[Three-dimensional vectorcardiography to predict CRT-responder].

Cardiac resynchronization therapy (CRT) is an accepted treatment for congestive heart failure (NYHA III-IV), but a substantial number of patients show no response to therapy. LBB, QRS width and echocardiographic measurements are parameters for indication, but they are not valid to predict hemodynamic response. A new method based on vector ECG analysis can deliver additional information, such as: parts or areas with late excitation, and with slow or fast depolarization speed. Electrical excitation is a prerequisite for contraction; this leads to the hypothesis that areas with late electrical activation will contract later. Algorithms for analysis of the vector ECG (determination of the vector -- time, area and speed) may help to identify responders and non-responders.