Effects of nicardipine and diltiazem on fractal features of short-term heart rate variability?application of coarse graining spectral analysis

Koh, Junken; Hidaka, Ichiro; Miyata, Masahiko

doi:10.1007/s005400200003

Cited by 4 publications

(1 citation statement)

References 29 publications

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“…In particular, diltiazem markedly increased HF power in contrast to propranolol, which had substantially no effect. Potent actions of sympathetic activation through the arterial baroreceptor reflex induced by Ca 2+ -channel antagonists may account for the discrepancy between the actions of propranolol and diltiazem [34] .…”

Section: Discussionmentioning

confidence: 99%

Three Different Bradycardic Agents, Zatebradine, Diltiazem and Propranolol, Distinctly Modify Heart Rate Variability and QT-Interval Variability

Yamabe

Sanyal²,

Miyamoto³

et al. 2007

Pharmacology

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Zatebradine, diltiazem and propranolol are all antiarrhythmic agents, and all induce bradycardia, but each is known to have a different initial molecular mechanism: zatebradine is a channel blocker of the hyperpolarization-activated inward current (I_f ); diltiazem is a blocker of the L-type Ca²⁺ channel (I_CaL), and propranolol is a β-blocker. To further investigate the mechanisms underlying their clinical effects, we studied their effects on heart rate variability (HRV) and QT-interval variability (QTV). To this end, guinea pigs were treated with either zatebradine (1.5 mg/kg, i.p.), diltiazem (40 mg/kg, i.p.) or propranolol (20 mg/kg, i.p.). A dose of each agent that decreased HR by 20–22% was used in this study. HRV and QTV were analyzed by a fast Fourier and/or a wavelet transform algorithm. Zatebradine, an I_f channel blocker, had no significant effect on HRV and QTV. Diltiazem, a non-dihydropyridine I_CaL blocker, increased high frequency (HF) power and decreased the power ratio of the low frequency (LF) range to the HF range (L/H) in HRV, and increased QTV. Propranolol, a non-selective β-antagonist, decreased LF power and L/H ratios in HRV, and appreciably reduced QTV. These differences in pharmacological action may help us better understand the antiarrhythmic and/or proarrhythmic actions of these agents when they are used clinically for reducing HR.

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Section: Discussionmentioning

confidence: 99%