New insight into device therapy for chronic heart failure

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 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.UBL - phd migration 201

Evaluation of pulmonary arterial hypertension: invasive or noninvasive?

Vascular Biology and Interventio

CMR-determined scar volume: predictive for ventricular tachycardias?

The interesting data reported by Bernhardt et al. strengthen the diagnostic benefit of CMR in patients with ischemic cardiomyopathy. Consequently, the presence, location and size of the CMR-determined scar tissue may be used for better risk stratification in patients with ischemic cardiomyopathy eligible for ICD therapy

Assessment of left ventricular volumes; reliable by gated SPECT?

Ventricular Dysfunction & Heart Failur

Assessment of left ventricular function: visual or quantitative?

Cardiovascular Aspects of Radiolog

Impact of contractile reserve on acute response to cardiac resynchronization therapy

Background: Cardiac resynchronization therapy (CRT) provides benefit for congestive heart failure, but still 30% of patients failed to respond to such therapy. This lack of response may be due to the presence of significant amount of scar or fibrotic tissue at myocardial level. This study sought to investigate the potential impact of myocardial contractile reserve as assessed during exercise echocardiography on acute response following CRT implantation. Methods: Fifty-one consecutive patients with heart failure (LV ejection fraction 27% ± 5%, 67% ischemic cardiomyopathy) underwent exercise Doppler echocardiography before CRT implantation to assess global contractile reserve (improvement in LV ejection fraction) and local contractile reserve in the region of the LV pacing lead (assessed by radial strain using speckle tracking analysis). Responders were defined by an increase in stroke volume ≥15% after CRT. Results: Compared with nonresponders, responders (25 patients) showed a greater exercise-induced increase in LV ejection fraction, a higher degree of mitral regurgitation and a significant extent of LV dyssynchrony. The presence of contractile reserve was directly related to the acute increase in stroke volume (r = 0.48, p<0.001). Baseline myocardial deformation as well as contractile reserve in the LV pacing lead region was greater in responders during exercise than in nonresponders (p<0.0001). Conclusions: Heart failure patients referred to CRT have less chance of improving under therapy if they have no significant mitral regurgitation, no LV dyssynchrony and no contractile myocardial recruitment at exercise

Optimal left ventricular lead position assessed with phase analysis on gated myocardial perfusion SPECT

The aim of the current study was to evaluate the relationship between the site of latest mechanical activation as assessed with gated myocardial perfusion SPECT (GMPS), left ventricular (LV) lead position and response to cardiac resynchronization therapy (CRT). The patient population consisted of consecutive patients with advanced heart failure in whom CRT was currently indicated. Before implantation, 2-D echocardiography and GMPS were performed. The echocardiography was performed to assess LV end-systolic volume (LVESV), LV end-diastolic volume (LVEDV) and LV ejection fraction (LVEF). The site of latest mechanical activation was assessed by phase analysis of GMPS studies and related to LV lead position on fluoroscopy. Echocardiography was repeated after 6 months of CRT. CRT response was defined as a decrease of a parts per thousand yen15% in LVESV. Enrolled in the study were 90 patients (72% men, 67 +/- 10 years) with advanced heart failure. In 52 patients (58%), the LV lead was positioned at the site of latest mechanical activation (concordant), and in 38 patients (42%) the LV lead was positioned outside the site of latest mechanical activation (discordant). CRT response was significantly more often documented in patients with a concordant LV lead position than in patients with a discordant LV lead position (79% vs. 26%, p < 0.01). After 6 months, patients with a concordant LV lead position showed significant improvement in LVEF, LVESV and LVEDV (p < 0.05), whereas patients with a discordant LV lead position showed no significant improvement in these variables. Patients with a concordant LV lead position showed significant improvement in LV volumes and LV systolic function, whereas patients with a discordant LV lead position showed no significant improvements.Cardiovascular Aspects of Radiolog

Evidence of scar tissue: contra-indication to cardiac resynchronization therapy?

Ventricular Dysfunction & Heart Failur

Cardiac resynchronization therapy; the importance of evaluating cardiac metabolism

Cardiac Dysfunction and Arrhythmia