Medical Fact of the Day – Heart Swinging
Today's fact comes from a case presented in the New England Journal of Medicine. The 39-year-old woman was being treated for melanoma, a skin cancer, but the disease showed steady spreading. Among other symptoms, her heart rate was 110 and blood pressure 82/64 mmHg (normally 60-70 and 120/80, respectively). This suggested some sort of heart defect, and an echocardiogram was taken to image the heart in action.
This picture, taken from this video, shows the heart swinging within the chest as it beats. Needless to say, this is not normal - the heart usually sits still within its cavity, happily pumping away.
This heart has gone wild. Arrows point to portions of the heart that have collapsed (not a good thing). From Kapoor JR, McConnell MV. NEJM 2009 Oct 29; 361(18):e37.
This happens because the chamber within which the heart usually sits - the pericardium - has filled with fluid when it should be snug against the heart. In this case, the space has filled with fluid because the metastatic cancer spread to the pericardium. The heart now has space to swing about as it beats.
When the pericardium fills with enough fluid, it increases pressure against the heart and can disrupt its normal function, leading to cardiac tamponade. In the picture above, you can see that chambers of the heart collapse after beating, a sign of too much pressure against the walls of the heart.
They eventually sucked out 1.6 liters of fluid, about 160x the amount of fluid usually in the space (10 mL).
Other reasons that pericardial effusion can occur include infection (with viruses, bacteria, or parasites) and inflammatory disorders.
Click here for a video of the swinging heart in action. It's well worth the time.
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