Diagnosis and treatment of small vessel occlusion using an occluder and lumen to discharge fluid

A system for measuring microvascular obstruction (MVO) in a body having an organ and a vessel supplying blood to the organ, the system comprising:

• a percutaneous transvascular catheter including:
• an occluder disposed on a distal portion of the percutaneous transvascular catheter and configured to be disposed in the vessel to block antegrade blood flow in the vessel;
• and
• a lumen having an outlet disposed distal to the occluder and configured to discharge infusate into the vessel distal to the occluder;
• a pressure sensor configured to sense a blood pressure in the vessel distal to the occluder;
• an infusion pump coupleable to the lumen of the catheter and configured to infuse an infusate into the vessel distal to the occluder via the lumen;
• and
• a computerized system coupled to the pressure sensor and to the infusion pump and configured to:
• cause the infusion pump to infuse an infusate into the vessel distal to the occluder at a first mean infusate flow rate for a first infusion time;
• cause the infusion pump to infuse an infusate into the vessel distal to the occluder at a second mean infusate flow rate, greater than the first mean infusate flow rate, for a second infusion time;
• measure the blood pressure in the vessel distal to the occluder with the pressure sensor at multiple points in time at least during each of the first infusion time and the second infusion time;
• calculate a value of dynamic microvascular resistance at each of the multiple points in time by:
• dividing a value of the blood pressure at each of the multiple points in time during the first infusion time by the first mean infusate flow rate;
• and
• dividing the value of the blood pressure at each of the multiple points in time during the second infusion time by the second mean infusate flow rate;
• and
• determine a change in a level of the MVO over the first infusion time and the second infusion time based on at least the value of the dynamic microvascular resistance calculated at each of the multiple points in time.