How to Determine Systolic Contraction Amplitudes

"Systolic contraction amplitude" refers to how much arterial pressure variance occurs during the left ventricle's contraction. Systolic blood pressure is the measurement pressure exerted when the heart contracts, while diastolic pressure measures the pressure the heart exerts when relaxed. Amplitude measures the farthest difference between a value and its average value. When physicians measure the systolic contraction amplitude for a patient, they are looking for significant differences between the average systolic blood pressure and, usually, the extreme highs. These numbers can prove useful when researchers want to compare the effectiveness of treatment methods for people who have heart disease.

Things You'll Need

• Echocardiography equipment

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Instructions

• 1

  Attach the patient to echocardiography equipment. Echocardiography uses sound waves to obtain a picture of what the heart is doing by bouncing the waves off the tissue and back to a transducer that turns the impulses into the image.

• 2

  Take multiple looping digital images of the heart in action. To measure the systolic contraction amplitude, you need images of the heart from several different perspectives — including the long-axis view, the two-chamber view and the four-chamber view — while it contracts and relaxes.

• 3

  Measure the maximum strain in each segment. The American Society of Echocardiography created a model that divides the left ventricle into 16 segments. Use this model to examine the digital images and approximate the highest amount of strain exerted on each of those segments.

• 4

  Obtain an average of the amplitudes. To calculate the systolic contraction amplitude, you must average the amplitudes for all 16 of those segments. The answer is referred to as the "global systolic contraction amplitude" ("GSCA").