Researchers patent novel method for measuring blood pressure in the heart

Researchers at Virginia Commonwealth University Medical Center have developed and patented a new, noninvasive means of measuring blood pressure inside the heart.

The measurement to determine central venous pressure (CVP) -- a reading that gives doctors important information about the volume of blood circulation and how well the heart is pumping -- now can be done using a simple blood pressure cuff and special electrodes connected to a computer.

The new technique, developed by researchers in VCU's Reanimation Engineering Shock Center (VCURES), determines CVP by monitoring blood volume changes in the arm in response to externally applied circumferential pressure to the brachial vein -- the large vessel in the arm that carries blood between the elbow and shoulder back to the heart.

Doctors space four monitoring electrodes along the arm and apply a blood pressure cuff on top of two of the electrodes near the shoulder. Over the course of a minute, the cuff is partially inflated and deflated allowing the monitoring electrodes to detect changes in blood volume and send data to a computer that determines the CVP.

Monitoring CVP of a critically ill or injured patient can be essential in determining how well blood is circulating to vital organs and if the heart is failing.

Until now, doctors had to thread a catheter through the neck or chest to a point near the right atrium -- the first of the heart's four pumping chambers -- to accurately determine CVP, a time consuming procedure that can lead to complications including infection, punctured lungs, bleeding and arrhythmias.

In a recent study published in the journal Resuscitation, VCU investigators used the method to measure CVP in critically ill or injured patients who already were undergoing CVP measurement using the conventional catheter technique. The investigators found the new noninvasive method was as accurate and precise as directly measuring CVP from the catheter.

"The ability to accurately monitor CVP in a safer, more efficient, noninvasive way will have tremendous patient benefits and enable health care workers to make more rapid treatment decisions," according to Kevin Ward, M.D., associate professor in the Department of Emergency Medicine at the VCU Medical Center, who co-authored the study and is a co-inventor of the technique. "This should ultimately lead to improved patient outcomes and fewer complications."