[Implantable defibrillator and ventricular resynchronisation]

Ventricular resynchronisation by pacing, introduced at the end of the 1990s, has revolutionised the management of advanced chronic cardiac failure. Its value in the reduction of haemodynamic mortality has been demonstrated in the latest studies. However, despite these decisive advances, patients with cardiac failure continue to have a high incidence of sudden death which, classically, according to its stage of progression, represents 28 to 68% of deaths in this condition. The implantable automatic defibrillator (IAD) has been shown to be effective in preventing sudden death, mainly in patients with severe left ventricular dysfunction. Based on these data, and in a context of rapid technological progress, devices capable of both defibrillating and resylchronising the heart have been introduced. The problems experienced at the beginning of their utilisation, mainly related to "double-counting" of left and right ventricular electrical activation have been resolved and the method is now technically feasible. A complication rate >10%, mainly due to the implantation of the left heart catheter, continues to bear witness to the difficulties of this technique and to the severity of the condition of patients referred for the treatment. The COMPANION trial has shown a greater reduction in mortality of patients treated by resynchronisation associated with IAD compared with resynchronisation alone or medical therapy in > or = Stage III cardiac failure. The SCD-HeFT trial has recently demonstrated that the primary prevention of global mortality by the IAD is effective in cardiac failure irrespective of the underlying cardiac pathology, especially in functional Stage II. These results should lead to significant increase in the indications for implantation of devices capable of both resynchronisation and defibrillation. However, the obvious problems of cost associated with the difficulty of the technique mean that a systematic attitude cannot be recommended. A case-by-case discussion has its place but the causal cardiac disease, ischaemic or not, does not seem to be a determining factor.