Variable Label (VAR)	Variable Name	Category	N(%)	N(Missing)	Mean(SD)	Median(Q1,Q3)	Range of Values	
A1. Blind_ID	BLIND_ID			16(0)	596.88(247.71)	715.00(423.50,778.50)	40.00-844.00	
								
A3. Study visit	STUDYVISIT	Stage III (FONTAN)	16(100.0)					
								
B1. Patient's age (years) at start of 24 hour ECG	PATIENT_AGE_ECG24_S			16(0)	3.34(1.07)	3.29(2.56,4.02)	1.60-5.43	
								
B3. Predominant rhythm	PRED_RHYTHM	Atrial Escape	1(6.3)					
								
		Junctional Escape	1(6.3)					
								
		Normal Sinus Rhythm	12(75.0)					
								
		Other	2(12.5)					
								
B3a. If predominant rhythm other, specify	PR_RHY_OTH			()	()	(,)	-	
								
B3b. If paced, specify mode	PACED_MODE	Skipped	16(100.0)					
								
B3b1. If paced mode other, specify	PACED_OTH			()	()	(,)	-	
								
B4. Other rhythms	OTH_RHYTHM	No	12(75.0)					
								
		Yes	4(25.0)					
								
B4a. Other rhythms: junctional escape beats	OTH_RHY_JUN	No	1(6.3)					
								
		Skipped	12(75.0)					
								
		Yes	3(18.8)					
								
B4b. Other rhythms: other	OTH_RHY_OTH	No	2(12.5)					
								
		Skipped	12(75.0)					
								
		Yes	2(12.5)					
								
B4b1. Other rhythms: other, specify	OTH_R_OTH_SP			()	()	(,)	-	
								
C1. Atrial ectopy	ATRIAL_ECTOP	No	8(50.0)					
								
		Yes	8(50.0)					
								
C1a. Atrial ectopy: Isolated	A_ECT_ISOL	Skipped	8(50.0)					
								
		Yes	8(50.0)					
								
C1a1. Atrial ectopy: Isolated, number of beats	A_NUM_BEATS			6(10)	7.33(13.09)	2.50(1.00,3.00)	1.00-34.00	
								
C1b. Atrial ectopy: Couplets	A_ECT_COUP	No	7(43.8)					
								
		Skipped	8(50.0)					
								
		Yes	1(6.3)					
								
C1b1. Atrial ectopy: Number of couplets	A_NUM_COUP			1(15)	1.00()	1.00(1.00,1.00)	1.00-1.00	
								
C1c. Atrial ectopy: Non-sustained tachyarrhythmia	A_NSUS_TACHY	No	8(50.0)					
								
		Skipped	8(50.0)					
								
C1c1. Non-sustained tachyarrhythmia, total number of episodes	A_NUM_TACHY							
								
C1c2. Non-sustained tachyarrhythmia, specify	A_TACHY_TYPE	Missing	8(50.0)					
								
		Skipped	8(50.0)					
								
C1c2i. If other, specify	A_TYPE_SP			()	()	(,)	-	
								
C1d. Atrial ectopy: Sustained tachyarrhythmia	AS_TACHY	No	8(50.0)					
								
		Skipped	8(50.0)					
								
C1d1. Sustained tachyarrhythmia, total number of episodes	AS_NUM_TACHY							
								
C1d2. Sustained tachyarrhythmia, specify type	AS_TACHY_SP	Missing	8(50.0)					
								
		Skipped	8(50.0)					
								
C1d2i. If other, specify	AS_TYPE_SP			()	()	(,)	-	
								
C2. Ventricular ectopy	VENTR_ECTOP	No	9(56.3)					
								
		Yes	7(43.8)					
								
C2a. Ventricular ectopy: Isolated	V_ECTOP_ISOL	Skipped	9(56.3)					
								
		Yes	7(43.8)					
								
C2a1. Ventricular ectopy: Isolated, number of beats	V_NUM_BEATS			6(10)	122.00(224.02)	16.50(1.00,129.00)	1.00-568.00	
								
C2b. Ventricular ectopy: Couplets	V_ECT_COUP	No	6(37.5)					
								
		Skipped	9(56.3)					
								
		Yes	1(6.3)					
								
C2b1. Ventricular ectopy: Couplets, total number	V_NUM_COUP			1(15)	145.00()	145.00(145.00,145.00)	145.00-145.00	
								
C2c. Ventricular ectopy: Non-sustained tachyarrhythmia	V_NSUS_TACHY	No	6(37.5)					
								
		Skipped	9(56.3)					
								
		Yes	1(6.3)					
								
C2c1. Ventricular ect Non-sustained tachyarrhythmia, number of epi	V_NUM_TACHY			1(15)	3.00()	3.00(3.00,3.00)	3.00-3.00	
								
C2d. Ventricular ectopy: Sustained tachyarrhythmia	VS_TACHY	No	7(43.8)					
								
		Skipped	9(56.3)					
								
C2d1. Ventricular ect: Sustained tachyarrhythmia, number of episod	VS_NUM_TACHY							
								
D1. Length of recording	LENGTH_REC			14(2)	22.92(2.64)	24.00(23.90,24.00)	14.50-24.20	
								
D2. Average heart rate (entire recording)	AVE_H_RATE			16(0)	92.75(14.54)	94.50(88.50,100.50)	48.00-111.00	
								
D3. Maximum heart rate (entire recording)	MAX_H_RATE			16(0)	152.38(26.22)	158.00(144.00,168.00)	73.00-182.00	
								
D4. Minimum heart rate (entire recording)	MIN_H_RATE			16(0)	58.00(13.44)	54.50(49.00,63.50)	40.00-85.00