In recent years, a number of new cardiac interventional procedures have been introduced. Catheter ablation procedures for atrial fibrillation (AF) have been refined and are now considered a good... Show moreIn recent years, a number of new cardiac interventional procedures have been introduced. Catheter ablation procedures for atrial fibrillation (AF) have been refined and are now considered a good treatment option in patients with drug-refractory AF. In cardiac pacing, cardiac resynchronization therapy (CRT) is now standard of care for patients with drug-refractory heart failure. At the same time, CRT may also be beneficial in patients with heart failure after long-term right ventricular (RV) apical pacing. Finally, new percutaneous procedures for valvular heart disease have been introduced for patients that are deemed inoperable. At the same time, various imaging modalities have been further developed and important advances have been made in the integration of different imaging modalities. The aim of the present thesis was to explore the role of multimodality imaging in cardiac interventional procedures. In Part I, the integration of different imaging modalities during catheter ablation procedures for AF was studied. In addition, the effects of these procedures on left atrial and left ventricular (LV) size and function were investigated. Part II studied the effects of RV apical pacing on LV dyssynchrony and mechanics, and the effect of upgrade to CRT. Finally, in Part III the role of imaging in new percutaneous procedures for valvular heart disease was explored. Show less