[Cardioresynchronizing therapy in treatment of cardiac insufficiency]

The authors analyze the effectiveness of cardioresynchronizing therapy (CRT) in patients with cardiac insufficiency (CI) and intraventricular conductivity disorder. The results of completed randomized studies (CONTAK-CD, MIRACLE-ICD, MUSTIC-AF, RD-CHF, COMPANION, PATH-CHF, PATH-CHF II, MUSTIC-SR, MIRACLE, MUSTIC-AF, CARE-HF) and their metanalysis are evaluated; drawbacks of these studies are demonstrated. CRT has been demonstrated to increase survival rate due to slowing down CI progress; total mortality falls thanks to CRT even without defibrillation function. High efficacy and safety of CRT in patients with CI and profound systolic dysfunction have been demonstrated; quality of life increases by 7.6 points and by 8 points in patients with III to IV functional class CI. At the same time, there is a need for additional investigations of CRT for adequate selection of patients and optimization of stimulation modes. It is not quite clear yet for what functional class CI CRT will be most effective, which criterion is most important for patient selection, whether biventricular stimulation has advantages over left-ventricular one, and whether it is necessary to stimulate the atriums or their detection is enough. Few studies on chronic atrial arrhythmias have been conducted, thus it is not known to which extent CRT is effective in this category of patients.