Systems and Methods for Evaluating Neuromodulation Therapy Via Hemodynamic Responses

A method of determining a treatment site within a blood vessel, the method comprising:

• delivering a distal portion of a neuromodulation catheter to a target site within a renal artery of a human patient;
• applying a first stimulus at and/or proximate to the target site via the distal portion of the neuromodulation catheter;
• measuring, via the distal portion of the neuromodulation catheter, a first hemodynamic response of the renal artery to the first stimulus;
• applying energy to the target site via the distal portion of the neuromodulation catheter, wherein the energy is sufficient to temporarily stun renal nerves proximate to the renal artery;
• after energy application, applying a second stimulus at and/or proximate to the target site via the distal portion of the neuromodulation catheter;
• measuring, via the distal portion of the neuromodulation catheter, a second hemodynamic response of the renal artery to the second stimulus;
• determining a difference between the first hemodynamic response and the second hemodynamic response, wherein—
• when the difference is above a predetermined threshold indicative of renal nerve stimulation, applying neuromodulation energy to the target site, and
• when the difference is below the predetermined threshold, repositioning the distal portion of the neuromodulation catheter to a new target site along the renal artery, and repeating the method until the difference of the first and second hemodynamic responses is above the predetermined threshold.

A method of evaluating neuromodulation therapy, the method comprising:

• delivering a first distal portion of a first catheter to a first target site within a renal artery of a human patient, wherein the first distal portion includes at least a first electrode;
• delivering a second distal portion of a second catheter to a second target site within a renal vein of a human patient, wherein the second distal portion includes at least a second electrode;
• applying a first stimulus to the renal artery and renal vein with the first and second distal portions of the first and second catheters;
• measuring impedance across the first and second electrodes caused by the first stimulus to determine a first impedance;
• delivering neuromodulation energy to a neuromodulation site within the renal artery;
• after delivering neuromodulation energy, applying a second stimulus to the renal artery and the renal vein with the first and second distal portions of the first and second catheters;
• measuring impedance across the first and second electrodes caused by the second stimulus to determine a second impedance;
• and
• comparing the first and second impedances to determine efficacy of the neuromodulation.