Cardiologist

the study of the heart and its functions in health and disease.
Contemporary Examples

Even her 46-year marriage to Dr. Leonard Gordon, a cardiologist, turned out to be a sham.
Rita Moreno, SAG Life Achievement Award Winner, Talks Brando, Elvis And West Side Story Sandra McElwaine January 14, 2014

Natterson-Horowitz is a cardiologist at the David Geffen School of Medicine at UCLA.
‘Zoobiquity’: What Animals Can Teach Us About Our Health Carl Zimmer June 16, 2012

His two older sisters are accomplished – a cardiologist and a Ph.D. zoologist.
Mohammed Atta and the Egypt Revolution Terry McDermott February 13, 2011

Farzand Omar is a cardiologist who hails from a family of Aleppo businessmen.
Bashar al-Assad Lost The Support of Aleppo’s Wealthy When the Shelling Started Mike Giglio August 31, 2012

She is going home to be with her 13-year-old son, Robert Cole, and cardiologist husband, Robert.
Washington’s Protocol Chief Capricia Marshall Steps Down Sandra McElwaine August 10, 2013

noun
the branch of medical science concerned with the heart and its diseases
n.

1847, from cardio- + -logy. Cardiologist attested from 1885.

cardiology car·di·ol·o·gy (kär’dē-ŏl’ə-jē)
n.
The medical study of the structure, function, and disorders of the heart.
cardiology
(kär’dē-ŏl’ə-jē)
The branch of medicine that deals with diagnosis and treatment of disorders of the heart.
cardiology [(kahr-dee-ol-uh-jee)]

The branch of medicine devoted to the study and care of the heart and circulatory system.