The duration of the acceleration phase of pulmonary systolic flow was measured by pulsed Doppler echocardiography in 39 normal subjects and 67 patients with heart disease to evaluate the reliability of this Doppler index as an estimate of pulmonary arterial pressure. The mean (SD) Doppler index in patients with abnormal mean pulmonary arterial pressure (greater than 15 mm Hg) was significantly shorter than that in normal subjects (110 (30) ms vs 150 (10) ms). The Doppler index was significantly related to the mean pulmonary arterial pressure (r = -0.75) the pulmonary blood flow (r = 0.46), and the total pulmonary vascular resistance (r = -0.68). Forty four of 45 patients with an abnormal index (less than or equal to 120 ms) showed abnormal mean pressure (greater than 15 mm Hg). Without exception patients with a low index (less than or equal to 90 ms) had distinct pulmonary hypertension (greater than or equal to 25 mm Hg). Twelve of 22 patients with a normal index (greater than or equal to 130 ms), however, also showed abnormal pressures. Nine of the 12 had an atrial septal defect and they had high pulmonary arterial pressure associated with high blood flow. Eighteen patients with valvar heart disease, whose mean pulmonary arterial pressure ranged from 16 mm Hg to 24 mm Hg, had a significantly shorter acceleration phase and a higher total vascular resistance than 11 patients with atrial septal defect in whom the pressure range was similar (120(20) ms vs 140 (20) ms, 3.8 (1.1) hybrid resistance unit vs 1.6 (0.5)). Thus although the acceleration time of the pulmonary systolic flow is useful for the evaluation of pulmonary hypertension, it is a complex index that is affected not only by pulmonary arterial pressure but also by pulmonary blood flow and pathological changes in the pulmonary vascular bed.,Myelopathy is a well recognised but rare association withMycobacterium tuberculosis infection, but has not been described with atypical mycobacteria. We report two cases of disabling myelopathy in association with pulmonary infection byMycobacterium kansasii andMycobacterium malmoense; the myelopathy is presumed to be a para-infectious phenomenon.
Pulmonary hypertension is an uncommon but lethal complication of polymyositis. A 69-year-old woman is described who had a 20-month history of polymyositis and cardiac failure and in whom severe pulmonary hypertension was noted terminally when she was first seen at our clinic. She died within 24 hours of admission, and autopsy revealed severe plexogenic pulmonary vascular disease.
Pulmonary hypertension developed in two women who had been taking fenfluramine for over eight months for weight reduction. On withdrawing the drug symptoms and electrocardiographic evidence of pulmonary hypertension disappeared in both cases. In one patient, however, the evidence recurred after rechallenge with fenfluramine. These findings are strong evidence that fenfluramine may cause pulmonary hypertension. Hence any patient taking the drug should report immediately any deterioration in exercise tolerance.
We studied the separate and combined effects of hyperventilation and administration of dopamine and tolazoline in five infants with pulmonary hypertension managed with indwelling pulmonary artery catheters. In five infants the right-to-left shunt reversed during ventilator-induced respiratory alkalosis (pH>7.6). Response to drugs was variable and unpredictable. One infant could be oxygenated at normal pH during combined dopamine and tolazoline infusion. Other infants showed no response to drugs, or became worse during infusion. The ratio of pulmonary artery to systemic artery pressure averaged 1.14 with standard therapy, but decreased to 0.98 following respiratory alkalosis alone, to 0.87 following drug infusions, and to 0.70 following the combination of alkalosis and drug infusion. These changes were significant by analysis of variance at <0.02, <0.001, and <0.001, respectively. Systemic oxygenation was satisfactory in all cases when the pulmonary to systemic pressure ratio was <1.0.
Six neonates of 35 to 42 weeks' gestation had findings of persistent pulmonary hypertension and died between one and 6 days of age despite intensive medical therapy. Each patient had pulmonary artery pressure near or above systemic level, with a right-to-left shunt via the foramen ovale and/or ductus arteriosus. At postmortem, morphometric analysis of the peripheral pulmonary vascular bed revealed extension of muscle into small arteries, which was severe in five of six patients; all alveolar duct and wall arteries (<30 μm external diameter), normally nonmuscular, were fully musularized. In these five patients medial wall thickness of the normally muscular intra-acinar arteries was doubled; arterial size and number, however, were normal in all. This striking structural maldevelopment of the peripheral pulmonary arterial bed occurred or was initiated in utero and does not merely represent a failure of the fetal pattern to regress. We suggest that this particular group of patients remained refractory to all current modes of therapy because of these severe structural pulmonary vascular changes.
Two children presented with sleep disturbances due to enlarged tonsils and adenoids. One child died during induction of anaesthesia, and postmortem examination showed hypertrophy of the right ventricle and atrium. As a result a prospective survey was carried out of children undergoing tonsillectomy or adenoidectomy, or both. During a nine-month period an electrocardiogram was taken in 92 children. Three electrocardiograms (3.3%) showed evidence of right heart strain. The children with abnormal electrocardiograms had symptoms of sleep disturbance with apnoea, snoring, and daytime somnolence. These symptoms and the electrocardiographic changes were reserved by adenotonsillectomy. The prevalence of pulmonary hypertension in children with enlarged tonsils and adenoids is still underestimated. When signs and symptoms of sleep disturbance, particularly snoring, are present an electrocardiogram should be obtained and a cardiologist's opinion sought before embarking on routine surgery in view of the potentially fatal consequences.