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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 7/7/2021, 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

196 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 4.7
Courtesy, Respect & Concern 4.9
Patient Rating of Doctor 4.9

33 Patient Comments

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 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.

Reviewed on Jun 15, 2021

The Doctor's patience with ALL of my questions, his detailed explanation of my issues and procedures is the reason I chose to have the procedure there

Reviewed on May 14, 2021

Doctor Callahan and his team are AWESOME!

Reviewed on Apr 30, 2021

I have the upmost respect for Dr.Callahan. thank you for being there for me..

Reviewed on Apr 20, 2021

Dr Callahan is always a pleasure. He listens to me and addresses all my concerns. He is always honest about all the options I have concerning my health. He is always looking for ways to improve my situation.

Reviewed on Apr 14, 2021

Dr Callahan listened patiently, answered my many questions, and together, we made the best decisions about where we go next with changing out my ICD. I am grateful to have him as my Electrophysiological cardiologist!

Reviewed on Apr 14, 2021

Dr Callahan is professional, respectful and a credit to the clinic.

Reviewed on Mar 26, 2021

Dr. Callahan and his staff are excellent

Reviewed on Mar 24, 2021

Very good experience, Dr. Callahan is always a very good listener. He is very helpful in every way. I am very fortunate to have him as my main cardiologist.

Reviewed on Mar 19, 2021

Dr Callahan is very professional and takes time to answer all my questions

Reviewed on Mar 19, 2021

We are very happy with Dr Callahan

Reviewed on Mar 17, 2021

Dr Callahan was very thorough, patient and informative.

Reviewed on Feb 26, 2021

Dr. Callahan is a wonderful person. He is always patient and kind. I am very fortunate to have him as my Doctor.

Reviewed on Feb 26, 2021

One of the best doctors at Cleveland clinic

Reviewed on Feb 26, 2021

One of the best doctors with a genuine concern for your health and well being.

Reviewed on Feb 19, 2021

excellent doctor

Reviewed on Jan 29, 2021

Dr. Callahan is a good listener, and easy to understand.

Reviewed on Jan 29, 2021

Top notch doctor! He took his time with us and answered all questions thoroughly.

Reviewed on Jan 29, 2021

Dr Callahan was easy to talk with and answered my questions and said if I had any questions or concerns I could call anytime.

Reviewed on Jan 29, 2021

dr Callahan is great

Reviewed on Jan 26, 2021

I trust Dr. Callahan with my life. Literally.

Reviewed on Dec 17, 2020


Reviewed on Dec 9, 2020

Cleveland clinic main campus is the best I love Dr. Callahan

Reviewed on Oct 30, 2020

the doc has been great explaining makin sure I understood and included me in decisions

Reviewed on Oct 28, 2020

Dr. Thomas Callahan surpasses expectations of excellence. He listens carefully, and makes me feel that he genuinely cares about my well-being.Dr. Callahan assists with medical concerns as an entire person with wholistic approach, not merely minoring himself to specific cardiac issues.

Reviewed on Sep 22, 2020

Doctor Callahan is terrific. He listens and works with you. He is compassionate, explains well, and seeks your input. I have complete faith in Doctor Callahan.

Reviewed on Sep 22, 2020

Doctor Callahan is outstanding. My not knowing about the appointment until 3 days beforehand was a bit concerning.

Reviewed on Sep 21, 2020

First experience with Cleveland Clinic. I was impressed with level of care and professionalism exhibited by the staff, Doctors and Nurses. Thank you for a great experience.Dane Scofield

Reviewed on Sep 8, 2020

Dr. Callahan is excellent. He has helped me to have a good quality of life. He is very personable and caring.

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