Electrophysiological Findings in Idiopathic Recurrent Ventricular Fibrillation: Special Reference to Mode of Induction, Drug Testing, and Long-Term Outcomes

Electrophysiological studies can be useful in the presence of idiopathic ventricular fibrillation (VF) and may be used when selecting antiarrhythmic drugs. However, the yield, the mode, and the long-term reproducibility of the induction of VF have not yet been fully elucidated. Eight patients with idiopathic VF underwent electrophysiological study. The mean age (± SD) was 45 ± 17 years. Six were males and two were females. Diagnosis was done by exclusion. VF was induced in 6 (75%) of 8 patients using double extra stimuli at coupling intervals of 233 ± 39 and 191 ± 20 ms for the first and second extra stimuli, respectively. Of note, VF was induced by stimulation exclusively at the origin of the premature ventricular beat, which was the first complex of VF in two patients. In another patient, VF was initiated by two premature stimuli and also by a pause produced by rapid pacing. The inducibility of VF was reproduced 9–18 months after the first induction in all of the four patients studied. When the ability of antiarrhythmic drugs to suppress VF inducibility was confirmed, no recurrence was observed during the follow-up period of 40–160 months, but a recurrence of VF was observed in one of two nonresponders. In one patient, amiodarone administration failed in preventing VF induction 9 months after initiation of therapy, and reassessment of long-term drug-efficacy might be indicated in some patients. In conclusion, idiopathic VF was highly inducible (75%) with double extra stimuli. In this study, it was induced from a specific site (2/8) or by a pause (1/8). Induction of VF seemed to be reproduced 9–18 months after the first study. The outcome was considered favorable when the inducibility of VF was suppressed by antiarrhythmic drugs.     

Successful Radiofrequency Current Catheter Ablation of Sustained Ventricular Tachycardia

We performed radiofrequency current catheter ablation in two patients with nonischemic sustained ventricular tachycardia (VT). In one patient, two morphologically distinct VTs were induced by electrical stimulation. One showed right bundle branch block pattern and the other left bundle branch block pattern. The earliest site of activation during each VT was determined at the septum of the right ventricle. However, these two sites were close to the His-bundle elecfrogram recording area. In the other patient, a VT with a left bundle branch block pattern occurred spontaneously after the administration of isoproterenol. The earliest site of activation during VT was determined at the outflow tract of the right ventricle. During tachycardia, radiofrequency current ablation (40 W ± 30 sec) was delivered to the earliest site of activation, A few seconds after fulguration, each VT was terminated and additional radio-frequency currents were given near these sites. After the ablation, VT could not be induced by the electrical stimulations, nor did it recur. No side effects were observed and the atrioventricular conduction remained intact. We feel that nonischemic VTs could possibly be treated by using radiofrequency current catheter ablation.     

Preparation and opioid activities of N-methylated analogs of [D-Ala2, Leu5]enkephalin

Analogs of opioid pentapeptide [D-Ala², Leu⁵]enkephalin were prepared using two kinds of N-methylation reactions, namely quaternization and amide-methylation. Quaternization reaction with CH³I-KHCO³ in methanol was applied to the deprotected N-terminal group of the pentapeptide derivatives affording trimethylammonium group-containing analogs. [Me₃⁺ Tyr¹,D-Ala², Leu⁵]enkephalin and its amide were found to show opioid activity on guinea pig ileium assay only slightly lower than the parent unmethylated peptides. Application of amide-methylation reaction using CH₃I-Ag₂O in DMF to the protected pentapeptide yielded a pentamethyl derivative in which all of the five N atoms were methylated. Deprotection of the derivative gave pentamethyl analogs of [D-Ala², Leu⁵]enkephalin, which showed no significant activity on the guinea pig ileum assay and opiate-receptor binding assay.     

Class IC Antiarrhythmic Drugs, Flecainide and Pilsicainide, Produce ST Segment Elevation Simulating Inferior Myocardial Ischemia

ST Elevation with Flecainide and Pilsicainide . Flecainide and pilsicainide, Class IC antiarrhythmic drugs with slow kinetics, were administered to a 64-year-old man experiencing ventricular tachycardia. Both drugs suppressed the arrhythmia, but caused ST segment elevation in leads II, III, and aVF. No evidence of ischemic heart disease was detected. Withdrawal of the drugs eliminated the ST change. Because these drugs frequently are used to treat tachyarrhythmias in patients who may present with chest pain, this rare ECG manifestation of Class IC drugs should he recognized to avoid misdiagnosis of acute interior myocardial infarction.     

Efficacy of hypothermic perfusion using University of Wisconsin solution in extended hepatectomy with hepatic inflow occlusion in a canine model

This study was designed to elucidate the efficacy of University of Wisconsin (UW) solution for preventing liver injury, when used as a hypothermic perfusate infused into the systemic circulation during extended hepatectomy with hepatic inflow occlusion. Adult mongrel dogs (9.5–17.5 kg, n= 14) were subjected to 75% hepatectomy under 60 min hepatic inflow occlusion. The animals were divided into two groups. The UW group (n= 7) underwent hypothermic perfusion using 4°C UW solution (core temperature of the liver: 12.3±0.2°C). The control group designated as the Ringer's lactate (LR) group (n= 7) underwent hypothermic perfusion using 4°C LR solution. The perfusate was introduced into the systemic circulation via the hepatic vein. Blood from the hepatic vein was sampled, and alanine amino-transferase, purine nucleoside phosphorylase activities and the ammonia concentration were measured. The 7 day survival rate was higher in the UW group than in the LR group. The parameters of liver function were less significantly altered in the UW group than in the LR group. The plasma ammonia concentration was significantly (P<0.05) lower 6h after reperfusion in the UW group than in the LR group. A small volume of hypothermic perfusion of the liver using UW solution was safe if it returned to systemic circulation. Hypothermic perfusion of the liver using UW solution may be effective for preventing hepatic tissue injury during extended hepatectomy with hepatic vascular occlusion.     

Mucoid pseudocyst of the obturator nerve

A 71-year-old man visited the outpatients' clinic of National Saitama Hospital, Japan, complaining of pain in the right leg. Magnetic resonance imaging (MRI) revealed a cystic mass adjacent to the right side of the urinary bladder. He underwent the removal of the cystic mass and the pathological diagnosis was a mucoid pseudocyst of the obturator nerve. After tumor resection, the pain was diminished and he has been free of disease for 3 years.     

A Study of Reflux Esophagitis in an Apparently Healthy Population

Abstract: To study reflux esophagitis in the general population, we reviewed the records of 64,171 apparently healthy Japanese adults, 48, 706 men and 15,465 women, who had undergone automated multiphasic health testing and services (AMHTS), a comprehensive routine medical health check, that includes double-contrast upper gastrointestinal roentgenograms. All subjects suspected of having gastrointestinal disease underwent a flexible fiberscopy as indicated. Reflux esophagitis was thus confirmed in 101 subjects. The prevalence of refla esophugitis was 0.20% among men and 0.04% among women (men vs. women p<0.001) and its frequency increased with age in both men (p<0.001) and women (p<0.05). Endoscopic classification according to the Savary-Miller criteria yielded 48, 27, 23, and patients in Stage I, II, III and IV, respectively. In this series, 49/101 (48.5%) of the esophagitis patients had concurrent upper gastrointestinal abnormalities. The incidence of heavy smoking and excessive drinking of alcohol was significantly higher in the patients with reflux esophagitis (p<0.001 and p<0.005, respectively) as compared with the normal population.     

Some sensory stimuli generate spontaneous K-complexes

Abstract The present study was performed in order to determine whether spontaneous K-complex are induced by sensory stimuli. Electroencephalogram (EEG) segments in stage 2 sleep containing an evoked K-complex or spontaneous K-complex were separately averaged with respect to the peak of N300, one of the main components constituting the K-complex. Small negative and positive components were found immediately before the main components of spontaneous K-complex in averaged EEG. These two components were judged to correspond to N100 and P200 induced by the sound stimulus. The present findings suggest that the spontaneous K-complex is not a spontaneous phenomenon but that it is induced by sensory stimuli.