Cardiovascular hemodynamics and specifics of 24-hour bp profile in patients with hypertrophic cardiomyopathy and inadequate bp reaction on physical exertion

Abstract

Inadequate reaction of blood pressure (IRBP) in physical exertion in patients with hypertrophic cardiomyopathy (HCMP) is one of the risk factors of sudden cardiac death. Aim. To study structural and functional parameters of the heart, vessels and 24-hour blood pressure parameters in patients with HCMP and IRBP in physical exertion. Material and methods. 17 patients with HCMP (13 women, mean age 54,0±11,4 y.) underwent echocardiography (EchoCG), ambulatory blood pressure monitoring (ABPM) with assessment of vessels rigidity, exercise test on treadmill. By the results of treadmill test the patients were selected into 2 groups: I group (n=10, of those 7 women, mean age 51,4±13,9 y.) with IRBP, II group (n=7, of those 6 women, mean age 56,0±9,3 y.) with normal BP reaction in physical exertion. Results. Presence of IRBP in physical exertion was associated: with more significant diastolic dysfunction of the left ventricle (LV): the correlation is found with the peak delayed diastolic filling on mitral valve (peak A mv) (r=-0,76, p=0,002), relation of the velocities of early and delayed diastolic filling on the mitral valve (E/A mv) (r=0,53, p=0,03); decreased volume of LV: correlation with end-diastolic volume (EDV); end systolic volume (ESV) (r=-0,55, p=0,03); increased stiffness of arterial wall: correlation with the velocity of pulse wave (PWVao) (r=0,7, p=0,005), ambulatory index of vessel rigidity (AASI) (r=0,49, p=0,05), augmentation index (Axi) (r=-0,51, p=0,04). In discriminate analysis the EDV, E/A and AASI were the most significant predictors of IRBP. The functions were invented that make, by the highest value, an separation of a patients into one of 2 groups: I group (n=10, of those 7 women, mean age 51,4±13,9 y.) with IRBP, II group (n=7, of those 6 women, mean age 56,0±9,3 y.) with normal reaction of BP to physical exertion. Results. IRBP in exertion has been associated with: more significant diastolic dysfunction of the left ventricle (LV): the correlation found with the peak late diastolic filling on mitral valve (peak A) (r=-0,76, p=0,002), relation of the velocities of early and late diastolic filling on mitral valve (E\A mv) (r=0,53, p=0,03); decrease of the LV volume: end systolic volume (ESV) (r=-0,55; p=0,03); increased stiffness of arterial wall: correlation with the pulse wave velocity (PWVao) (r=0,7; p=0,005), ambulatory index of vessel rigidity (AASI) (r=0,49, p=0,05), augmentation index (Axi) (r=-0,51; p=0,04). During discrimination analysis the EDV, E/A and AASI were the most significant predictors of IRBP. The functions are formulated that make distinction of the patients for one of two groups: group 1 (F1) with IRBP in exertion, group 2 (F2) with adequate BP reaction: F1=0,995xEDV-6,854xE/Amv+1,937xAASI-33,833; F2=0,531xEDV- 3,651xE/Amv+21,685xAASI-23,029. Conclusion. Patients with HCMP and IRBP to exertion have more prominent diastolic LV dysfunction with its decreased volume, increased arterial wall stiffness. The model invented that makes by the three cardiohemodynamical parameters to prognosis the development of IRBP to exertion in HCMP patients.