The Cauchy problem for a hyperbolic equation with the data on a time-like surface of general form and the associated inverse problem are investigated. In the considered case, in different to the known results, the hyperbolic equation coefficients are non-analytical in respect to (x,t) variables and D+ domain is not necessarily convex.
Decreased heart rate variability (HRV) is associated with increased mortality risk in various diseases. The objective of this investigation: to study HRV in patients with sickle cell anemia (SCA) and to assess the effect of pulmonary arterial hypertension (PAH) on HRV in these patients. Materials and methods. HRV registration and Doppler echocardiographic assessment of systolic pulmonary arterial pressure (PAP) was carried out in 61 stable patients with SCA and 24 healthy subjects. Results. Low frequency power (LFP) and high frequency power (HFP) were decreased in SCA patients compared to healthy subjects. Among SCA patients, PAH pa . . .tients had lower LFP and HFP than patients without PAH. In SCA patients, systolic PAP showed significant negative correlation with LFP and HFP. Conclusion. HRV is significantly decreased in SCA patients, especially in those with PAH. HRV may be particularly useful in early detection of PAH patients who may have worse prognosis and higher mortality risk