A medical electrical lead is disclosed that is adapted for placement in the coronary sinus, or a branch vein thereof. The lead includes a first and second pace/sense electrode. A selection mechanism is provided to select either the first or the second electrode for use as a cathode, with the other electrode...http://www.google.com.hk/patents/US6901289?utm_source=gb-gplus-share專利 US6901289 - System for providing electrical stimulation to a left chamber of a heart
