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 & Pacing Section
  • Cardiovascular Medicine Department
  • Cardioversion
  • Catheter Ablation
  • Clinical Trials
  • Implantable Cardioverter Defibrillator
  • Lead Extraction (ICD, Pacemaker)
  • Lifevest
  • Pacemaker Implant
  • Pulmonary Vein Ablation Procedure
View all 13 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 +


Is Cleveland Clinic Part of Your Insurance?

Review a list of accepted insurance plans for our Northeast Ohio locations or learn more about purchasing a contracted managed care plan.

View All Plans

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 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
Cleveland, OH USA

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

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 5/3/2019, Dr. Callahan has reported the financial relationships with the companies listed below. 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.

Consulting and/or Speaking. Dr. Callahan receives fees of $5,000 or more per year as a paid consultant, speaker or member of an advisory committee for the following companies:

  • Biotronik, Inc.

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

278 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
Knows Medical History 4.9
Time Spent with Patient 4.9
Patient Rating of Doctor 4.9

25 Patient Comments

Reviewed on Aug 16, 2019

Dr. Callahan was great. Explained things very well and give confidence to me.

Reviewed on Aug 13, 2019

Dr. Callahan was extremely excellent. Would like to rate him higher. He took the time to listen and answer all my concerns. Really appreciated his eye contact throughout the appointment.

Reviewed on Aug 13, 2019

Dr. Callahan always takes his time and talks with me about any of my concerns. I never feel rushed. He is great at his job.

Reviewed on Jul 19, 2019

Dr Callahan was good about asking and answering questions, and then listened very carefully to me. I really appreciated that.

Reviewed on Jul 12, 2019

Dr Callahan gave me total confidence in the procedure I'll be having soon.He answered any question I had and answered most of them before I asked.

Reviewed on Jul 2, 2019

Wonderful doctor!

Reviewed on Jun 21, 2019

waited 1 hour in exam room to see doctor

Reviewed on Jun 14, 2019

I felt very at ease with the time spent with the care provider and more assured about what I needed to do. I was confident with his recommendations and felt more at peace with my situation.

Reviewed on Jun 14, 2019

Dr Callahan was was terrific. He was kind and took the time to help me understand the results of my test. I felt very comfortable with his explanation and would like to proceed with treatmentt at the Cleveland Clinic.

Reviewed on May 31, 2019

I've had very good experience at Cleveland Clinic and very much appreciate being a patient of Dr. Callahan. He is very good to work with, answers my questions, helps me understand the changes that are made to my device.

Reviewed on May 31, 2019

There were no delays. Everything progressed along right on time and I was in to see Dr. Callahan before my scheduled appointment.

Reviewed on May 29, 2019

Dr Callahan was able to see me within few days

Reviewed on May 13, 2019

Very good experience. Dr. Callahan is always very nice and has lot of patience. He is a good listener. I am very fortunate to have him as my main cardiologist. Very helpful in every way.

Reviewed on May 13, 2019

Dr. Callihan very knowledgeable

Reviewed on Apr 15, 2019

I am very pleased with how thorough Dr Callahan is in his explanation of possible treatment options . I am also pleased with his willingness to listen to concerns and explain with visual aids

Reviewed on Apr 12, 2019

Doctor Callahan concentrated on my problems and listened intently. Very important to me that he listened I intern listened to what he had to say more intently than I sometimes do in other circumstances.

Reviewed on Feb 22, 2019

at the end of the week and last appt dr Callahan was totally engaged caring kind & gentle sense of humor. thorough too

Reviewed on Feb 11, 2019

Dr. Callahan was excellent. He was highly knowledgeable, patient and personable. He explained everything I needed to know and more. My wife and i left there feeling secure and fully informed regarding the decision we have to make. Very impressive.

Reviewed on Jan 18, 2019

Dr Calliahnan is excellent at what he does. He and his attendant made my wife and I very comfortable and she was personable. Tom is very good at making us at ease with this device.

Reviewed on Jan 18, 2019

My experience was very good as usual with Dr. Callahan. He is always very kind and taking good care of his patience. He is a good listener and try to help in every wry. Also I am very pleased that there are very good team of RN who checked my Pace Maker. They really helped me and now I feel much better.

Reviewed on Jan 14, 2019

My experience was very positive. Professionalism was shown by all of the hospital and medical staff. Dr. Callahan's attention to my concerns and frustration was above and beyond. He listened! He explained all the different options of treatment and then allowed me to make the choice that I felt was best for me at this time. He encouraged me to stay in touch and he said he would respond as soon as possible. I left feeling hopeful and knowing I had found the best doctor for me. I don't have to look any further.

Reviewed on Jan 11, 2019

best provider I have ever seen.

Reviewed on Dec 28, 2018

Dr Callahan listened closely and answered all my questions; I did not feel rushed.

Reviewed on Nov 6, 2018

I never felt hurried and Dr. spent a lot more time with me compared to cardiologists in my area. He was wonderful!!

Reviewed on Sep 25, 2018

Dr Callahan is always addresses my medical needs. He takes his time with me and speaks in terms that I understand. All in all he is a great doctor.

Related Videos Featuring Thomas Callahan, MD

Related Videos Featuring Thomas Callahan, MD

Back to Top