Described herein is a method and system for gap detection in ablation lines. Microelectrodes are implemented at a distal tip of a catheter to provide localized gap detection along an ablation line. A pacing protocol is used to sequence through each of the microelectrode pairs for a tissue location. If living tissue is present, the pacing signal travels through the living tissue to pulse the heart. An operator will see a capture signal and know that there is a gap in the ablation line. The ablation electrode is then used to ablate the tissue in the gap. Pacing and ablation are therefore performed at the same place without the need to switch between instruments and/or catheters. In an implementation, a force sensor can automate the pacing protocol by determining which microelectrode pair is contacting the tissue. Moreover, signaling between microelectrode pairs can determine contact between the catheter and the tissue.