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Denise L. Janosik, MD

Mercy Clinic
Denise L. Janosik, MD, Mercy

Denise L. Janosik, MD

Specialty

  • Cardiology

Online Services

Schedule Online
(4.9/5)
619 Ratings | 177 Comments
Accepting new patients
Location of Your Visit
Mercy Clinic Heart and Vascular - Clayton-Clarkson Suite 230-A
15945 Clayton Road, Suite 230ABallwin, MO 63011
Mercy Clinic Heart and Vascular - Clayton-Clarkson Suite 230-APhone: (636) 256-5240

Select a Location

To schedule an in-person or video visit (available only through certain locations).

Mercy Clinic Heart and Vascular - Old Tesson Suite 260
12348 Old Tesson Road, Suite 260St. Louis, MO 63128
Phone: (314) 251-1777
12.3 Miles
Mercy Clinic Heart and Vascular - Mercy Heart Hospital St. Louis
625 S. New Ballas Road, Suite 2015St. Louis, MO 63141
Phone: (314) 251-1700
13.5 Miles
Mercy Clinic Heart and Vascular - Clayton-Clarkson Suite 230-A
15945 Clayton Road, Suite 230ABallwin, MO 63011
Phone: (636) 256-5240
21.0 Miles

Select a Visit Type

To ensure the highest quality patient care, please select the most appropriate visit type, as length of visits vary. If you do not see your visit type, please call.

Existing Patient - Office Visit

I've seen this provider within the last three years and need an appointment (other than for a routine physical or well check). This is a standard visit length.

Questions? Call:
(636) 256-5240
Need a Heart Expert?
Whether you've had a heart attack, suffer from atrial fibrillation, or experience rapid heart rhythms, Mercy heart specialists can help. If you have an HMO plan, your insurance may require a referral from your primary care physician. Please contact your primary care physician prior to your appointment with the specialist to obtain the necessary referral.

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Location and Contact Information

About Denise L. Janosik, MD

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      Education
      Medical School
      • Saint Louis University
      Fellowships
      • Saint Louis University-Cardiovascular Disease
      • Saint Louis University-Electrophysiology
      Residency
      • Saint Louis University-Internal Medicine
      Specialty
      Board Certifications
      • American Board of Internal Medicine (Cardiovascular Disease)
      • American Board of Internal Medicine
      Affiliations
      • Mercy Hospital St. Louis
      Languages
      • English
      Looking for more options?
      Find the Mercy provider who's right for you.
      View all Cardiology providers.
      Looking for more options?
      Find the Mercy provider who's right for you.
      View all Cardiology providers.

      Patient Ratings and Comments

      Rating

      From 619 patients
      (4.9/5)
      The provider rating is an average based on Mercy Clinic's post-care survey responses. To find out more, check out our frequently asked questions.

      Comments

      Viewing 1-3 of 177 comments
      Highlights from patients about their experience with this provider:
      • May 8, 2025
        (5/5)
        Dr. Janosik has been a wonderful helper in keeping my heart healthy. I trust her and feel very comfortable talking and asking questions. She even called me personally to explain a test. Above and beyond in advising me.
      • May 6, 2025
        (5/5)
        Dr Janosik is very considerate, compassionate and caring. She and the staff always do a great job. when she runs late she does apologize.
      • May 6, 2025
        (5/5)
        Dr. JANOSIK listens carefully. You can tell she is compassionate and cares for her patients.