Methods and systems are provided to manage display of cardiac signals. The methods and systems receive a first data steam along a first communications path conveyed with first throughput and receiving a second data stream along a second communications path transmitted with second throughput. The first and second throughputs are asynchronous with respect to one another. The first and second data streams carry cardiac signals sensed by external and implanted electrodes, respectively, for one or more common events. The methods and systems store data from the first and second data streams in first and second memory buffers. The methods and systems synchronize the data stored in the first and second memory buffers with one another by performing at least one of: temporally offsetting activation of the storing operation for the first and second data streams with respect to one another； or managing an amount of the data maintained in at least one of the first memory buffer or the second memory buffer. The methods and systems co-display cardiac signals associated with the first and second data streams on a display by reading the data from the first and second memory buffers at a data display rate.
