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Gregory M. Marcus


Cardiologist and electrophysiologist

Dr. Gregory Marcus is a cardiologist and electrophysiologist who specializes in the diagnosis and treatment of arrhythmias, including cardiac mapping and catheter ablation for atrial fibrillation, supraventricular tachycardias and ventricular arrhythmias. He is also an expert in implanting pacemakers, biventricular devices and defibrillators.

In his research, Marcus studies heart rhythm disturbances, and the health effects of common lifestyle factors such as alcohol, caffeine, smoking and other substances, and leads several large projects to use sensors, smart phones and other technologies to conduct clinical research.

Marcus earned his medical degree from George Washington University School of Medicine & Health Sciences. He completed his residency at Stanford Medicine. He then completed his training in cardiovascular medicine and cardiovascular electrophysiology at UCSF.

  • Education

    George Washington University School of Medicine, 1998

  • Residencies

    Stanford Hospital and Clinics, Internal Medicine, 2002

    UCSF Medical Center, Cardiology, 2004

  • Fellowships

    UCSF Medical Center, Cardiac Electrophysiology, 2006

  • Board Certifications

    Clinical Cardiac Electrophysiology, American Board of Internal Medicine

  • Academic Title


Where I see patients (2)

    My reviews


    Overall Experience
    122 Ratings
    About our process
    Nov 04, 2023
    Getting a good fit with a provider is hard to figure out in advance. I would recommend Dr Marcus without hesitation but explain that he is more focused and efficacious than a nurturing type of physician. This is ok. It's an observation not a judgment. I am very satisfied with the care received.
    Oct 14, 2023
    I'd like to give him 5 plus.
    Sep 29, 2023
    I don't remember receiving anything about the follow up. It might be in my notes but I don't have them with me.
    Sep 17, 2023
    I have always been very satisfied with my health care at UCSF.
    Jul 12, 2023
    I have nothing but high regard and respect for UCSF PERIOD!
    Jun 26, 2023
    Always helpful
    May 15, 2023
    Great experience
    Mar 11, 2023
    I always recommend UCSF to all my family & friends.
    Feb 12, 2023
    Dr. Marcus has been excellent throughout this journey. I am very grateful.
    Dec 05, 2022
    Dr Marcus is an excellent caring provider. He listens carefully to my questions and encourages me to ask about any concerns. He shares the appropriate information to address my questions and concerns. He is extremely knowledgeable and very down to earth.
    Nov 19, 2022
    Oct 22, 2022
    I could not be more satisfied with the care I have been receiving from Dr. Marcus
    Oct 01, 2022
    It was a good appointment.
    Sep 11, 2022
    I had a fairly brief consultation with Dr Marcus which he had scheduled at my request. It did allow sufficient time to address my main questions. I will be able to use the upcoming Care Team call to address my remaining questions.
    Sep 10, 2022
    Dr Marcus and his team member Ruth provided excellent and compassionate care very pleased
    Sep 08, 2022
    Overall it was a great experience. Great job.
    Jul 25, 2022
    Dr Marcus is great and always has been
    Jul 06, 2022
    Dr Marcus was very thorough in his questions about my case and he listened carefully and asked appropriate follow up questions. His manner put me at ease. He involved me in decisions about further evaluations and tests. He seemed genuinely interested and sympathetic to my concerns.
    May 18, 2022
    Dr Marcus truly seems to understand my lifestyle and cares that I get the help I need in order to live like I had been before my heart issues.
    Feb 19, 2022
    Very satisfied with my provider
    Decorative Caduceus

    Volunteers to Investigate Best Results for Ablation and Novel Therapies for Atrial Fibrillation

    Time to atrial fibrillation, after employing a 3-month blanking period. Atrial Fibrillation Recurrence includes patient-reported symptoms of AF or Kardia-based ECG evidence of AF.


    Decorative Caduceus

    The MARY-JANE Cannabis and Heart Rhythm Trial

    Participants will be wearing a continuously recording ECG monitor for two weeks. The primary outcome will be change in premature atrial contraction (PAC) and PVC frequency due to cannabis consumption or avoidance during the monito...


    Decorative Caduceus

    Does Eliminating Coffee Avoid Fibrillation?

    The number of patient's with AF and/or AFlutter recurrence following direct current electrical cardioversion will be compared


    Decorative Caduceus

    The Heart Rhythm Twins Study

    This will be measured using a wearable EKG monitor.