Definition and Overview

Cardiology is the branch of medicine that deals with the study and treatment of disorders of the cardiovascular system, specifically the heart, veins and arteries. Considered as a sub-specialty in internal medicine, it focuses on the diagnosis and treatment of cardiovascular conditions that range from congenital defects to heart diseases including congestive heart failure and coronary artery disease. Meanwhile, cardiologists are physicians who specialize in cardiology and are responsible for the medical management of various heart diseases. They carry out and interpret diagnostic tests and perform interventional procedures including angioplasty. They are different from cardiac surgeons who perform invasive procedures such as chest and heart surgery.

What Cardiologists treat

Among ailments diagnosed and treated by cardiologists include:

  • Cardiovascular diseases including atherosclerosis, aneurysm, deep vein thrombosis, varicose veins, and vasculitis
  • Congenital heart defects
  • Disorders of the coronary circulation including acute coronary syndrome (ACS), angina pectoris (ischemia), atherosclerosis (plaque build-up in blood vessels), coronary heart disease, myocardial infarction and restenosis (narrowing of coronary artery)
  • Disorders of the heart valves including the aortic, mitral, pulmonary and tricuspid valves
  • Disorders of the myocardium (heart muscles) such as cardiomyopathy (deterioration of the myocardium) and myocardial rupture
  • Disorders of the pericardium (outer lining of the heart) including pericardial effusion, pericardial effusion, and pericarditis.
  • Disorders related or leading to a cardiac arrest, which includes asystole (absence of electrical activity), pulseless ventricular tachycardia (no pulse), and ventricular fibrillation
  • Heart failure
  • Primary tumors of the heart
  • Ventricular hypertrophy (left and right)

Subspecialties in Cardiology

There are several sub-specialties in cardiology, which includes:

  • Nuclear Cardiology – this focuses on properly diagnosing cardiovascular diseases using infarction imaging, planar imaging, myocardial perfusion imaging and SPECT (single photon emission computed tomography).

  • Interventional Cardiology – the study that involves the use of intravascular catheter-based techniques in treating coronary artery disease, congenital cardiac and valvular conditions. Interventional cardiologists perform congenital heart defect corrections, valvuloplasties, coronary thrombectomy and angioplasties.

  • Echocardiography – this involves the use of machines equipped with ultrasound technology to create images of the heart chambers, valves and nearby structures. Echocardiography is used in identifying infections and structural abnormalities of the heart valves.

  • Cardiac Electrophysiology – this involves the study of the mechanism of electric currents occurring in the heart muscles to determine heart health. Electrophysiology tests measure electrical signals in the heart and diagnose abnormal heart rhythms (arrhythmias) and accelerated heart beat (tachycardia).

Cardiologist training

To qualify for training (fellowship) in cardiology, a physician must receive three years of training in internal medicine after medical school. This means a total of 10 years of medical education is required in order to practice cardiology. During the fellowship, a cardiologist receives intensive and specialized training for three years where he is trained on how to properly evaluate, diagnose and treat a variety of acute and chronic heart conditions.

The training program covers cardiovascular anatomy, physiology, metabolism and molecular biology, along with cardiovascular pharmacology that includes prescription drugs, metabolism, indications and adverse effects. Cardiologists also receive intensive training in cardiovascular pathology, biostatistics, and epidemiology.

Cardiologists acquire knowledge and competence in performing as well as interpreting procedures including physical examination, cardioversion, heart catheterization, insertion and management of pacemakers, and cardiovascular rehabilitation. They also acquire skills as well as learn techniques for managing coronary artery disease, hypertension, arrhythmias, cardiomyopathy, pericardial, valvular and pulmonary heart diseases, among others. Once training is completed, the physician then takes a cardiology examination overseen by the American Board of Internal Medicine or its equivalent in the doctor's home country.

When to See a Cardiologist

A cardiologist is the right specialist to see for any conditions of the heart. A general practitioner will refer you to a cardiologist if he or she notices symptoms that suggest a heart condition, which typically include chest pains, dizzy spells, shortness of breath, or inexplicable fatigue. The cardiologist will often require special tests to make a diagnosis before presenting patients with treatment options.

What to expect in a Cardiologist visit

Your cardiologist will first review your medical history and perform a thorough physical examination that includes checking the blood pressure, weight, breathing, and heartbeat. Depending on your symptoms, additional tests may be performed including:

  • Blood Tests – to rule out other health conditions or diseases
  • Echocardiogram – a test to visualize the structure and function of the heart
  • Stress test – to measure the performance of the heart and its limitations
  • Ambulatory ECG – to check for abnormal heart rhythms
  • Cardiac Catheterization – A test wherein a small tube is placed near the heart to record electrical impulses
  • Cardiovascular magnetic resonance imaging (MRI) – determines abnormalities in the mechanical functions of the heart
  • Holter monitoring – a portable ECG machine to continuously monitor heart function for a specified period
  • Electrocardiography – to measure the electrical activity of the heart

The results of the tests are then interpreted to determine accurate diagnosis and recommend the most appropriate treatment plan to relieve the symptoms. Cardiologists may advise proper diet, cardiac rehabilitation, interventional techniques and lifestyle changes to prevent the further onset or worsening of the vascular condition. For more serious symptoms conditions, cardiologists may recommend you to see a cardiovascular surgeon if invasive treatment is necessary.


  • American Heart Association, National Health Services (NHK UK) Medical News Today Archives. “What is Cardiology” Available:
  • Remedy Health Media. “What is a Cardiologist” Available:
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