A medical system, comprising: a medical device having a treatment assembly, the treatment assembly comprising a distal electrode array with a plurality of electrodes coupled to the array, the array being manipulatable to define an open circle circular geometric configuration; a control unit operable to: measure an impedance of a first pair of the plurality of electrode pairs; transmit radiofrequency ablation energy between the plurality of electrode pairs; selectively terminate the transmission of radiofrequency ablation energy from at least one pair of electrode pairs when, after a period of time between six seconds and nine seconds from the beginning of transmission of the radiofrequency ablation energy: the measured impedance in either of the electrodes in the first pair of electrodes is a predetermined percentage above a measured minimum impedance; and a measured power is above a predetermined power threshold; and generate an alert indicating at least one of the formation and release of microbubbles proximate the first pair of electrodes, the termination of the transmission of radiofrequency ablation energy between the first pair of the plurality of electrode pairs is independent of the transmission of radiofrequency ablation energy between electrode pairs on the treatment assembly other than the first pair of the plurality of electrode pairs. a medical device having a treatment assembly, the treatment assembly comprising a distal electrode array with a plurality of electrodes coupled to the array, the array being manipulatable to define an open circle circular geometric configuration; a control unit operable to: measure an impedance of a first pair of the plurality of electrode pairs; transmit radiofrequency ablation energy between the plurality of electrode pairs; selectively terminate the transmission of radiofrequency ablation energy from at least one pair of electrode pairs when, after a period of time between six seconds and nine seconds from the beginning of transmission of the radiofrequency ablation energy: the measured impedance in either of the electrodes in the first pair of electrodes is a predetermined percentage above a measured minimum impedance; and a measured power is above a predetermined power threshold; and generate an alert indicating at least one of the formation and release of microbubbles proximate the first pair of electrodes, the termination of the transmission of radiofrequency ablation energy between the first pair of the plurality of electrode pairs is independent of the transmission of radiofrequency ablation energy between electrode pairs on the treatment assembly other than the first pair of the plurality of electrode pairs. measure an impedance of a first pair of the plurality of electrode pairs; transmit radiofrequency ablation energy between the plurality of electrode pairs; selectively terminate the transmission of radiofrequency ablation energy from at least one pair of electrode pairs when, after a period of time between six seconds and nine seconds from the beginning of transmission of the radiofrequency ablation energy: the measured impedance in either of the electrodes in the first pair of electrodes is a predetermined percentage above a measured minimum impedance; and a measured power is above a predetermined power threshold; and generate an alert indicating at least one of the formation and release of microbubbles proximate the first pair of electrodes, the termination of the transmission of radiofrequency ablation energy between the first pair of the plurality of electrode pairs is independent of the transmission of radiofrequency ablation energy between electrode pairs on the treatment assembly other than the first pair of the plurality of electrode pairs. the measured impedance in either of the electrodes in the first pair of electrodes is a predetermined percentage above a measured minimum impedance; and a measured power is above a predetermined power threshold; and generate an alert indicating at least one of the formation and release of microbubbles proximate the first pair of electrodes, the termination of the transmission of radiofrequency ablation energy between the first pair of the plurality of electrode pairs is independent of the transmission of radiofrequency ablation energy between electrode pairs on the treatment assembly other than the first pair of the plurality of electrode pairs.