Principles of multimode pacing.

Although physiologic pacing systems have multiplied recently, their functional evaluation by ECG analysis remains an area of relative complexity. More thorough and detailed specifications of operation are necessary to aid the clinician in his effort to understand and assess the function of a DDD pacer. Elimination of cross-talk via various available methods should simplify interpretation. Awareness by physicians will provide the necessary feedback to the designers to create more physiologic systems in the future.