Strings containing left bundle branch conductive tissue in the left ventricle. Observations in man

Several reports have demonstrated the presence of strings within the heart chambers e.g.: on the basis of autopsy materials (Goforth 1926, Knoblich et al. 1962, Hudson 1965, Gould 1968, Roberts 1969, Franck 1970, Olsen & Valentine 1972) or by echocardiography (Nishimura et al. 1981, Choo et al. 1982, Lindvall et al. 1982, Asmussen submitted for publication). Prompted by the echocardiographic observations by Asmussen (Asmussen submitted for publication) we tested the hypothesis that left ventricular strings may contain left bundle branch conductive tissue. During a six months' survey period at the Laboratory of Pediatric Pathology we found two such cases. It is suggested that left bundle branch block and/or hemiblock may be a consequence of this abnormality in the event of stretching or rupture of such strings.