Established and evolving indications for cardiac resynchronisation

Heart Rhythm Considerations in Heart Transplant Candidates and Considerations for Ventricular Assist Devices: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates—2006

“…3 The ventricular contraction pattern associated with LBBB results in the following abnormalities 1 : abnormal ventricular septal motion with movement paradoxical to the lateral wall of the left ventricle, and thus a decrease in regional left ventricular ejection fraction (LVEF) 2 ; a delay in mitral valve opening and aortic valve closure resulting in a shortened left ventricular (LV) filling time 3 ; and mitral regurgitation, caused or aggravated by dyssynchronous activation of papillary muscles and the surrounding myocardium and incomplete closure of the mitral valve caused by late ventricular contraction. 2,3 In addition to dyssynchrony resulting from underlying cardiac pathologies, some data suggest that cardiac dyssynchrony induced by a pacemaker (right ventricular [RV] or combined right atrial [RA] and RV) may increase the risk for the development of heart failure. 4 Irrespective of the underlying pathology, QRS Ͼ120 milliseconds is associated with increased mortality.…”

“…This abnormality may be due to both disturbed electrical activation and regional abnormalities in contraction due to ischemia, myocardial scarring or replacement of myocardium by infiltrative diseases. 1,2 Approximately 33% of patients with systolic heart failure have evidence of abnormal electrical activation on surface electrocardiogram (ECG), seen as a QRS duration of Ͼ120 milliseconds, most commonly as a left bundle branch block (LBBB). 3 The ventricular contraction pattern associated with LBBB results in the following abnormalities 1 : abnormal ventricular septal motion with movement paradoxical to the lateral wall of the left ventricle, and thus a decrease in regional left ventricular ejection fraction (LVEF) 2 ; a delay in mitral valve opening and aortic valve closure resulting in a shortened left ventricular (LV) filling time 3 ; and mitral regurgitation, caused or aggravated by dyssynchronous activation of papillary muscles and the surrounding myocardium and incomplete closure of the mitral valve caused by late ventricular contraction.…”

Sincronia ventricular em portadores de miocardiopatia dilatada e indivíduos normais: avaliação através da ventriculografia radioisotópica

“…However, according to the current selection criteria, patients with QRS <120 ms are not candidates to CRT 1,8,26 . Several studies have suggested that the measurement of ventricular dyssynchrony degree by means of diagnostic methods, such as nuclear magnetic resonance, echocardiogram with tissue Doppler and radionuclide ventriculography could better predict the response to CRT [8][9][10][11][12][14][15][16][17]26 .…”

“…However, increasing evidence has shown a poor correlation between the clinical and functional response to CRT and the duration of QRS interval 8,9 . On the other hand, direct measurements of electromechanical dyssynchrony based on simple and non-invasive imaging methods may improve the selection criteria and better predict the response to CRT 9,10 . Some studies have used radionuclide ventriculography (RNV) to assess synchrony of ventricular movements, by means of phase and amplitude parametric images [11][12][13][14][15][16][17][18][19][20] .…”

Echocardiographic Assessment of Ventricular Asynchrony in Dilated Cardiomyopathy and Congenital Heart Disease: Tools and Hopes

“…New imaging modalities, in particular various echocardiographic approaches, have been described. [22][23][24][25] The intentions of this article are to: (1) discuss the different echocardiographic approaches and techniques in selection and optimization of CRT; (2) assess the actual and potential role of echocardiography in the treatment of these patients; and (3) highlight some new applications such as in congenital heart disease.…”