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Department Cardiovascular Medicine
Primary Location Cleveland Clinic Main Campus
Type of Doctor Adults Only
Languages English
Surgeon No
Cleveland Clinic Main Campus
Primary Location

Cleveland Clinic Main Campus


Additional Locations

Specialties & Treatments

Treatment & Services

  • Advanced Ischemic Heart Disease Center
  • Atrial Fibrillation Center
  • Biventricular Pacemaker
  • Cardiac Electrophysiology
  • Cardiac Electrophysiology & Pacing Section
  • Cardiovascular Medicine
  • Cardiovascular Medicine Department
  • Cardioversion
  • Catheter Ablation
  • Clinical Trials
  • Implantable Cardioverter Defibrillator
  • Lead Extraction (ICD, Pacemaker)
  • Lifevest
  • Pacemaker Implant
  • Pulmonary Vein Ablation Procedure
View all 15 Treatment & Services +

Specialty in Diseases & Conditions

  • Abnormal Heart Beats - Women
  • Abnormal Heart Rhythms
  • Arrhythmogenic Right Ventricular Dysplasia
  • Atrial Fibrillation
  • Atrial Flutter
  • Bradyarrhythmias
  • Cardiac Implantable Electronic Device Infection
  • Heart Palpitations
  • Long QT Syndrome (LQTS)
  • Sudden Cardiac Death (Sudden Cardiac Arrest)
  • Supraventricular Tachycardia
  • Syncope
  • Ventricular Fibrillation
  • Ventricular Tachycardia
  • Wolff-Parkinson-White Syndrome (WPW)
View all 15 Specialties +


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About Thomas Callahan, MD

Thomas Callahan, IV, MD, is Staff Physician and Director of Inpatient Services in the Section of Pacing and Electrophysiology of the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute at Cleveland Clinic. He is also the Associate Program Director for Cleveland Clinic’s cardiology and electrophysiology fellowships.

In addition to office visits, Dr. Callahan also offers scheduled follow up virtual visits to select patients, through the Cleveland Clinic Express Care ® Online app. This platform allows patients to see their physician live, using their smartphone, tablet or computer.

Specialty interests: Abnormal heart rhythm, atrial fibrillation, sudden cardiac death, supraventricular tachycardia, ventricular tachycardia, PVCs, Wolff-Parkinson-White syndrome, biventricular pacemaker, catheter ablation, implantable cardiac defibrillator, lead extraction

Number of Procedures Performed: Dr. Callahan has performed more than 900 catheter ablation procedures throughout his career.

Success rates: Cleveland Clinic has been ranked the #1 hospital for cardiology and heart surgery by U.S. News & World Report since 1994. Success rates for specific procedures are available at

Education and Training: Dr. Callahan received his undergraduate degree from Oberlin College, OH. He received his master's degree from the University of Michigan, and he earned his medical degree from Eastern Virginia Medical School, Norfolk. He joined Cleveland Clinic in 2003 and completed fellowships in Cardiovascular Medicine Cardiac Electrophysiology and Pacing. Prior to coming to Cleveland Clinic, he was a resident at the Hospital of the University of Pennsylvania, where he was Chief Resident in internal medicine.

Publications and Speaking:  Dr. Callahan has authored and co-authored many articles published in leading medical journals.

About Dr. Callahan: “I enjoy my field because we have the ability to make many patients feel dramatically better. I am also excited by the constant advancement in the field.”

Leisure Activities: Dr. Callahan is a private pilot. He also enjoys skiing and spending time with his family.

Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - Cleveland Clinic
Cardiovascular Medicine
Cleveland, OH USA

Residency - Hospital of the University of Pennsylvania
Internal Medicine
Philadelphia, PA USA

Internship - Hospital of The University of Pennsylvania
Internal Medicine
Philadelphia, PA USA

Medical Education - Eastern Virginia Medical School
Norfolk, VA USA

Graduate School - University of Michigan
Ann Arbor, MI USA

Undergraduate - Oberlin College
Oberlin, OH USA


  • Internal Medicine - Cardiovascular Disease
  • Internal Medicine - Clinical Cardiac Electrophysiology
  • Internal Medicine - Cardiovascular Disease

Specialty Interests

Abnormal heart rhythm, atrial fibrillation, sudden cardiac death, supraventricular tachycardia, ventricular tachycardia, PVCs, Wolff-Parkinson-White syndrome, biventricular pacemaker, catheter ablation, implantable cardiac defibrillator, lead extraction

Awards & Honors

  • 2006, Dawson Award for Clinical Excellence and Humanism
  • 2004, Frederic J. Pashkow Award for Clinical Excellence
Research & Publications

Research & Publications

See publications for Thomas Callahan, MD.

(Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)

Industry Relationships

Industry Relationships

Cleveland Clinic physicians and scientists may collaborate with the pharmaceutical or medical device industries to help develop medical breakthroughs or provide medical expertise or education. Cleveland Clinic strives to make scientific advances that will benefit patient care and support outside relationships that promise public benefit. In order for the discoveries of Cleveland Clinic physicians' and scientists' laboratories and investigations to benefit the public, these discoveries must be commercialized in partnership with industry. As experts in their fields, Cleveland Clinic physicians and scientists are often sought after by industry to consult, provide expertise and education.

To assure professional and commercial integrity in such matters, Cleveland Clinic maintains a program that reviews these collaborations and, when appropriate, puts measures in place to minimize bias that may result from ties to industry. Cleveland Clinic publicly discloses the names of companies when (i) its physicians/scientists receive $5,000 or more per year (or, in rare cases, equity or stock options) for speaking and consulting, (ii) its physicians/scientists serve as a fiduciary, (iii) its physicians/scientists receive or have the right to receive royalties or (iv) its physicians/ scientists hold any equity interest for the physician's/scientist's role as inventor, discoverer, developer, founder or consultant.* In publicly disclosing this information, Cleveland Clinic tries to provide information as accurately as possible about its physicians' and scientists' connections with industry.

As of 4/26/2022, Dr. Callahan has reported no financial relationship with industry that is applicable to this listing. In general, patients should feel free to contact their doctor about any of the relationships and how the relationships are overseen by Cleveland Clinic. To learn more about Cleveland Clinic's policies on collaborations with industry and innovation management, go to our Integrity in Innovation page.

Public Health Service-Reportable Financial Conflicts of Interest. Cleveland Clinic scientists and physicians engage in basic, translational and clinical research activities, working to solve health problems, enhance patient care and improve quality of life for patients. Interactions with industry are essential to bringing the researchers' discoveries to the public, but can present the potential for conflicts of interest related to their research activities. Click here to view a listing of instances where Cleveland Clinic has identified a Public Health Service (PHS)-Reportable Financial Conflict of Interest and has put measures in place to ensure that, to the extent possible, the design, conduct and reporting of the research is free from bias.

* Cleveland Clinic physicians and scientists subscribe to the guidance presented in the PhRMA Code on Interactions with Healthcare Professionals and the AdvaMed Code of Ethics on Interactions with Health Care Professionals. As such, gifts of substantial value are generally prohibited.

Patient Satisfaction Reviews

211 Patient Satisfaction Reviews

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our nationally-recognized Press Ganey Patient Satisfaction Survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

Responses are measured on a scale of 1 to 5 with 5 being the best score.

The comments are submitted by patients and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of Cleveland Clinic.

Overall Star Ratings
4.9 out of 5
Explains 4.9
Listens 4.9
Courtesy, Respect & Concern 4.9
Patient Rating of Doctor 4.9

42 Patient Comments

Reviewed on May 4, 2022

Again, my.Again, my experience was outstanding. Dr. Callahan helped me decide on a PVI ablation and my follow up course of treatment. It was a real two way discussion.

Reviewed on May 3, 2022

Dr Callahan is a very compassionate dr, listens well.

Reviewed on Apr 29, 2022

Dr. Callahan was amazing! He went above and beyond in every way! I would highly recommend him to anyone needing to be seen for cardiology

Reviewed on Apr 14, 2022

The care provided by the physicians/doctors was outstanding.

Reviewed on Apr 11, 2022

*Dr. Bhat, *Dr. Courson & NP *Jessica Lebecray were wonderful and I'm grateful for the care they gave me.. Thank you!

Reviewed on Apr 8, 2022

Dealing with Dr Callahan and his support group couldn't be better

Reviewed on Apr 5, 2022

Great visit with Dr Callahan

Reviewed on Apr 5, 2022

Dr. Callahan is the BEST. He is caring, kind, and extremely helpful, I know, I can't have a better DOCTOR. Thank goodness, I made the decision many years ago to entrust my care to the Cleveland Clinic.

Reviewed on Mar 2, 2022

Dr Callahan and his staff are "THE BEST" and really do care about how you feel and to give you the information to feel even better.

Reviewed on Feb 8, 2022

Dr. Callahan was very knowledgeable and accommodating with all of my questions. I would highly recommend him based on the first interview.

Reviewed on Feb 2, 2022

I am always very pleased with the team. My Cardiologist Dr. Callahan is a very pleasant and concerned about my health. He always try to help me In all my questions and concerned. I am really happy to have him as my cardiologist and feel that I am very fortunate to have him as my heart physician. God bless him

Reviewed on Jan 28, 2022

Would rather meet with Do tor Callahan in person, but do so appreciate the video visit, coupled with Dr. Calahan's extreme empathy and terrific health care. After all, how you are treated is key to a patient, and Dr. Calahan always makes me feel special, and is so very supportive.

Reviewed on Jan 21, 2022

I was very pleased with Dr. Callahan and want to continue treatment with this doctor. He was very attentive to what I said and provided options to what my concerns were. Overall, a very good experience.

Reviewed on Jan 12, 2022

Dr. Callahan was great! Very thorough and informative. Provided so much information about my issue that I had very few questions. The few questions I had were answered and all information provided by Dr. Callahan was In terms I was able to understand throughout the visit. I am very confident I am in good hands for my procedure.

Reviewed on Dec 28, 2021

All care providers related to visit were attentive and solicitous of my mental and physical well being. This was a great visit.

Reviewed on Dec 25, 2021

The doctors were very specific in my condition and very generous of their time answering my questions.

Reviewed on Nov 30, 2021

Dr Callahan is outstanding in every way!

Reviewed on Nov 30, 2021

Dr outstanding

Reviewed on Nov 24, 2021

Dr Callahan and his staff provided excellent care. The only issue was trying to get an appointment.

Reviewed on Nov 24, 2021

The doctor is very patient and very good at explaining what is happening to me , doesn't mind repeating himself and doesn't give 100 percent guarantees of the procedure working the first time all the time which is good

Reviewed on Nov 24, 2021

The Dr is great at doing all of the above

Reviewed on Nov 17, 2021

Dr. Callahan is not only an extremely good doctor but a kind and likable person.

Reviewed on Nov 16, 2021

Very happy with Dr. Callahan

Reviewed on Nov 12, 2021

Dr. Callahan is outstanding; I couldn't ask for a better physician. He's very competent, honest, respectful, down to earth and caring.

Reviewed on Nov 2, 2021

Everyone I came in contact with was friendly, helpful and a pleasure to deal with. Dr. Callahan and his nurse were beyond kind and very informative about my problem.

Reviewed on Oct 19, 2021

Everything went well from scheduling the appointment, setting up virtual visit and talking with Dr. Callahan who is amazing at explaining the results of my tests and answering my questions. I feel very fortunate to have Dr. Callahan as my doctor at the Cleveland Clinic.

Reviewed on Oct 19, 2021

Absolutely wonderful experience during virtual visit with Dr. Callahan. He is so thorough in explaining results of my tests, answering questions and what steps he is considering after further tests are completed and results are reviewed. Very fortunate and thankful to have Dr. Callahan as my doctor at this number one heart clinic in the United States.

Reviewed on Oct 19, 2021

Dr. Callahan's staff are always courteous and caring whenever I call them no matter what I need or questions I have regarding appointments, tests, setting up virtual meeting and much more.

Reviewed on Oct 12, 2021

Dr Tang is excellent!

Reviewed on Oct 12, 2021

Dr Tang and Dr Callahan we're excellent!

Reviewed on Oct 6, 2021

Dr Callahan always treat me with respect. He is always proactive with my health, explains things so I can understand and gives me all my options.

Reviewed on Oct 5, 2021

Dr Callahan is a physician I would recommend to anyone. His expertise and compassion is not often seen in the medical environment now

Reviewed on Sep 24, 2021

Dr Callahan is great! Takes way more time with you than expected.

Reviewed on Aug 30, 2021

Dr Callahan was wonderful. Spent all the time I needed and never felt rushed. Listened and answered all of my questions.

Reviewed on Aug 13, 2021

The whole team are very efficient. Dr. Callahan calls the patients and try to help to solve any question we have.

Reviewed on Aug 13, 2021

Very good over all . Best experience I have with the team of Doctors and Nurses whom I have seen In Cleveland Clinic. Dr. Callahan Is an outstanding

Reviewed on Aug 10, 2021

Dr Callahan explains everything in detail. He listens to my concerns and we talk about options for treatment. He brought up a solution regarding speaking to my pulmonologist to come up with a plan together to assist in relieving the symptoms I am currently having with Afib meds vs breathing issues.

Reviewed on Aug 10, 2021

Dr. Callahan is excellent at his profession. And has always been responsive.

Reviewed on Jul 30, 2021

Wait time on phone is terrible and can never get appt in time frame that dr wants me to come back. This time I went directly to dr and got it.

Reviewed on Jul 30, 2021

Dr. Callahan is very kind and professional. He treats me with respect and high regard at all times. I feel very fortunate to be his patient.

Reviewed on Jul 30, 2021

I am so pleased with Cleveland Clinic. I will recommend Dr. Callahan quickly and confidently.

Reviewed on Jul 30, 2021

Dr. Callahan is honest and straight forward in his discussion. His follow-up regarding my questions was outstanding.

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