The Patient Was…

Cardiology is one of the most prestigious medical specialties. It’s role in combatting heart disease, the world’s leading disease-related cause of death and disability, often places it at the very top of medical specialty rankings.  The American College of Cardiology (ACC), arguably the premier medical specialty society in the world, lists over 50,000 members, the core of whom are FACCs, or Fellows of the American College of Cardiology.

While the ACC includes non-physician members, all of them are primarily involved in cardiovascular disease in their professional lives. Thus, researchers and other scientists, and other types of practitioners may become members of the ACC. But a U. S. physician must be a board- certified cardiologist to qualify for FACC designation. At present, board-certification is granted by the American Board of Internal Medicine (ABIM), since Cardiology is a recognized sub-specialty of the broader field of Internal Medicine.

The growth of Cardiology as a sub-specialty of medicine has been astounding since the founding of the American College of Cardiology, in 1949, by 13 doctors. When I became board-certified in the 1970s, there were only 1,000 board-certified cardiologists in the entire country (although about 10,000 U. S. physicians called themselves cardiologists, according to sources), and only 300 of us were in private practice, the rest being in academic medicine. Currently, ABIM data indicate about 40,000 Cardiology board-certifications, with about 30,000 still active.

The field of Cardiology now has its own sub-specialties, of course. These include Electrophysiology (disorders of heart rhythm), Pediatric Cardiology dealing with children afflicted with heart disease, Heart Failure (inadequate pumping function of the heart), Valvular Heart Disease (disorders of the valves controlling blood flow through the four heart chambers), Congenital Heart Disease (inherited structural heart problems), Heart Surgery, Interventional Cardiology (catheter-based procedures with access through the blood vessels), Cardiac Imaging (including cardiac ultrasound [echocardiography],  MRI, and CAT scans), as well as other specialized areas of interest.

What is notable is that these sub-specialty areas are all still within and confined to the general field of Cardiology.

Recently, however, a new world of Cardiology sub-specialty areas of interest has emerged, a world of what might be called “hyphenated cardiology.” Prominent among these are Cardio-Oncology and Cardio-Obstetrics.

The names are self-explanatory: the first combines cardiology and oncology (cardiovascular disease and cancer), the second cardiology and medical management of pregnancy and childbirth. But just what are these connections between heart disease and cancer, and heart disease and obstetrics, that warrant separate sub-specialties in medical care?

Cardio-Oncology suggests concern with cancers of the heart, but this is not the case. Suffice to say that while there are cancers of the heart, they are quite rare. They may be primary, arising in the heart itself, or more likely secondary, spreading to the heart from another site within the body. The very infrequent occurrence of cancers of the heart would hardly warrant a separate specialty. So, what is this Cardio-Oncology all about?

The emergence of this new area of cardiology stems primarily from the recent growing success in treating cancers of many types. The emergence of new anti-cancer chemotherapy drugs, advances in immunotherapies using the body’s complex immune system, newer radiation therapies, and better surgical techniques, have all combined to extend the lives of many patients who previously would have succumbed to their cancers. Long-term cancer survival is now a reality in many circumstances. The problem —  and it admittedly seems odd to consider better survival a problem  —   is that many of the advances in cancer treatment, especially chemotherapy drugs and certain types of radiation therapy, carry serious risks to the structure and function of the heart.

The cardiac damage of cancer treatment, known as cardiotoxicity, can affect the heart muscle and its pumping performance, the heart’s electrical system and its rhythm control, and even the coronary arteries that supply the heart structures with necessary blood. The damage can be such that a patient who survives their cancer may die from heart disease.

The best strategies and tactics for the prevention, treatment, and follow-up of patients with cardiotoxicity related to cancer treatment, are still evolving. Current guidelines proposed by both oncology and cardiology experts suggest that cardiac care should be an integral part of cancer management, especially in patients with underlying risk factors for heart disease and those whose cancer treatment are known to be potentially cardiotoxic.

The situation in regard to Cardio-Obstetrics is somewhat different from that of Cardio-Oncology. Whereas the latter is primarily related to more successful treatment of patients with otherwise fatal malignancies, the former is based on better recognition of the physiological changes that occur in pregnancy and the impact of underlying risk factors for heart disease in pregnant women.

In the past, cardiologists’ interest in obstetrics revolved largely around pregnant woman with known cardiac disease, often congenital structural heart defects that they were born with. During my years of Fellowship training in cardiology, I helped to run a Cardio-Obstetrics clinic in our hospital. The patients all had congenital heart disease of various types that comprised their ability to handle the normal physiological changes of pregnancy. We published our experience in a prominent Obstetrics medical journal, and it is unlikely that many cardiologists were even aware of it.

Greater recognition of the physiological changes in pregnancy, and their effects on women with underlying heart disease or even just risk factors for heart disease, is now a major concern of the sub-specialty of Cardio-Obstetrics. These physiologic changes are quite profound and affect many organ systems in the body. Of course, changes within the reproductive system are prominent, but those within the cardiovascular system are quite profound, as well. These include  a large increase in the amount of blood the heart has to pump, an increase in the heart rate (number of heart beats per minute) and the amount of blood pumped with each heart muscle contraction, and an expansion of the blood volume (the total amount of blood circulating through the body).

The consequences of the increases in blood flow accompanying pregnancy were of particular interest to me in my years of medical practice, in what might be considered a profitable way. The more and faster blood flows, the more sounds it makes as it courses through the heart and blood vessels. These sounds can be interpreted, or misinterpreted, as pathologic heart murmurs due to structural abnormalities in the cardiovascular system. I saw many women on referral from obstetricians who heard these sounds as they examined their pregnant patients and thought they might represent true cardiac abnormalities rather than innocent flow sounds.

Cardio-Obstetrics also concerns itself with other conditions that raise the risk of danger to pregnant women and their fetuses. Such things as high blood pressure, diabetes, abnormal lipids (elevated cholesterol and other blood fats), obesity, blood clotting, and management of various medications, are all part of the Cardio-Obstetrics universe.

As science advances and more is learned about various medical conditions and changes in body physiology, one might anticipate new medical sub-specialties arising. The world of “hyphenated medicine” may only be in its infancy, but the two current and prominent examples of Cardio-Oncology and Cardio-Obstetrics provide ample energy and engagement right now.