共查询到20条相似文献,搜索用时 31 毫秒
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MDShinji Kinoshita MDYoshinori Tanabe MDTatsuo Satoh 《Journal of electrocardiology》1996,29(4):341-345
A case of concealed ventricular bigeminy is reported in which the number of sinus QRS complexes intervening between two successive noninter-polated extrasystoles was always uneven. Coupling intervals of manifest extrasystoles to the preceding sinus QRS complexes were almost fixed and much longer than sinus QT intervals. Bradycardia-dependent disappearance of manifest bigeminy and tachycardia-dependent appearance of extrasystoles occurred in this case. Apparently, 2:1 block of sinus impulses occurred in the reentrant pathway, with markedly depressed conductivity. Concealed electrotonic conduction of blocked sinus impulses in the pathway of extrasystoles may have favored the appearance of the subsequent manifest extrasystoles without concealed conduction owing to two-level block. A possible explanation for the mechanism of such concealed bigeminy is presented, which uses the concepts of longitudinal dissociation and electrotonic inhibition in the reentrant pathway with markedly depressed conductivity. 相似文献
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Vincenzo Carbone Lilia Oreto Giuseppe Oreto 《Annals of noninvasive electrocardiology》2013,18(1):90-94
A Holter recording obtained from a patient with atrial fibrillation showed ventricular extrasystoles often in bigeminal rhythm. Most extrasystoles were followed by a long return cycle, and only in a few instances the postextrasystolic interval was short. The latter phenomenon was interpreted as a manifestation of poor retrograde concealed penetration of the ventricular impulse into the atrioventricular (A‐V) junction: accordingly, an ensuing relatively early fibrillation impulse reached the ventricular chamber, since it did not find the A‐V node refractory. These events are similar to what happens in interpolated ventricular extrasystoles occurring during sinus rhythm, the absent or minimal concealed retrograde penetration of the ectopic impulse into the A‐V node being necessary to permit anterograde conduction of the ensuing sinus impulse. Analysis of the recording also revealed that a very long (>2 second) interval between two consecutive narrow beats only occurred after an “interpolated” extrasystole. This was interpreted with the same mechanism underlying the “postponed compensatory pause” observed at times after interpolated ventricular extrasystoles during sinus rhythm: the minimal or nil penetration of the ventricular ectopic impulse into the A‐V junction, followed by conduction of an ensuing early atrial impulse, “shifts to the right” the A‐V nodal refractory period, preventing conduction of several further supraventricular impulses and generating a pause. Both interpolated ventricular extrasystoles and the phenomenon of “postponed compensatory pause” are, thus, conceivable during atrial fibrillation, although no definite demonstration is possible. 相似文献
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JAVIER JIMÉNEZ‐DÍAZ M.D. JUAN J. GONZÁLEZ‐FERRER M.D. GIOVANNA U. HEREDIA M.D. JAVIER MORENO‐PLANAS M.D. Ph.D. 《Journal of cardiovascular electrophysiology》2014,25(4):447-449
A 74‐year‐old man underwent an electrophysiological study because of Mobitz type II second‐degree atrioventricular (AV) block with narrow QRS and frequent junctional extrasystoles. During the study, there were very frequent single His bundle depolarizations with multiple coupling intervals that reproduce the ECG findings. In this case, some His bundle extrasystoles result in retrograde concealed conduction and prolonged local refractoriness in the AV node that manifest as block of the next atrial impulse. 相似文献
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Coexisting Preexcitation Syndrome and Intermittent Heart Block Presenting as Neonatal Seizures 总被引:1,自引:0,他引:1
RONALD J. KANTER M.D. ALFREDO DEL RIO M.D. CARLOS MIRETTI M.D. JORGE GONZALEZ-ZUELGARAY M.D. † 《Journal of cardiovascular electrophysiology》1999,10(5):736-740
An infant presented with neonatal syncope and seizures. An ECG showed a preexcitation pattern, most compatible with Wolff-Parkinson-White (WPW) syndrome. Rhythm monitoring during an event demonstrated prolonged periods of complete AV block with no ventricular escape mechanism. We postulated that ventricular asystole was initiated by mechanical or autonomic influences on the accessory pathway and sustained by electrophysiologic interactions between the accessory pathway and the junctional escape focus. This is the first case report of a newborn having coexisting congenital AV block and WPW syndrome. 相似文献
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GIUSEPPE ORETO M.D. JOEP L.R.M. SMEETS M.D. LUZ-MARIA RODRIGUEZ M.D. CARL TIMMERMANS M.D. HEIN J.J. WELLENS M.D. 《Journal of cardiovascular electrophysiology》1994,5(4):345-349
Supernormal Conduction. This report describes a patient with tachycardia-dependent left bundle branch block (LBBB) and atrial extrasystoles, some of which were followed by an unexpectedly narrow QRS complex. His-bundle recordings and premature atrial stimulation were performed to analyze the mechanism underlying the normalized intraventricular conduction of some of the early atrial impulses. The results suggested the presence of supernormal conduction in the left bundle branch (LBB), because(1) the HV interval was identical in LBBB complexes and in early narrow QRS complexes; (2) during single lest stimulation using different paced atrial cycle lengths, there was a well-defined range of H1 , H2 , intervals resulting in normalization of intraventricular conduction; and (3) atrial pacing with a cycle length of 500 msec resulted in alternation between wide and narrow QRS complexes. These findings rule out alternative mechanisms that could explain the unexpectedly normal intraventricular conduction of early impulses. 相似文献
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Frank J. Molnar MSc MDCM Sophiya Benjamin MBBS MD Stacey A. Hawkins BA MA CPG PhD Student Melanie Briscoe OT Sabeen Ehsan MBBS MD MHI 《Journal of the American Geriatrics Society》2020,68(10):2207-2213
Every year, millions of patients worldwide undergo cognitive testing. Unfortunately, new barriers to the use of free open access cognitive screening tools have arisen over time, making accessibility of tools unstable. This article is in follow-up to an editorial discussing alternative cognitive screening tools for those who cannot afford the costs of the Mini-Mental State Examination and Montreal Cognitive Assessment (see www.dementiascreen.ca ). The current article outlines an emerging disruptive “free-to-fee” cycle where free open access cognitive screening tools are integrated into clinical practice and guidelines, where fees are then levied for the use of the tools, resulting in clinicians moving on to other tools. This article provides recommendations on means to break this cycle, including the development of tool kits of valid cognitive screening tools that authors have contracted not to charge for (i.e., have agreed to keep free open access). The PRACTICAL.1 Criteria ( PRACTI cing C linician A ccessibility and L ogistical Criteria Version 1 ) are introduced to help clinicians select from validated cognitive screening tools, considering barriers and facilitators, such as whether the cognitive screening tools are easy to score and free of cost. It is suggested that future systematic reviews embed the PRACTICAL.1 criteria, or refined future versions, as part of the standard of review. Methodological issues, the need for open access training to insure proper use of cognitive screening tools, and the need to anticipate growing ethnolinguistic diversity by developing tools that are less sensitive to educational, cultural, and linguistic bias are discussed in this opinion piece. J Am Geriatr Soc 68:2207–2213, 2020. 相似文献
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T Hardarson A Kristinsson G Skúladóttir H Asvaldsdóttir S P Snorrason 《Journal of internal medicine》1989,226(1):33-37
Previous work has shown that in experimental animal models a lower incidence of arrhythmias and sudden death was observed if the animals were fed cod liver oil or fish oil. After a 48-h control period starting, on average, 8 days after the onset of symptoms, 18 men who were recovering from acute myocardial infarction were given 20 ml d-1 cod liver oil for 6 weeks, either immediately after the control period, weeks 0-6 (n = 10), or during weeks 6-12 (n = 8). Forty-eight-hour Holter monitoring was carried out before cod liver oil administration and at the end of weeks 6 and 12. The eicosapentaenoic acid content of plasma phospholipids was increased by 230% during cod liver oil administration. However, no significant change was observed in the 24-h prevalence of ventricular extrasystoles or other arrhythmias during the study period. The mean ln number of ventricular extrasystoles was 2.95 +/- 0.51 (+/- SEM) during cod liver oil ingestion and 2.63 +/- 0.30 when not taking cod liver oil. 相似文献
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