JG
Accepting patients
Affiliated with a Castle Connolly Top Hospital
Who is Dr. Granquist, Cardiologist in Hartford, CT?
Dr. John Granquist, MD is a Cardiologist, who primarily practices in Hartford, CT with 2 additional practice locations. He is board certified. Dr. Granquist is fluent in English, and is currently seeing new patients. Dr. Granquist’s practice accepts Medicare, UnitedHealthcare, Aetna, Cigna and other major insurance plans. To book an appointment or to confirm insurance options, please call Dr. Granquist’s office at (860) 522-0604.
What languages does Dr. Granquist speak?
Dr. Granquist and their clinical team can communicate with patients in the following languages:
English
What conditions does Dr. Granquist treat?
As a Cardiologist, Dr. Granquist diagnoses, treats, and manages a wide range of conditions. This condition information is derived from anonymized insurance claims and highlights the medical conditions most commonly treated by Dr. Granquist. It provides insight into the doctor’s areas of experience and expertise based on real-world patient encounters from the past two years, updated quarterly.
Also known as:
- Arrhythmia
- Irregular heartbeat
- Heart rhythm disorder
- Cardiac dysrhythmia
ICD-10 Codes:
- I499: Cardiac arrhythmia, unspecified
Also known as:
- Chest Pain
- Chest discomfort
- Thoracic pain
- Upper body pain
ICD-10 Codes:
- R079: Chest pain, unspecified
Also known as:
- Muscle Weakness
- Muscle Disorder
- Loss of strength
- Fatigue
- Muscle fatigue
ICD-10 Codes:
- R531: Weakness
Also known as:
- Other Pre-Procedure Examination
- Various pre-op checks
- Miscellaneous pre-surgery exams
- Other pre-treatment assessments
ICD-10 Codes:
- Z01818: Encounter for other preprocedural examination
Also known as:
- Abnormal EKG
- Heart Health Tests
- Irregular Electrocardiogram
- Unusual Heart Rhythm Test
- ECG Abnormalities
ICD-10 Codes:
- R9431: Abnormal electrocardiogram [ECG] [EKG]
Also known as:
- Shortness of Breath
- Breathing Problems
- Difficulty breathing
- Breathlessness
- Dyspnea
ICD-10 Codes:
- R0602: Shortness of breath
Also known as:
- Chest Pain
- Chest discomfort
- Thoracic pain
- Pectoral pain
ICD-10 Codes:
- R0789: Other chest pain
Which procedures does Dr. Granquist perform as a Cardiologist?
As a Cardiologist, procedures performed by a Dr. John Granquist may include:
- Absent Pulmonary Valve Repair
- Anomalous Coronary Artery Angiography
- Anticoagulation Management
- Aortic Stenosis Repair
- Aortic Valve Repair / Replacement
- Aortopulmonary Window Repair
- Arterial Doppler
- Balloon Septostomy
For detailed information, please contact Dr. Granquist's office.
Does Dr. Granquist accept my insurance?
Dr. Granquist accepts most major insurance plans. Important: Please call our office at (860) 522-0604 before your appointment to verify that your specific plan and network are accepted.
What insurance plans does Dr. Granquist accept in Hartford, CT?
Dr. Granquist in Hartford, CT accepts plans from many carriers. While this list is updated regularly, it is not a guarantee of coverage.
Top Insurances
ArcBest Corporation
CarePartners of Connecticut
CVS Health (formerly Aetna)
Department of Veterans Affairs
Elevance Health Inc. (formerly Anthem)
Medicare
OptumRx
State of Connecticut
State of Tennessee
UnitedHealthcare
View All Insurances
Where is Dr. Granquist's office located?
Dr. John Granquist's Primary Practice
85 Seymour St Ste 719
Hartford, CT 06106
(860) 522-0604
Recognitions
Castle Connolly Doctor’s Choice Awards
Doctor’s Choice - 2025
Among the most nominated for the Castle Connolly Top Doctor recognition in 2025
What is Dr. Granquist's NPI number?An National Provider Identifier (NPI) is a unique ID number that identifies doctors and healthcare providers nationwide.
Dr. Granquist's National Provider Identifier (NPI) number is 1699821892.
What common questions do patients ask about Dr. Granquist?
Here are answers to patients Frequently Asked Questions (FAQ’s) about Dr. Granquist
What is Dr. John Granquist's specialty?
Dr. Granquist is a Cardiologist near Hartford, CT. An internist specializing in cardiovascular diseases focuses on the diagnosis and management of complex heart and blood vessel conditions, including heart attacks and life-threatening arrhythmias. Contact Dr. Granquist to book an appointment today.
Is this Dr. John Granquist affiliated with a ranked Castle Connolly Top Hospital?
Yes, Dr. Granquist is affiliated with Hartford Hospital, MidState Medical Center which are a Castle Connolly Top Hospitals. Castle Connolly Top Hospitals are healthcare institutions recognized for their excellence in specific medical procedures and overall patient care. They are identified through a rigorous peer nomination process, evaluating factors like patient outcomes, quality of care, and expertise. The list recognizes hospitals that excel in 20 or more specific medical procedures, representing the top 25% nationwide. Castle Connolly Top Hospitals
Where can I learn more about Cardiologist?
Explore Cardiologist with insights from trusted medical experts on EverydayHealth.com, where you'll find the most relevant content and helpful condition guides for up-to date information about symptoms, causes, diagnosis, treatment and more. See all our health guides to find trusted information on medical conditions from our experts at Everyday Health.
Is John Granquist accepting new patients in Hartford, CT?
Yes, Dr. John Granquist is accepting new patients at this time.
Does Dr. John Granquist offer online booking?
Please contact Dr. Granquist's office at (860) 522-0604 for information about online booking, telehealth, or to schedule an appointment.
How can I make an appointment with John Granquist?
Please contact Dr. Granquist's office at (860) 522-0604 for information regarding telehealth appointment availability or for scheduling assistance.
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