ACTA FAC. MED. NAISS. 2003; 20 (3): 169-173

Original article

THE CORRELATION BETWEEN VENTRICULAR ARRHYTHMIAS, HEART RATE VARIABILITY AND LEFT VENTRICULAR SYSTOLIC FUNCTION IN PATIENTS AFTER MYOCARDIAL INFARCTION
 

Dragan Đorđević, Stevan Ilić, Marina Deljanin Ilić, Branko Lović, Ivan Tasić, Dejan Petrović, Aleksandar Nikolić
Institute for prevention, treatment and rehabilitation of rheumatic and cardiovascular diseases, Ni{ka Banja
 

SUMMARY

Both left ventricular dysfunction and common ventricular premature complexes roughly double the risk of death. The aim of this study was to examine relationship between ventricular arrhythmias and heart rate variability in patients with reduced left ventricular (LV) systolic function.
Sixty-six patients after myocardial infarction with frequency of premature ventricular beats higher then 10 per hour were examined. Patients were divided in two groups: the first group had 37 patients with LV ejection fraction (LVEF) greater than 40% whereas the second group had 29 patients with LVEF Ł 40%. Both groups of patients were compared with 20 healthy persons without significant arrhythmias. The clinical examination, 24-hour Holter monitoring, heart rate variability and echocardiographic research were carried out. The following parameters of heart rate variability were analysed: SDNN, SDANN, RMS-SD, N-N' > 50 ms, their 24 hour values, daily and night values and daily minus night values.
There were 8/37 (21.6%) patients with nonsustained ventricular tachycardia (3 or more ventricular premature beats) in the first group and 7/29 (24.1%) patients in the second group. The patients from the second group had significantly lower average values of all parameters of heart rate variability during the period of 24 hours when compared to the patients from the first group (SDNN: 85.4 - 26.5 ms vs. 103.5 - 23.2 ms; p < 0.01; SDANN: 74.1 - 17.6 ms vs. 84.5 - 21.4 ms; p < 0,05; RMS-SD: 20.2 - 8.3 ms vs. 24.9 - 9.1 ms; p < 0,05; N-N' > 50 ms: 2.1 - 2.4 % vs. 6.4 - 9.3 %; p < 0,05). All parameters of heart rate variability were significantly greater in the control group than in both groups of patients (p < 0.0001). We found out weak, but statistically significant correlations between LVEF and the folowing parameters of heart rate variability in all the examined patients: SDNN r = 0,322 (p < 0,05); SDANN r = 0,318 (p < 0,05); RMS-SD r = 0,266 (p < 0,05); N-N' > 50 ms r = 0,258 (p < 0,05). Daily minus night values of heart rate variability had no correlation with LVEF.
The patients with reduced left ventricular ejection fraction had lower parameters of heart rate variability than patients with preserved left ventricular ejection fraction. No correlation between heart rate variability and ventricular arrhythmias was found. In patients after myocardial infarction SDNN may be used as an additional parameter for risk stratification and prognosis.

Key words: heart rate variability, ventricular arrhythmias, myocardial infarction, left ventricular systolic function