Adenosine A(2A) receptor 1083 T > C polymorphism is not associated with the positivity of HUT and its proposed role in predisposition to VVS was not confirmed. CC genotype may be associated with lower sympathetic activity during HUT.

non-responders (2.14 ± 2.9 vs. -0.94 ± 1.74, p = 0.042). Patients with increased deformation in the LV lead area during dobutamine stimulation were more likely to be responders to CRT compared to patients without increased deformation in this area (81% vs. 20%, p = 0.0002). They exhibited significant increase in LVEF (8.8% ± 10.3% vs. 0.3% ± 6.4%, p = 0.01). LV electrode localization in viable myocardium was a good predictor of response to CRT (AUC 0.852, p < 0.0001). Conclusions: Regional contractile reserve assessed by strain rate echocardiography during dobutamine infusion predicts the response to CRT. (Cardiol J 2014; 21, 5: 524-531)

In patients undergoing ILR implantation bradycardia is a frequent finding despite the negative conventional diagnostic testing. Absence of prodromal symptoms, male gender and age >65 years are risk factors for bradycardia and pacemaker implantation.

OBJECTIVES: The evidence is confl icting regarding the role of barorefl ex in patients with vasovagal syncope. The aim of the study was to measure barorefl ex sensitivity (BRS) and hemodynamic parameters during head up tilt test (HUT) with nitroglycerine stimulation. METHODS: Nitroglycerine stimulated HUT was performed in 51 patients with the history of recurrent syncope (mean age 46± 19 years, 18 men, 23 women). Cardiac output (CO), stroke volume (SV), left-ventricular ejection time (LVET) and total peripheral resistance (TPR) were assessed during HUT by volume-clamp method using a beat-to-beat photopletysmography. Spontaneous BRS sensitivity was computed using a sequential BRS calculation. RESULTS: HUT was positive after nitroglycerine administration in 28 patients and negative in 23 patients. BRS was lower at the time of syncope in HUT positive group compared to end-test values in HUT negative group (0.54±0.27 vs 0.72±0.35, p = 0. 03). At the time of syncope, CO was signifi cantly lower in HUT positive patients compared to HUT negative patients (2.6±1.4 vs 4.3±1.4 l/min, p < 0.0001), similarly as SV (34.7±14.7 vs 49.2±19 ml, p=0.005 ). LVET was signifi cantly higher in syncopal patients (282.27±26.2 vs 240.5±58.8 ms, p=0.002) and TPR did not differ between two groups. CONCLUSIONS: Reduced BRS may contribute to the development of the vasovagal syncope by inability to adequately counteract hypotension resulting from decreased cardiac output at the time of syncope (Tab. 3, Ref. 18). Text in PDF www.elis.sk.

OT reduced symptoms in 74% patients who trained regularly. However, the compliance to training was low. Possible mechanism of OT is reconditioning effect on baroreceptor reactivity in upright position.