an increased risk of mortality secondary to congestive cardiac failure^5,8. Outside infancy the majority of studies found no association with age and risk of SCD.
Symptoms	A wide range of symptoms can be seen in childhood HCM and the role of symptoms in risk stratification for SCD has not been systematically assessed.
Family history of SCD	Only 1 paediatric study has reported a significant association with SCD¹⁵.
ECG changes	QTc dispersion has been reported to be associated with SCD in 2 studies^13,17.
	Other ECG parameters that have been analysed include RS sum²³ and heart rate variability^31,32.
Abnormal BP response to exercise	No studies have reported a significant association with SCD
Left atrial enlargement	Increased left atrial size was associated with an increased risk of SCD in two studies^17,24,25
Left ventricular outflow tract obstruction	Only 1 paediatric study reported an increased risk of SCD with increasing LVOT gradient¹⁷. A gradient above 30mmHg was not predictive of SCD in this study.
Restrictive physiology	Echocardiographic markers for restrictive physiology may increase the risk for SCD^17,24,25
Late Gadolinium enhancement (LGE) on cardiac Magnetic Resonance	The presence of LGE has been shown to be associated with increased LV wall thickness/mass^33,34. An independent role for LGE in predicting SCD in childhood HCM has not been show.