Effect of Acute Blood Pressure Reduction on Oxygen Uptake Kinetics at the Onset of Exercise in Hypertensive Patients

Abstract

SUMMARYThe aim of the present study was to investigate the adverse effects of hypertension on the cardiovascular system in daily activities and the effect of acute blood pressure reduction on oxygen (O 2 ) uptake kinetics.Twenty hypertensive patients were included in the study group. Patients performed treadmill exercise tests (2.5 km/hour and 5 inclines) twice, before and after blood pressure reduction with sublingual captopril. In the control group, ten hypertensive patients underwent two tests one hour apart without blood pressure reduction brought about by drug therapy. The changes in O 2 kinetic values (O 2 deficit and mean response time [MRT]) between the two tests were investigated.In the study group, the O 2 deficit and MRT values measured during the first exercise testing were found to be 547 ± 183 mL and 40 ± 9 seconds, while those in the second exercise testing were 401 ± 127 mL and 34 ± 7 seconds, respectively. In the control group, the O 2 deficit and MRT values measured during the first exercise test were 491 ± 217 mL and 42 ± 16 seconds and 515 ± 159 mL and 41 ± 13 seconds in the second exercise test. The differences in O 2 deficit and MRT in the study group were considered to be statistically significant (P = 0.008 and P = 0.004, respectively).Based on our findings, there was a significant improvement in O 2 kinetic values with an acute reduction in blood pressure in hypertensive patients, most likely as a result of an improved response in cardiac output. (Jpn Heart J 2004; 45: 799-805)

Heart Rate and Oxygen Uptake Kinetics in Type 2 Diabetes Patients – A Pilot Study on the Influence of Cardiovascular Medication on Regulatory Processes

“…It has been shown, that T2DM influences cardiac mechanoenergetic efficiency and cardiac hypertrophy [30][31][32][33]. The respective medication in the T2D c and T2D p group might have improved cardiac function, as has been supposed in previous studies [9][10][11]. However, as can be observed in ▶Fig.…”

“…This is in line with the results of the T2D p and T2D group, in the present study. Taniguchi et al [10] showed a positive effect of beta blockers (after one year of treatment) and Dayi et al [11] for ACE inhibitors (administered shortly before the exercise test) on V'O 2 pulm kinetics in hypertensive subjects and in patients with dilated cardiomyopathy. They explained this effect by improved cardiac function (improved left ventricular ejection fraction).…”

“…There are indices, that both types of drugs can improve the responses of the cardiovascular, respiratory and metabolic system to changing work rates (WR) at submaximal exercise intensities [9][10][11][12], which can be described with oxygen uptake (V'O 2 ) kinetics. V'O 2 kinetics give information on the adjustment of the cardiovascular and respiratory and metabolic system and therefore aspects of transport and metabolic processes to changes in WR.…”

“…To the best of our knowledge, no data are available regarding HR kinetics in patients taking cardiovascular drugs. Although faster HR kinetics as indicators for kinetics of Q' have been considered as a potentially influencing factor for faster V'O 2 pulm kinetics [10,11], they were not yet measured in this context. It was shown that beta blockers increase RR interval variability and vagal tone in patients with former uncomplicated myocardial infarction [15].…”

Comparação Dos Níveis De Aptidão Física Entre Hipertensos E Normotensos

“…Níveis de aptidão cardiorrespiratória baixos podem interferir diretamente nas atividades de vida diária desses pacientes e como verificado por Dayi et al 12 , durante as atividades diárias a fadiga é comum em pacientes com hipertensão e que isso ocorre mesmo quando baixos níveis de exercícios são exigidos. Lim et al 13 afirmam que a capacidade de exercício é 30% menor em pacientes hipertensos se comparados com normotensos.…”