There are many different ways in which you or your health care provider can test your heart rate, or pulse. Choosing the site at which you will test depends on convenience, purpose and need for extreme accuracy. Doctors measure apical heart rate with a stethoscope, and is the most accurate, non-invasive way of obtaining a full heart assessment, without doing an electrocardiogram.
When most people think of finding a pulse, they think of the wrist. This is termed your radial pulse because it is taken on the radial artery. This is the most common and convenient way of assessing the heart rate. Other areas to look for a pulse are: the carotid artery, which is located in the neck and used most when exercising; the femoral artery in the groin, which is often used for heart catheterization tests; and the pedal pulses in the feet, used to discern circulation in your lower limbs. You typically are able to feel these pulses.
The principle difference between these other types of pulse rates and your apical heart rate, is the apical pulse you must listen for the apical pulse with a stethoscope because you cannot feel it. The book "Fundamental Nursing Skills and Concepts" by Barbara Kuhn Timby, advises that to locate your apical heart rate, place the stethoscope to the mid-chest, slightly toward the left side and on the apex--tip--of the heart. To find the apex, move the scope slightly below the left nipple, in line with the mid-clavicle, or collarbone. Listen for one full minute.
When measuring your apical pulse, your health care provider is listening to the count, rhythm, strength and equality of the heart as it contracts, pushing blood out and through your circulatory system. The sound she hears in a healthy adult is described as a "lub dub," the sound your heart makes as it tightens and then relaxes.
The two sounds should be equal, rather than one being predominantly weaker, thready or "bounding," which is louder and more forceful. According to the New York Times Health Guide, the rhythm is assessed to rule out any irregular beats or skipped beats, which are indicative of a problem. The most common atypical rhythms are dysrhythmia, palpitations and fibrillations. A trained ear will also listen for murmurs and flutters. If your doctor hears an irregularity, he will usually order a Doppler study or an electrocardiogram and echocardiogram to be done to find the source and effects of this abnormal heart rate.
According to Shelton State Community College's Instructional Nursing Skills curriculum, the factors that can affect your apical heart rate or pulse include exercise, temperature, the posture you are in, bleeding or hemorrhaging, blood pressure problems, drugs, emotions or stress and the condition of your lungs.