Impedance Cardiography Has Been Saving Lives Quietly For Decades.

There are few medical tests more easily recognized than impedance cardiography.  The sight of electrical sensors carefully positioned on a patient’s chest is a familiar one in movies, television, and real life medical situations. Usually referenced as an ICG, this test is based on the movement of blood through the body and how much resistance (or impedance) is present to the flow of blood.  

Four disposable sensors are put on the neck and chest of the patient and they transmit electrical and impedance changes in the thorax.  These signals are used to measure and calculate the flow of blood through the body and the forces that are impacting the blood flow.  These forces impacting blood flow are called hemodynamics and knowing how much resistance and what type can provide an enormous amount of information to health care professionals. 

ICG’s work by transmitting current through the patient’s chest.  The current seeks the path of least resistance which in the human body is the blood filled aorta.  The impedance cardiography measures the impedance or resistance to the current from the blood in the aorta and then as the heart beats the blood volume and speed in the aorta changes. The ICG measures these changes as well and then uses the changes in impedance to measure and calculate hemodynamic parameters. 

Getting enough oxygen to all the different parts of the body is crucial for health and well being, and the main job of the cardiopulmonary system is to get enough oxygen and nutrients to all the different parts of the body and then remove all the metabolic waste products.   When disease comes into play, the resistances to blood flow in different parts of the body can make the oxygen delivery system falter or in some cases fail.  Impedance cardiography measures the resistance to the blood flowing in the system and can point out if there’s an issue and what type of resistance is occurring.  

This is lifesaving information as well as a wonderful tool to verify good health.  The health profession relies on many tests and machines to assist them in learning what is happening inside the human body without having to resort to invasive tests.  The ICG is one of the best tools they have to determine the health and well being of patients as well as defining what might be going amiss.