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Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Clinical Professor Vibeke E. Hjortdal, University of Copenhagen, Denmark
- Second opponent: Associate Professor Rune Mo, NTNU - Norwegian University of Science and Technology
- Third member and chair of the evaluation committee: Professor II Signe Søvik, University of Oslo
Chair of the Defence
Professor II Henrik Schirmer, University of Oslo
Principal Supervisor
Professor II Vegard Bruun Bratholm Wyller, University of Oslo
Summary
Heart transplantation is lifesaving and a rescue treatment for patients with end-stage heart failure. Normally, heart function is intimately controlled by the autonomic nervous system. However, due to the transplant procedure, the donor heart loses all nervous connections.
Prior studies report a gradually regrowth of autonomic nerve endings over time, resulting in a partial reinnervation of the donor heart. However, the timing and functional consequences of this autonomic reinnervation is largely unknown.
The aim of the thesis was to investigate autonomic cardiovascular regulation and hypertension development in patients early after transplant surgery and during the first year after surgery within a prospective cohort study also including a comparable group of healthy controls. The methods included application of functional test of autonomic cardiovascular control such as passive upraising (head-up tilt), forced expiration against resistance (Valsalva maneuver) and isometric exercise (handgrip) combined with continuous, non-invasive recordings of cardiovascular variables (heart rate, blood pressures, stroke volume, cardiac output, and peripheral vascular resistance).
Regrowth of efferent sympathetic autonomic nerves to the sinoatrial node of the donor heart was demonstrated within 6 months after transplant surgery, and increased at 12 month follow-up. Indirect signs of reinnervation of afferent low-pressure cardiopulmonary receptors were observed within 12 months. Parasympathetic (vagal) efferent reinnervation was not demonstrated.
Hypertension was present early after transplantation, with a further increase during the first year. The altered autonomic cardiovascular control was demonstrated to be a likely contributor to hypertension development, but the strongest impact was inflicted by donor sex (increased risk with female donor sex).
Additional information
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