How to Interpret Cardiac Rhythms

The heart is just as important as the brain in sustaining life. This muscle keeps blood circulating through the body, allowing the life-giving fluid to perform important tasks, such as delivering vital oxygen to the extremities. There are numerous conditions that can disrupt the effectiveness of the heart, including holes, blocked arteries and loss of the electricity that keeps the heart pumping. Doctors can interpret these problems by listening to the rhythm of the heart, which will lose its regular beat when something is wrong. The tools doctors use to make this diagnosis are the stethoscope, blood pressure cuff and electrocardiogram.

Instructions

• 1

  Listen for a rapid beat of the heart, which indicates sinus tachycardia. This is not a serious medical condition, merely an elevated heart rate due to environmental factors such as stress, adrenaline and exercise. The opposite of this, sinus bradycardia, is less than 60 beats per minute. Athletes usually have a low heart beat because of their frequent exercise. Certain medications can cause this condition, as well as shock or extreme pain. In the latter instance, a person may feel lightheaded from the slowed heartbeat.

• 2

  Make a note of the beats per minute, then give the patient several minutes to relax and calm down. If the heart beat continues to race at a high rate, then the person is suffering from tachycardia. The heart cannot sustain a high beat rate for long and will eventually fail and kill the patient. Shocking the heart with electricity can restore the regular rhythm.

• 3

  No heartbeat at all is called ventricular fibrillation. This happens when the heart loses its electrical charge and merely jiggles instead of beating. When this happens, the heart must be knocked out of the fibrillation state, so a "defibrillator" is used to shock it back into action. Usually the heart suffers fibrillation when a blocked artery doesn't supply enough blood to the heart (a heart attack), but drug overdoses and poisoning can cause this, too.

• 4

  Listen for the heart to skip a few beats, or to give several beats in rapid succession. This is ventricular flutter, an early warning sign that the heart is headed toward complete fibrillation. At this stage the heart has enough juice to keep beating, but it's rapidly failing.

• 5

  Listen for an incredibly fast beat, between 150 and 200 beats per minute. This is the result of paroxysmal supraventricular tachycardia. This is not usually a life-threatening condition, but is uncomfortable for the patient. Ask the person if she is also experienced shortness of breath or if she has the sensation of a full throat. The condition can be triggered by congenital defects, as well as caffeine, narcotics such as cocaine and methamphetamine, and over-the-counter cold medicine.