Norrish et al reported a model for predicting sudden cardiac death in a pediatric patient with hypertrophic cardiomyopathy (HCM). The authors are from multiple institutions from around the world.
Patient selection: pediatric patient with hypertrophic cardiomyopathy
Parameters:
(1) maximal left ventricular wall thickness (MWT) in mm on transthoracic echo (TTE)
(2) mean for MWT
(3) standard deviation for MWT
(4) LA diameter in mm by M-mode or 2D echo in the parasternal long axis plane
(5) mean for LA diameter
(6) standard deviation for LA diameter
(7) unexplained syncope
(8) nonsustained ventricular tachycardia (NSVT; >= 3 consecutive ventricular beats at a rate >= 120 bpm and < 30 seconds in duration)
(9) maximal left ventricular outflow track (LVOT) gradientin mm Hg (based on aortic outflow velocity)
z-score for MWT =
= ((patient MWT) - (mean MWT)) / (standard deviation)
z-score for left atrial diameter =
= ((patient LA diameter) - (mean LA diameter)) / (standard deviation)
|
Parameter
|
Finding
|
Points
|
|
z-score for MWT
|
|
(0.2171364 * ((MWT z score) - 11.09)) - (0.0047562 * (((MWT z-score)^2) - 174.12))
|
|
z-score for LA diameter
|
|
0.130365 * ((LA diameter z-score) - 1.92)
|
|
unexplained syncope
|
absent
|
0
|
|
|
present
|
0.429624
|
|
NSVT
|
absent
|
0
|
|
|
present
|
0.1861694
|
|
maximal LVOT gradient
|
|
-0.0065555 * ((gradient) - 21.8)
|
total score =
= SUM(points for all of the parameters)
probability of sudden cardiac death at 5 years=
= 1 - (0.949437808^(EXP(score)))
Performance:
• The area under the ROC curve is 0.69.
