This thesis provides insights in characteristics of newly introduced echocardiographic parameters in healthy children and their use in follow-up of patients with a congenital heart defect (CHD)... Show moreThis thesis provides insights in characteristics of newly introduced echocardiographic parameters in healthy children and their use in follow-up of patients with a congenital heart defect (CHD) after surgery. In healthy children, reference values and characteristics of two echocardiographic techniques, tissue Doppler imaging (TDI) and speckle-tracking strain imaging, are described. TDI-derived velocity parameters are reproducible and feasible in children. Yet use of age or growth-dependent reference values is recommended, especially in neonates. Speckle-tracking strain-derived global peak strain parameters have a good reproducibility, are age-independent and remain unchanged during periods of significant growth, such as the neonatal period. We encourage use of these parameters. In contrast, the limited reproducibility of parameters describing intraventricular time-differences is worrying. Our follow-up studies in CHD patients undergoing corrective surgery with cardiopulmonary bypass, describe a significant decrease in biventricular performance immediately postoperatively. Subsequently, left ventricular performance recovered to control values. In contrast, right ventricular performance remained impaired in most subgroups of CHD patients up to one year postoperatively. Considering the prognostic value of right ventricular performance parameters, these studies underline the need for careful evaluation of both left and right ventricular performance postoperatively. Furthermore, a longer-lasting negative influence of cardiopulmonary bypass on ventricular performance was suggested. Show less
Klitsie, L.M.; Roest, A.A.W.; Hulst, A.E. van der; Stijnen, T.; Blom, N.A.; Harkel, A.D.J. ten 2013
CRT has evolved as a successful treatment strategy in selected patients with drug refractory heart failure. Evidence of large clinical trials established the beneficial effects of CRT in addition... Show moreCRT has evolved as a successful treatment strategy in selected patients with drug refractory heart failure. Evidence of large clinical trials established the beneficial effects of CRT in addition to optimal medical treatment on both morbidity and mortality. Nonetheless, about 30% of patients do not demonstrate response to CRT. Several patient characteristics have a strong influence on both response at 6 months follow-up and prognosis during long-term follow-up. In addition to these patient characteristics, the position of the LV pacing lead in relation to the site of latest activation and potential scar tissue may have a great influence on outcome. Integration of patient characteristics, LV lead position with information on LV dyssynchrony and scar tissue may help to improve patient selection and response to CRT. It is not unlikely that the favorable effects of CRT will be extended to other patient groups in the coming years. These groups include asymptomatic (NYHA class I) patients, patients with a narrow QRS complex (<120 ms) or patients with heart failure but preserved LVEF (__45%). CRT also seems to improve other conditions frequently observed in patients with heart failure. The improved LV systolic function induced by CRT increases cerebral blood flow and also results in stabilization of renal function. Finally, patients with severe functional MR and high operative risk also derive benefit from CRT. Perhaps CRT may one day be used as an effective treatment strategy in these patient groups. Show less
The presence of a decreased left ventricular (LV) function after myocardial infarction has demonstrated to be of considerable clinical importance. In this thesis, the role of 2D echocardiography to... Show moreThe presence of a decreased left ventricular (LV) function after myocardial infarction has demonstrated to be of considerable clinical importance. In this thesis, the role of 2D echocardiography to evaluate LV function in ischemic heart disease was investigated. In the first part of the thesis, recently introduced echocardiographic parameters to describe LV function were studied and their importance for prognosis after myocardial infarction was evaluated. In addition, in the second part of the thesis, the role for echocardiography in the decision making around advanced treatment options in heart failure such as cardiac resynchronization therapy (CRT) and cardiac surgery was explored. 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
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
