Controlled tissue ablation techniques

Apparatus for use with tissue of a renal nerve passing longitudinally within a wall of a renal artery of a subject, the apparatus comprising:

• a catheter, configured to be placed within the renal artery;
• one or more stimulating electrodes coupled to the catheter and configured to stimulate the tissue of the renal nerve by passing a stimulating current through the wall of the renal artery;
• a sensor configured to sense blood pressure information of the subject;
• and
• a control unit, configured to:
• drive the one or more stimulating electrodes to stimulate the tissue of the renal nerve,
• receive the blood pressure information from the sensor,
• based on the received blood pressure information, compute a maximum intra-heartbeat blood pressure increase rate for at least one heartbeat that follows a start of the driving of the one or more stimulating electrodes to stimulate the tissue of the renal nerve,
• compare the maximum intra-heartbeat blood pressure increase rate to a threshold, and
• generate, in response to the comparison, an output indicating whether an ablation of the tissue of the renal nerve should be performed.