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EFFECTS OF CORONARY ARTERIOGRAPHY ON ATRIOVENTRICULAR-CONDUCTION - STUDIES WITH HIS-BUNDLE ELECTROGRAPHY

AMERICAN HEART JOURNAL 1976年第2期91卷 203-209页

作者： ABE, S ITOH, M KAMEI, T OHYAMA, K KASEDA, N UNAKAMI, H YURI GEN HOSP DEPT MEDHONJOJAPAN YURI GEN HOSP CARDIOL DIV38 HIGASHIMACHIHONJO 015JAPAN

The effect of coronary arteriography on atrioventricular (A-V) conduction was studied in 26 patients with the use of His bundle electrography. Slowing of atrioventricular conduction (prolonged A-H interval) was observed in all 26 patients following either left or right coronary arteriography without a detectable change in the H-V interval. In four patients with left coronary preponderance in arterial distribution pattern, prolonged A-H interval was produced only by injecting the contrast material into the left coronary artery. Conversely, in the remaining 22 patients either with right preponderance or balanced distribution, prolongation of the A-H time was a result of opacification of the right coronary artery. The A-H interval at peak prolongation (133.9±18.7 [S.D.] msec.) was significantly higher than the control measurement (98.3±15.7 msec.) (P<0.001). Prolongation of the A-H interval started around 4 seconds after the initiation of injection, reached its peak at an average of 7.7 seconds, and subsided within 20 seconds. When intracoronary injection of 6 ml. of normal saline was made in these 26 patients, no change was observed in the His bundle electrograms. On the other hand, hypertonic (20 per cent) glucose solution, when injected into coronary arteries, had an effect remarkably similar to that of contrast material on A-V conduction. These findings suggest that prolonged A-H interval observed during coronary arteriography may be a result of osmotic effect of the contrast material, rather than hypoxia resulting from dilution of coronary blood flow.

关键词：希氏束/药物作用冠状血管造影术冠心病/放射摄影术心电描记术心脏传导系统/药物作用容积渗克分子浓度成年人老年人女(雌)性人类男(雄)性中年人

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Preventing ventricular fibrillation by flattening cardiac restitution

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2000年第11期97卷 6061-6066页

作者： Garfinkel, A Kim, YH Voroshilovsky, O Qu, ZL Kil, JR Lee, MH Karagueuzian, HS Weiss, JN Chen, PS Univ Calif Los Angeles Sch Med Div Cardiol Dept Med Cardiol Los Angeles CA 90095 USA Univ Calif Los Angeles Sch Med Dept Physiol Sci Los Angeles CA 90095 USA Univ Calif Los Angeles Sch Med Dept Physiol Los Angeles CA 90095 USA Univ Calif Los Angeles Sch Med Cardiovasc Res Lab Los Angeles CA 90095 USA Univ Calif Los Angeles Sch Med Cedars Sinai Med Ctr Los Angeles CA 90095 USA

Ventricular fibrillation is the leading cause of sudden cardiac death. In fibrillation, fragmented electrical waves meander erratically through the heart muscle, creating disordered and ineffective contraction. Theoretical and computer studies, as well as recent experimental evidence, have suggested that fibrillation is created and sustained by the property of restitution of the cardiac action potential duration (that is, its dependence on the previous diastolic interval). The restitution hypothesis states that steeply sloped restitution curves create unstable wave propagation that results in wave break, the event that is necessary for fibrillation. Here we present experimental evidence supporting this idea. In particular, we identify the action of the drug bretylium as a prototype for the future development of effective restitution-based antifibrillatory agents. We show that bretylium acts in accord with the restitution hypothesis: by flattening restitution curves, it prevents wave break and thus prevents fibrillation. It even converts existing fibrillation. either to a periodic state (ventricular tachycardia, which is much more easily controlled) or to quiescent healthy tissue.

关键词：动作电位/药物作用抗心律失常药/药理学抗心律失常药/治疗应用溴苄胺化合物/药理学溴苄胺化合物/治疗应用心脏起搏人工计算机模拟色满卡林/药理学色满卡林/治疗应用心舒期/生理学药物设计药物评价临床前荧光染料心脏传导系统/药物作用心脏传导系统/病理生理学模型生物学吡啶鎓化合物猪心室颤动/药物疗法心室颤动/病理生理学心室颤动/预防和控制动物

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INTERRELATIONSHIPS BETWEEN EXTERNAL POTASSIUM CONCENTRATION AND LIDOCAINE - EFFECTS ON CANINE PURKINJE-FIBER

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AMERICAN HEART JOURNAL 1975年第2期89卷 221-226页

作者： OBAYASHI, K HAYAKAWA, H MANDEL, WJ UNIV CALIF DEPT MED LOS ANGELES CA USA CEDARS SINAI MED CTR 4833 FOUNTAIN AVE LOS ANGELES CA 90029 USA

Lidocaine produced significant shortening of both effective refractory period and action potential duration at all external K concentrations tested. The effective refractory period: action potential duration ratio was always greater than 1 following lidocaine administration at any of the external K concentrations. This effective refractory period:action potential duration relationship was considered to be 1 of the major mechanisms of antiarrhythmic drug effect. Although K concentrations in the higher physiologic range may alter the electrophysiologic properties of lidocaine, many of the previous electrophysiologic properties considered as vital in terms of the drug''s antiarrhythmic actions persist. At high external K concentrations the alterations in lidocaine''s electrophysiologic effects such as changes in the phase O dV/dt [change in velocity until time] and membrane responsiveness are not likely to be the mechanism of action of this antiarrhythmic drug in ventricular specialized conducting tissue.

关键词：动作电位/药物作用电生理学心脏/药物作用心脏传导系统/药物作用利多卡因/药理学膜电位/药物作用灌流钾/血液钾/代谢钾/药理学浦肯野纤维/药物作用刺激化学性动物狗

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FACILITATION OF AV NODAL RECIPROCATION BY PROCAINAMIDE

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AMERICAN HEART JOURNAL 1976年第4期91卷 460-467页

作者： FABREGAS, RA HAN, J GOEL, BG YOON, MS ALBANY MED CTR HOSP ELECTROCARDIOG LAB ALBANY NY USA UNION UNIV ALBANY MED COLL DEPT MED ALBANY NY 12208 USA

Procainamide is known to depress conduction through the A-V node, and this property may facilitate the development of ventricular reciprocal beats or echoes. The occurrence of ventricular reciprocal beats was studied in 20 open-chest dogs before and after the administration of procainamide. While the ventricle was paced by basic stimuli, early ventricular premature beats were introduced at various coupling intervals to induce ventricular echoes. When ventricular echoes could be induced in a given heart, there was a continuous range of coupling intervals (or echo zone) within which ventricular echoes occurred. In the control state, no echo occurred in eight dogs and the echoes developed in 12 dogs with the mean echo zone of 38.3 msec. The effect of procainamide was studied at its therapeutic blood levels about 25 minutes after an intravenous injection of the drug in a dose of 10 mg. per kilogram. Of the first group of eight dogs, in which no echo occurred in the control state, four dogs developed ventricular echoes after the administration of procainamide with the mean echo zone of 29.3 msec. for the group. Of the second group of 12 dogs, in which ventricular echoes were induced in the control state, the administration of procainamide increased the echo zone in 10 dogs with the mean echo zone of 67.8 msec. for the group. Ventricular reciprocal beats were often sustained to produce short runs of supraventricular tachycardia in five dogs after the administration of procainamide. The results demonstrated a potentially deleterious effect of procainamide in facilitating the induction of A-V nodal reciprocation by closely coupled ventricular premature beats.

关键词：房室结/药物作用房室结/病理生理学心脏传导系统/药物作用心室心脏起搏器人工动物

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Differential effects of beta-adrenergic agonists and antagonists in LQT1, LQT2 and LQT3 models of the long QT syndrome

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JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 2000年第3期35卷 778-786页

作者： Shimizu, W Antzelevitch, C Masonic Med Res Lab Utica NY 13501 USA

OBJECTIVES To define the cellular mechanisms responsible for the development of life-threatening arrhythmias in response to sympathetic activity in the congenital and acquired long QT syndromes (LQTS). METHODS Transmembrane action potentials (AP) from epicardial (EPI), M and endocardial (ENDO) cells and a transmural electrocardiogram were simultaneously recorded from an arterially perfused wedge of canine left ventricle. We examined the effect of beta-adrenergic agonists and antagonists on action potential duration (APD(90)), transmural dispersion of repolarization (TDR) and the development of Torsade de Pointes (TdP) in models of LQT1, LQT2 and LQT3 forms of LQTS. RESULTS I-Ks block with chromanol 293B (LQT1) homogeneously prolonged APD(90) of the three cell types without increasing TDR. Addition of isoproterenol prolonged QT and APD(90) of M but abbreviated that of EPI and ENDO, causing a persistent increase in TDR;Torsade de Pointes developed or could be induced only in the presence of isoproterenol. I-Kr block with d-sotalol (LQT2) and augmentation of late I-Na with ATX-II (LQT3) prolonged APD(90) of M more than EPI and ENDO, causing increases in QT and TDR. TdP developed in the absence of isoproterenol. In LQT2 isoproterenol initially prolonged, then abbreviated, the APD(90) of M but always abbreviated EPI, thus transiently increasing TDR and the incidence of TdP. In LQT3, isoproterenol always abbreviated APD(90) of the three cell types, causing a persistent decrease in TDR and suppression of TdP. The arrhythmogenic as well as protective actions of isoproterenol were reversed by propranolol. CONCLUSIONS Our data suggest that beta-adrenergic stimulation induces TdP by increasing transmural dispersion of repolarization in LQT1 and LQT2 but suppresses TdP by decreasing dispersion in LQT3. The data indicate that beta-blockers are protective in LQT1 and LQT2 but may facilitate TdP in LQT3. (C) 2000 by the American College of Cardiology.

关键词：动作电位/药物作用肾上腺素能β激动剂/药理学肾上腺素能β受体拮抗剂/药理学强心药/药理学色满类/药理学腔肠动物毒液类/药理学疾病模型动物心电描记术/药物作用心脏传导系统/药物作用心率/药物作用心室/神经支配心室/病理生理学异丙肾上腺素/药理学 QT延长综合征/药物疗法 QT延长综合征/病理生理学神经毒素类/药理学钾通道阻滞剂普萘洛尔/药理学索他洛尔/药理学磺胺类/药理学交感神经系统/药物作用交感神经系统/病理生理学治疗结果动物狗

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PRIMARY ALCOHOLIC HEART-DISEASE

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ANNALS OF THE NEW YORK ACADEMY OF SCIENCES 1975年第APR25期252卷 237-242页

作者： TALBOTT, GD BALTIMORE PUBL INEBRIATE PROGRAM BALTIMORE MD 21203 USA

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ELECTROPHYSIOLOGY AND PHARMACOLOGY OF CARDIAC-ARRHYTHMIAS .4. CARDIAC ANTIARRHYTHMIC AND TOXIC EFFECTS OF DIGITALIS

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AMERICAN HEART JOURNAL 1975年第3期89卷 391-399页

作者： ROSEN, MR WIT, AL HOFFMAN, BF COLUMBIA UNIV COLL PHYS & SURGDEPT PHARM630 W 168TH STNEW YORKNY 10032

The interactions are described between the autonomic nervous system, the cardiac cell, and digitalis in the hope of clarifying the mechanisms thought responsible for the antiarrhythmic and the toxic effects of digitalis. Although much of the information reported was obtained from studies of experimental animals, the authors attempted, where possible, to correlated these observations with clinical events. It is of interest that in recent studies, digitalis induced delayed afterdepolarizations have been elicited in human atrial tissues. While this observation is encouraging with respect to the applicability of the data obtained from studies on canine and rabbit hearts, the extent to which delayed afterdepolarizations are responsible for the clinical spectrum of digitalis toxicity in the human must be subject of considerable further study.

关键词：动作电位/药物作用房室结/药物作用洋地黄糖甙类/治疗应用心电描记术电生理学心脏/病理生理学心房/药物作用心脏传导系统/药物作用心率浦肯野纤维/药物作用动物人类

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ELECTROPHYSIOLOGIC EFFECTS OF ISOPROTERENOL ON CARDIAC CONDUCTION SYSTEM IN MAN

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AMERICAN HEART JOURNAL 1975年第1期90卷 25-34页

作者： VARGAS, G AKHTAR, M DAMATO, AN US PHS HOSP CARDIOPULM LAB HOSP Staten Isl NY 10304 USA

The effects of isoproterenol (ISOP) on the functional properties of the A-V conduction system were studied in 16 patients using Hisbundle recordings and the atrial extrastimulus technique. In all patients, ISOP at an infusion rate of 1 mcg. per minute resulted in sinus acceleration and enhancement of A-V nodal conduction, but had no effect on His-Purkinje conduction time. ISOP significantly decreased both functional and effective refractory periods of the A-V node. The relative refractory period of the His-Purkinje system decreased by a small amount in five patients in whom the parameter could be compared before and after the drug.

关键词：房室结/药物作用希氏束/药物作用电刺激心电描记术心脏导管插入术心脏传导系统/药物作用异丙肾上腺素/药理学心脏起搏器人工浦肯野纤维/药物作用不应期电生理学/药物作用成年人老年人女(雌)性人类男(雄)性中年人

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Aging alteration of cardiac vagosympathetic balance assessed through the tone-entropy analysis

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JOURNALS OF GERONTOLOGY SERIES A-BIOLOGICAL SCIENCES AND MEDICAL SCIENCES 1999年第5期54卷 M219-M224页

作者： Oida, E Kannagi, T Moritani, T Yamori, Y Kyoto Univ Grad Sch Human & Environm Studies Appl Physiol Lab Sakyo Ku Kyoto 6068501 Japan Fdn Kyoto Prevent Med Ctr Kyoto Japan

Background. Age-associated alterations of cardiac autonomic functions have been investigated intensively through heart rate variability analyses. However, changes with age in cardiac vagosympathetic balance remain to be elucidated. Methods. We studied 142 male subjects (30-69 yr) at a health care center in Kyoto, Japan. Electrocardiographic data were collected from subjects in a recumbent position for 10 min in the morning. Analysis was done by classifying the subjects into four age groups. In a pharmacological experiment carried out in December 1996, tone was verified to reflect the cardiac vagosympathetic balance, and entropy the total autonomic neural efferent activity. We assessed the heart rate variability through the tone-entropy (T-E) analysis that was described previously. In essence, two indexes, tone and entropy, were defined on a distribution of successive variations of heart period. Results. No significant differences were detected in clinical conditions among the four age groups. Tone increased and entropy decreased significantly with age. The aging process was expressed as a curvilinear path in T-E space. Compared to the pharmacological experiment, it was observed that aging degenerated the heart function from an ordinary to a denervated one. The same aging path was superimposed in the opposite direction on the heart recovery path after dynamic exercise in which cardiac vagosympathetic balance tended toward vagus division, corresponding with restoration of total autonomic activity. Conclusions. An age-related reduction in cardiac autonomic function was consistent with previous reports. The vagosympathetic balance was altered with this reduction: vagal predominance was impaired significantly in proportion to the withdrawal of total cardiac autonomic activity.

关键词：肾上腺素能β受体拮抗剂/药理学衰老/生理学阿托品/药理学自主神经系统/生理学传出通路/生理学心电描记术运动(Exercise)/生理学心脏/生理学心脏传导系统/药物作用心脏传导系统/生理学心率/药物作用心率/生理学神经元传出/生理学抗副交感神经药/药理学普萘洛尔/药理学仰卧位交感神经系统/药物作用交感神经系统/生理学抗交感神经药/药理学迷走神经/药物作用迷走神经/生理学成年人老年人人类男(雄)性中年人

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ELECTROPHYSIOLOGY AND PHARMACOLOGY OF CARDIAC-ARRHYTHMIAS .7. CARDIAC EFFECTS OF QUINIDINE AND PROCAINE AMIDE .B.

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AMERICAN HEART JOURNAL 1975年第1期90卷 117-122页

作者： HOFFMAN, BF ROSEN, MR WIT, AL COLUMBIA UNIV COLL PHYS & SURGDEPT PHARMACOL630 W 168 STNEW YORKNY 10032

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