Sequential changes of magnetocardiogram in rat models of experimental myocardial infarction / 대한내과학회지

BACKGROUND: Magnetocardiogram (MCG), which records the changes of magnetic fields generated by the heart's electrical activity, theoritically can provide unique data for clinical application. To date, MCG has been investigated only at a single time point after myocardial infarction (MI) with severe left ventricular dysfunction in rats. The purpose of the present study was to investigate sequential changes of MCG after MI and to evaluate effects of infarct size on MCG. METHODS: Acute MI were induced by the permanent ligation of left coronary artery in 22 rats. Magnetic fields were recorded just above a rat with Nb Superconducting Quantum Interference Device (SQUID) gradiometer inside a magnetically shielded room. MCG was measured before and immediately after surgery and it was subsequently recorded at the time points of 1, 4 and 6 hours postoperatively. MCG was also measured at 1, 3, 7 and 21 days after surgery. RESULTS: Elevation of ST segment and appearance of pathological Q wave on the MCG were evident immediately after the ligation of coronary artery and persisted to 6 hours after MI. On MCG, ST segment was depressed and T wave was inverted from 1 day after MI. In rats with small- and moderate-sized MI (infarct size or = 30%). CONCLUSION: Evolutional changes of MCG were well-recognized up to 21 days after MI. Furthermore, the infarct size can be expressed by the extent of Q wave and ST segment depression on MCG. Taken together, these data indicate that MCG is a helpful modality for the diagnosis, evaluation of infarct size and follow up after MI.

Change of Autonomic and Peripheral Nerve Function after the First Twelve Months of Dialysis in End-stage Renal Disease / 대한신장학회잡지

BACKGROUND: The efficacy of dialysis on the autonomic and peripheral nerve function has been a subject of considerable debate. In addition, no longitudinal study on the course of uremic neuropathy in end-stage renal disease (ESRD) during dialysis has been reported. We carried out a prospective study to investigate the effect of dialysis on the autonomic and peripheral nerve function during the first 12 months of dialysis. METHODS: Twenty-five patients with ESRD (14 on HD and 11 on CAPD; 11 diabetic and 14 non- diabetic) were enrolled. Autonomic nerve function test and median nerve conduction velocity study were done at the initiation of dialysis and then repeated after 12 months of dialysis. RESULTS: At the initiation of dialysis, sympathetic nerve function and parasympathetic nerve function were abnormal in all HD and CAPD patients. After 12 months of dialysis, no significant changes occurred in autonomic function test. There was no significant difference in autonomic function test between HD and CAPD patients. There was no significant difference in median nerve conduction velocity between HD and CAPD patients after 12 months of dialysis. At the initiation of dialysis, 6 of 11 diabetic and 4 of 14 non-diabetic patients had abnormal median nerve conduction velocity. After 12 months of dialysis, normalization of median nerve conduction velocity occurred only in 3 non-diabetic patients. There was a singinficant difference in median nerve conduction velocity between diabetic and non-diabetic patients after 12 months of dialysis. CONCLUSION: We conclude that dialysis does not significantly alter the autonomic nerve function during the first 12 months of dialysis, but may improve the peripheral nerve function in non-diabetic uremic patients.

A Case of Spontaneous Renal Artery Dissection Causing Renal Infarction in a Previously Healthy Man / 대한신장학회잡지

Spontaneous renal artery dissection is an uncommon cause of renal infarction. Previous reports of spontaneous renal artery dissection has been associated with hypertension or fibromuscular dysplasia. We report herein the case of a previously healthy, normotensive patient with renal infarction due to spontaneous renal artery dissection who remained normotensive throughout his course without therapy. A previously healthy 31-year-old man with well- documented normotension had a sudden onset of right flank pain and delayed onset of elevation of lactic dehydrogenase, hematuria, and proteinuria. Thin section spiral computerized tomogram shows linear intraluminal filling defect suggesting intimal flap. Angiography shows dissection of main right renal artery. Six months later, he has remained well and normotensive without therapy. To our knowledge, this is the first case of spontaneous renal artery dissection in normotensive patients in Korea.

Two Cases of Gitelman's Syndrome Diagnosed by Renal Clearance Study / 대한신장학회잡지

We have experienced two patients who had hypokalemic metabolic alkalosis as well as hypomagnesemia and hypocalciuria with elevated plasma renin activity. We have performed renal clearance study after water loading, administration of furosemide and thiazide in two patients and two normal controls. Maximal free water clearance per 100 mL glomerular filtration rate(CH2O) and distal fractional chloride reabsorption[CH2O/(CH2O+CCl)] in our patients were reduced than the controls. Chloride clearance(CCl) was increased after furosemide administration but not after thiazide administration. Distal fractional chloride reabsorption[CH2O/(CH2O+CCl)] was dramatically decreased by furosemide administration in our patients, whereas thiazide had little effect on it. Fractional excretion of sodium, chloride, magnesium, calcium was increased by furosemide administration, whereas thiazide administration had little effect on this parameters. These findings suggested the presence of a defect in the distal convoluted tubule rather than in the thick ascending loop of Henle. Herein, we report two cases of Gitelman's syndrome diagnosed by renal clearace study after water loading, administration of furosemide and thiazide.