BACKGROUND

Functional deterioration of cardiovascular system often correlates with reduced diurnal variability of sinus rhythm (SRV). This correlation significantly weakens in idiopathic pulmonary hypertension (IPH). In patients with IPH older than 50 years, functional deterioration of cardiovascular system is often accompanied by increased diurnal SRV. Analysis of Holter ECG monitoring data shows that diurnal SRV is significantly affected by rapid regulation of sinus rhythm manifested by double fractures of the rhythmogram (DFR). Influence of DFR on SRV is characterized by the incidence of DFR and higher SRV in segments of rhythmogram with DFR compared to those without DFR.

OBJECTIVE

To study the effect of DFR on diurnal SRV in patients with IPH.

MATERIAL AND METHODS

We analyzed the results of Holter ECG monitoring in 86 patients aged 18—55 years with IPH of various functional classes and compared these data with 67 healthy individuals of the same age.

RESULTS

IPH and further functional deterioration generate similar trends in SRV dynamics. IPH leads to higher incidence of DFR in patients over 30 years old. At the same time, IPH and further functional deterioration stimulate a decrease of SRV in people younger 49 years. In patients aged 50—56 years, the tendency to SRV decrease remains on the part of the rhythmogram without DFR and changes to the opposite one on the part of the rhythmogram with DFR. In addition, IPH increases the differences between SRV in segments with and without DFR.

CONCLUSION

DFR reflect the processes of sinus rhythm regulation which are similarly affected by pulmonary hypertension and increase of its functional class.