Sinoatrial node dysfunction induces cardiac arrhythmias in diabetic mice

Table 2 Heart-rate variability parameters obtained in anesthetized control (db/+) and diabetic (db/db) mice before and after 16 hours fasting

	Db/+, fed	Db/db, fed	Db/+, fasted	Db/db, fasted
RR, ms	124 ± 4	131 ± 3	137 ± 4 †	154 ± 4*†
HR, bpm	483 ± 17	458 ± 12	438 ± 11 †	390 ± 10*†
SDRR, ms	4.4 ± 1.0	5.0 ± 0.9	5.3 ± 0.8	6.0 ± 1.6
SD∆RR, ms	2.1 ± 0.3	3.2 ± 0.6	2.8 ± 0.6	4.7 ± 0.7*
pRR6,%	3 ± 4	11 ± 5^a	8 ± 3	22 ± 6*
LF Power, μs²	0.9 ± 0.2	0.9 ± 0.4	1.0 ± 0.4	2.5 ± 1.0
HF Power, μs²	2.4 ± 0.6	7.9 ± 3.8	6.1 ± 3.4	15.4 ± 4.3^a
LF Power, %	32 ± 4	17 ± 4	17 ± 4	15 ± 5
HF Power, %	67 ± 4	84 ± 4	84 ± 4	86 ± 5
LF/HF	55 ± 11	25 ± 10	24 ± 9	19 ± 4
n	12	12	10	9

Abbreviations: HR (bpm) heart rate in beats per minute, SDRR standard deviation of RR intervals, SD∆RR standard deviation of the difference between successive RR intervals, pRR6 percentage of normal consecutive RR intervals differing by >6 ms, LF power absolute and normalized power contained within the low frequency range (0.15-1.5 Hz), HF power absolute and normalized power contained within the high frequency range (1.5-5.0 Hz). See reference [27]. Two-way ANOVA with a post hoc Bonferroni t test when appropriate. *, P < 0.05 versus db/+ mice; †, P < 0.05 versus fed mice of the same genotype; ^a, P = 0.063 versus db/+. One mouse was excluded from the db/+, fasted group due to technical difficulties with anesthesia.

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