impedance cardiographyImpedance Cardiography (ICG) is a non-invasive technology that measures the total electrical conductivity of the thorax, the area between the neck and the abdomen. The test measures changes over a continuous period to record data such as heart rate, cardiac output, ventricular ejection time, and stroke volume. It is used to detect the impedance changes via a high-frequency, low magnitude current flowing through the chest between two pairs of electrodes located outside of the measurement area.

To prepare, the patient just needs to wear a shirt that opens in the front. For some men, a small area of the chest may need to be shaved for the sticky pads to adhere. Four pairs of electrodes on sticky pads are placed at the neck and the diaphragm level, delineating the thorax to detect the ECG signal, which is basically used as a timing clock of the cardiovascular system. The patient just needs to lie still and remain quiet during the test. With each heartbeat, the blood volume and velocity in the aorta changes, the ICG measures the corresponding change in impedance and its timing. It is a diagnostic tool to measure hemodynamics, which is how blood flows. Hemodynamics is an important part of cardiovascular physiology related to the force that the pumping heart has to use to circulate blood through the cardiovascular system.

The cardiovascular system’s primary function is the transport of oxygen, using blood as the vehicle. A healthy cardiovascular system can provide adequate oxygen to all the organs and maintains a balance between oxygen demand and oxygen delivery. For a healthy patient, the cardiovascular system always increases blood flow as a response to increased oxygen demand. In a hemodynamically compromised patient, the system is not as able to satisfy an increased oxygen demand and the blood flow to organs becomes lower – causing a decrease in the needed oxygen. Organs that do not receive enough oxygen may eventually fail. Examples of symptoms caused by low oxygen in the blood include tiredness, male impotence, digestive disorders, sleepwalking, intolerance of environmental temperature changes, fainting, and decreased coordination.

Impedance Cardiography diagnostic testing may be needed to monitor your general blood flow as it affects the functioning of your heart and cardiovascular system. It is a method that can be used to also diagnosis high blood pressure (hypertension) and to examine the functioning of the ventricle – the bottom pumping chamber – of your heart. Test results are studied carefully to establish whether any previous medical treatment has been effective, used as a guide when making adjustments to certain types of pacemakers, and aids in determining if other treatment measures need to be implemented.

Prevention is always the best option, so we strongly endorse focusing on your heart health to stop or decrease the chance of developing a cardiovascular condition. Major risk factors include having unhealthy blood cholesterol levels, high blood pressure, diabetes, smoking, and being overweight or obese. A lack of physical activity or a sedentary lifestyle can worsen the risk for cardiovascular disease. Watching what you eat – with emphasis on a plant-based, whole foods diet – can greatly help.

Your heart & health are important at South Strand Cardiology