RT-232
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Correlation between heart rate
variability and ventricular arrhythmias. Different patterns in patients with myocardial
infarction and arrhythmogenic right ventricular cardiomyopathy
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Antonio Franco Folino, Gianfranco
Buja, Lorenza Dal Corso, Andrea Nava.
Department of Cardiology, University of Padua, Italy
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Abstract
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The influence of autonomic nervous system in the
genesis of life-threatening arrhythmias is well documented in coronary artery disease. On
the other hand, it is a common finding the occurrence of ventricular arrhythmias during
physical exercise in subjects with arrhythmogenic right ventricular cardiomyopathy (ARVC).
The aim of our study was to evaluate heart rate variability and its correlation with
ventricular arrhythmias in patients with myo-cardial infarction (MI) and in patients with
ARVC.
We studied 55 patients with MI (50 males, 5 females, mean age 59 ± 11) and 43
patients with ARVC (25 males, 18 females, mean age 37 ± 14). Thirty healty subjects
comprised the control group.
Time domain analysis of heart rate variability was performed on 24-hour Holter
records. The index considered was the standard deviation of all normal-to-normal RR
intervals (SDNN). The ventricular arrhythmias evidenced during the same Holter record used
for heart rate variability analysis were evaluated and codified following the Lown
classification.
Both the study groups showed a decreased SDNN in comparison with control group
(control group 176 ± 34, MI group 108 ± 29, ARVC group 156 ± 36; p < 0.001). The
patients with MI evidenced a lower value of SDNN in comparison with the subjects with ARVC
(p < 0.001). The ventricular arrhythmias were not correlated with SDNN in patients with
MI (r = -0.04, p = ns). On the contrary, a significant correlation was evidenced between
ventricular arrhythmias and SDNN in ARVC group (r = -0.63, p < 0.001).
Our study showed a increased sympathetic activity in both the study groups with a
significant prevalence in patients with MI. However, we found a good correlation between
SDNN and ventricular arrhythmias in the ARVC group but not in MI patients. These findings
suggest that the influence of autonomic nervous system in the genesis of ventricular
arrhythmias could be exerted by different mechanisms in the two cardiac diseases.
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Key Words
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Heart rate variability
myocardial infarction, arrhythmogenic right ventricular cardiomyopathy, ventricular
arrhythmias, Holter ECG, time domain analysis, autonomic nervous system, sympathetic
activity, OA
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