Cardiology — Find Specialists & Top Hospitals Worldwide | MyMedicPlus

Cardiology is the branch of internal medicine devoted to the diagnosis, treatment, and prevention of diseases of the heart and blood vessels — collectively known as cardiovascular disease. Cardiovascular disease remains the leading cause of death globally, making cardiologists among the most important specialists in modern medicine. They manage a broad population ranging from young athletes with arrhythmias to elderly patients with complex heart failure and valve disease.

The field has several major subspecialties, each requiring additional fellowship training beyond the core cardiology fellowship. Interventional cardiology involves catheter-based procedures to open blocked coronary arteries, close structural defects, and repair valves without open surgery. Clinical cardiac electrophysiology focuses on heart rhythm disorders, including implantation of pacemakers, defibrillators, and performing catheter ablation to eliminate arrhythmia circuits. Heart failure and transplant cardiology manages patients with advanced ventricular dysfunction. Preventive cardiology targets risk factor reduction through lipid management, hypertension control, and lifestyle intervention.

The distinction between cardiology and cardiac surgery is important: cardiologists are non-surgical physicians who manage most heart conditions using medications and catheter-based procedures. When open surgery is required — such as coronary artery bypass grafting or valve repair — the patient is referred to a cardiothoracic surgeon, though the cardiologist typically remains involved in pre- and post-operative care.

Cardiologists evaluate and manage a broad range of conditions affecting the heart and vascular system:

• Coronary artery disease (CAD): Narrowing of the coronary arteries by atherosclerotic plaque, leading to angina (chest pain on exertion) or acute myocardial infarction (heart attack).
• Heart failure: Reduced ability of the heart to pump sufficient blood to meet the body's needs, causing fatigue, fluid retention, and breathlessness; classified as HFrEF (reduced ejection fraction) or HFpEF (preserved ejection fraction).
• Atrial fibrillation (AF): The most common sustained arrhythmia, causing irregular heartbeat, stroke risk, and heart failure; managed with rate or rhythm control strategies.
• Ventricular tachycardia and fibrillation: Dangerous fast rhythms originating in the ventricles that can cause sudden cardiac death if not treated promptly with defibrillation or ablation.
• Hypertension: Persistently elevated blood pressure causing progressive damage to the heart, kidneys, brain, and blood vessels; often managed in concert with primary care.
• Valvular heart disease: Dysfunction of the aortic, mitral, tricuspid, or pulmonary valves causing stenosis (narrowing) or regurgitation (leakage), ranging from asymptomatic to requiring intervention.
• Cardiomyopathy: Disease of the heart muscle itself, including dilated, hypertrophic, and restrictive types, leading to heart failure and arrhythmia risk.
• Pericarditis and myocarditis: Inflammation of the pericardial sac or heart muscle, often caused by viral infections or autoimmune conditions.
• Peripheral arterial disease (PAD): Atherosclerosis affecting arteries supplying the legs and other organs, causing claudication and limb-threatening ischaemia.
• Pulmonary hypertension: Elevated blood pressure in the pulmonary arteries, a serious condition requiring specialist management with targeted vasodilator therapies.

Cardiologists use a wide array of diagnostic and therapeutic procedures, many of which are performed without surgery:

• Electrocardiogram (ECG/EKG): Records the heart's electrical activity to diagnose arrhythmias, heart attacks, and conduction abnormalities — a fundamental first-line test.
• Echocardiography: Ultrasound imaging of the heart to assess chamber size, wall motion, valve function, and ejection fraction; available as transthoracic (TTE) or transesophageal (TEE) approaches.
• Exercise stress testing: Assesses heart function, blood pressure response, and arrhythmia induction during graded physical exertion on a treadmill or bicycle.
• Nuclear cardiology (myocardial perfusion imaging): Uses radioactive tracers to identify areas of reduced blood flow to the heart muscle at rest and during stress.
• Cardiac CT angiography (CCTA): Non-invasive imaging of the coronary arteries to detect plaque and stenosis, increasingly used instead of invasive angiography in selected patients.
• Coronary angiography (cardiac catheterisation): Invasive procedure using contrast dye and X-ray fluoroscopy to directly visualise coronary artery anatomy; often performed in combination with intervention.
• Percutaneous coronary intervention (PCI/stenting): Catheter-based opening of blocked coronary arteries using balloon dilation and deployment of a metal stent.
• Implantable cardioverter-defibrillator (ICD) implantation: Device placed under the skin to monitor heart rhythm and deliver life-saving shocks in the event of ventricular fibrillation.
• Catheter ablation: Uses radiofrequency energy or cryotherapy to destroy abnormal electrical pathways causing arrhythmias, particularly atrial fibrillation.
• Transcatheter aortic valve replacement (TAVR): Minimally invasive replacement of a stenotic aortic valve without open surgery, now widely available for patients at high or intermediate surgical risk.

Prompt referral to a cardiology specialist is warranted in several key clinical scenarios. Any patient presenting with chest pain or chest pressure — particularly if it is exertional, radiates to the arm or jaw, or is accompanied by sweating and nausea — requires immediate cardiac evaluation; this may represent unstable angina or an acute myocardial infarction requiring emergency care.

Unexplained shortness of breath at rest or with minimal exertion, especially in a patient with cardiac risk factors, warrants echocardiography and specialist assessment to rule out heart failure or valvular disease. Syncope or pre-syncope (fainting or near-fainting) may indicate a dangerous arrhythmia, particularly if it occurs during exertion or without warning.

Palpitations that are frequent, prolonged, or associated with lightheadedness suggest an arrhythmia needing Holter monitoring and electrophysiology evaluation. A family history of sudden cardiac death before age 50, hypertrophic cardiomyopathy, or inherited arrhythmia syndromes (long QT syndrome, Brugada syndrome) warrants proactive screening. Patients with uncontrolled hypertension (sustained readings above 160/100 mmHg despite two or more medications) or LDL cholesterol above 190 mg/dL not responding to high-dose statins benefit from specialist input.

The training pathway to become a cardiologist is extensive. After completing a 4-year medical degree (MD or DO), candidates enter a 3-year internal medicine residency, during which they develop broad medical knowledge and management skills across all organ systems. Following residency, they must pass the American Board of Internal Medicine (ABIM) internal medicine certification examination.

Cardiologists then complete a 3-year fellowship in cardiovascular disease, which includes rotations in echocardiography, cardiac catheterisation, electrophysiology, coronary care, and heart failure. At the conclusion of fellowship, they sit the ABIM cardiovascular disease board certification examination. This credential demonstrates competency across general cardiology and qualifies the physician to practice as a non-invasive cardiologist.

Subspecialty fellowships require additional training: interventional cardiology adds 1 year, electrophysiology adds 1–2 years, and advanced heart failure and transplant cardiology adds 1–2 years. Each subspecialty has its own board certification pathway. In total, a subspecialist cardiologist may spend 11–13 years in postgraduate training before independent practice. In the UK, the equivalent pathway leads to specialist registration with the GMC in cardiology via the Joint Royal Colleges of Physicians Training Board (JRCPTB).

Most patients are referred to a cardiologist by their primary care physician following an abnormal ECG, elevated cardiac risk assessment, or concerning symptoms. For urgent symptoms such as chest pain or syncope, emergency department evaluation and direct cardiology consultation are appropriate.

When seeking elective cardiology care, verify your cardiologist's board certification through the ABIM website. Consider whether you need a general cardiologist, an interventionalist, or an electrophysiologist based on your specific condition. For your first appointment, bring all prior ECGs, echocardiogram reports, stress test results, and a complete list of medications. Major cardiac centres offer multidisciplinary heart teams where cardiologists, cardiac surgeons, and other specialists collaborate on complex decisions such as valve repair versus replacement, or stenting versus bypass surgery.