Welcome to the Cardiovascular Systems Laboratory
Research Overview
The Cardiovascular Systems Laboratory is a group of dedicated human integrative physiologists. Together with our collaborators, we aim to better understand the mechanisms that underpin cardiovascular disease processes such as hypertension and stroke.
Current Projects
Minimisation of brain injury after stroke
Stroke is a debilitating cardiovascular disease in which blood flow and therefore oxygen delivery to the brain is significantly reduced. In New Zealand, stroke is the third leading cause of adult mortality and the most common cause of adult disability affecting approximately 2,000 people each year. Because the ability of survivors to function indepedently in the long-term is directly related to the total extent of brain injury, interventions that prevent secondary stroke complications can potentially play a major role in limiting the overall health burden of stroke. However, whilst considerable efforts have been made in stroke prevention and later rehabilitation, few effective neuroprotection strategies exist for minimising brain injury acutely following a stroke. We're are undertaking a new study looking at low-dose Calcium Channel Blocker therapy as a neuroprotection agent in acute stroke.
Effects of alcohol consumption of brain blood flow regulation
The question of what is a safe amount of alcohol to drink is unknown by most New Zealanders and medical experts alike. This research examines the acute impact of alcohol consumption of fundamental processes governing cerebral blood flow. The results may be used to develop evidence-based policies, guidelines, and campaigns to minimise the acute harm of alcohol consumption. Findings will also inform the design and interpretation of further research in patient cohorts.
Influence of tobacco smoking on dynamic cerebral autoregulation
Little is known of how tobacco smoking, a major cardiovascular risk factor, alters Cerebral autoregulation (CA), the mechanism that maintains brain blood flow within physiological ranges. CA once impaired, increases the risk of brain haemorrhage, a debilitating form of cardiovascular disease. We will test the hypothesis that smoking blunts CA.
Mechanisms of cerebral autoregulation
Brain function is critically dependent on the regulation of cerebral blood flow (CBF), with dysfunction having dire consequences. CBF dysregulation is a key factor in debilitating cerebrovascular diseases such as ischemic stroke and dementia. Understanding the mechanisms of normal CBF control is therefore crucial to both treatment and prevention of these conditions. Our objective is to establish cerebral vascular compliance as a new mechanism of CBF regulation. Employing a mix of experimental and mathematical modelling techniques, this research will establish the basic science groundwork for new modes of diagnosis and novel treatment targets for diseases that affect the cerebral circulation.
The cardiovascular effects of renal nerve ablation in resistant hypertension
Hypertension is a significant risk factor for coronary artery disease, stroke, heart failure, vascular disease and chronic renal failure and is estimated to be present in more than 20% of the world’s adult population. In adults over 40 years of age, each 20mmHg increase in systolic blood pressure is associated with a doubling of mortality risk due to cardiovascular disease. An exciting new therapy for patients with resistant hypertension has been developed over the last 4-5 years that targets the renal sympathetic nerves. This procedure involves percutaneous catheter-based radio-frequency (RF) ablation in the renal artery to disrupt both afferent and efferent renal sympathetic nerve activity. The objective of this research is to examine the changes in cardiac function, control of blood pressure, and cerebral autoregulation following renal nerve ablation.
Baroreflex sensitivity and cerebral autoregulation in heart failure
The arterial baroreflex is a fundamental mechanism involved in the regulation of blood pressure, and its impairment contributes to morbidity and mortality in heart failure. The objective this research is to understand how baroreflex function and cerebral autoregulation might be altered in heart failure. The findings will generate new insights into the link between heart failure and higher incidence of stroke seen in this population.
Funding
Health Research Council
National Heart Foundation
Wellington Medical Research Foundation