Prospective pre- and post-race evaluation of biochemical, electrophysiologic, and echocardiographic indices in 30 racing thoroughbred horses that received furosemide

Table 1 Selected ECG and echocardiogram parameters recorded prior to race and within 30–60 min after the race start time are listed

	Pre-race (T0)	RI (pre-race)	Post-race (T1)	RI (post-race)	P value
ECG
PR interval (sec)	0.279 (+/−0.049)	0.211–0.381	0.193 (+/−0.035)	0.146–0.259	<0.0001
QRS duration (sec)	0.098 (+/−0.013)	0.075–0.118	0.093 (+/−0.012)	0.073–0.113	.0789
QT interval (sec)	0.445 (+/− 0.053)	0.355–0.567	0.353 (+/− 0.047)	0.271–0.436	<0.0001
QTc interval (sec)	0.507 (+/− 0.051)	0.438–0.591	0.417 (+/− 0.024)	0.371–0.454	<0.0001
ST segment (mV)	1.3 (0.6,2.3)	0.2–2.9	1.8 (+/−1.0)	0.4–3.6	0.1115
HR (bpm)	39 (32,45)	26–63	86 (69,100)	58–126	<0.0001
Echocardiogram
LAD Sax (cm)	10.9 (+/−0.7)	9.8–12.2	10.1 (+/−0.9)	8.4–11.4	<0.0001
LAD Lax (cm)	13.0 (+/−0.7)	11.8–14.7	11.8 (+/− 1.1)	10.1–13.5	<0.0001
Ao (cm)	7.5 (+/−0.6)	6.6–8.6	7.3 (+/−0.5)	7.4–8.4	0.1547
IVSd (cm)	3.3 (+/−0.4)	2.7–4.0	3.5 (+/−0.4)	2.8–4.2	0.0117
LVIDd (cm)	12.1 (+/−1.0)	10.5–13.7	10.9 (+/−1.2)	8.5–13.0	<0.0001
LVIDs (cm)	6.9 (+/− 1.1)	5.0–8.7	5.5 (+/−1.2)	3.3–7.4	<0.0001
LVFWd (cm)	2.8 (+/−0.3)	2.2–3.4	2.8 (+/−0.5)	2.2–3.7	0.7321
FS (%)	42.2 (+/−7.6)	30.8–58.0	50.0 (+/−8.2)	38.4–67.1	<0.0001

Pre- (T0) and post-race values (T1) were compared and the P value is reported. The P value is bolded when a significant difference between T0 and T1 was present. The QT interval was corrected for HR (QTc) using Bazett’s formula. Normally distributed data is reported in mean +/− standard deviation. Non-parametric data is reported in median with interquartile range in parenthesis. Reported with reference intervals (RI) computed using a non-parametric approach (ie. without any distributional assumptions) using percentiles 0.025 and 0.975 to report 95% reference range

ISSN: 1746-6148