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ALARMING ELECTROCARDIOGRAPHIC CHANGES CAUSED BY INADEQUATELY INSULATED TEMPORARY EPICARDIAL ELECTRODES
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replacement. The premature discharge of the child resulted from the widespread but grave misconception that the rat poison consisted of a short-acting warfarin compound. When the child was traced a month later he had, despite no evidence of bleeding, a prothrombin time of 23-4 s (control 15) and a PTT of 60 s (control 38). Specific factor assays showed decreased vitamin-K-dependent factors VII (37%), IX (42 %), and X (42%) and a protein in vitamin K absence (PIVKA) level of 28% (normal 0-2%). The
for the initial discrepancies between prothrombin time, PTT, and specific factor levels is not known. Clotting profiles were repeated three times on the admission day to monitor the response of specific therapy. It is possible that the factor assays followed part of this therapy. There could have been a delay in the factor assays with a sponaneous rise in factor levels. On clinical grounds there can be little doubt that the prothrombin time and PTT were correct. Repeatedly high PIVKA levels and the whole presentation, as recounted in the letter, indicates that this was a bromodialone-induced coagulation disorder involving the vitamin-K-dependent factors. reason
Department of Paediatrics, University of Witwatersrand, Bersham
M. C. GREEFF
2013, South Africa
ALARMING ELECTROCARDIOGRAPHIC CHANGES CAUSED BY INADEQUATELY INSULATED TEMPORARY EPICARDIAL ELECTRODES
SiR,—Temporary epicardial electrodes are commonly used for the diagnosis and treatment of cardiac arrhythmias after open heart surgery,l especially valvular and anti-arrhythmic operations. Such electrodes (one attached to each atrium and two to the right ventricle) were implanted in a 41-year-old man after successful endocardial resection of a left free-wall accessory pathway for the control of drug refractory arrhythmias associated with the WolffParkinson-White syndrome. The external ends of the temporary electrodes were situated near the lower end of the sternum and were inadequately insulated in the early postoperative period. An alarming electrocardiogram in V4 was recorded (figure). It was subsequently shown that both direct and indirect contact (through conducting gel) between the recording lead of an electrocardiographic machine and the epicardial electrode could severely distort the electrocardiographic appearance by combined recording of epicardial electrogram and the surface electrocardiogram. Changes in the repolarisation phase could simulate acute myocardial ischaemia and infarction. Although the changes were best seen in lead V4, more extensive changes (from V3-6) could be produced depending on the positions of the epicardial wires and the recording leads and the amount of conducting gel in the field.
It is known that epicardial electrodes should be properly insulated to prevent electric discharges to the heart from external electric fields. We found that inadvertent recording from uninsulated epicardial electrodes could cause changes in the electrocardiogram that simulate myocardial damage. Such changes are usually localised to anterior chest leads and are not seen in the limb leads. Department of Cardiological Sciences, St George’s Hospital Medical School, London SW17 0RE
C. P. LAU N. STRATIGIS A. J. CAMM
1. Waldo AL, MacLean WAH Diagnosis and treatment of cardiac arrhythmias following open heart surgery: Emphasis on the use of atrial and ventricular wire electrodes. Mount Kisco, NY. Futura Publishing, 1980.
INCIDENTAL NEUROBLASTOMA
SIR,-Dr Kosloske and her colleagues (Sept 5, p 565) report 7 of neuroblastoma detected "incidentally" during examinations for another complaint. 3 patients were more than 12 months old at diagnosis. 6 had thoracic neuroblastomas and 1 had an abdominal neuroblastoma. 5 tumours were stage 1,1stage II, and 1
cases
stage III. All 7 children had done well. Mass screening for neuroblastoma at 6 months of age was initiated at some districts in Japan in 1985 and by the end of 1986,89 cases had been detected.1 86 were symptom-free; the other 3 had fever with sweating, anaemia, and poor weight gain. In 25 (31 %) of the 80 cases with abdominal neuroblastoma an abdominal mass was not palpable on routine physical examination by a paediatric oncologist, but all 80 abdominal masses were detected by echography, and the patients demonstrated increasing urinary vanillylmandelic acid (VMA) excretion. The 9 thoracic neuroblastomas had no abnormal findings on physical examination but were detected by chest X-ray. 66 neuroblastomas were diagnosed before the age of 8 months (the screening being done at 6 months). 19 tumours were stage I, 39 stage II, 11 stage VIII, 12 stage IV, and 8 were stage IVs. The removed primary masses weighed 4-260 g -
(median 50). 2 children with abdominal neuroblastomas have died-1 with
progressive neuroblastoma at 5 years of age and the other from a complication of surgery. Both thoracic and abdominal neuroblastomas detected by screening had a good prognosis. An "incidental neuroblastoma" simply means a small primary mass which is detected earlier than it would be otherwise. Although Kosloske et al suggest that careful physical examination and review of routine X-rays may lead to early detection of neuroblastomas, we would recommend the addition of measurement of urinary catecholamine metabolites and abdominal echography for abdominal neuroblastomas or chest X-ray for thoracic neuroblastomas, because we find these examinations to be most useful.
Supported by grants from the Japanese Ministry of Health and Welfare. Department of Paediatrics and Children’s Research Hospital, Kyoto Prefectural University of Medicine, Kamikyoku, Kyoto, 602 Japan
TADASHI SAWADA HIDEKAZU KAWAKATU YOSHIHIRO HORII TOHRU SUGIMOTO
1. Sawada
T, Sugimoto T, Matsumura T, et al. Mass screening for neuroblastoma in infancy. Presented at the Children’s Hospital of Philadelphia fourth symposium on advances m neuroblastoma research. (Philadelphia, May 16, 1987).
SOMATOSENSORY EVOKED POTENTIALS AND SPINAL DECOMPRESSION SICKNESS
Electrocardiographic appearances recorded in lead V4 with epicardial electrodes in indirect contact through conducting gel. Normal electrocardiogram is shown top left. RA and atrial electrodes and RV right ventricular electrode. =
LA = right and left
SiR,—Or Palmer and colleagues (Dec 12, p 1365) report on spinal cord degeneration in three of eleven divers who died accidentally. We have done an electrophysiological study of ten amateur divers admitted to hospital with type II decompression sickness. These nine men and one woman aged 16-40 had 1-7 years of diving experience and the alleged greatest depth was 18-41 m. All had neurological symptoms (paraesthesiae in the legs 8, lower lunb paresis 2, headache or limb pain 7, sphincter disturbance 3). The neurological examination revealed lower limb paresis (2,
replacement. The premature discharge of the child resulted from the widespread but grave misconception that the rat poison consisted of a short-acting warfarin compound. When the child was traced a month later he had, despite no evidence of bleeding, a prothrombin time of 23-4 s (control 15) and a PTT of 60 s (control 38). Specific factor assays showed decreased vitamin-K-dependent factors VII (37%), IX (42 %), and X (42%) and a protein in vitamin K absence (PIVKA) level of 28% (normal 0-2%). The
for the initial discrepancies between prothrombin time, PTT, and specific factor levels is not known. Clotting profiles were repeated three times on the admission day to monitor the response of specific therapy. It is possible that the factor assays followed part of this therapy. There could have been a delay in the factor assays with a sponaneous rise in factor levels. On clinical grounds there can be little doubt that the prothrombin time and PTT were correct. Repeatedly high PIVKA levels and the whole presentation, as recounted in the letter, indicates that this was a bromodialone-induced coagulation disorder involving the vitamin-K-dependent factors. reason
Department of Paediatrics, University of Witwatersrand, Bersham
M. C. GREEFF
2013, South Africa
ALARMING ELECTROCARDIOGRAPHIC CHANGES CAUSED BY INADEQUATELY INSULATED TEMPORARY EPICARDIAL ELECTRODES
SiR,—Temporary epicardial electrodes are commonly used for the diagnosis and treatment of cardiac arrhythmias after open heart surgery,l especially valvular and anti-arrhythmic operations. Such electrodes (one attached to each atrium and two to the right ventricle) were implanted in a 41-year-old man after successful endocardial resection of a left free-wall accessory pathway for the control of drug refractory arrhythmias associated with the WolffParkinson-White syndrome. The external ends of the temporary electrodes were situated near the lower end of the sternum and were inadequately insulated in the early postoperative period. An alarming electrocardiogram in V4 was recorded (figure). It was subsequently shown that both direct and indirect contact (through conducting gel) between the recording lead of an electrocardiographic machine and the epicardial electrode could severely distort the electrocardiographic appearance by combined recording of epicardial electrogram and the surface electrocardiogram. Changes in the repolarisation phase could simulate acute myocardial ischaemia and infarction. Although the changes were best seen in lead V4, more extensive changes (from V3-6) could be produced depending on the positions of the epicardial wires and the recording leads and the amount of conducting gel in the field.
It is known that epicardial electrodes should be properly insulated to prevent electric discharges to the heart from external electric fields. We found that inadvertent recording from uninsulated epicardial electrodes could cause changes in the electrocardiogram that simulate myocardial damage. Such changes are usually localised to anterior chest leads and are not seen in the limb leads. Department of Cardiological Sciences, St George’s Hospital Medical School, London SW17 0RE
C. P. LAU N. STRATIGIS A. J. CAMM
1. Waldo AL, MacLean WAH Diagnosis and treatment of cardiac arrhythmias following open heart surgery: Emphasis on the use of atrial and ventricular wire electrodes. Mount Kisco, NY. Futura Publishing, 1980.
INCIDENTAL NEUROBLASTOMA
SIR,-Dr Kosloske and her colleagues (Sept 5, p 565) report 7 of neuroblastoma detected "incidentally" during examinations for another complaint. 3 patients were more than 12 months old at diagnosis. 6 had thoracic neuroblastomas and 1 had an abdominal neuroblastoma. 5 tumours were stage 1,1stage II, and 1
cases
stage III. All 7 children had done well. Mass screening for neuroblastoma at 6 months of age was initiated at some districts in Japan in 1985 and by the end of 1986,89 cases had been detected.1 86 were symptom-free; the other 3 had fever with sweating, anaemia, and poor weight gain. In 25 (31 %) of the 80 cases with abdominal neuroblastoma an abdominal mass was not palpable on routine physical examination by a paediatric oncologist, but all 80 abdominal masses were detected by echography, and the patients demonstrated increasing urinary vanillylmandelic acid (VMA) excretion. The 9 thoracic neuroblastomas had no abnormal findings on physical examination but were detected by chest X-ray. 66 neuroblastomas were diagnosed before the age of 8 months (the screening being done at 6 months). 19 tumours were stage I, 39 stage II, 11 stage VIII, 12 stage IV, and 8 were stage IVs. The removed primary masses weighed 4-260 g -
(median 50). 2 children with abdominal neuroblastomas have died-1 with
progressive neuroblastoma at 5 years of age and the other from a complication of surgery. Both thoracic and abdominal neuroblastomas detected by screening had a good prognosis. An "incidental neuroblastoma" simply means a small primary mass which is detected earlier than it would be otherwise. Although Kosloske et al suggest that careful physical examination and review of routine X-rays may lead to early detection of neuroblastomas, we would recommend the addition of measurement of urinary catecholamine metabolites and abdominal echography for abdominal neuroblastomas or chest X-ray for thoracic neuroblastomas, because we find these examinations to be most useful.
Supported by grants from the Japanese Ministry of Health and Welfare. Department of Paediatrics and Children’s Research Hospital, Kyoto Prefectural University of Medicine, Kamikyoku, Kyoto, 602 Japan
TADASHI SAWADA HIDEKAZU KAWAKATU YOSHIHIRO HORII TOHRU SUGIMOTO
1. Sawada
T, Sugimoto T, Matsumura T, et al. Mass screening for neuroblastoma in infancy. Presented at the Children’s Hospital of Philadelphia fourth symposium on advances m neuroblastoma research. (Philadelphia, May 16, 1987).
SOMATOSENSORY EVOKED POTENTIALS AND SPINAL DECOMPRESSION SICKNESS
Electrocardiographic appearances recorded in lead V4 with epicardial electrodes in indirect contact through conducting gel. Normal electrocardiogram is shown top left. RA and atrial electrodes and RV right ventricular electrode. =
LA = right and left
SiR,—Or Palmer and colleagues (Dec 12, p 1365) report on spinal cord degeneration in three of eleven divers who died accidentally. We have done an electrophysiological study of ten amateur divers admitted to hospital with type II decompression sickness. These nine men and one woman aged 16-40 had 1-7 years of diving experience and the alleged greatest depth was 18-41 m. All had neurological symptoms (paraesthesiae in the legs 8, lower lunb paresis 2, headache or limb pain 7, sphincter disturbance 3). The neurological examination revealed lower limb paresis (2,