Dr Costas O'Mahony


BSc (Hons), MBBS (Lond), FRCP (UK), MD (Res)

GMC number: 6028275



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Dr Costas O’Mahony is a consultant cardiologist. He studied medicine at Imperial College London and graduated with a first class BSc(Hons) in immunology in 1998 and with distinction in medicine in 2001. He was awarded membership of the Royal College of Physicians in 2004 and completed cardiology training at the Heart Hospital and London Chest Hospital in 2014.

Dr O’Mahony runs a cardiomyopathy clinic and general cardiology clinic. He performs invasive haemodynamic assessments, cardiac biopsies, alcohol septal ablation and percutaneous coronary intervention.

Dr O’Mahony was awarded an MD(Res) by University College London for research in sudden cardiac death in hypertrophic cardiomyopathy. He contributed to the 2014 ESC guidelines on the diagnosis and management of hypertrophic cardiomyopathy and lead the development of a risk prediction model for sudden cardiac death in HCM (HCM Risk-SCD). His current research is focused on clinical outcomes in cardiomyopathies and risk prediction modeling.

Special interests

  • Coronary artery disease
  • Percutaneous coronary intervention
  • Hypertrophic Cardiomyopathy
  • Alcohol Septal Ablation
  • Dilated Cardiomyopathy
  • Arrhythmogenic Cardiomyopathy
  • Cardiac Amyloid.

Dr O’Mahony has expertise in the prevention, diagnosis and treatment of heart disease. He consults in all areas of adult cardiology, with a special interest in coronary artery disease and cardiomyopathy (heart muscle disease).

Patients with symptoms of chest pain (angina), shortness of breath, ankle swelling, palpitation, dizzy spells or fainting are evaluated, and investigations are promptly organised to allow accurate diagnosis and treatment.

Individuals without symptoms who are at risk of developing heart problems in the future (e.g. those with diabetes, high blood pressure, high cholesterol, close relatives with heart disease) are assessed and provided with a personalised management plan to reduce risk and improve long-term health. Those with relatives suffering from cardiomyopathy (dilated, hypertrophic, restrictive or arrhythmogenic) are screened to determine if they are affected.

A clinic consultation is typically followed by investigations to gain a better understanding of the problem. Common first-line, non-invasive investigations include blood tests, ECG (electrocardiogram), Echocardiogram (cardiac ultrasound), 24-hour Holter (ECG monitor), 24-hour blood pressure monitor, CT coronary angiogram and cardiac MRI. If required, invasive procedures (e.g. right and left heart catheterisation, coronary angiography) are undertaken and treatment with percutaneous coronary intervention (stents) delivered.

Treatments and tests offered by Dr Costas O'Mahony at Nuffield Health

  • Cardiac MRI
  • Electrocardiogram (ECG)

Locations Dr Costas O'Mahony works with

Related experience


  • European Association of Percutaneous Coronary Intervention
  • British Cardiovascular Intervention Society
  • Association for Inherited Cardiac Conditions (UK)
  • European Society of Cardiology Working Group on Myocardial diseases
  • European Society of Cardiology

Other posts held

  • Consultant Cardiologist, St Bartholomew’s & Whipps Cross Hospitals

Insurers Dr Costas O'Mahony works with

Dr Costas O'Mahony works with the following private medical insurance providers:

  • WPA