Zentner et al reported a simple score to screen a patient with an inherited cardiac disorder for mutational probability. This can help to guide genetic testing on the patient. The authors are from Royal Melbourne Hospital and University of Melbourne in Australia.
Patient selection: inherited cardiac disorder
Parameters:
(1) diagnostic certainty
(2) high risk features (young, ECG, echocardiography, MRI)
(3) pathologic high risk
(4) other high-risk features
(5) symptoms
(6) family history
(7) specific diagnosis
Young: < 35 years old for arrhythmia, cardiomyopathy or sudden death; < 50 years old for thoracic aortic dissection or dilatation.
ECG changes: QTc > 500 ms; conduction block; bidirectional ventricular tachycardia
Echocardiography or MRI: left ventricular wall > 30 mm; late gadolinium enhancement on MRI
Pathology: hypertrophic cardiomyopathy; arrhythmogenic ventricular cardiomyopathy
Other risk features: Marfan phenotype; multiple aneurysms; multiple vascular abnormalities; Brugada syndrome in a Southeast Asian patient
Symptoms: syncope, arrhythmia, aborted cardiac arrest; heart failure; aortic dilation or dissection
|
Parameter
|
Finding
|
Points
|
|
diagnosis
|
not certain
|
0
|
|
|
certain
|
2
|
|
high risk features
|
none
|
0
|
|
|
>= 1
|
1
|
|
pathologic high risk
|
no
|
0
|
|
|
yes
|
1
|
|
other high risk features
|
no
|
0
|
|
|
yes
|
1
|
|
symptoms
|
none
|
0
|
|
|
1
|
1
|
|
|
>= 2 (multiple)
|
2
|
|
family history
|
none
|
0
|
|
|
1 relative
|
1
|
|
|
>= 2 relatives (multiple)
|
2
|
|
diagnosis
|
dilated cardiomyopathy
|
1
|
|
|
hypertrophic CM
|
1
|
|
|
arrhythmogenic CM
|
1
|
|
|
Marfan syndrome
|
1
|
|
|
other
|
0
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 10 (maximum seen in study was 7)
• The higher the score the greater the likelihood of a mutation.
|
Score
|
Percent Mutation
|
|
1
|
5%
|
|
2-7
|
((score) - 1) * 15%
|
