Definition and Overview

Congestive cardiomyopathy is the most common type of cardiomyopathy, a term used to refer to all diseases that affect the muscles of the heart. In congestive cardiomyopathy, the walls of the heart chambers dilate or stretch, causing the organ’s muscles to become weak, which prevents the heart from effectively pumping blood throughout the body.

The condition, which is also called dilated congestive cardiomyopathy, accounts for as many as 87% of all cardiomyopathy cases and is one of the causes of heart failure.

Other types of cardiomyopathies are:

  • Primary cardiomyopathy - Characterised by changes in the structure of the heart muscles

  • Hypertrophic cardiomyopathy - A condition in which the heart muscle becomes abnormally thick.

  • Restrictive cardiomyopathy - A rare type of cardiomyopathy in which the heart muscle does not relax normally between heartbeats or when the blood returns from the body (diastole).

  • Ischemic cardiomyopathy - Primarily caused by coronary artery disease or a previous heart attack

  • Idiopathic congestive cardiomyopathy

Causes of Condition

While the main cause of congestive cardiomyopathy is unknown in most cases, doctors have identified some factors that can significantly increase a person’s risk of developing the condition. These include:

  • Genetics - Studies show that up to one-third of patients diagnosed with congestive cardiomyopathy have inherited their condition from either one or both their parents.

  • Coronary artery disease, in which the arteries responsible for supplying blood to the heart becomes narrowed or completely blocked due to the formation of blood clots or plaque buildup.

  • Heart attack

  • High blood pressure

  • Thyroid disease

  • Coxsackievirus B

  • Viral infections, especially those that cause the heart muscle to become inflamed

  • Some nutritional and metabolic disorders

  • Complications of a recent childbirth

  • Some medicines, including doxorubicin or daunorubicin

  • Sarcoidosis

  • Wegener’s granulomatosis

  • Alcoholism

  • Diabetes

Congestive cardiomyopathy, which is more common among patients aged between 20 and 60 years old, usually originates in the left ventricle or the main pumping chamber of the heart. When left untreated, the condition may eventually lead to congestive heart failure as the muscles continue to weaken. Aside from the link between congestive heart failure and cardiomyopathy, the latter is also associated with arrhythmias, blood clots in the heart, and heart valve problems.

Key Symptoms

The key symptoms of congestive cardiomyopathy are:

  • Shortness of breath

  • Angina

  • Syncope or fainting

  • Fatigue

  • Enlarged heart

  • Pulmonary oedema

  • Dizziness

  • Swollen legs and ankles

  • Elevated jugular venous pressure

  • Low pulse pressure

  • Mitral or tricuspid regurgitation

  • Arrhythmias

  • Heart murmur

If there is irregular heart rhythm in the ventricles, the patient is also at risk of sudden cardiac arrest or unexpected death caused by the sudden loss of heart function.

Who to See and Types of Treatments Available

Patients who experience the above symptoms should consult a heart specialist or cardiologist right away. The cardiac specialist will perform a physical exam and review the patient's medical history to identify the causes of the patient's symptoms. He may also order the following imaging tests:

  • Chest x-ray - This is effective in determining whether the heart has enlarged and if there are other abnormalities to take note of.

  • Electrocardiogram (ECG or EKG) - Detects damage to the heart muscle and determines the extent of the problem.

  • Echocardiogram or cardiac catheterisation - Creates images of the heart using sound waves to check for enlarged wall chambers or abnormal heart valves.

The management of cardiomyopathy commonly combines the following treatment methods:

1.) Medications - Medications are used primarily to relieve the patient’s symptoms. These may include:

  • Diuretics - By removing excess water and salt from the body, diuretics help treat high blood pressure.

  • Digitalis - This drug is very effective in strengthening the heart’s pumping action.

  • Anticoagulants - Prevent the formation of blood clots that can block blood vessels.

  • Vasodilators

  • Beta-blockers

  • ACE (angiotensin-converting enzyme) inhibitors

  • Angiotensin receptor blockers

Vasodilators, beta-blockers, and ACE inhibitors work similarly; they expand blocked or narrowed blood vessels so that blood will flow freely. This way, the heart does not have to work too hard to meet the body's needs.

2.) Lifestyle changes - To relieve symptoms of the condition, patients are instructed to adopt a healthier lifestyle. For many patients, this means:

  • Smoking cessation

  • Diet changes

  • Exercising regularly

  • Stop drinking alcohol

3.) Long-term/continuous care

4.) Pacemakers and defibrillators - These devices, which are implanted in the chest through a minimally invasive surgical procedure, prevent arrhythmias from occurring by pacing the heart.

If the patient does not seem to respond to these treatments and if they are suffering from severe dilated cardiomyopathy, they can be considered for a heart transplant. The procedure, which remains to be the last resort for end-stage heart failure, involves replacing the patient's heart with a healthy heart from a deceased donor.

The prognosis for patients with congestive cardiomyopathy is heavily dependent on the severity of the condition and their overall health. Studies show that the five-year survival rate is 50% while the 10-year survival rate is at 25%. Most deaths linked with congestive cardiomyopathy are primarily due to the sudden onset of abnormal heart rhythms.

References:

  • Abelmann WH. “Treatment of congestive cardiomyopathy.” Postgrad Med J. 1978 Jul; 54(633):477-84. https://www.ncbi.nlm.nih.gov/pubmed/360197

  • Keren A, Gottlieb S, Tzivoni D, et al. “Mildly dilated congestive cardiomyopathy: Use of prospective diagnostic criteria and description of the clinical course without heart transplantation.” AHA Journals. http://circ.ahajournals.org/content/circulationaha/81/2/506.full.pdf

  • Burke AP. “Dilated cardiomyopathy pathology.” 2015. Medscape. http://emedicine.medscape.com/article/2017823-overview

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