An echocardiogram,referred to casually as a cardiac echo or just echo, is an ultrasound examination of the heart. It is a safe and painless test that can be completed in less than an hour. The echocardiogram employs sound waves to examine the heart’s structure and motion. It can produce detailed images of the heart’s chambers and valves. It is capable of measuring the size of the chambers to within small fractions of an inch as well as measuring the thickness of the walls of the heart.
The echocardiogram can also measure the pressure change (or pressure gradient) between the left ventricle and the aorta. Doctors commonly use the echocardiogram to assess the pumping function of the heart by measuring the ejection fraction. Normally, the heart ejects approximately 60 percent of the blood in the left ventricle every time the heart beats. Patients with ejection fractions of approximately 40–45 percent have mildly depressed ejection fractions; patients with ejection fractions of about 30–40 percent have moderately depressed ejection fractions; and patients with ejection fractions in the 10–25 percent range have severely depressed ejection fractions. It is important to keep in mind that someone with a normal ejection fraction reading can still have heart failure.
Diastolic dysfunction is a term physicians use to describe the effects of the heart muscle that has become so thick and stiff that the ventricle does not expand for blood coming in from the atrium. Therefore, the ventricle holds a smaller-than-usual volume of blood. While the percentage of blood pushed out in each heartbeat is high (the ejection fraction), the amount of blood pushed out in each heartbeat is low (the cardiac output). The patient suffers heart failure because the total amount of blood pumped isn’t enough to meet the body’s needs.
Victoria’s comment:I mentioned before that I get an echocardiogram at least once a year from my cardiologist. He uses it to check my ejection fraction. I didn’t know till I read this book that the echocardiogram can also look at the heart valves and aorta.