Tests for heart failure

The most useful test for diagnosing heart failure is an echocardiogram. This painless test uses sound waves to create a moving video image of your heart at work. It's generally a simple test that involves lying down with electrodes and a small sound wave transmitter placed on your chest.

An echocardiogram (or "echo") shows how well your heart is filling with blood and pumping it out to the rest of your body. It can also show the precise areas of your heart that are not contracting (squeezing out blood) normally or that have been damaged in some way.

This is important because, in many cases, more than one part of the heart is damaged and contributing to heart failure.

The most important heart function your doctor can measure with an echocardiogram is called the ejection fraction. This is a measure of how the left ventricle (the heart's pumping chamber) is pumping blood out with each heartbeat.

A healthy heart normally has an ejection fraction of more than 50%. When that number falls below 40%, it usually means you're experiencing heart failure.

Other tests for heart failure

Your doctor may also suggest other tests that can help identify heart failure or its causes:

• Electrocardiogram (or ECG)
  This test is used to measure the rate and rhythm of your heartbeat. It may also show if you've had a heart attack or if the walls of your heart's pumping chambers (ventricles) have thickened.
• Chest X-ray
  This test creates a picture of your heart and lungs. It can show if your heart is enlarged, if you have fluid in your lungs, or if you have lung disease.
• B-type natriuretic peptide (BNP) blood test
  This blood test is relatively new. It measures the level of a hormone your heart makes, called BNP. Levels of BNP in the blood increase with heart failure.
• Holter monitor
  This test involves carrying a small monitoring box attached to electrodes on your chest. A Holter monitor continuously records your heart rhythm, typically for 24 hours.
• Cardiac blood pool scan (also called radionuclide ventriculography)
  With this test, a safe radioactive substance that can be seen by a special camera is injected into a vein. The camera then takes pictures showing the outline of your heart chambers and the blood vessels leading to your heart. It also shows how well your heart is pumping blood.
• Coronary catheterization
  A thin, flexible tube is passed through an artery in your upper leg (groin) area or arm and into the arteries around your heart. This lets your doctor look inside your arteries for any blockage and check the pressure and blood flow in your heart.
• Exercise stress test
  This test evaluates how your heart responds to exercise. Electrocardiogram and blood pressure readings are taken before, during, and after physical activity. This activity usually involves walking on a treadmill or pedaling a stationary bike until you reach a certain heart rate.
• Thyroid function tests
  These include blood tests, imaging tests, and other tests to determine how well your thyroid gland is working. An overactive or underactive thyroid gland can lead to heart failure.

Stages of heart failure

Doctors often classify heart failure using a scale of one to four. These four classes of heart failure are based on how severe your symptoms get during different levels of activity.

Class I: The mildest form of heart failure. You can perform everyday activities without feeling short of breath or tired.

Class II: Moderate physical activity causes symptoms.

Class III: Minimal physical activity causes symptoms.

Class IV: The most severe form of heart failure. Even at rest, you feel short of breath.

Information for Patients about BiDil®

BiDil is approved for use in addition to routine heart medicines to treat heart failure in black patients, to extend life, improve heart failure symptoms, and help patients stay out of the hospital longer. There is little experience in patients with heart failure who experience significant symptoms while at rest. Most patients in the clinical study of BiDil received routine heart failure medicines.

Important Safety Information

Tell your doctor about any allergies you have, especially if you're sensitive to nitrates, such as nitroglycerin tablets or isosorbide dinitrate (Sorbitrate® or Isordil®). BiDil has a nitrate component, so you need to let your doctor know.

Tell your doctor if you're taking any erectile dysfunction or pulmonary hypertension drugs, like Viagra®/Revatio™ (sildenafil), Levitra® (vardenafil) or Cialis® (tadalafil). Mixing these with BiDil may cause a sudden drop in blood pressure, fainting, chest pain, or heart attack.

Also tell your doctor if you are taking any medication to decrease blood pressure because when taken with BiDil, blood pressure may become too low.

Drinking alcohol when taking BiDil could make you feel very lightheaded. We recommend that you try to avoid drinking alcohol while taking BiDil.

It is possible you'll get headaches, especially at first. For some patients, Tylenol® (acetaminophen) helps ease the discomfort. Keep your doctor posted on your headache progress and Tylenol use; he or she may want to adjust your dosage.

If you experience dizziness, call your doctor. Please make sure to tell your doctor about any of the signs or symptoms mentioned below or about any unusual events that worry you.

Drinking less fluids than your doctor recommends or losing fluid due to diarrhea, sweating, or vomiting may cause low blood pressure, lightheadedness, or fainting. If fainting occurs, stop taking BiDil and contact your doctor immediately.

Lightheadedness may occur when standing, especially after sitting or lying down.

If you experience any achy and/or swollen joints, unexplained fever for more than a few days, skin rashes, chest pain, prolonged weakness or fatigue (even after a good night's sleep), or any other unexplained signs or symptoms, make sure to tell your doctor as they may be signs of a serious medical condition.

You may also experience rapid heartbeat that could lead to chest pain or aggravate chest pain, or numbness or tingling in the hands or feet.

Sorbitrate is a registered trademark of AstraZeneca LP; Isordil is a registered trademark of Bioavail Corporation; Viagra is a registered trademark and Revatio is a trademark of Pfizer Inc.; Levitra is a registered trademark of Bayer Healthcare, GlaxoSmithKline, and Schering-Plough; Cialis is a registered trademark of Lilly ICOS LLC. Tylenol is a registered trademark of McNeil Pharmaceuticals, a Division of McNeil PPC, Inc.

Please see full Prescribing Information for BiDil.