Emery-Dreifuss muscular dystrophy (EDMD) and limb-girdle muscular dystrophy type 1B (LGMD1B) are characterized by cardiac dysrhythmias, late-onset cardiomyopathy, slowly progressive skeletal myopathy and contractures of the neck, elbows and ankles. The causative mutation is either in the emerin gene (X-linked recessive EDMD) or lamin A/C gene (autosomal dominant EDMD2 or LGMD1B). We report three cases of EDMD, EDMD2 and LGMD1B. A 14-yr-old boy showed limitation of cervical flexion and contractures of both elbows and ankles. Sinus arrest with junctional escape beats was noted. He was diagnosed as X-linked recessive EDMD (MIM 310300). A 28-yr-old female showed severe wasting and weakness of humeroperoneal muscles. Marked limitation of cervical flexion and contractures of both elbows and ankles were noted. Varying degrees of AV block were noted. She was diagnosed as autosomal dominant EDMD2 (MIM 181350). A 41-yr-old female had contractures of both ankles and limb-girdle type muscular dystrophy. ECG revealed atrial tachycardia with high grade AV block. She was diagnosed as autosomal dominant LGMD1B (MIM 159001). Cardiac dysrhythmias in EDMD and LGMD1B include AV block, bradycardia, atrial tachycardia, atrial fibrillation, and atrial standstill, causing sudden death necessitating pacemaker implantation. Cardiologists should know about these unusual genetic diseases with conduction defects, especially in young adults.

our knowledge, this is the first report of LMNA gene mutations in Korean patients with EDMD2 and LGMD1B.

Background and Objectives Neurocardiogenic syncope is believed to be caused by a transient imbalance of autonomic nervous system. Actually, there were significant differences in heart rate variability HRV indices during head-up tilt test between patients with neurocardiogenic syncope and normal controls. But there was no definite evidence for it during daily activity. So, we tried to evaluate HRV during daily activity with 24-hour ambu-latory electrocardiography monitoring. Materials and Methods 27 patients with neurocardiogenic syncope or presyncope mean age 45 3 and 25 normal volunteers mean age 47 2 comparable for age and sex underwent 24-hour ambulatory electrocardiography. Head-up tilt test was used to diagnose neurocardiogenic syncope or presyncope in patients group. HRV was analysed over the whole 24 hours, using time and frequency domain parameters. Student's t-test was applied. Results There were no significant differences in HRV measures between two groups, over 24-hour period and day-time and night-time period. But the hourly HRV measures showed a transient decrease of LF, LFnorm and LF HF ratio in patients group compared to normal control group. Conclusions These results indicate that patients with neurocardiogenic syncope or presyncope suffer from temporarily decreased sympathetic tone with normal parasympathetic tone. So, transient additive change of autono-mic nervous tone may cause syncope or presyncope in these patients. Korean Circulation J 2000 ; 30 6 : 716-723

Emery-Dreifuss muscular dystrophy (EDMD) is a degenerative myopathy characterized by mild, slowly progressing weakness, muscle atrophy, and early contracture of the neck, ankle and elbow. Heart involvement becomes apparent during the teenage years and is characterized by cardiac conduction defects and the infiltration of the myocardium by fibrous and adipose tissues. Heart block can eventually lead to sudden death, and therefore, early treatment with a cardiac pacemaker may improve symptoms and be lifesaving in patients with heart block. We describe our experience of pacemaker implantation in a 14-year old boy with X-linked recessive EDMD and emerin gene mutation. His electrocardiogram findings showed junctional escape beats, and his clinical features, i.e., ECG, nerve conduction test, electromyography and muscle biopsy findings were compatible with EDMD. He was implanted with a VVI type permanent pacemaker following an electrophysiologic study. ( 본 연구진은 lamin 유전자 돌연변이에 의한 EDMD

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