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Heart rate variability analysis during head-up tilt test predicts nitroglycerine-induced syncope.

Efremov K, Brisinda D, Venuti A, Iantorno E, Cataldi C, Fioravanti F, Fenici R - Open Heart (2014)

Bottom Line: HRV parameters were analysed from 5 min intervals selected during pretest supine rest (phase 1), the first 5 min (phase 2) and the last 5 min (phase 3) of passive 20 min of tilting, prior to the administration of nitroglycerine.In group 1, the HRV spectral parameters high frequency (HF) and total power (TP) had a significant decrement from phases 2 to 3 (p=0.012 and 0.027, respectively), while in group 2 the average HF and TP values did not change.If confirmed on a wider population, HRV analysis could replace nitroglycerine administration and shorten the duration of the tilt test.

View Article: PubMed Central - PubMed

Affiliation: Catholic University of the Sacred Heart, Biomagnetism Center, Clinical Physiology , Rome , Italy.

ABSTRACT

Objective: The aim of this study was to determine whether or not heart rate variability (HRV) analysis during the first 20 min of head-up tilt testing could predict whether patients will develop syncope after nitroglycerine administration.

Design: 64 patients with previous loss of consciousness underwent head-up tilt testing with the Italian protocol, which involves the administration of nitroglycerine after 20 min of tilt. HRV parameters were analysed from 5 min intervals selected during pretest supine rest (phase 1), the first 5 min (phase 2) and the last 5 min (phase 3) of passive 20 min of tilting, prior to the administration of nitroglycerine. Differences in power (ms(2)) of the spectral components between the various phases of tilting were calculated for each patient and expressed as Δ.

Results: 20 patients (group 1, 9 women, mean age 43.2±24.5 years) had a syncope during tilt testing after nitroglycerine, while the other 44 (group 2, 24 women, mean age 41±20.5 years) did not. In group 1, the HRV spectral parameters high frequency (HF) and total power (TP) had a significant decrement from phases 2 to 3 (p=0.012 and 0.027, respectively), while in group 2 the average HF and TP values did not change. The Δ of spectral parameters between phases 2 and 3 were able to differentiate between the two groups and to predict syncope after nitroglycerine administration (p<0.05).

Conclusions: HRV analysis within the first 20 min of passive tilting demonstrated that patients with nitroglycerine-induced syncope are characterised by a progressive decrement of parasympathetic activity, which does not occur in patients with a negative response to nitroglycerine. If confirmed on a wider population, HRV analysis could replace nitroglycerine administration and shorten the duration of the tilt test.

No MeSH data available.


Related in: MedlinePlus

Example of sequential spectral analysis during the tilt test. Boxes on the tachogram (A) indicate the three 5 min epochs (Ph1: basal rest supine; Ph2: onset of passive tilt and Ph3: end of passive tilt) when HRV parameters are calculated. Spectral analysis evidence of physiological prevalence of the vagal (HF) component in the supine position (B), and its decrease (with concomitant increase of the LF component) during the subsequent phases (C and D) of the study (HF, high frequency; HRV, heart rate variability; LF, low frequency; nu, normalised units). NTG, nitroglycerin; PSD, power spectral density; RR, interval between subsequent R waves.
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OPENHRT2014000063F1: Example of sequential spectral analysis during the tilt test. Boxes on the tachogram (A) indicate the three 5 min epochs (Ph1: basal rest supine; Ph2: onset of passive tilt and Ph3: end of passive tilt) when HRV parameters are calculated. Spectral analysis evidence of physiological prevalence of the vagal (HF) component in the supine position (B), and its decrease (with concomitant increase of the LF component) during the subsequent phases (C and D) of the study (HF, high frequency; HRV, heart rate variability; LF, low frequency; nu, normalised units). NTG, nitroglycerin; PSD, power spectral density; RR, interval between subsequent R waves.

Mentions: All measurements were performed from three short-term (5 min) time intervals selected: (1) during the basal rest phase in the supine position, just before the start of tilting (phase 1), (2) during the first 5 min of HUT (phase 2) and (3) during the last 5 min before the administration of nitroglycerine (phase 3; figure 1).


Heart rate variability analysis during head-up tilt test predicts nitroglycerine-induced syncope.

Efremov K, Brisinda D, Venuti A, Iantorno E, Cataldi C, Fioravanti F, Fenici R - Open Heart (2014)

Example of sequential spectral analysis during the tilt test. Boxes on the tachogram (A) indicate the three 5 min epochs (Ph1: basal rest supine; Ph2: onset of passive tilt and Ph3: end of passive tilt) when HRV parameters are calculated. Spectral analysis evidence of physiological prevalence of the vagal (HF) component in the supine position (B), and its decrease (with concomitant increase of the LF component) during the subsequent phases (C and D) of the study (HF, high frequency; HRV, heart rate variability; LF, low frequency; nu, normalised units). NTG, nitroglycerin; PSD, power spectral density; RR, interval between subsequent R waves.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4195932&req=5

OPENHRT2014000063F1: Example of sequential spectral analysis during the tilt test. Boxes on the tachogram (A) indicate the three 5 min epochs (Ph1: basal rest supine; Ph2: onset of passive tilt and Ph3: end of passive tilt) when HRV parameters are calculated. Spectral analysis evidence of physiological prevalence of the vagal (HF) component in the supine position (B), and its decrease (with concomitant increase of the LF component) during the subsequent phases (C and D) of the study (HF, high frequency; HRV, heart rate variability; LF, low frequency; nu, normalised units). NTG, nitroglycerin; PSD, power spectral density; RR, interval between subsequent R waves.
Mentions: All measurements were performed from three short-term (5 min) time intervals selected: (1) during the basal rest phase in the supine position, just before the start of tilting (phase 1), (2) during the first 5 min of HUT (phase 2) and (3) during the last 5 min before the administration of nitroglycerine (phase 3; figure 1).

Bottom Line: HRV parameters were analysed from 5 min intervals selected during pretest supine rest (phase 1), the first 5 min (phase 2) and the last 5 min (phase 3) of passive 20 min of tilting, prior to the administration of nitroglycerine.In group 1, the HRV spectral parameters high frequency (HF) and total power (TP) had a significant decrement from phases 2 to 3 (p=0.012 and 0.027, respectively), while in group 2 the average HF and TP values did not change.If confirmed on a wider population, HRV analysis could replace nitroglycerine administration and shorten the duration of the tilt test.

View Article: PubMed Central - PubMed

Affiliation: Catholic University of the Sacred Heart, Biomagnetism Center, Clinical Physiology , Rome , Italy.

ABSTRACT

Objective: The aim of this study was to determine whether or not heart rate variability (HRV) analysis during the first 20 min of head-up tilt testing could predict whether patients will develop syncope after nitroglycerine administration.

Design: 64 patients with previous loss of consciousness underwent head-up tilt testing with the Italian protocol, which involves the administration of nitroglycerine after 20 min of tilt. HRV parameters were analysed from 5 min intervals selected during pretest supine rest (phase 1), the first 5 min (phase 2) and the last 5 min (phase 3) of passive 20 min of tilting, prior to the administration of nitroglycerine. Differences in power (ms(2)) of the spectral components between the various phases of tilting were calculated for each patient and expressed as Δ.

Results: 20 patients (group 1, 9 women, mean age 43.2±24.5 years) had a syncope during tilt testing after nitroglycerine, while the other 44 (group 2, 24 women, mean age 41±20.5 years) did not. In group 1, the HRV spectral parameters high frequency (HF) and total power (TP) had a significant decrement from phases 2 to 3 (p=0.012 and 0.027, respectively), while in group 2 the average HF and TP values did not change. The Δ of spectral parameters between phases 2 and 3 were able to differentiate between the two groups and to predict syncope after nitroglycerine administration (p<0.05).

Conclusions: HRV analysis within the first 20 min of passive tilting demonstrated that patients with nitroglycerine-induced syncope are characterised by a progressive decrement of parasympathetic activity, which does not occur in patients with a negative response to nitroglycerine. If confirmed on a wider population, HRV analysis could replace nitroglycerine administration and shorten the duration of the tilt test.

No MeSH data available.


Related in: MedlinePlus