The straight back syndrome

Abstract

Twenty asymptomatic subjects with innocent systolic murmurs due to the straight back syndrome were studied. The diagnoses of the referring doctor were atrial septal defect in 10, pulmonary stenosis in 4 and systolic murmur of unknown etiology in 6 subjects. An ejection systolic murmur of varying intensity and loudest over the pulmonary area was heard in all subjects. In 4 subjects, an associated systolic thrill was also palpable. The following radiologic findings on the chest X-ray were noted: straightening of the dorsal spine and marked reduction in the antero-posterior diameter (mean 8.4 cms) of the chest in all 20 subjects; left-ward displacement of the heart in 5; prominent pulmonary artery in 3; and a 'pancake' appearance of the heart in 2 subjects. The electrocardiogram was completely normal in 19 subjects. In one, frequent ventricular extrasystoles were seen. Right heart catheterization carried out in 8 subjects revealed essentially normal findings. Pulmonary function tests done in 16 subjects showed mild restrictive defects in 2. M Mode echocardiography done in 12 subjects showed normal findings and specifically no mitral valve prolapse. The straight back syndrome is yet another important cause of pseudo heart disease. Careful clinical examination, electrocardiographic and radiologic analysis nearly always enable a correct diagnosis to be made. Of crucial importance is the need to recognise the clinical signs that are produced by an uncomplicated loss of normal thoracic vertebral curvature, so as to obviate the misdiagnosis of organic cardiac disease, where none actually exist.