By Kavita Gandhi, MD, Kristin Dwyer MD, MPH, and Patricia Henwood, MD, FACEP
Last night on shift, you brought in the ultrasound to evaluate a 28-year-old male, originally from Ethiopia, presenting with signs and symptoms concerning for heart failure. As you try to evaluate his squeeze, you note the mitral valve doesn’t look quite right (as below). You recall the medical student who presented the patient noted a low-pitched, rumbling, decrescendo, diastolic murmur best auscultated at the left lower sternal border…hmm, rheumatic heart disease (RHD) is on your differential and you wish you knew how to get a better sense of this during your bedside echo…
RHD, caused by an autoimmune reaction to untreated group A strep infections, is the most common cause of acquired heart disease in many children in developing countries around the world.1 It still affects children in the United States, though much less commonly, with an incidence of acute rheumatic fever (ARF) approaching 2 cases per 100,000 per year.2 The pathology of RHD involves thickening and fibrosis of the mitral and aortic valves, which leads to valve stenosis and, over time, heart failure. Close to 16 million people are estimated to be currently affected by RHD worldwide, with the highest incidence in sub-Saharan Africa, south-central Asia, the Pacific, and indigenous populations of Australia and New Zealand.1 The early diagnosis of valvular pathology in patients with RHD has been a goal of health care providers in countries with a high incidence of ARF. For this reason, the use of bedside echo in screening programs in school aged children has been studied in several countries in Africa.3
The World Heart Federation has published criteria on the use of bedside echo to diagnose RHD, based on pathology of the mitral and aortic valve.4 These involve the use of 2D (B-mode) continuous wave Doppler and color Doppler evaluation of each of these valves in the parasternal long axis and apical four chamber views of the heart to evaluate for abnormal valve morphology and thickening, as well as regurgitant jets across the valves. Mitral valve leaflet thickening, mitral valve stenosis, and mitral regurgitation are the most common echo findings in RHD. In your parasternal long view, while looking for decreased valve opening, be sure to look out for the classic “hockey stick” or “elbow” appearance and “ballooning” of the anterior mitral value leaflet during diastole as shown in Figure 1.5 Worldwide, RHD is the cause for 95-99.3% of all cases of mitral valve stenosis in patients <50 years of age, so if you see this finding in a younger patient with heart failure symptoms, there is a good chance they may have this disease.5
Figure 1. Parasternal long axis, rheumatic mitral valve disease
You can also put color Doppler on and look for a regurgitant jet (MR) across the mitral valve which would suggest abnormal mitral valve structure and motion (Figure 2).
Figure 2. Color Doppler of regurgitant jet across MV in apical four chamber view.6
MR was the most common finding, with prevalences approaching 95%, in confirmed RHD cases in several studies conducted in countries with a high incidence of ARF.5 So, next time you hear that rumbling diastolic murmur, remember to put a probe on the patient and look for valvular pathology!