A retractable multi-use cardiac monitor is provided that includes a memory, and first and second sensing connectors positioned on outsides of first and second housings, respectively. The first and second sensing connectors are configured to detect electrocardiogram (ECG) signals that are stored onto the memory as ECG data. The second housing of the retractable multi-use cardiac monitor also includes a wire retractor configured to extend and retract a wire that connects the second and first housings, and that defines an interelectrode distance between the first and second sensing connectors. The retractable multi-use cardiac monitor further includes systems and methods for determining a length for the interelectrode distance that is optimum in terms of strength and fidelity of the detected ECG signals. The retractable multi-use cardiac monitor further includes a wireless radio configured to transmit a portion of the stored ECG data from the memory to a destination.