Microvascular coronary dysfunction (MCD) (abnormities in small blood vessels/arteries in heart) with symptoms of persistent chest pain, primarily impacts women. There are an estimated 2-3 million women in the US with MCD and about 100,000 new cases annually. Recent data from our research group suggests that coronary microvascular disease impairs the way the heart relaxes. This pilot study will attempt to exacerbate this phenotype in an effort to better understand the pathophysiology of the disease. The investigators will recruit 30 volunteers total (10 healthy calibration subjects, 10 women with microvascular disease, and 10 age-match women for the group with microvascular disease). Subjects will undergo a series of "stress" maneuvers in conjunction with advanced cardiac magnetic resonance imaging.

Inclusion Criteria:

1. Fully understanding and willing to undergo study procedures
2. Male or Female greater than or equal to 18 years of age
3. Understanding and willing to sign consent form.

Exclusion Criteria:

1. History of cardiovascular, pulmonary, or neurological disease
2. Hypertension (sitting blood pressure >140/90 mmHg, with measurements recorded on at least 2 occasions)
3. Diabetes
4. Unable to give informed consent;
5. Contra-indication to CMRI testing, including claustrophobia and metallic implants
6. Adherence or retention issues;
7. Women who are pregnant.
8. Allergy to animal dander.