Table 1.

Characteristics of Children with Familial Dilated Cardiomyopathy or Idiopathic Dilated Cardiomyopathy.

Characteristic	Overall	FDCM	IDCM	P Value*
N†	870	223	647
Age at diagnosis
Mean (SD), years	4.9 (5.9)	6.2 (6.4)	4.5 (5.8)	0.001
Median (IQR), years	1.2 (0.3–10.3)	3.3 (0.3–12.1)	1.0 (0.3–9.2)	0.04
Age < 1 year at diagnosis, %	47.4	42.2	49.2	0.07
Male, %	50.6	54.7	49.1	0.16
Race/ethnicity, %				0.06
White	54.2	60.1	52.2
Black	21.2	16.1	23.0
Hispanic	17.3	15.1	18.0
Other	7.3	8.7	6.8
Congestive heart failure at diagnosis, %	74.6	64.1	78.2	< 0.001
Family history of sudden death, % (total n)	10.5 (727)	39.0 (159)	2.5 (568)	< 0.001
Left ventricular echocardiographic z-scores, mean (SD)
End-diastolic dimension (total n = 699, 175, 524)	4.71 (2.60)	4.12 (2.61)	4.91 (2.57)	< 0.001
End-systolic dimension (total n = 614, 160, 454)	6.35 (3.00)	5.79 (2.89)	6.55 (3.01)	0.006
Fractional shortening (total n = 713, 183, 530)	−8.74 (3.95)	−7.85 (3.98)	−9.06 (3.89)	< 0.001
End-diastolic posterior wall thickness (total n = 553, 145, 408)	−0.60 (2.58)	−0.63 (2.66)	−0.59 (2.56)	0.86
End-diastolic septal thickness (total n = 515, 126, 389)	−0.98 (1.92)	−0.67 (1.99)	−1.09 (1.88)	0.03
Mass (total n = 545, 143, 402)	2.49 (2.78)	2.32 (3.08)	2.55 (2.67)	0.43
Medications at diagnosis (n)
Any cardiac medication	94.7% (786)	91.4% (198)	95.8% (588)	0.03
Anticongestive therapy¶	86% (843)	82.2% (213)	87.3% (630)	0.07
Antiarrhythmic therapy	20.6% (462)	13.7% (139)	23.5% (323)	0.02
ACE inhibitor	62.7% (461)	60.9% (138)	63.5% (323)	0.60
Beta blocker	13.2% (461)	15.1% (139)	12.4% (322)	0.46
Carnitine	1.5% (461)	0.7% (139)	1.9% (322)	0.68

FDCM, familial dilated cardiomyopathy; IDCM, idiopathic dilated cardiomyopathy; IQR, interquartile range.

^*P values compare the differences between FDCM and IDCM.

^†Sample size is smaller than the total stated for selected variables (family history; LV mass).

^¶Anticongestive therapy is defined as digoxin and/or diuretics