The Fontan procedure is currently the palliative solution for children born with a univentricular heart. Despite an improved survival rate, many patients still suffer from complications, such as... Show moreThe Fontan procedure is currently the palliative solution for children born with a univentricular heart. Despite an improved survival rate, many patients still suffer from complications, such as heart failure. For this reason, both patients with and without heart failure are often treated with angiotensin-converting enzyme (ACE) inhibitors, although the effectiveness is unclear. In this thesis, we investigated various aspects of the Fontan circulation to assess not only the efficacy and side effects of ACE inhibition, but also the limitations of exercise capacity and the response of the circulation of these patients to acute volume loading tests. We showed that short-term ACE inhibition had no positive effects on exercise capacity, haemodynamics and cardiac function. It also appeared to have no negative effect on the Fontan circulation, apart from side effects during the titration period. Furthermore, we found that even relatively healthy young Fontan patients have reduced exercise capacity associated with diastolic dysfunction and aortic stiffness. Nevertheless, we found that paediatric Fontan patients are able to respond adequately to acute volume changes and they seem to adapt well to the Fontan circulation. Show less
Various non-invasive imaging techniques are available for the diagnosis of coronary artery disease (CAD). Multi-slice computed tomography (MSCT) is an upcoming technique that allows direct... Show moreVarious non-invasive imaging techniques are available for the diagnosis of coronary artery disease (CAD). Multi-slice computed tomography (MSCT) is an upcoming technique that allows direct visualization of the coronary arteries. Apart from the assessment of atherosclerosis, MSCT can also provide important information on the global and regional left ventricular (LV) function. However, it should be realized that the hemodynamic consequences of atherosclerosis can not be obtained by MSCT imaging, and that functional testing, with for example nuclear imaging, will remain necessary to determine therapeutic strategy. CAD is the most common cause of chronic heart failure. Recently, cardiac resynchronization therapy (CRT) has become implemented in the treatment of patients with severe heart failure. Although the improvement in systolic function after CRT implantation can be considerable, 20% to 30% of patients do not respond to CRT. It has been shown that the presence of LV dyssynchrony is an important predictor of response to CRT. Gated SPECT allows not only the assessment of myocardial perfusion (scar tissue and viable myocardium) but also the evaluation of LV dyssynchrony. As many patients with heart failure undergo nuclear imaging with SPECT, integrated assessment of LV dyssynchrony, viability and scar tissue may be an attractive option. Show less
