The Phonocardiogram in Endomyocardial Fibrosis.

Endomyocardial fibrosis is a common cause of heart failure in Uganda. A clinico-pathological study of this cardiopathy reported by Ball et al. (1954) established that the fibrotic process, while involving the endocardium of the apices of the ventricles, not infrequently extends to the chorda, tendinee and the cusps of the atrioventricular valves, tethering them down and producing atrioventricular incompetence. Clinically, this group which comprises the majority of cases presents as classical mitral regurgitation often with tricuspid regurgitation, and is associated very frequently with considerable atrial dilatation. An abnormal atrial electrocardiogram associated with low voltage QRS complexes and flattening or inversion of T waves has been found in over half of a series of 30 patients proved at necropsy to have endomyocardial fibrosis (Williams and Somers, 1960). We believe these electrocardiographic abnormalities to be distinctive of endomyocardial fibrosis. In this paper we report on the phonocardiographic signs in 14 consecutive cases of clinically diagnosed endomyocardial fibrosis with atrioventricular regurgitation admitted to Mulago Hospital during a three-month period in 1958. There were 8 male and 6 female patients and their ages ranged from 12 to 65 years. All the patients studied had been in congestive heart failure when first seen and in each instance heart failure had been controlled at the time of taking of the sound records. The diagnosis of atrioventricular regurgitation due to endomyocardial fibrosis was reached by careful exclusion of other causes of heart failure, particularly mitral stenosis, anmmia, aortic valve disease, and hypertensive heart disease. In practice the finding of an apical pansystolic murmur transmitted to the left axilla, sometimes as far as the left scapular region, accompanied by radiological evidence of expansion of the left atrium during ventricular systole, was regarded as evidence of mitral regurgitation. In four of the patients studied there was organic tricuspid regurgitation in addition to the mitral lesion. Tricuspid regurgitation was diagnosed on the basis of a systolic murmur over the tricuspid area with inspiratory increase (Carvallo et al., 1951) and systolic pulsation of the jugular veins and the liver. A three-channel simultaneous electrocardiogram, carotid pulse pick-up, and phonocardiogram recording unit, manufactured by Messrs. Cardiac Recorders, London, was used throughout. The murmur of mitral regurgitation was recorded from the area of maximal auscultatory intensity which was usually well outside the mid-clavicular line in the fifth interspace. Records were taken at the end of expiration. In the four cases with tricuspid regurgitation the phonocardiogram was recorded from the base of the xiphoid process or the lower end of the left sternal edge in both expiration and inspiration. The simultaneous electrocardiographic lead recorded was lead II. All tracings were made with a film speed of 100 mm. a second.