Figliozzi et al reported a nomogram for predicting cardiac involvement in Fabry disease. This can help to identify a patient who may require a more complete cardiac assessment. The authors are from mulitple institutions in Italy, the United States and Switzerland.
Patient selection: Fabry disease
Parameters:
(1) QRS in msec, from 80 to 160
(2) QT interval in msec, from 320 to 560
(3) Sokolow Lyon index, from 1 to 6.5
(4) P wave to PR segment ratio, from 0 to 5
points for QRS =
= (0.896 * (QRS)) - 71.7
points for QT interval =
= (0.304 * (QT)) - 97.3
points for Sokolow-Lyon index =
= (16.2 * (SLI)) - 16.2
points for P wave to PR segment ratio =
= 20 * (ratio)
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 333.9
value of X =
= (0.073 * (score)) - 7.27
probability of Fabry involvement of the heart =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.90 in the test group and 0.81 in validation.
