Search

Implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT) have been introduced during the recent years to improve survival, decrease hospital readmissions and mortality, and to improve functional status and quality of life for patients with heart failure and left ventricular systolic dysfunction (LVSD). Studies which evaluated the use of CRT or ICD alone or compared CRT with CRT-ICD in patients with heart failure and LVSD are listed in this article. The results obtained are already influencing clinical practice in the US, where it has been estimated that 90% of patients receiving a CRT device now are being implanted with an ICD component. However, it is still today debated whether patients with LVSD and heart failure should be routinely offered a CRT-ICD. In fact, there are some issues that still should be solved before to establish indication for CRT-D in all heart failure patients with an indication for CRT: 1) a non complete agreement among the different societies which wrote recommendations for guidelines (a comparative table is reported); 2) a better identification of implantable patients and an amelioration of utilized devices; 3) economic and ethical ramifications of this therapy. Anyway still now the crucial question is: ''Can resynchronization be done in isolation or must be accompanied by an ICD device?''. To answer to this question we can only express which is, in our opinion, the actual position of many physicians who work in the field of pacing and electrophysiology: ''The lesson to be learned is that we still can not predict surely which patient will die of sudden death. Until a method of identifying the high risk patients can be developed, the safest strategy should be to advise a combined ICD-CRT device for patients with indication for CRT''.

Cardiac resynchronization therapy (CRT) reduces the severity of functional mitral regurgitation (FMR) in patients with heart failure and left bundle branch block. Our hypothesis was that the induction of a more synchronous mitral valve anulus contraction can be a mechanism of FMR reduction in CRT patients.An echo tissue Doppler imaging (TDI) examination was performed at baseline and 6 months after biventricular pacing system implant in 30 patients (4 females and 26 males, 74.1+/-6.1 years) with dilatative or ischemic chronic heart failure, NYHA class = orIII, ejection fraction (EF) = or35% and QRS = or140 ms. EF, Myocardial Performance Index (MPI), left end-diastolic and systolic volumes (LVEDV, LVESV), mitral regurgitation jet area/left atrial area (JA/LAA), effective regurgitant orifice area (EROA), mitral anulus contraction (MAC) were evaluated. Using TDI, at the 6 left ventricle (LV) basal segments the time to the peak myocardial sustained systolic velocity (Ts) and the standard deviation (SD) of TS were evaluated.At 6 months follow-up NYHA class, EF, MPI were significantly improved, LV volumes were reduced. FMR degree, evaluated both as JA/LAA and EROA, was significantly reduced. This effect was associated with the 6 basal segments resynchronization and with a more effective annular contraction.Our data show that CRT by resynchronizing left ventricular basal segments produces a more effective mitral valve annulus contraction and contributes to FMR improvement. Further studies need to evaluate if this could be taken into account as new therapeutic perspective of functional mitral valve regurgitation.