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
Even with the remarkable results of cardiac resynchronization therapy (CRT) in the large randomized trials, approximately 30-40% of the patients failed to improve after CRT when the established... Show moreEven with the remarkable results of cardiac resynchronization therapy (CRT) in the large randomized trials, approximately 30-40% of the patients failed to improve after CRT when the established selection criteria are used, highlighting the need for improvement of the current criteria. In addition, the exact mechanism and effects of CRT on echocardiographic and clinical parameters such as mitral regurgitation, strain and incidence of ventricular arrhythmias are currently unknown. The aim of the current thesis was to further explore these issues using varying non-invasive imaging techniques such as echocardiography, nuclear imaging, magnetic resonance imaging as well as device-based diagnostics. The results of Part I demonstrate that presence of mechanical dyssynchrony within the LV as measured with echocardiography is an important predictor of response after CRT. Also, other factors may influence response such as the presence and location of scar tissue in the LV as well the position of the LV pacing lead. Part II describes the acute and long-term benefit (LV function, strain, mitral regurgitation, myocardial blood flow, oxidative metabolism), prognosis, interruption of CRT and optimization of device settings. In addition, implantable cardioverter-defibrillator (ICD)-backup is preferred in all CRT candidates since 21% experienced appropriate ICD therapy within 2 year after implantation. Show less
