Issue: 2018, Vol. 23, No. 1
VENTRICULAR RHYTHM IRREGULARITY IN PERMANENT FORM OF ATRIAL FIBRILLATION: POSSIBILITIES TO ESTIMATE AND TO USE IN CLINIC
- atrial fibrillation, ventricular contraction rate, heart rhythm variability, Holter electrocardiography
- Objective is to analyze ventricular rhythm irregularity in patients with permanent form of atrial fibrillation in dependence on the effectiveness of ventricular contraction rate monitoring and to estimate the clinical significance of such approach. Materials and methods. 114 patients with permanent form of atrial fibrillation, average age 59.4 ± 10.9 years were enrolled in the study. Rhythm disorder duration was amounting to 2 months - 25 years. Echocardiography and Holter electrocardiography monitoring with ventricular contraction rate estimation were performed in the patients. All patients were divided into two groups: the first one was composed of the persons with effective monitoring of ventricular contraction rate (73 patients) and the second one was formed of insufficient monitoring of ventricular contraction rate (41 patients). The irregularity of ventricular rhythm was evaluated upon the data of Holter electrocardiography monitoring by mathematic apparatus of heart rhythm variability technique.Results. In the analysis of heart rhythm variability parameters some differences between the groups were revealed: average RR, daily SDNN, SDNNi, rMSSD, pNN50% and TINN. The meanings of these parameters of heart rhythm variability were higher in patients with effective monitoring of ventricular contraction rate. The most reliable parameter turned to be pNN50% (p = 0.00002). In order to determine clinical significance of ventricular rhythm irregularity characteristics the prognostic model was developed to reach the effective monitoring of ventricular contractions rate in patients with atrial fibrillation; it was based upon the indices of echocardiography, heart rhythm variability parameters; the latter were reduced by factor analysis. The given model was realized in the form of computer program “The prognostic system for effective treatment for patients with permanent form of atrial fibrillation”. The prognostic time of daily normal systole maintenance in patient was calculated (in %) by this program; and in the meanings >50% the possibility of the effective monitoring of ventricular contraction rate in this patient was prognosticated. The adequacy of this prognostic model was evaluated by the comparison of the prognostic results and the results of clinical observation by 2 mentioned techniques.Conclusion. The persons with effective monitoring of ventricular contraction rate had more expressed irregularity of ven- tricular rhythm (pNN50% higher meanings) in comparison with the persons with ineffective monitoring of ventricular contraction rate. The combined analysis of heart structural morphological alterations, parameters of irregularity of ventricular contraction upon the findings of Holter monitoring by mathematic model allowed to prognosticate the possibility to reach the effective control of ventricular contraction rate in patients with permanent form of atrial fibrillation.