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Changes in Total Cardiac Output and Oxygen Extraction During Exercise in Patients Supported With an HVAD Left Ventricular Assist Device
Author(s) -
Schmidt Thomas,
BjarnasonWehrens Birna,
Mommertz Stephanie,
Hannig Meike,
SchulteEistrup Sebastian,
Willemsen Detlev,
Reiss Nils
Publication year - 2018
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/aor.13102
Subject(s) - cardiology , vo2 max , arteriovenous oxygen difference , cardiac output , medicine , ventricular assist device , hemodynamics , ejection fraction , heart failure , stroke volume , heart rate , blood pressure
Following implantation of a left ventricular assist device (LVAD), acceptable functional performance is now being achieved; however, peak VO 2 and peak work load (watts) remain considerably limited. Maximum physical capacity is essentially dependent on generated cardiac output (CO) and arteriovenous oxygen difference (avDO 2 ). We investigated the changes in CO and avDO 2 during exercise in LVAD patients with an HVAD pump (HeartWare Inc., Framingham, MA, USA). Approximately 6 weeks after implantation, 20 patients (100% male, 60.8 ± 7.3 years old, BMI 25.7 ± 3.3) underwent a six‐minute walk test (6MWT), a cardiopulmonary exercise test (CPET), and noninvasive hemodynamic measurement. The mean six‐minute walking distance (6MWD) was 403 m (68% of predicted), and mean peak VO 2 was 10.9 mL/kg/min (39% of predicted). Mean total CO improved from 3.8 L at rest to 7.0 L at maximum exercise. The mean avDO 2 increased from 7.4 mL/dL (44% of oxygen content) at rest to 13.2 mL/dL (75% of oxygen content) at maximum exercise. There was a significant increase in both total CO ( P < 0.01) and avDO 2 ( P < 0.05) between rest and sub‐maximum exercise. As exercise levels increased, however, no further significant changes were achieved. Long‐term studies, especially in combination with exercise programs, would be desirable in order to observe the development of these parameters.