A 22-year-old woman with a right atrial myxoma prolapsing to the right ventricle is described. The haemodynanmc findings were similar to those of cases of prolapsing myxoma of the left atrium; a notching on the ascending limb of the right ventricular pressure curve, and an initial negative, irregular deflection on the pulmonary artery pressure curve with a pronounced rise in the mean right atrial pressure (18 mmHg) were found. On deep inspiration there was a significant deepening of the y descent from 12 mmHg to 2 mmHg, indicating a changing, dynanic obstruction of the right ventricle inflow tract. These haemodynamic features can be helpful in the diagnosis ofprolapsing right atrial myxoma.Myxomata of the atria are uncommon, especially in the right atrium (Sannerstedt et al., 1962;Morrissey et al., 1963). Recently, Sung et al. (1975) differentiated between two types of left atrial myxoma: type I, in which the tumour prolapses during diastole into the left ventricle, and type II, which is non-prolapsing. Sung described a notch in the upstroke of the left ventricular pressure curve and a rapid y descent in the pulmonary arterial wedge pressure curve as characteristic of the prolapsing type.The purpose of this report is to present a case of a right atrial myxoma, prolapsing during diastole into the right ventricle, producing haemodynamic features similar to those described by Sung for the prolapsing left atrial myxoma.
Case reportA 22-year-old single woman of Arabian origin had been completely well until 6 months before her admission, when she began complaining of palpitation, frequent cough, and haemoptysis; one month before admission her complaints became worse with pain in the right posterior thorax, frequent nausea and vomiting, and a loss of 7 kg in weight. On admission she had a temperature of 37 9°C; there was no cyanosis, clubbing, or dyspnoea; her blood pressure was 120/80 mmHg, pulse rate 110/ min, with regular rhythm. There was pronounced jugular venous engorgement with prominent a and v waves and a negative Kussmaul sign. Auscultation of the lungs revealed poor air entry into the right lung base and a pleural friction rub at the left base. The apex beat was palpated in the left fifth interspace in the midclavicular line; no right ventricular heave was noted. A diastolic thrill at the lower left sternal border was palpable; the first heart sound was prolonged and accentuated. The second sound was normal; a grade 4/6 mid-diastolic presystolic murmur extending into the first sound and early systole was heard at the lower left sternal border. The character of the murmur was similar to a pericardial friction rub; the intensity of the murmur was unaffected by the position of the patient but increased slightly on deep inspiration. The liver was palpable 5 cm below the costal margin and tender; the spleen was not palpable. There was mild pitting oedema in both legs.The electrocardiogram showed sinus rhythm with a rate of I10/min, tall P waves in leads II, III, and aVF. The QRS axis was + 1200, and there were n...