Cardiovascular Journal of Africa: Vol 26 No 6 (November/December 2015)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 6, November/December 2015 214 AFRICA
Autonomic imbalance assessed by time-domain heart
rate variability indices in primary Raynaud’s phenomenon
Kubilay Karabacak, Murat Celik, Erkan Kaya, Murat Kadan, Gokhan Arslan, Ufuk Demirkilic
Abstract
Objectives: The pathogenesis of primary Raynaud’s phenom-
enon (RP) seems to be multifactorial and autonomic nervous
dysfunction is one factor. Heart rate variability (HRV) is one
of the most reliable parameters to demonstrate autonomic
dysfunction. Our aim was to evaluate the time-domain HRV
in patients with primary RP.
Methods: A time analysis of HRV was performed in patients
with primary RP and age- and gender-matched healthy
controls. The results of the study and control group were
compared.
Results: Thirty patients with primary RP [all men, median
(IQR) age: 21 (2) years) and 31 age- and gender-matched
healthy controls (median (IQR): 21(3) years) were enrolled
in the study. We found a statistically significant difference
between the primary RP patients and control subjects in
terms of time-domain HRV parameters (p < 0.05 for all).
Conclusion: Our study showed the presence of autonomic
nervous dysfunction of heart function in patients with
primary RP.
Keywords: heart rate variability, autonomic nervous system,
Raynaud’s phenomenon
Submitted 7/9/14, accepted 24/3/15
Published online 15/4/15
Cardiovasc J Afr 2015; 26: 214–216
DOI: 10.5830/CVJA-2015-032
Raynaud’s phenomenon (RP) is a vascular disorder depicted by
a repeated course of fading of the fingers and/or toes, which is
caused by reversible vasospasm.1 The prevalence of RP varies
between three and 4%.2 Primary RP (Raynaud’s disease) occurs
as an isolated symptom, whereas secondary RP (Raynaud’s
syndrome) is associated with another disease or condition.
About 8–9% of all RP are primary cases.2,3 Primary RP has a
greater female predominance and is seen at an earlier age than
secondary RP.2
The pathogenesis of RP is not fully elucidated. Intravascular
and neural mechanisms play a pivotal role in this process.4
Increased sympathetic activity is often thought to be one of the
causes in the aetiology of primary RP. Increased sympathetic
activation in the chronic phase may also lead to desensitisation
of the sinus node to neural input and parasympathetic tone,
thereby causing autonomic dysfunction.
Heart rate variability (HRV) analysis shows sympathovagal
balance and has been used as an easy, non-invasive and reliable
test for the identification of dysfunction of the autonomic
nervous system in certain diseases. Since sympathovagal balance
is affected in favour of sympathetic activation in patients with
primary RP, in this study, we evaluated the baseline function of
the autonomic nervous system assessed by 24-hour HRV analysis
in patients with primary RP.
Methods
Patients referred to our Cardiovascular Department for suspicion
of primary RP during the period October 2012 to May 2013
were evaluated in this study. The evaluation of past medical
history, physical examination, an initial 12-lead ECG and then
24-hour Holter monitoring for HRV analysis were performed in
all patients.
Diagnosis of Raynaud’s phenomenon was confirmed with
the three-phase cold test. All patients were also evaluated for
secondary RP. On physical examination, all patients were
examined for skin ulceration, telangiectasia, muscle weakness
and connective tissue diseases such as scleroderma.
In our study, we tried to exclude metabolic factors that may
affect the heart rate. Patients with hypothermic or hyperthermic
status, injury, anaemia, infection or history of any chronic
disease, such as connective tissue disorder or diabetes mellitus,
were excluded. Also, structural heart disease, supraventricular or
ventricular arrhythmias, atrial fibrillation, sick sinus syndrome,
atrioventricular block, haematological or neurological disease,
the use of any drug that has an impact on heart rate (such
as beta-adrenergic blockers and anti-arrhythmic drugs) were
accepted as other exclusion criteria.
All HRV measurements were performed at rest. The patients
were advised not to take part in vigorous exercise during the
HRV measurement.
The control group consisted of age- and gender-matched
healthy subjects. An informed consent was obtained from all
subject enrolled in this study, which was conducted in accordance
with the regulations of Declaration of Helsinki. The regional
ethics committee of our Institute approved the study protocol.
HRV analysis
A 24-hour Holter ambulatory ECG monitoring (Rozinn RZ
152 digital Holter recorder, Rozinn Electronics, Inc, Glendale,
Department of Cardiovascular Surgery, Gulhane Military
Academy of Medicine, Ankara, Turkey
Kubilay Karabacak, MD,
Erkan Kaya, MD
Murat Kadan, MD
Gokhan Arslan, MD
Ufuk Demirkilic, MD
Department of Cardiology, Gulhane Military Academy of
Medicine, Ankara, Turkey
Murat Celik, MD