Table 3. ECG findings in T.cruzi seropositive blood donors by LVEF.

ECG variables	LVEF<0.50	LVEF> = 0.50	p-value*
	N = 36	N = 461
Rhythm
Sinus tachycardia	0	0
Sinus bradycardia	1 (3)	20 (4)
Frequent VPB	2 (6)	10 (2)
Frequent SPB	3 (8)	6 (1)	0.02
Atrial fibrillation or flutter	2 (6)	0	0.005
Pacemaker	3 (8)	2 (<1)	0.003
Intraventricular block
LBBB	1 (3)	0
RBBB	10 (28)	70 (15)	0.04
LAFB	13 (38)	61 (13)	<0.0001
LAFB+RBBB	9 (25)	9 (2)	<0.0001
Incomplete LBBB	0	13 (3)
Incomplete RBBB	5 (14)	30 (7)
Atrioventricular block
First degree	2 (6)	12 (3)
Second degree	0	1 (<1)
Third degree	0	0
Ischemic
Old MI	4 (11)	8 (2)	0.008
Major isolated ST-T abnormalities	7 (19)	16 (3)	<0.0001
Minor isolated ST-T abnormalities	12 (33)	47 (10)	<0.0001
ST segment elevation	0	20 (4)
Other
LVH	0	1 (<1)
Short PR interval	0	16 (3)
Major QT prolongation	1 (3)	2 (<1)
Minor QT prolongation	1 (3)	7 (2)
Low QRS amplitude	1 (3)	16 (3)

^*Reported if <0.05. VBP: ventricular premature beats; SPB: supraventricular premature beats; LBBB: left bundle branch block; RBBB: right bundle branch block; LAFB: left anterior fascicular block; Old MI: Old myocardial infarction, defined as major Q wave or minor Q waves with ST-T abnormalities; LVH: Left ventricular hypertrophy; major QT prolongation: QTi>115%; minor QT prolongation: QTi>111%; QTi: QT prolongation index: (QT/656) * (HR+100).