Purpose: In Japan, the electrocardiogram (ECG) in emergency hospital transport is usually performed using three electrodes. However, as compared to the conventional 12-lead ECG, the three-electrode ECG is considered to be inferior for the diagnosis and monitoring of ischemic heart disease. In this paper, we evaluated the usefulness of a synthesized 12-lead ECG (Syn-ECG) constructed from four of the standard 12 leads, to investigate whether the diagnostic capability of this system would be comparable to that of the standard 12-lead ECG (Stn-ECG). Methods: Twelve-lead ECGs were synthesized in 54 patients (38 males, 16 females; average age, 68 years) with abnormal Q waves and ST-segment changes in the Stn-ECG. Leads I, II, V₂ and V4 were used to synthesize the other leads. The Q wave, R wave and S wave amplitudes and the ST-segment and T wave changes in the Stn-ECG were compared to those in the Syn-ECG by calculating Spearman's correlation coefficient. Results: Significant equilateral correlations were found among the Q wave, R wave and S wave amplitudes and in the ST-segment (including the magnitude of elevation and depression) and T wave changes in the two lead systems. The characteristics of the waveforms were similar in the two types of ECG's, but the voltage levels of the waves in the Syn-ECG were slightly different from those in the Stn-ECG. Conclusion: We concluded that the Syn-ECG can yield sufficient precision for the diagnosis and monitoring of ischemic heart disease, and that it can contribute to improved pre-hospital diagnostic evaluation of cases of ischemic heart disease.

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Fire-fighting helicopters have been inefficiently employed as a substitute for emergency medical services (EMS) helicopters in many regions of Japan. To improve the quality of medical helicopter missions, we estimated the need for medical helicopter services in the secluded area of Ehime, Kamiukena-gun, which has a population of 15, 849. During the two years of the study period (2000-2001), ambulances transported 1, 249 patients to medical centers in the Matsuyama-city area. Among these patients, 229 seriously ill patients (72.2/10, 000 person-years) were transported by ambulance during the daytime, when helicopter service is available. We divided the whole district of Kamiukena-gun into 44 areas and calculated the mean transport time from each area to the Matsuyama-city hospitals by ambulance; the mean transport times ranged from 46 to 145 minutes. We also estimated the transport time by helicopter from each area to the University Hospital in three situations: a helicopter was requested (#1) at the time of the 119 emergency call, (#2) by emergency medical technicians (EMTs) at the scene of an accident, or (#3) after transporting a patient to a local clinic. Helicopter service was calculated to be superior to ambulance service if the helicopter was dispatched before the ambulance reached the scene. The total helicopter transport times were 20 to 40 minutes shorter for 54 of the 229 serious cases that had been transported during the daytime and more than 40 minutes shorter for the 31 serious cases who would have met the conditions for situation #1, described above. Helicopter service was estimated to not have any benefit on reducing the total transport time in situation #3, described above. Fire-fighting helicopters are “slow starters”, since they need approximately 15 extra minutes to prepare for medical missions and pick up a doctor on route. The best way to overcome these limitations is to inform the helicopter station at the same time as the placement of the 119 call; this would require concrete guidelines for helicopter dispatch based on an efficient medicalcontrol system.

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Rhabdomyolysis in four children was evaluated by bone scintigraphy using ^99mTecnetium-methyldiphosphate (^99mTc-MDP). The ages of the patients ranged from 7 to 14 years old. The causes of rhabdomyolysis were toxic shock syndrome in one patient, excessive exercise in one patient and cardiopulmonary arrest after cardiac surgery and after drowning in two patients. Peak serum creatine kinase (CK) and myoglobin (Mb) levels ranged from 5, 093 to 91, 150IU/l and 7, 486 to 111, 900ng/ml, respectively. Peak serum CK and Mb levels reached during the period from the first to third ICU day. Renal impairment occurred in the patient with toxic shock syndrome. After treatment with continuous hemodiafiltration, the renal impairment improved. Bone scintigraphy using ^99mTc-MDP was performed during the period from the third to fifth ICU day. Abnormal accumulation of radioactivity was found in the two patients in whom rhabdomyolysis had been caused by excessive exercise and cardiopulmonary arrest after drowning. Despite the fact that peak CK raised to 12, 500IU/l in the patient of toxic shock syndrome, abnormal accumulation of radioactivity was not found. It was shown that bone scintigraphy using ^99mTc-MDP is available for evaluation of rhabdomyolysis in children as it is in adults. However, in children with rhabdomyolysis, greater elevation of CK may be required to detect abnormal accumulation of radioactivity by bone scintigraphy using ^99mTc-MDP compared with that in adults.

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Hypothermia is usually caused by exposure to cold ambient temperatures. Some patients, however, have no obvious historyof cold exposure. Hypothyroidism should be recognized as a cause of hypothermia in certain situations. We report a case of transient central hypothyroidism presenting as hypothermia. A 74-year-old woman presenting with a disturbance in consciousness for the second time was transferred to our department because of deep hypothermia without exposure to cold ambient temperatures. Active rewarming normalized her body temperature, but her consciousness disturbance persisted. We performed an endocrinological examination to reveal the cause of the consciousness disturbance and subsequently diagnosed her as having hypothyroidism, based on a low serum-free T₄ level. An additional thyrotropin-releasing hormone (TRH) test showed a decrease in thyroid-stimulating hormone (TSH) in response to TRH, suggesting that the hypothermia was caused by central hypothyroidism. Hormone supplementation was performed, and her consciousness disturbance rapidly improved. Since her serum-free T₄ level gradually increased over the course of several weeks, we speculated that her hypothyroidism was transient. An endocrinological examination should be considered in patients who present with hypotermia accompanied by a consciousness disturbance to reveal the underlying disorder.

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