Shape Medical Systems (St. Paul, Minnesota) is offering a much simpler and less intensive way of testing for measuring ventilation parameters for patients who have suffered from cardio-illness.

The Shape HF Cardiopulmonary Testing System was given FDA approval at the end of March and objectively measures CRT response in real time while the patient is exercising, according to Shape Medical. Objectivity is the key selling point of the device.

"Typically patients are given questionnaires or surveys – more subjective means to test for CRT responses," Clarence Johnson, president/COO of Shape Medical told Diagnostics & Imaging Week.

Here's how the device works.

As the patient exercises at a steady state heart rate, the physician adjusts therapy settings every two minutes, enough time for the adjustments to be reflected in breathing physiology. At the end of the test, during which four to five therapy settings are tested, the Shape-HF System uses a proprietary computer algorithm to rank the physiological response to exercise at each setting.

The physician then reviews the results and chooses the therapy setting he or she believes is most appropriate for the patient. The exercise includes walking on a treadmill at a very low intensity of one mile per hour with the treadmill set at a 2% grade.

"Other methods have proven to be very difficult for patients," Johnson said. "The Gas inhalation test for example is very difficult and has often found to bring patients to the point of exhaustion."

CRT is a widely used method for treating patients with severe heart failure when alternative treatment options have been exhausted. According to Dr. Abraham Kocheril, professor of medicine and director of Clinical Electrophysiology at the University of Illinois at Chicago where the Shape-HF System has already been installed, "The CRT response rate in heart failure patients is about 70%. The Shape-HF System is likely to help us get the remaining 30%—those we call non-responders—feeling better."

Johnson added that because patient breathing efficiency is so sensitive to changes in CRT settings, using gas exchange parameters to assess these changes provides a completely objective method for defining response to CRT therapy.

Plans call for the company to try and get approval in Europe.

"We don't have CE mark yet. This is a device that will have a wide appeal in Europe," Johnson said "But we thought we would go after the domestic market first."

The company stressed that the Shape-HF System is the only device that objectively measures CRT response in real time while the patient is exercising. The system is cost-effective, easy to use, and the test is easy on the patient.

"It's very easy to use and training for the system can be done in 30 minutes to an hour," Johnson told D&IW. "All of the muss and the fuss are taken out of the process."

To date this is the only product the five-year-old company has released.

CRT is used in severe cases of heart failure to restore synchrony between the heart chambers—the atria and two ventricles—during the heartbeat.

In patients with advanced heart failure the heart may not beat strongly enough to supply adequate oxygen to peripheral tissues, and poor blood flow to the lungs disrupts the process of exchanging needed oxygen for carbon dioxide, a waste product of normal metabolism. Combined, these effects lower the amount of oxygen in the blood, which decreases the patient's ability to exercise and causes inefficient, labored breathing.

Typically shortness of breath on even mild exertion is a key symptom in heart failure during CRT therapy. The company said that a positive response to CRT therapy improves breathing efficiency during exercise, and that it makes sense that parameters that can measure patient breathing efficiency, can be used to determine the proper CRT settings.