| Summary: | Aim: To evaluate cardiovascular adaptation to increased afterload during handgrip isometric exercise (HIE) in untreated hypertensive patients.
Methods: 75 untreated hypertensive patients (age 54±7years, 44 males, BP 153/93 mmHg) underwent simultaneous EchoCG and blood pressure (BP) acquisition at rest and during HIE. End-systolic pressure was determined as 0,9 x brachial systolic BP (SBP). Arterial elastance (Ea) and LV elastance (Ees) were calculated as end-systolic pressure (ESP) /stroke volume (SV) and ESP/end-systolic volume (ESV). Ventricular-arterial coupling index was assessed as Ea/Ees. Efficiency of left ventricle (ELV) was evaluated by stroke work (SW)/pressure-volume area (PVA) ratio. SW=ESPхSV, PVA=SW+PE (ESPхESV/2-end diastolic pressure xESP/4). p<0,05 was considered significant.
Results: Ea/Ees<0,5 was found in 76% (n=57, 18 female) before HIE. In 38% (n=22, 4 (23%) female) Ea, Ees, Ea/Ees and SW/PVA did not change significantly. In 11% there was further decrease of Ea/Ees associated with significant increase of ELV. In 51% (n=29, 14 (49%) female) Ea/Ees increased due to increase of Ea from 1,98±0,32 to 2,35±0,41 (p<0,05) while Ees increased from 5,95±2,2 to 4,58±1,0 (p<0,05). Ea/Ees increase was associated with decrease of ELV from 0,89±0,02 to 0,84±0,02 (p<0,05) indicating cardiovascular misadaptation to HIE.
In subjects (n=18, 3 female) with normal Ea/Ees 0,5–1,2 before HIE Ea/Ees and ELV did not change in 8 (49%, all males). In 10 subjects (3 female) Ea/Ees decreased due to significant increase of Ees (from 3,15±0,68 to 5,02±1,34 (p<0,05), and ELV increased from 0,81±0,03 to 0,88±0,01 (p<0,05).
Conclusion: Cardiovascular misadaptation to afterload is the most prevalent type of reaction to HIE in subjects with decreased baseline Ea/Ees and may be also observed in subjects with normal baseline ventricular-arterial coupling. This misadaptation in subjects with baseline ventricular arterial uncoupling is associated with female gender.
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