A data transfer component receives cardiac data from a heart sensor while the data transfer component is electromechanically coupled with the heart sensor sensitive to heart activity. A standard electromechanical interface of the data transfer component and a counterpart of the heart sensor are repeatedly connectable and disconnectable. The received data is stored in the data transfer component. The stored data is transferred from the data transfer component to an external device while the data transfer component is electromechanically coupled with the external device by using a coupling between the standard electromechanical interface of the data transfer component and a counterpart of the external device which are repeatedly connectable and disconnectable.