Heart diseases and conditions: Understanding abnormalities

There are many diseases and conditions that affect the heart. As a group, heart disease is the leading cause of death the world over. In the United States, it is the most common cause of death for both men and women. According to the CDC, 1 in every 4 deaths is due to a heart condition. The most frequent type is coronary heart disease but there are many other types as well.

We know that the heart has valves, muscular walls, and vessels supplying it with oxygen and nutrition called coronary arteries. Any one of these structures can be afflicted by disease. The heart also has an electrical system that can become dysfunctional, giving rise to rhythm abnormalities (arrhythmias). Some heart conditions are present at birth and are known as congenital defects. By considering which structure they are affecting, we can categorize most of the heart diseases and conditions into the following types:

  • Coronary heart disease
  • Arrhythmias
  • Valvular heart disease
  • Heart muscle disease
  • Congenital defects

Let’s look into these in more detail, and also list some pertinent sources of information on the subject.

Coronary heart disease

Coronary arteries become thicker and narrower by a process known as atherosclerosis. This can reduce the heart’s blood supply. When oxygen demands are not met, ischemia will occur. Ischemia manifests as pain in the chest or angina. If an artery gets completely occluded with a clot, cardiac muscle will die. This is called infarction, commonly known as a heart attack.


Rhythm disturbances can range from irregularities of the heart rate such as bradycardia if too slow and tachycardia if too fast, irregular beats, to completely berserk rhythms such as flutter and fibrillation. Clinically, the spectrum extends from some arrhythmias that are fairly benign and can just be overlooked to those that are life-threatening and need urgent medical attention. Management strategies include drugs, defibrillators and pacemakers.

  • Arrhythmias: Readers can click on this link to discover information about arrhythmias including symptoms and an explanation on how the heart beats. Readers will also learn what an ECG is and what it means.
  • University of Maryland Medical Center — Arrhythmias: This link takes readers to the University of Maryland arrhythmia page that answers the question of what arrhythmias are. Readers may click on links to go directly to information on types, tests and treatments.
  • Tachycardia: Click this link to open the webpage for tachycardia. The page is the definition page for the disorder. The reader will have the option to click on specific links to information on the Mayo Clinic website about symptoms, causes, risk factors and more.

Valvular heart disease

Valves maintain unidirectional blood flow in the heart and when something goes wrong with them, different problems can arise. In stenosis, a valve is too stiff and narrow. It will not open wide enough causing obstruction to blood flow. During regurgitation, a valve is leaky and allows backflow of blood. Another condition is where a loose, weak valve will prolapse into the next chamber.

Rheumatic fever, an illness that may occur after throat infections, has a propensity to damage heart valves. Valvular heart disease is the result of rheumatic fever in so many cases, a distinct clinical entity rheumatic heart disease (RHD) deals specifically with the issue.

  • Valvular heart disease — Johns Hopkins Medicine: This link opens the valvular heart disease page on the John Hopkins Medicine website. The page is an overview of the topic covering the symptoms, causes, diagnosis, and treatment of valvular heart disease.
  • Heart and blood conditions — Rheumatic heart disease: This link opens to the website for Seattle Children’s Hospital and information about rheumatic heart disease and rheumatic fever. Children ages 5 to 15 years are in the age group that is at the greatest risk of developing rheumatic fever. Rheumatic heart disease is a late complication of rheumatic fever.
  • Rheumatic heart disease: Click this page to read facts about this heart condition. In addition to the facts, readers are also given information on its treatment.
  • Rheumatic fever and rheumatic heart disease: This link opens to the website for the Children’s Hospital of Philadelphia. On this particular page, readers are given information on both rheumatic fever and rheumatic heart disease, with more details about rheumatic fever.

Heart muscle disease

The clinical term used for a disease that affects heart muscle is cardiomyopathy. An enlarged heart with weak walls is dilated cardiomyopathy. When the walls are abnormally thick, it’s hypertrophic cardiomyopathy (a cause of sudden death in athletes). These are the two chief forms of heart muscle disease. Cardiomyopathies can be the result of a variety of causes such as ischemia, hypertension, infections, toxins, and certain drugs. They could also be genetic in origin. In cases where no specific cause can be ascertained, the cardiomyopathy is termed idiopathic.

Congenital defects

As regards birth defects, abnormalities involving the heart are very common. Causes of congenital heart malformations can be genetic or environmental. An example of the former is Down’s syndrome which often involves heart defects. The latter include some maternal illnesses and infections during pregnancy, drug abuse, alcoholism, smoking, and certain medications. However, in many cases, there is no apparent cause. Congenital defects can manifest as abnormal heart chambers or valves, or ‘holes’ in the heart. While some children may not require any treatment at all or just conservative management, others will require surgical intervention.

  • Five facts about congenital heart defects: This is an article on the CDC website. The page reviews congenital heart disease facts including life expectancy and how the problem can be prevented.
  • Congenital heart defects — Parent information: This link takes readers to a PDF brochure about the disease. The brochure explains the causes, diagnosis and different types of congenital heart defects. Available treatment options are also reviewed.
  • KidsHealth — Congenital heart defects: This is an article that appears on the KidsHealth website. It is directed toward parents and describes common congenital heart defects, their signs and symptoms, and how they are diagnosed.
  • MedlinePlus — Congenital heart defects: Click on this link for a very brief overview of congenital heart defects. Signs of severe defects in newborns are listed and many further links to additional information are provided.

See also our page on heart disease in women for further discussion of abnormalities. We offer 100% online and accredited ACLS certification which you can complete at your own pace and get certification for your workplace or your loved ones. It only takes 3 to 5 hours to get certified.

This page was written by on Jun 3, 2016.
This page was last reviewed and updated by on Jun 22, 2020.