How is heart failure diagnosed?

When diagnosing heart failure, your doctor first looks at three areas:

• Medical history: Your doctor will ask you many questions about your symptoms and medical history. Your doctor will want to know:
  • If you have any other health conditions such as diabetes, kidney disease, angina, high blood pressure or other heart problems
  • If you smoke
  • If you drink alcohol and how much you drink
  • What medications you are taking
• Physical exam: Your doctor will listen to your heart and give you a complete physical exam Your doctor will look for signs of heart failure as well as any other illnesses that may have caused your heart to weaken.
• Tests: Certain tests can help your doctor determine the extent of heart failure. Your doctor will tell you which of these tests you should have:
  • Blood tests — to evaluate kidney and thyroid function as well as to check cholesterol levels and presence of anemia. Anemia is a blood disorder that occurs when there is not enough hemoglobin (the substance in red blood cells that enables the blood to transport oxygen through the body) in a person's blood.
  • B-type Natriuretic Peptide (BNP) blood test - BNP is a substance secreted from the ventricles or lower chambers of the heart in response to changes in pressure that occur when heart failure develops and worsens. The level of BNP in the blood increases when heart failure symptoms worsen, and decreases when the heart failure condition is stable. The BNP level in a person with heart failure - even someone whose condition is stable - is higher than in a person with normal heart function.
  • Chest X-ray — shows the size of your heart and whether there is fluid build-up around the heart and lungs.
  • Echocardiogram (or echo) — a graphic outline of the heart's movement. During an echo, a wand is placed on the surface of your chest. This wand sends ultrasound waves that provide pictures of the heart's valves and chambers so the pumping action of the heart can be studied. Echo is often combined with an ultrasound to find changes in the blood flow across the heart's valves and the pressure within the heart's chambers.
  • Ejection fraction (EF) — test that determines how well your heart pumps with each beat. This test measures how much blood is pumped out of the heart with each beat, and how much blood pumps through the heart with each beat. A normal EF is generally greater than 50 percent, which means that over half of the blood volume is pumped out of the heart with each beat.
    An EF of less than 40 percent usually confirms a diagnosis of systolic heart failure. An EF greater than 40 percent means that your heart failure is due to another cause, such as a valve disorder or diastolic dysfunction. Please note, however, that people with diastolic dysfunction can have a normal EF.
    Systolic dysfunction occurs when the heart muscle doesn't contract with enough force, so there is not enough oxygen-rich blood to be pumped throughout the body. Diastolic dysfunction occurs when the heart contracts normally, but the ventricle doesn't relax properly so less blood can enter the heart. Your doctor can discuss which condition is present in your heart.
  • Electrocardiogram (EKG or ECG) — records the electrical impulses traveling through the heart. During the test, small, flat, sticky patches called electrodes are placed on your chest. The electrodes are attached to an electrocardiograph monitor (EKG) that charts your heart's electrical activity on graph paper.