Heart Failure
Heart failure is a progressive condition affecting patients whose heart cannot pump enough blood to meet the needs of their body. Unlike other common cardiac disorders, such as heart attacks (myocardial infarctions or MI) or arrhythmias (abnormally fast or slow, or irregular cardiac activity), the heart does not suddenly lose its function, but, usually, weakens gradually over a period of time.
In the early stages of heart failure, the heart and the vascular system (veins, arteries and capillaries) might compensate for the weakening of pumping activity, producing only mild to moderate symptoms. Over time, this burden causes the heart to enlarge and the heart muscles to weaken further, limiting the amount of blood that can be pumped throughout the body.
The contraction of the heart muscle can become disorganized, with different parts of the heart contracting at different times, reducing pump efficiency. A vicious cycle begins and symptoms worsen when the body cannot adjust to small additional burdens, such as light exercise. At this stage other organs become involved, with fluid accumulating in the lungs, feet and legs, and even the abdomen.
Warning: This information should not be used as a substitute to consultation from a physician.
The causes of heart failure are multiple and can be present many years before symptoms develop. Damage to the heart muscle by a heart attack is a common starting point. Other chronic conditions, such as high blood pressure, heart valve disease, diabetes, arterial disease, lung disease and familial causes are the main contributors.
Symptoms and screening test results are not enough to make an accurate diagnosis because of the complexity of the condition and its frequent association with other diseases. More specific tests may be necessary to gain further insight into the patient’s condition and its origins, including chest x-ray, cardiac ultrasound and other cardiac imaging techniques, electrocardiogram (ECG), special blood tests, exercise testing, or cardiac catheterization.
Warning: This information should not be used as a substitute to consultation from a physician.
Medications
After lifestyle and dietary modifications, which include leading an active lifestyle and maintaining a healthy diet to reduce blood pressure and cholesterol, one method for management of heart failure is medications. The types of drugs used to treat heart failure are shown in the table below. Their prescriptions and dosages depend on the severity of symptoms, and they may be used alone or in combination.
American College of Cardiology/American Heart Association 2005 Drugs Recommended for Routine Use1
Drug Recommendation for Routine Use
Angiotensin Converting Enzyme (ACE) Inhibitors 1st line therapy with strong clinical evidence
Angiotensin Receptor Blockers (ARBs) Used when ACE inhibitors are not tolerated
Diuretics Reduce blood volume. Recommended in combination with ACE Inhibitors. Several types available
ß-adrenergic blockers Recommended for class II-IV heart failure
Spironolactone Recommended in advanced heart failure as adjunct
Digoxin Recommended when atrial fibrillation is present
Non-pharmacological treatments
A rapidly growing treatment option for patients suffering from heart failure is Cardiac Resynchronization Therapy (CRT). When heart failure is associated with disorganized ventricular contractions, special types of implantable devices may be appropriate to deliver CRT. These can either be:
Cardiac resynchronization therapy pacemakers (CRT-P) pace both ventricles to restore a synchronized cardiac contraction and improve the performance of the heart.
Cardiac resynchronization therapy defibrillators (CRT-D) combine the former device with the capability of automatically delivering high-energy electric shocks to stop a sudden, abnormally rapid heart rhythm. Defibrillators are used primarily when heart failure is associated with a high risk of dangerously rapid, abnormal heart rhythms also known as ventricular tachycardia and ventricular fibrillation.
There are other non-pharmacological means of treating heart failure. These include surgical techniques to correct contributing factors such as valve repair or replacement, implant of a left ventricular assist device which helps the pumping action of the heart and, ultimately, heart transplantation.
1. Hunt, Sharon Ann et al; ACC/AHA 2005 Guideline Update for the Diagnosis and Management of Chronic Heart Failure in the Adult;4.3.1.2: 23-34.
Warning: This information should not be used as a substitute to consultation from a physician.