While an echocardiogram (ECG) looks like a not-so-impressive barrage of waves on paper, it allows a cardiologist to gain a tremendous deal of insight about a patient’s heart.
The shape of certain waves and the length of intervals between waves can translate to significant findings like left ventricular hypertrophy (enlargement), a myocardial infarction (heart attack) at some point in the past, and even an accessory conduction pathway which bypasses the normal nodal conduction. Coupled with other rudimentary facets of a cardiology exam (namely auscultating with the bell and diaphragm of one’s stethoscope), it’s pretty amazing how far the art of diagnosing cardiac conditions has come.
Studying how the ECG works has been of particular interest to me. Determining how different electrical vectors produce a net axis of conduction and translating that information to a concrete diagnosis and treatment regimen nicely unifies my love of physics and medicine. Even variables as simple as cardiac pressure, total vascular resistance, and flow rates bring back memories of Ohm’s Law; if one considers voltage to be an “electrical pressure gradient”, then the equations which describe electrical current and cardiac flow are identical. Another unification between physics and medicine. 🙂
Furthermore, treatments have proven to be incredibly effective. You’ve got a bad aortic valve? Oh, let’s just replace the whole thing without even having to open your chest. Your cholesterol is too high? Let’s give you a statin which will not only lower your LDL but markedly reduce the event of an inflammatory or thrombotic catastrophe. You still manage to clog a heart vessel… or two… or three… or four? Let’s just replace them all with grafts! 🙂 You’ve happened to screw up your heart in every conceivable way imaginable yet are otherwise healthy? Let’s get you on a transplant list so we can entirely replace your defective organ.
I imagine that the cardiologists a century ago would have never dreamt that their field would achieve this level of diagnostic and therapeutic success! Yet in spite of how far cardiology has come, heart diseases still account for the majority of deaths in the United States. Consequently, a great deal of work must still be done (on the preventative end) to help improve those statistics.