[Clinical Value of Algorithms of Minimization of Right Ventricular Pacing in Patients With Sick Sinus Syndrome and History of Atrial Fibrillation].

PURPOSE: to assess effectiveness of algorithms of minimization of right ventricular pacing (MRVP) for prevention of progression of atrial fibrillation (AF), lowering of frequency of hospitalizations due to cardiovascular causes, and mortality in patients with sick sinus syndrome (SSS) and history of paroxysmal AF compared with standard compared with dual-chamber pacing (DDDR). MATERIALS AND METHODS: We included in this single-center prospective study 74 consecutive patients with indications to permanent DDDR pacing because of SSS combined with documented history of paroxysmal AF. Patients were randomized in the groups of DDDR pacing (n=36) and with activated algorithms of MRVP (n=38). Pacemaker check up was made after 6 months during 1 year after device implantation. Primary composite endpoint included development of persistent AF, hospitalization due to cardiovascular causes, and all cause death. RESULTS: During follow-up there was no statistically significant difference in achievement of the primary endpoint (27.8 and 18.4% in groups of DDDR pacing and activated algorithms of MRVP respectively (relative risk 1.29% confidence interval 0.43 to 3.86; p=0.25). Rate of development of persistent AF in both groups was comparable (8.6 and 5.3% in DDDR and MRVP groups, respectively; p=0.47). Median AF burden was 6.0 (0;42) and 6.0 (0;42) min/day in DDDR and MRVP groups, respectively (p=0.67). CONCLUSION: Our study failed to demonstrate advantages of the use of algorithms of decreasing "unmotivated" right ventricular pacing over standard regimen of standard DDDR pacing in patients with SSS and history of paroxysmal AF.

[Adaptation to Intermittent Hypoxia-Hyperoxia in the Rehabilitation of Patients With Ischemic Heart Disease: Exercise Tolerance and Quality of Life].

AIM: to assess effect of interval hypoxic-hyperoxic training (IT) on exercise tolerance and quality of life of patients with ischemic heart disease (IHD) receiving optimal medical therapy, as well as the safety of IHHT use. METHODS: Patients with stable IHD with functional class II and III angina (n=46) were randomized into two groups: IHHT (n=27, 15 treatments in 3 weeks), and IHHT imitation (n=19). Cardiopulmonary stress test was performed to evaluate the following parameters of exercise tolerance: peak oxygen consumption (VO2peak, VO2peak/kg), % of predicted peak oxygen consumption (%VO2 peak) and anaerobic threshold (VO2AT). MOS SF-36, SAQ, HADS questionnaires were used for assessment of quality of life (QL). RESULTS: Exercise tolerance (VO2peak/kg) after course of IHHT significantly increased (p=0.03) and remained significantly elevated during subsequent month (p=0.036). Marked improvement was also observed in patients subjective perception of QL. This was evidenced by dynamics of characteristics of physical functioning as well as of psychological state, significant increase of values on all scales of disease-specific questionnaire SAQ, reduction of depression and anxiety according to dynamics of HADS scores. These effects persisted in 1 month after IHHT. IHHT was safe and well tolerated. Side effects were minimal (transient slight dizziness, feeling of shortage of air) and did not require IHHT termination. CONCLUSION: We received clinical confirmation of safety and effectiveness in of IHHT in medically treated patients with stable angina. IHHT was associated with significant improvement of exercise tolerance, subjective perception of QL, reduction of number of angina attacks. Thus, IHHT has significant potential as component of complex treatment and rehabilitation of patients with stable angina.