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

Cleveland Clinic Main Campus

Specialties & Treatments

Treatment & Services

  • Cardiovascular Disease Risk Prevention
  • Cardiovascular Imaging
  • Cardiovascular Imaging Section
  • Cardiovascular Medicine
  • Cardiovascular Medicine Department
  • General Cardiology
  • Heart Imaging
  • Noninvasive Diagnostic Testing
  • Pericardial Diseases Center
  • Stress Testing
View all 10 Treatment & Services +

Specialty in Diseases & Conditions

  • Amyloidosis
  • Aneurysms
  • Angina
  • Aorta Disease
  • Aortic Aneurysms
  • Aortic Occlusion (Blockage)
  • Aortic Regurgitation
  • Aortic Stenosis
  • Atherosclerosis
  • Atrial Fibrillation
  • Atrial Septal Defects
  • Cardiovascular Disease
  • Congenital Valve Disease
  • Coronary Artery Disease
  • Endocarditis
  • Heart Attack
  • Heart Disease
  • Heart Murmur
  • Heart Related Illnesses
  • Heart Valve Disease
  • Heart Valve Infections
  • High Blood Pressure (Hypertension)
  • High Cholesterol
  • Marfan Syndrome
  • Mitral Valve Prolapse
  • Mitral Valve Regurgitation
  • Mitral Valve Stenosis
  • Myxomas
  • Pericardial Cyst
  • Pericardial Disease
  • Pericardial Effusion
  • Pericarditis
  • Pulmonary Valve Disease
  • Pulmonary Valve Stenosis
  • Restrictive Cardiomyopathy
  • Rheumatic Heart Disease
  • Tricuspid Valve Disease
View all 37 Specialties +


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About Allan Klein, MD

Allan Klein, MD, is the Director of Cardiovascular Imaging Research, Director of the Center for the Diagnosis and Treatment of Pericardial Diseases, and a staff cardiologist in the Section of Cardiovascular Imaging, the Robert and Suzanne Tomsich Department of Cardiovascular Medicine, at the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute.  He is also the Course Director for Diastology and Contrast Echo & New Technologies Courses—currently his 15th annual course.  He is board-certified in internal medicine and cardiovascular medicine.   A Canadian by birth, Dr. Klein speaks fluent French and English. 

In addition to office visits, Dr. Klein 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:  cardiovascular imaging (echocardiography, cardiac MR and computed tomography); pericardial diseases; restrictive cardiomyopathies; valvular heart disease; atrial fibrillation; and diastolic heart failure.

Number of Procedures Performed: Dr Klein reads well over 2000 echocardiograms per year and performs TEE and intraoperative echocardiogram for the interventional structural program. The pericardial center evaluates over 2100 patients per year of which Dr Klein sees the majority of patients. He is also heads the pericardiocentesis simulation program which trains the cardiology fellows and performs pericardiocentesis.

Success Rates: Cleveland Clinic is nationally and internationally renowned for the world’s best cardiovascular care. Success rates for specific procedures are available at: http://my.clevelandclinic.org/heart/about-heart-vascular-institute/treatment-outcomes.aspx

Education and Training: Dr. Klein received his medical degree from McGill University in Montreal, Quebec after completing an undergraduate degree in microbiology and immunology, graduating with honors.  While in medical school, he received several scholarships and graduated in the top 10 percent of his class.  Dr. Klein completed his clinical training at Mount Sinai Hospital in Toronto and the Royal Victoria Hospital in Montreal.  He completed a Cardiology Residency from the University of Ottawa Heart Institute and a Research Fellowship from the Mayo Clinic in Rochester, Minn.  He was appointed to Cleveland Clinic in 1989.

Research, Publications and Speaking:  In addition to his scholarships and academic achievements, Dr. Klein won the E.G.D. Murray Prize in Microbiology and Immunology as an undergraduate and has received multiple American Society of Echocardiography Outcomes Research Awards.

Dr. Klein has been course director and workshop leader at numerous medical specialty conferences focused on clinical trials, imaging modalities and clinical protocols, to name a few.  He currently serves as Professor of Medicine at the Cleveland Clinic Lerner College of Medicine of Case Western University.  Dr. Klein was a member of the Lerner College of Medicine Admissions Committee.
He has been the principal investigator for multicenter clinical trials in atrial fibrillation (ACUTE I, ACUTE II, and CLOTS); studies in diastolic function (ADEPT); valvular heart disease (Anorexigens and Valve Disease); and catheter ablation and pulmonary vein flow (ROTEA).  He has published key articles in such prestigious journals such as New England Journal of Medicine, Lancet, European Heart Journal, Circulation, and the Journal of the American College of Cardiology.  He chaired the Writing Committee for the document entitled “American Society of Echocardiography clinical recommendations for multimodality cardiovascular imaging of patients with pericardial disease:  Endorsed by the Society for Cardiovascular Magnetic Resonance and Society of Cardiovascular Computed Tomography.”

In June 2016, Dr. Klein was appointed President of the American Society of Echocardiography (ASE).. He is now immediate Past President.  He has served on the Board of Directors of the ASE and has been the Chair of the Industry Relations Committee and Chair of the Guidelines and Standards Committee.  Dr. Klein is also on the Writing Committee for the National Board of Echocardiography and served on the Board of Advisors of Cardiovascular Credentialing International.  He serves as a peer reviewer for more than 15 professional journals and grades abstracts for the American College of Cardiology, the ASE, the American Heart Association, and the European Society of Cardiology.

He has been an invited lecturer at many national and international symposia and conferences, speaking on topics related to his specialty interests.  Dr. Klein has authored or co-authored more than 280 peer-reviewed articles in professional journals, co-authored 40 chapters in medical textbooks and published 430 abstracts.  He is a co-editor of 2 books entitled "Diastology: Clinical Approach to Diastolic Heart Failure." as well as "Clinical Echocardiography Review: A Self-Assessment Tool."  Dr. Klein completed  a 2nd edition of the "Clinical Echocardiography Review:  A Self-Assessment Tool."  He has been the director and co-director of the Annual Diastology and Valve Summit courses for the last 20 years. He is also section editor on pericardial diseases for ACC.org and Current Cardiology reports.

About Dr. Klein: "I am a people person and enjoy the patient interaction. I am delighted in helping patients of all ages get better. With my clinical and imaging skills, I like to make a difference on a day to day basis."

Leisure time activities:  Dr. Klein is an avid sportsman and enjoys playing ice hockey, cycling, spinning, hiking and plays many sports. He enjoys reading and traveling around the world.

Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - Mayo Clinic
Cardiovascular Diseases
Rochester, MN

Residency - University of Ottawa Heart Institute
Ottawa, Ontario,

Residency - Royal Victoria Hospital
Internal Medicine
Montreal, Quebec,

Internship - Mount Sinai Hospital
Internal Medicine
Toronto, Ontario,

Medical Education - McGill University Faculty of Medicine
Montreal, QC Canada

Undergraduate - McGill University
Montreal, Quebec,

Additional Training

  • Leading in health care business program, Cleveland Clinic

Professional Highlights

  • Past three years:

    Notification “In the Spotlight” column of the Cleveland Clinic Professional Staff Update announced the recent appointment of Vice President of the ASE.  After a one-year term, president-elect and then president , 2014
  • Invited Visiting Professor at Mount Sinai Hospital for Anandi L. Sharma Visiting Professorship and Simon Dack, MD Memorial Lecture, Heart Failure with Preserved Ejection Fraction with live presentation at www.heart-talks.org, 2015
  • 13th Annual Tajik/Seward Lectureship, Cleveland Clinic HVI National Leadership  and Diseases Center and IPU Development, 2015
  • Section Editor for Pericardial Disease for ACC.org, 2016
  • Key Note Speaker:  “Constrictive Pericarditis in the 21st Century” at the Portuguese Congress of Cardiology, 2016
  • Elected President of the American Society of Echocardiography, 2017
  • Notification in the Cleveland Clinic “Weekly Scoop:  News from the Chief of Staff 5 Questions section on providing a one-stop-shop for patients with pericardial disease, 2017
    Physician’s Weekly article, “Key Concepts in Managing Complicated Pericarditis”  2017
  • Guest Co-Editor for Progress in Cardiovascular Disease 2017;59(4):325-26,  2017
  • Co-Editor of “Clinical Echocardiography Review:  A Self-Assessment Tool.” 2nd Edition.  Wolters Kluwer, 2017


  • Internal Medicine
  • Internal Medicine - Cardiovascular Disease

Specialty Interests

Amyloidosis, Heart Valve Disease, Pericardial Disease, Pericarditis, Cardiovascular imaging, Echocardiogram, Non-invasive Diagnostic Testing

Awards & Honors

  • Fellowships: American College of Cardiology, Royal College of Physicians (Canada), American Society of Echocardiography, American Heart Association, European Society of Cardiology
  • Mentor for the winner of the Laeneec Young Clinician Award at the American Heart Association Scientific Sessions,  2008
  • Guideline Chair, American Society of Echocardiography Clinical for Multimodality Cardiovascular Imaging of Patients with Pericardial Disease, 2013
  • Invited Visiting Professor at Mount Sinai Hospital for Anandi L. Sharma Visiting Professorship and Simon Dack, MD Memorial Lecture, Heart Failure with Preserved Ejection Fraction with live presentation at www.heart-talks.org, 2015
  • 13th Annual Tajik/Seward Lectureship, Cleveland Clinic HVI National Leadership and Diseases Center and IPU Development, 2015
  • Section Editor for Pericardial Disease for ACC.org., 2016
  • Elected President of the American Society of Echocardiography, 2017
  • Guest Co-Editor for Progress in Cardiovascular Disease 2017;59(4):325-26, 2017
  • Co-Editor of “Clinical Echocardiography Review:  A Self-Assessment Tool.” 2nd Edition.  Wolters Kluwer, 2017
  • Co-Editor of “Diastology:  Clinical Approach to Diastolic Heart Failure.”  Saunders Elsevier, Philadelphia, 2018

Innovations & Patents

  • Dr. Klein has pioneered the use of transesophageal-guided cardioversion in patients with atrial fibrillation in his landmark paper in the New England Journal of Medicine published in 2001 and the European Heart Journal in 2006. 

    He directs the largest pericardial center in the world which evaluates complex patients with different pericardial diseases.


  • American Society of Echocardiography
  • American Heart Association
  • American College of Cardiology
  • Royal College of Physicians of Canada
  • Society of Cardiovascular Computed Tomography
Research & Publications

Research & Publications

See publications for Allan Klein, 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 3/31/2024, Dr. Klein 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. Klein receives fees of $5,000 or more per year (or, in rare cases, equity or stock options) as a paid consultant, speaker or as a member of an advisory committee for the following companies:

  • Pfizer, Inc.
  • Kiniksa Pharmaceuticals Corp.

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

183 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
4.7 out of 5
Explains 4.7
Listens 4.7
Courtesy, Respect & Concern 4.7
Patient Rating of Doctor 4.7

33 Patient Comments

Reviewed on Jun 5, 2024

Very knowledgeable and friendly physician.

Reviewed on Jun 5, 2024

Dr Klein has provided excellent and trustworthy cardiac care for many years. He is consistent, attentive, having excellent comprehension of my specific cardiac condition and needs. He is kind, respectful and personable.

Reviewed on May 30, 2024

20 years of excellent care by Dr. Allen Klein.

Reviewed on May 9, 2024

Dr Klein has an awesome team! I find Dr Klein & Mary very compassionate & knowledgeable! His fellow was great also unfortunately I don't remember his name.

Reviewed on May 1, 2024

Dr. Klein and his staff are top notch! I have been seeing Dr. Klein for over 15 years and always have a very positive experience.

Reviewed on Apr 4, 2024

Dr Klein was outstanding, as usual

Reviewed on Mar 14, 2024

This was my 6mo fu with Dr klein. He had no idea who I was or my case. He reviewed a picture from mri I had that day and without the report told me I was had inflammation. I found out the next day from mri report I had zero inflammation which certainly changes my treatment plan. I still have not been contacted. Furthermore, as he was in a rush to leave, I asked to go over my blood work. I left confused and worried about everything. Me and my husband felt as if he didn't care. He was not thorough. We paid out of pocket, took off 3 days from work to seek care at cleveland clinic. I am so disappointed.

Reviewed on Jan 11, 2024

Dr Klein is the best doctor there is no one like him that's why I travel so far and only trust him with my heart

Reviewed on Jan 11, 2024

Dr. Klein has been my cardiologist since 1991. I will continue as his patient as long as possible.

Reviewed on Dec 21, 2023

Dr. Klein and his staff were thorough and very friendly. He took the time to hear the full account of my heart issue. His responses were well thought out and easy to understand. He took time to get to know me as a person. I would highly recommend Dr. Klein.

Reviewed on Dec 20, 2023

Answered questions above regarding my visit with Dr Klein

Reviewed on Dec 7, 2023

The primary/senior physician did not ask how I was doing, did not discuss multiple serious side effects and new iatrogenic heart condition, and again refused to discuss the full and requested drug information for his desired medication. He ignores questions or comments he does nor want to address, and is not respectful of me as a person or patient.

Reviewed on Dec 7, 2023

Since my concerns are not being addressed, and I feel I am being disrespected and dismissed, it has been one of the most frustrating and stressful medical care experiences of my life. This is arguably one of the most serious illnesses of my life.This is unacceptable. I need and should receive the compassionate and respectful care of providers willing to listen and work with me. That is not the current care I am receiving.

Reviewed on Dec 7, 2023

Dr. Klein and his staff are beyond belief in providing the level of excellent care for us. It was a difficult diagnosis, and this was my first time at the clinic. I was included in meetings about my diagnosis and treatmemt and always treated with such kindness and dignity.

Reviewed on Nov 22, 2023

Dr Klein has been caring for my husband and myself for 25 years. Dr Klein is the best cardiologistknowledgeable, personable, professional, listens well, Is conscientious, communicates on our level, and truly cares about us as his patients. He goes above and beyond to take care of our heart health. Dr Klein is a blessing and a treasure.

Reviewed on Nov 22, 2023

Dr. Kline treated me as nothing more than a number. He was rude and snarky when I asked questions. He also told me they do not check my lab results and if I see something concerning to ask him. That is unacceptable!!

Reviewed on Nov 2, 2023

I can't say enough about my experience at Cleveland Clinic. Dr Klein and all of his staff were fantastic!

Reviewed on Oct 19, 2023

Dr. Klein is a very caring Doctor. I trust him with my life!

Reviewed on Oct 18, 2023

Dr.Klein and Mary Heine cnp was always great.

Reviewed on Sep 28, 2023

Dr Kline is a great and caring doctor and I appreciate him and his teams help and care. Also, Amber has been great and a very big help.

Reviewed on Sep 28, 2023

Dr Kline and his team have been amazing and I truly appreciate him and his teams help.

Reviewed on Sep 28, 2023

From the secretaries to the support staff to the physicians, what a fabulous place

Reviewed on Sep 21, 2023

Dr. Klien and his student doctor were amazing! They went over my test explaining everything and gave me very clear answers along with being compassionate.

Reviewed on Sep 13, 2023

Excellent in all areas; physician completely collaborates with the patient.

Reviewed on Sep 6, 2023

Always wonderful with Dr Klein.

Reviewed on Sep 6, 2023

Dr. Klein is the best!

Reviewed on Aug 30, 2023

I have been a patient of Dr. Klein since 2015. I have received exceptional care from him. The entire experience has been outstanding,from the redcoats,secretaries,nurses to the food service & the garage(which can fit my Dodge diesel trucks height). This is why I have made the 300+ mile trip to the Cleveland Clinic over 2 dozen times. He diagnosed my problem in 1 visit after 1 & 1\2 years of being misdiagnosed in Scranton,Pa. As far as I am concerned it has been a world class experience.

Reviewed on Aug 17, 2023

Love Dr Klein, he is always so attentive in detail and Compares last year's results to current

Reviewed on Jul 19, 2023

Both the Resident and Dr. Klein were thorough, talented and caring during my visit. Thank you

Reviewed on Jul 19, 2023

Always amazed on how Dr. Klein and his helping Resident/Fellow preview my medical history before visiting me. I understand they are very busy, but know what is important, hear my issues, and get to my issues quickly and come to a medical decision and course of action.

Reviewed on Jul 13, 2023

Dr. Klein listened to me on everything I had to say. Couldn't be happier with him and the staff!!!

Reviewed on Jun 29, 2023

Dr Klein saved my life.

Reviewed on Jun 29, 2023

Dr. Klein saved my life.

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