Biomedical subjects

N Aihara

Publications and source records attributed to N Aihara.

At least 73 records · Page 4Linked to original sources

PubMed1995

Effects of verapamil and propranolol on early afterdepolarizations and ventricular arrhythmias induced by epinephrine in congenital long QT syndrome.

OBJECTIVES: This study used monophasic action potentials to investigate the effects of verapamil and propranolol on epinephrine-induced repolarization abnormalities in congenital long QT syndrome. BACKGROUND: Early afterdepolarizations have been suggested to play a significant role in QT prolongation and ventricular arrhythmias in congenital long QT syndrome. Calcium channel blocking as well as beta-adrenergic blocking agents are reported to be effective in the management of this syndrome. METHODS: Monophasic action potentials from 2 to 4 sites were recorded simultaneously in eight patients with the long QT syndrome (22 sites) and in eight control patients (23 sites) and were obtained during constant atrial pacing 1) before epinephrine infusion; 2) during epinephrine infusion (0.1 microgram/kg body weight min); 3) after verapamil injection (0.1 mg/kg) during epinephrine infusion; and 4) after both propranolol (0.1 mg/kg) and verapamil injections. RESULTS: Early afterdepolarizations were recorded in two of the eight patients (2 of 22 sites) during the control state. During epinephrine infusion, early afterdepolarizations were recorded in six patients (six sites), and ventricular premature complexes were induced in three and torsade de pointes in one. Epinephrine prolonged 90% monophasic action potential duration from 348 +/- 48 (mean +/- SD) to 381 +/- 49 ms (22 sites, p < 0.0005) and increased the dispersion of action potential duration (difference between the longest and shortest action potential duration) from 36 +/- 20 to 64 +/- 34 ms (p < 0.005). Verapamil eliminated (two sites) or reduced (four sites) early afterdepolarizations and abolished ventricular premature complexes in two of the three patients as well as suppressing torsade de pointes. Verapamil shortened the action potential duration to 355 +/- 28 ms (p < 0.01 vs. epinephrine) and decreased the dispersion to 44 +/- 19 ms (p < 0.05 vs. epinephrine). Propranolol further eliminated (two sites) or reduced (two sites) early after depolarizations, abolished ventricular premature complexes in the remaining one patient and further shortened the action potential duration to 337 +/- 32 ms (p = 0.09 vs. verapamil). In the control patients, none of the early afterdepolarizations, ventricular arrhythmias or marked prolongations of action potential duration were induced by epinephrine, and neither verapamil nor propranolol changed repolarization variables. CONCLUSIONS: These results indicate that both verapamil and propranolol can improve repolarization abnormalities induced by epinephrine in congenital long QT syndrome.

Action Potentials↗

PubMed1995

Intrathecal administration of endothelin-1 in the rat: impact on spinal cord blood flow and the blood-spinal cord barrier.

The purpose of this study was to examine the integrity of the blood-spinal cord barrier after intrathecal administration of endothelin-1 (ET-1) in the rat spinal cord. A laser Doppler probe was positioned in the exposed subarachnoid space at the T8 vertebral level. In the first experiment, horseradish peroxidase (HRP), a marker of barrier integrity, was given intravenously prior to the intrathecal application of ET-1. Blood flow was then recorded for 3 h, after which the anesthetized animals were euthanized. In the second experiment, animals exposed to endothelin were recovered after confirming a 50% reduction in blood flow. HRP was given 10 min prior to euthanasia at 24 h post infusion. The intensity of staining for HRP was quantified by optical density in fixed sections of spinal cord. There was a significant sustained reduction in spinal cord blood flow and significant barrier breakdown to HRP at both 3 and 24 h after administration of the peptide. Based upon these results we conclude that intrathecal infusion of ET-1 reduces spinal cord blood flow and results in prolonged breakdown of the blood-spinal cord barrier.

Animals↗

PubMed1995

Percutaneous transvenous mitral commissurotomy immediately restores quick response of VO2 to mild exercise despite insignificant increases in peak VO2.

Percutaneous transvenous mitral commissurotomy (PTMC) increases peak oxygen uptake (VO2) chronically, but not acutely, despite early symptomatic improvements. Analysis of transient VO2 responses to submaximal exercise (an exercise regimen more comparable to the patients' daily activities than that provided by maximal exercise testing), may be sensitive in detecting the acute hemodynamic benefits of PTMC. Since no methods are available to accurately estimate the transient response of VO2, we developed a new technique, using random exercise. In 15 patients who underwent successful PTMC, we repeated the conventional maximal exercise test and the random exercise test before and within a few days after PTMC. For the random exercise test, we intermittently imposed upright bicycle exercise at 50 W, according to a random binary sequence, while measuring breath-by-breath VO2. After determining the transfer function relating workload to VO2, we computed the high resolution VO2 response to a hypothetical step increase in exercise. Despite improvements in resting hemodynamics and New York Heart Association (NYHA) Class, peak VO2 improved insignificantly (952 +/- 271 vs 1,029 +/- 342 ml/min, P = 0.063) shortly after successful PTMC. In contrast, the amplitude of the VO2 step response increased significantly in the early-to-mid portion (28-76s; P < 0.01-0.05). The remaining portion was unchanged. Consequently, the time constant shortened from 64 +/- 26 to 48 +/- 22s (P < 0.05). The maximal Borg scale value during random exercise decreased significantly (13.1 +/- 1.8 vs 11.4 +/- 1.1; P < 0.01). We conclude that the VO2 step response, using the random exercise test, is more sensitive than peak VO2 in detecting the functional improvement that is coupled with the hemodynamic improvement immediately after PTMC.

Adult↗

PubMed1995

Effects of long-term treatment with low-dose pravastatin on biliary lipid and bile acid composition in patients with nonfamilial hyperlipoproteinemia.

We tested the possibility that pravastatin, a competitive inhibitor of hepatic hydroxymethyl glutaryl coenzyme A (HMG CoA) reductase, would alter cholesterol saturation of gallbladder bile by decreasing its cholesterol saturation index and/or degree of fatty acyl chain unsaturation in lecithin. Eighteen patients with type IIa hyperlipoproteinemia were treated with pravastatin 10 mg/d for 12 months. Gallbladder bile samples were aspirated with a duodenal tube by stimulating gallbladder contraction with intramuscular administration of cerulein before and after treatment. Serum cholesterol level was significantly reduced by 20% after 3 months, and this level was maintained after 12 months. In contrast, the cholesterol saturation index of gallbladder bile was not altered after 3 months (1.52 +/- 0.20 v 1.70 +/- 0.24), but it decreased significantly after 12 months (0.95 +/- 0.11, P < .01). The degree of fatty acyl chain unsaturation tended to decrease, although this was not statistically significant except for the decrease in molar percent of linoleate after 3 months. These findings suggest that long-term treatment with an inhibitor of HMG CoA reductase improves bile lithogenicity even at a comparatively low dose, and can decrease the incidence and complications of cholesterol gallstones.

Adult↗

PubMed1995

Long-term outcome of verapamil-sensitive sustained left ventricular tachycardia in patients without structural heart disease.

OBJECTIVES: This study attempted to determine the long-term outcome of verapamil-sensitive sustained left ventricular tachycardia in patients without apparent structural heart disease. BACKGROUND: Several types of idiopathic ventricular tachycardia have been reported, and their clinical, electrophysiologic and electropharmacologic characteristics are different. It is possible that the prognosis of each type of ventricular tachycardia might also be different. METHODS: We studied mortality and morbidity in 37 consecutive patients (27 male, 10 female; mean [+/- SD] age 33 +/- 14 years) with verapamil-sensitive sustained left ventricular tachycardia who had no apparent structural heart disease. Patients were followed up for 1 to 13 years (mean 5.8). Verapamil repeatedly terminated ventricular tachycardia in all patients. Ventricular tachycardia originated from the inferior and inferoseptal regions of the left ventricle in 33 patients and the superior and superioseptal regions in 4. Severity of ventricular tachycardia was classified according to the extent to which symptoms limited daily activities. Ventricular tachycardia was mild (minimal limitation) in 14 patients, moderate (some limitation) in 17 and severe (severe limitation) in 6. RESULTS: Fourteen patients with mild ventricular tachycardia were followed up without any drug therapy, and the ventricular tachycardia remained mild in all patients. Antiarrhythmic therapy was initiated empirically in the 23 patients with moderate and severe ventricular tachycardia (verapamil in 20, propranolol in 2, digoxin in 1). Moderate ventricular tachycardia became mild ventricular tachycardia after drug therapy in all patients, but the six patients with severe ventricular tachycardia showed no improvement. The six patients with severe ventricular tachycardia had nonpharmacologic therapy (cryosurgery in one, catheter ablation in four, antitachycardia pacing device in one). During the follow-up period, all patients remained alive except for one who died suddenly after implantation of an antitachycardia pacing device. CONCLUSIONS: 1) The long-term prognosis of verapamil-sensitive sustained left ventricular tachycardia in patients without apparent structural heart disease is good. 2) Verapamil is the drug of choice for alleviating symptoms, but nonpharmacologic therapy is necessary in some patients.

Adolescent↗

PubMed1995

Immunolocalization of endothelin in the traumatized spinal cord: relationship to blood-spinal cord barrier breakdown.

The purpose of this study was to determine the relationship between endothelin-1 (ET-1), a prominent vasoactive agent, and the breakdown of the blood-spinal cord barrier along the axis of the cord after a moderate spinal cord injury. In the first study rats (n = 10) were euthanized 24 h after spinal cord injury and compared to sham (n = 5) and unoperated (n = 10) controls. Endothelin and immunoglobulins (IgG) were immunolocalized in adjacent sections of spinal cord using semiquantitative immunocytochemical techniques. In the second study animals were pretreated with the endothelin antagonist Bosentan (n = 6) or vehicle (n = 6) prior to spinal cord injury. Animals were euthanized at 24 h postinjury. Ten minutes prior to euthanasia animals were given horseradish peroxidase (HRP) intravenously. After perfusion fixation sections of cord were prepared for quantitative HRP histochemistry. After spinal cord injury there was enhanced staining for endothelin along the axis of the cord that correlated with the anatomical pattern of barrier breakdown to IgG. In those animals that were pretreated with Bosentan, there was a significant reduction in barrier breakdown along the axis of the injured cord as compared to those animals that received vehicle only. Taken together, this data implicate involvement of endothelin in the axial pattern of barrier breakdown after spinal cord injury.

Animals↗

PubMed1995

Altered immunoexpression of microglia and macrophages after mild head injury.

In this study we examined the temporal response of microglia and macrophages to mild head injury in the rat. Microglia and macrophages were identified by their distinct morphology and by immunophenotype. With regard to the latter, antibodies to OX42 and ED1 were used to define microglia and macrophages, respectively. Although there was no change in the morphology of brain macrophages after mild head injury, the morphology of microglia was dramatically altered. Microglial cell bodies appeared larger with a more elaborate arborization of cellular processes. After head injury certain populations of macrophages and microglia were more intensely immunostained. By 3 days postinjury these intensely stained cells exhibited a characteristic distribution in the brain. Prominently stained microglia were detected in the thalamus, hippocampus, lateral and medial geniculate body, and the substantia nigra. Intensely stained macrophages were located primarily in the cortex and subarachnoid space adjacent to the site of impact. By 7 days postinjury intensely immunostained macrophages and microglia were widespread throughout the injured cortex. These results demonstrate that microglia and macrophages are sensitive to mild head injury. Early changes in the macrophage population are more directly correlated with the most damaged tissue and may reflect migration of these cells from either the subarachnoid space or across the damaged blood-brain barrier. The early widespread microglial response in regions exhibiting no overt neuronal cell damage suggests that these cells are responding to more subtle factor(s) that are expressed in the mildly traumatized brain.

Animals↗

PubMed1995

Physiological and pathological responses of TU waves to class Ia antiarrhythmic drugs.

Abnormal repolarization associated with torsades de pointes is expressed as QT prolongation. The physiological response to class Ia antiarrhythmic drugs is also reflected in prolongation of the QT interval. However, the essential difference between pathological and physiological prolongation is not clear. The purpose of this investigation was to differentiate between pathological and physiological changes in the repolarization waves of surface electrocardiograms (ECG) induced by class Ia drugs. In 18 patients without a history of torsades de pointes or syncope (control group), TU waves were compared before and after the administration of class Ia drugs (physiological response). In eight patients with torsades de pointes induced by class Ia drugs (torsades de pointes group), the TU waves at torsades de pointes were compared with those before drug administration (pathological response). In the control group, although the QTc (measured in lead II and corrected for heart rate by Bazett's formula) was increased significantly (0.40 +/- 0.04 to 0.44 +/- 0.05 s, P < 0.001), the U-amp (amplitude of the U wave measured in a precordial lead where the T and U waves were clearly differentiated) remained unchanged. In the torsades de pointes group, however, the QTc was increased (0.42 +/- 0.04 to 0.54 +/- 0.07 s, P < 0.02); the U-amp was also increased, significantly (0.09 +/- 0.07 to 0.27 +/- 0.18 mV, P < 0.05). Thus, enlargement of the U wave may help to differentiate between the physiological and pathological responses to class Ia drugs.

Anti-Arrhythmia Agents↗

PubMed1995

Dynamic relationship between the Q-aT interval and heart rate in patients with long QT syndrome during 24-hour Holter ECG monitoring.

The purpose of this study was to investigate the dynamic relationship between heart rate and the Q-aT interval (the interval from the Q wave to the T wave apex) in patients with long QT syndrome. The QT to heart rate relation is useful for evaluating abnormalities of the ventricular repolarization, but its clinical application to the long QT syndrome requires accurate computer aided measurement of the QT interval and the sampling of a large number of beats. Therefore, the Q-aT interval was used on the basis of some reports that the heart rate dependency of the QT interval was concentrated in the Q-aT interval. Recent advances in the computer technology have allowed analysis of the relationship between the Q-aT and RR intervals on Holter ECG recordings. However, in addition to a prolonged QT interval, most patients with long QT syndrome have bizarre and variable T waves and the influence of this T wave morphology on the Q-aT to heart rate relation has not been clarified. We investigated the dynamic relationship between the Q-aT interval and heart rate in 10 patients with long QT syndrome and 11 control subjects using our original computer algorithm for the analysis of 24-hour Holter ECG recordings. The patients showed morphological T wave changes associated with heart rate changes during Holter recordings and these affected the Q-aT interval. The patients showed the following characteristics in the relationship between the major T wave peak and the RR interval: (1) a modestly decreased correlation between Q-aT and RR than in the control subjects (a median r value of 0.87 vs 0.93; P = 0.001); and (2) a steeper Q-aT/RR slope than in controls (a median slope of 0.24 vs 0.16; P < 0.05). Abnormal and variable T wave morphology in the long QT patients was closely related to a modestly decreased correlation between Q-aT and RR than in the control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

[Noninvasive recording of His-Purkinje activity in man].

To clarify the etiology of the prepotentials (PPs) between the end of P wave and the onset of QRS complex (P'-R segment) in signal averaged electrocardiogram (SAECG), SAECG was recorded in 26 healthy volunteers and 15 patients with idiopathic left ventricular tachycardia (VT) and electrophysiologic study (EPS) was done in those 15 VT patients. The PPs which had three components (PP1, PP2, PP3) were recorded in 14 of the 26 volunteers (53.8%) and 10 of the 15 VT patients (66.7%). The intervals from the PPs to the onset of QRS complex were 45.4 +/- 6.6, 30.6 +/- 5.6, 16.0 +/- 4.7 ms, respectively. These intervals in SAECG were very similar to the intervals from the electrograms of His bundle, right bundle, Purkinje network to the onset of QRS complex in EPS. The PPs in SAECG were thought to represent the electrical activity of His bundle, right bundle and Purkinje network.

Adult↗

PubMed1995

[Usefulness of time domain analysis of signal averaged electrocardiography in patients with sustained ventricular tachycardia and intraventricular conduction disturbance].

To determine the usefulness of time domain analysis of signal averaged electrocardiography (SAECG) in predicting the occurrence of sustained ventricular tachycardia (SVT) in patients with intraventricular conduction disturbance (IVCD), SAECG was recorded in 70 patients with IVCD; 24 of whom had a history of SVT. We divided patients into two groups; patients with rigth bundle branch block pattern (RBBB group, 36 patients) and left bundle branch block pattern (LBBB group, 34 patients). TQRSD, T40 and V40 were compared between patients with and those without SVT in the RBBB and LBBB group, respectively. All three parameters in the RBBB group and only V40 in the LBBB group showed a significant difference between patients with and those without SVT. In RBBB group TQRSD > or = 160 ms, T40 > or = 40 ms, V40 < or = 14 microV can distinguish patients with SVT from those without SVT with a sensitivity and specificity of 77% and 78%, 85% and 70%, 77% and 74%, respectively. In the LBBB group, only V40 < or = 14 microV can distinguish patients with SVT from those without SVT with 82% sensitivity and 87% specificity.

Aged↗

PubMed1994

Degree of fatty acyl chain unsaturation in biliary lecithin dictates cholesterol nucleation and crystal growth.

To clarify factors involved in the formation of cholesterol gallstones, we studied the relationship between the degree of fatty acyl chain unsaturation of biliary lecithin and bile metastability. We used supersaturated model bile solutions (molar taurocholate/lecithin/cholesterol ratio (73:19.5:7.5), total lipid concentration 9 g/dl) that contained equimolar egg yolk or soybean lecithins or a sn-1 palmitoyl, sn-2 linoleoyl phosphatidylcholine. Gel permeation chromatographic studies showed that the vesicular cholesterol distribution and dimension were inversely related to the degree of unsaturation of the lecithin species, estimated by reverse phase, high-performance liquid chromatography. Differential interference contrast microscopy and assay of cholesterol crystal growth showed that a higher degree of fatty acyl chain unsaturation of the lecithin species was associated with a faster nucleation time and rate of crystal growth. Our results suggest that vesicular lecithins containing more unsaturated fatty acyl chains bind less tightly to cholesterol than lecithins containing predominantly saturated fatty acids, and that the biliary lecithin species dictates, in part, the nucleation and growth of cholesterol crystals in bile.

Bile↗

PubMed1994

Diagnostic value of recovery time measured by body surface mapping in patients with congenital long QT syndrome.

The QT interval of the resting 12-lead electrocardiogram is normal or borderline in some patients with congenital long QT syndrome (LQTS). Recently, several in vivo experimental studies have shown that the time of maximum dV/dt in the ST-T segment is correlated with the time of local ventricular recovery. The purpose of this study was to examine the value of the body surface recovery time measured by 87-lead body surface mapping for detecting LQTS. Body surface mapping and 12-lead electrocardiography were performed simultaneously in 18 patients with LQTS and 40 controls of similar age and sex. The recovery time (RT), that is, the interval between QRS onset and the time of maximum dV/dt in the ST-T segment, was measured automatically by computer from each of the 87 mapping leads, and the corrected RT (RTc) was calculated by Bazett's method. The QT interval was measured from each of the 12 standard electrocardiographic leads, and the corrected QT (QTc) interval was also calculated. The maximum RT and RTc, the minimum RT and RTc, and the RT and RTc dispersions (difference between maximum and minimum RT and RTc in each patient) were significantly longer in the LQTS group than in the control group. In addition, a maximum RT of 390 msec, a maximum RTc of 430 msec 1/2, an RT dispersion of 170 msec, and an RTc dispersion of 170 msec1/2 separated the 2 groups completely (i.e., no overlap). The maximum QT and QTc, the minimum QT and QTc, and the QT and QTc dispersions (difference between maximum and minimum QT and QTc in each patient) were also significantly longer in the LQTS group than in the control group. However, the maximum QTc was normal (< or = 440 msec1/2) or borderline (< or = 460 msec1/2) in 5 of the 18 LQTS patients, and none of these parameters clearly separated the 2 groups. These results suggest that measurement of RT by 87-lead body surface mapping is useful for diagnosing latent or borderline LQTS.

Adolescent↗

PubMed1994

Immunocytochemical localization of immunoglobulins in the rat brain: relationship to the blood-brain barrier.

The central nervous system has been traditionally regarded as an immunologically privileged area. This feature has been in part attributed to the blood-brain barrier, which provides a restrictive interface to circulating immunoglobulins (IgG). Recent kinetic studies suggest that the barrier to immune proteins is not absolute, but rather may be regulated by a specific transfer mechanism. In this study, we confirm the presence of IgG in the central nervous system by immunocytochemistry and demonstrate a close anatomical relationship between the distribution of this protein and the blood-brain barrier. IgG was immunolocalized in the normal rat brain by using monoclonal and polyclonal antibodies to IgG and its subclasses. On the basis of an initial evaluation, the most appropriate antibodies and dilutions were selected for subsequent analyses. In the first study, IgG and albumin were immunolocalized in adjacent sections. In the second study, horseradish peroxidase (HRP) was given intravenously prior to sacrifice, in order to examine artifacts related to perfusion fixation. The distribution of HRP and IgG was then examined in adjacent sections. In the third study, IgG was immunolocalized in sections of brain after mild traumatic head injury. A monoclonal antibody to IgG2a and a polyclonal antibody to IgG were selected on the basis of specificity and consistent, mutual localization. Distinct, patchy, perivascular staining, infrequently associated with labeled neurons, was noted throughout the brain. Electron microscopy confirmed the perivascular localization; IgG was localized along the basal lamina of microvasculature and within the adjacent parenchyma. Albumin and HRP did not exhibit a similar pattern of perivascular immunostaining. After head injury, prominent immunostaining for IgG was observed in the injured hemisphere. In summary, these data indicate that the normal rat brain contains IgG, which dramatically increases after head injury. The distinct perivascular distribution in the normal brain suggests local microvascular permeability. This permeability is selective for IgG, since albumin does not share a similar perivascular localization. The neuronal staining which is closely associated with perivascular label may reflect one intracellular route for extravasated IgG.

Albumins↗

PubMed1994

Simultaneous microanalysis of biliary cholesterol, bile acids and fatty acids in lecithin using capillary column gas chromatography: an advantage to assess bile lithogenecity.

Simultaneous determination of biliary lipids was performed by alkaline hydrolysis, the formation of the methyl ester derivatives of fatty acids that are constituents of phospholipids and of the acetylated methyl ester derivatives of bile acids, and subsequent analysis by capillary column gas chromatography. Complete separation and satisfactory recovery of cholesterol, bile acids, and fatty acids were achieved. Also, the accuracy of the calculation of the bile cholesterol saturation index was enhanced by computation. Since the degree of acyl chain unsaturation affects the cholesterol-holding capacity in vesicles, this method provides a unique insight into bile metastability by the quantitative assessment of fatty acids in lecithin.

Bile↗

PubMed1994

Striatal grafts in infarct striatopallidum increase GABA release, reorganize GABAA receptor and improve water-maze learning in the rat.

We grafted fetal striatal cells in ischemic rat models, and investigated graft survival/growth, GABA release, GABAA receptor reorganization and functional recovery. One hour intraluminal occlusion of the middle cerebral artery (MCA) induced ischemic infarct in the lateral part of the striatum and adjacent cortex. In ischemic rats, the acquisition of Morris' water-maze learning was significantly slower than that of control rats. In these animals GABA level in the globus pallidus, detected by microdialysis, was about the half of that of controls. However, after the grafts of fetal striatal cells in the striatopallidum, the acquisition was improved, thus no difference was observed in the time course of learning curves in control and grafted animals. GABA level recovered to almost normal level by the graft. It further increased by the treatment of a GABA uptake blocker (nipecotic acids) in the perfusion. In the grafts, GABAA receptor organization detected by autoradiography using [3H] labeled SR95531 was restored for more than 1 year after the graft. Data suggest that fetal striatal cell grafts in infarct striatum may partially reconstruct striatopallidal GABA projection and reorganize GABAA receptor. This might be a basis of improvement of function.

Animals↗

PubMed1994

Time-domain and frequency-domain analyses of the signal-averaged ECG in patients with sustained ventricular tachyarrhythmia and nonischemic heart diseases.

Signal-averaged electrocardiogram (ECG) variables were analyzed in 81 patients with ventricular tachyarrhythmia and nonischemic heart disease using the ART LVP 101 EPX system (Austin, TX): 15 ventricular tachycardia patients with arrhythmogenic right ventricular dysplasia (ARVD), 7 ventricular tachycardia patients with dilated cardiomyopathy, 25 patients with "idiopathic" verapamil-sensitive left ventricular tachycardia, 24 patients with "idiopathic" right ventricular tachycardia, and 10 "idiopathic" ventricular fibrillation (IVF) patients with rbbb pattern and ST-segment elevation in the precordial leads. Data from 52 normal control subjects were also analyzed. The first study was to test the hypothesis of any difference in signal-averaged ECG indices between patients with ARVD and patients with dilated cardiomyopathy. Longer filtered QRS duration and T40 and higher amplitude of the terminal filtered QRS complex outside the end of the standard QRS complex (log V-outside) were noted in patients with ARVD (filtered QRS duration, 172 vs 144 ms, P < .05; T40, 94 vs 62 ms, P < .05; log V-outside, 1.48 vs 0.56, P < .01). Endocardial mapping showed noticeable extension of fractionated electrograms in the right ventricle and longer duration of fractionated intracardiac electrograms in patients with ARVD, which might explain the difference in signal-averaged ECG indices between these two diseases. The second study was to test the hypothesis of and the variables that can suggest the arrhythmogenic substrate in patients with idiopathic ventricular tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

West syndrome associated with porencephaly.

A 3-year-old boy with West syndrome who was shown to have a cystic lesion on magnetic resonance imagings underwent surgical treatment. He had been initially managed with several antiepileptic drugs, but abnormalities on electroencephalography (EEG) persisted. Histological examination of the cystic wall obtained during surgery suggested porencephaly. Two years and 2 months later the child remained seizure-free and his EEG remarkably improved.

Adrenocorticotropic Hormone↗