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We studied the electrophysiologic effects of intravenous dilazep in 10 hospitalized patients.

We performed an electrophysiologic study (EPS) in 8 patients who had received corrective surgery for tetralogy of Fallot. The mean age was 30 years. An average of 15 years had elapsed after corrective surgery. Two patients had episodes of syncope. ECG showed normal sinus rhythm in 7 patients and atrial fibrillation in 1, and all had complete right bundle branch block. All patients had ventricular premature beats of grade 3 or higher of Lown's classification. Overdrive suppression test was performed in 6 patients. Corrected sinus node recovery time (CSNRT) ranged from 230 msec to 510 msec. Wenckebach block of atrioventricular nodal conduction occurred at rates of 130 to 170 bpm during atrial pacing. The H-V interval was prolonged to 60 msec in 1 patient, but was below 55 msec in the others. Programmed stimulation induced ventricular tachycardia (VT) in 3 patients, nonsustained VT in 2 and sustained VT in 1. In 2 of 3 patients, delayed potential or fragmentations were recorded in the outflow tract of the right ventricle. During the follow-up period of 20 months, 2 patients died suddenly. Their CSNRTs and H-V intervals were normal. Ventricular tachyarrhythmia seems to be important as a cause of late sudden death after repair of tetralogy of Fallot.

We evaluated the prophylactic effect of antiarrhythmic agents against induction of ventricular tachycardia by extrastimulation in 51 patients with recurrent ventricular tachycardia. These patients subsequently underwent 58 long-term trials with tested agents. In 39 trials an agent predicted to be effective by electrophysiologic study was administered, and in 19 a drug predicted to be ineffective was used. There were no clinical differences between the two treatment groups. During a mean follow-up period of 8.2 months, arrhythmias recurred significantly less frequently in the group treated with drugs predicted to be effective than in the other group (P < 0.001); at six months 80 per cent of the patients in the former group were successfully treated, as compared with 33 per cent in the latter group. At 18 months the corresponding figures were 68 per cent and 11 per cent. We conclude that the arrhythmia-induction technique accurately predicts the clinical effectiveness of drugs used in the long-term treatment of recurrent ventricular tachycardia.

A 75-year-old woman was admitted to the hospital because of a supraventricular tachycardia, long sinus pauses and ventricular tachycardia of the torsades de pointe type. Temporary ventricular pacing suppressed ventricular arrhythmias but supraventricular tachy-cardia persisted. An electrophysiologic study revealed the coexistence of sick sinus syndrome and cir-cus movement tachycardia due to a concealed left-sided accessory atrioventricular pathway. This case represents a previously undescribed form of the bradycardia-tachycardia syndrome. (PACE, Vol. 5, July-August, 1982)

Intravenous verapamil is a very effective therapy for terminating paroxysmal reciprocating junctional tachycardia (PRJT).1 Ventricular arrhythmias, usually ventricular premature complexes1 and, rarely, short runs of ventricular tachycardia,2 have been observed after conversion of PRJT by verapamil. In contrast, verapamil-induced atrial tachyarrhythmias are rare. To our knowledge, there have been only 2 previous reports of atrial fibrillation (AF) after administration of verapamil during PRJT: in 1 patient just before conversion3 and in another when verapamil failed to convert PRJT to sinus rhythm.4 We describe 2 patients who developed sustained AF shortly after conversion of PRJT to sinus rhythm by intravenous verapamil during electrophysiologic study.

A detailed electrophysiologic study in a 7 year old boy with incessant atrial tachycardia revealed the presence of an atrioventricular pathway conducting only in the ventriculoatrial direction. The results indicate a reentrant mechanism with the retrograde limb of the circuit entering the atrium in the region of the proximal to mid coronary sinus. The accessory pathway exhibited relatively long conduction times and conduction properties suggesting decremental conduction. Thus, an electrophysiologically atypical anomalous conduction pathway may be responsible for the occurrence of incessant atrial tachycardia in some children.

With the advent of echocardiography, the examination of motion of interventricular septum(IVS) and left ventricular posterior wall (LVPW) has become very important in the diagnosis of cardiac abnormalities. Some clinical reports on Wolff-Parkinson-White(WPW) syndrome, which is one of the conditions known to affect the motion of IVS and LVPW, demonstrate that, in Type A, LVPW shows early onset and peak formation of the anterior motion and that, in Type B, IVS shows early systolic posterior protrusion and subsequent paradoxical anterior motion, which are quite similar to those observed in left bundle branch block. Although some believe that unopposed systolic contraction of either right(RV) or left ventricle(LV) and/or reversed activation of IVS from right to left resulted in these abnormal motion, the exact mechanism still remain uncertain.

Electrophysiologic studies were performed on a 73-year-old man with swallowing-induced supraventricular tachycardia, in order to define the characteristics of this unique dysrhythmia in this patient. Swallowing reliably provoked an automatic atrial focus type of atrial tachycardia, which usually changed into an atrioventricular nodal reentrant tachycardia when a critical delay in atrioventricular nodal conduction (atrio-His interval greater than or equal to 340 msec) was achieved. The atrioventricular nodal reentrant form of tachycardia did not occur spontaneously. The ease of induction and the duration of the episodes of supraventricular tachycardia were facilitated with the intravenous administration of atropine and ouabain and were decreased with administration of procainamide hydrochloride.

An electrophysiologic study of peripheral nerve excitability was performed in patients with hyperkalemic periodic paralysis (HPP) and in normal controls. It was found that a marked degree of neural hyperexcitability existed in all patients with HPP who showed cold sensitivity. The results suggest involvement of the nerve cell membrane in the proximal segments of peripheral nerve. This testing method may be of value in differentiating the cold-sensitive variant of HPP.

A new antitachycardia pacemaker system was used in a 58 year old woman to terminate two different types of supravehtricular tachycardia by a single automatic pacing mode. During the invasive electrophysiologic study before pacemaker implantation (in the absence of medication), sustained episodes of atrioventricular (AV) nodal reentrant tachycardia and two short-lasting episodes of nonsustained atrial tachycardia were induced. After implantation, sustained episodes of both AV nodal tachycardia and atrial tachycardia were initiated. Both arrhythmias could be terminated reproducibly by a single pacing mode.

Accessory pathway electrograms are rarely recorded in patients with Wolff-Parkinson-White syndrome. In one patient, during electrophysiologic study, simultaneous local ventricular (V) accessory pathway (AP) and atrial (A) deflections were recorded during bipolar catheter endocardial mapping over the pathway. Analysis of changes in electrographic intervals during performance of the ventricular extrastimulus technique allowed characterization of the retrograde conduction properties of the pathway. As coupling intervals were decreased, an initial increase was seen in the AP2A2 interval with subsequent ventriculoatrial block between the accessory pathway and atrium. When coupling intervals were further decreased, the V2AP2 interval lengthened with ultimate block between the ventricle and accessory pathway. These findings support the concept of impedance mismatch as the cause of conduction block in accessory pathways with the distal junction of the accessory pathway being the most vulnerable.

The significance of fragmented activity obtained from the atrium during electrophysiologic study (EP study) was confirmed since it was al ways observed just at the onset of fi brillation. It was preceded by extra stimuli or atrial flutter, and the initial site of fragmentation varied from case to case. The premature-stimu lus-induced widening of the atrial wave was observed in some cases who had normal size of atrium and no heart failure. The widening was aug mented by administration of vera pamil but not by procainamide, suggesting that for such widening or fragmented activity, slow-fiber-medi ated conduction seems to be responsi ble. One case with intraatrial reen trant tachycardia developed fragmentation lasting for 1.0 second after verapamil. Therefore, some apparently nor mal atria may have a subclinical elec trophysiologic abnormality that can be disclosed by premature stimula tions or verapamil.

Summary A patient with atypical chest pain developed pre-excitation during exercise and isoproterenol infusion, with “ischemic” ST depression only during the pre-excited beats. Coronary angiography and myocardial lactate extraction showed no evidence of abnormal coronary vessels. Electrophysiologic study and pacing-induced tachycardia did not induce pre-excitation, whereas exercise induced progressive increase in pre-excitation. The data are consistent with an unusual form of pre-excitation, perhaps related to responsiveness of an accessory bypass tract to catecholamine stimulation. The data also show that the false positive exercise test in this syndrome is due to progressively increasing pre-excitation and therefore more abnormal repolarization.

he diagnosis of dual AV nodal pathways compliTcating concealed or manifest preexcitation, is usually made at the time of electrophysiologic study in pa tien ts with recurrent paroxysmal supraventriculax tachycardia. In these patients, electrophysiologic studies demonstrate discontinuous antegrade AV nodal conduction curves (dual AV nodal pathways, fast and slow), as well as a unior bidirectionally conducting anomalous pathway. In some of these patients, one or more tachycardias are induced.14 The tachycardias induced can include a fast AV reentrant tachycardia (antegrade fast pathway and retrograde anomalous pathway), a slow AV reentrant tachycardia (antegrade slow and retrograde anomalous pathway ) , and sometimes the usual variety of AV nodal reentrant paroxysmal tachycardia ( antegrade slow pathway and retrograde fast pathway).' In these cases, one then has to retrospectively examine electrocardiograms in an attempt to correlate induced and clinical tachycardias. In the present study, we report a patient with known Wolff -Parkinson-White syndrome, in whom dual pathways were diagnosed from electrocardiographic findings prior to electmphysiologic study. In this patient, the presence of dual pathways was clinically relevant, in that the patient suffered from two different spontaneous paroxysmal tachycardias.

OBJECTIVE: In this study, we present the comparison of demographic and clinical specialty in Patients with Electrophysiologic Study EPS from two different center R1: Government Hospital from East Region; R2: University Hospital from West Karadeniz Region .METHODS: Totally of 441 records of patients who presented with palpitation and underwent EPS were analyzed retrospectively in two different center between January 2010 and May 2012.RESULTS: Of these patients, 70,04 % n=188 from R1, and 64,36 % n=112 from R2 were female p=0.184 . There were statistical significance between the Socioeconomic status SES and educational status ES R1-R2 SES 39,6%-23,3% low, 49,4%-59,2% middle, 11%-17,5% high; p=0.031; R1-R2 ES 2,3%-3,4% literacy, 43,2%-21,1% elementary, 43,2%-45,6% secondary, 11,9%-29,9% higher; p=0.042 CONCLUSION: We thought that SES and ES have some roles about the formation of EPS patients population for different centers., AMAÇ: Bu çalışmamızda ülkemizin iki değişik bölgesinde yer alan biri Doğu Anadolu Bölgesinden devlet hastanesi diğeri üniversite hastanesi olmak üzere iki farklı EPS laboratuvarında R1: Doğu Anadolu, R2: Batı Karadeniz işleme alınan hastaların retrospektif olarak belirlenen klinik ve demografik özelliklerini karşılaştırmayı amaçladık.YÖNTEMLER: Her iki merkezde, çarpıntı yakınması ile Ocak 2010 ile Mayıs 2012 tarihleri arasında EPS işlemine alınan toplam 441 hastalanın kayıtları klinik ve demografik özellikleri açısından retrospektif olarak incelendi.BULGULAR: R1’de EPS işlemine alınan hastaların %70,04 n=188 , R2’de işleme alınan hastaların ise %64,36 n=112 kadın cinsiyetti. p=0.184 . R2’deki hastaların %23,3’ü düşük gelir grubunda iken, %59,2’si orta gelir grubunda ve %17,5 yüksek gelir grubunda idi. R1’de ise %39,6’sı düşük gelir grubunda iken, %49,4’si orta gelir grubunda ve %11 yüksek gelir grubunda idi p=0.031 . R2’deki hastaların %3,4’ü okur yazar, %21,1 ortaöğretim, %45,6 lise ve %29,9’u ise yükseköğretim grubunda iken, R1’deki hastaların %2,3’okur yazar, %43,2 ortaöğretim, %42,6 lise ve %11,9 yükseköğretim grubunda idi p=0.042 .SONUÇ: Farklı merkezlerde yapılan EPS işlemlerindeki hasta profillerinin oluşmasında sosyoekonomik ve eğitimsel statününde rol alabileceğini düşünmekteyiz.

The feasibility of atrial activation time imaging is investigated based on data sets of four patients who underwent an electrophysiologic study. Several pacing protocols with pacing sites at the right atrial appendage, coronary sinus, and high right atrium were part of the study and were employed to reconstruct the associated atrial activation time patterns. The localization error was estimated to be between 8 and 14 mm.

Objective: The aim of this study was to test the hypothesis that reinforcing the structuring of verbal material may bring about an improvement in contextualization processes in patients with formal thought-disordered schizophrenia. Method: A total of 38 schizophrenia patients with formal thought disorders and 24 matched healthy control subjects performed 2 lexical decision tasks, involving 2 levels of contextual structuring (with 16.7% and 33% of related words, respectively). The event-related potentials, N400 and late positive component (LPC), and behavioural variables (reaction times and error percentages) were analyzed. Results: A context-structuring effect was observed on LPC, but not on N400. In subjects with schizophrenia, the N400 anomalies (that is, increase in amplitude for the related words and reduction of the N400 effect) persisted in both context-structuring conditions. Similarly, a reduction in LPC amplitude for the unrelated word category, as well as a decrease in the LPC effect, was observed in these patients. Conclusions: The schizophrenia patients with formal thought disorders did not benefit from the structuring of the context to implement context integration strategies. This deficit appears to be stable. The results are discussed within the framework of a previously published model of language comprehension.

A 3-week-old neonate with supraventricular tachycardia unresponsive to traditional therapy was treated successfully with amiodarone. An electrophysiologic study suggested the presence of a concealed left-sided accessory atrioventricular pathway. Because of its significant side effects, amiodarone should be used only as a last resort in the treatment of neonatal supraventricular tachycardia.

We surveyed 12 medical centers with regard to the reuse of pacing catheters during electrophysiologic studies. The prevalence of superficial skin infections or bacteremia related to EP studies was extremely low, and was not significantly different in the catheter reuse group compared to the single use group. We conclude that catheter resterilization and reuse is safe and cost-effective.

Electrophysiologic investigations were carried out in 15 patients with limb-girdle muscular dystrophy, two patients with Becker's muscular dystrophy, and 22 patients with dystrophia myotonica. The results were compared with those obtained in 18 patients who had chronic progressive motoneuron disease and in 39 control subjects. These results were within normal limits in muscular dystrophies, with the exception of dystrophia myotonica, in which a neural disturbance is evident in the majority of patients. The results in motoneuron diseases were as expected for neurogenic disorders, loss of motor axons and compensatory increase of the amplitude of muscle potentials. There is no evidence of motoneuron dysfunction in muscular dystrophies, but in dystrophia myotonica, the muscles and nerves are affected independently by the pleiotropic gene of the disease.

Electrodiagnostic studies were performed at the time of peak neurological deficit in 26 episodes of the Guillain-Barre syndrome, and at intervals before and after this time in 13 cases. Of the patients 65.4% had made a complete clinical recovery at the termination of the study. The shortest recovery time from the onset of symptoms was four weeks and the longest was 34 weeks. A rapid recovery was associated with an acute progression of neurological deficit in the face of normal electrophysiologic study results throughout the illness (19.2%). Patients requiring the longest time to recover demonstrated various electromyographic abnormalities, but, in particular, all showed evidence of denervation (fibrillation, positive sharp waves, or both).

Ventricular dysrhythmias following intracardiac repair of tetralogy of Fallot have been previously demonstrated. Less attention has been directed to postoperative conduction abnormalities in these patients. Between October, 1982 and March, 1984 we performed hemodynamic and electrophysiologic studies in 11 patients (8 males/3 females) who had previously undergone repair of tetralogy of Fallot. A wide spectrum of conduction system abnormalities including sinus node dysfunction (5/11), atrioventricular node dysfunction (3/11), and His-Purkinje disease (7/11) were found. Confirmation that bifasicular disease cannot be reliably diagnosed from the surface electrocardiogram alone was obtained. Spontaneous and/or inducible ventricular dysrhythmias were documented in 5/11 patients. However, there was no consistent relationship between the presence or degree of residual right ventricular hypertension and the presence of ventricular dysrhythmias. We conclude that: 1) frequent conduction abnormalities as well as ventricular dysrhythmias may occur in patients following repair of tetralogy of Fallot; and 2) ventricular dysrhythmias may occur in these patients even when residual right ventricular hypertension is not present. We therefore recommend that all patients should undergo postoperative hemodynamic and electrophysiologic study following intracardiac repair of tetralogy of Fallot.

• Occupational exposure to ethylene oxide (ETO) was manifested as a subacute polyneuropathy, with bilateral footdrop and denervation potentials on electromyography as the principal abnormalities in three young adults whom we examined. To our knowledge, this is the second report of neurotoxic effects caused by long-term ETO exposure in humans and brings the number of patients described with symptomatic polyneuropathy to five.

Twenty-five patients with recurrent episodes of syncope, unexplained despite thorough medical and neurologic evaluation, underwent intracardiac electrophysiologic study with programmed stimulation. Electrophysiologic study yielded a presumptive diagnosis in 17 patients: nine with rapid ventricular tachycardia by programmed stimulation, three with intra-His conduction delays, one with symptomatic atrial flutter, one with sick sinus syndrome, and three with persistent hypervagotonia manifested as atropine-reversible prolongation of atrioventricular nodal refractoriness. Therapy based on these findings provided complete symptomatic relief in 14 and improvement in one of these 17 patients during a mean follow-up of 18 +/- 10 months. Therapy based on electrophysiologic testing was ineffective in two of the 17 patients. Syncope persisted in four of the eight patients in whom electrophysiologic study did not define a probable arrhythmic mechanism. These observations indicate that full electrophysiologic evaluation with programmed stimulation is useful in the diagnosis and therapy of recurrent unexplained syncope.

CM and AP VDLs for continuous trains of clicks were recorded from guinea pigs having permanently fixed round‐window membrane electrodes. The experimenter monitored oscilloscope‐displayed evoked responses on line by manual adjustment of a motor driven recording attenuator. Bekesy‐audiometric‐type graphical traces were obtained having at least 8‐dB discrepancy (“amplitude” or envelope width) between descending and ascending VDLs. Comparable VDLs were also recorded photographically by making alternate down‐up sweeps across nominal threshold level with no feedback control of the attenuator. Frame‐by‐frame analysis of the film was made off line by measuring stimulus pulse intensity associated with the disappearance (descending VDL) and reappearance (ascending VDL) of the evoked response. No significant overlap of descending and ascending thresholds was found using the photographic method. Statements in the audiologic literature postulating hypothetical auditory nerve processes underlying Bekesy trace width are challenged. [Supported in part by NINDS.]

Nonsustained ventricular tachycardia (VTns) predicts mortality in several settings but its significance in patients (pts) with a history of sustained ventricular tachyarrhythmias is unknown. Pts in ESVEM were randomized to guidance method and to drug independent of VTns events. We grouped pts (n = 486) by frequency of VTns events on baseline 48hr drug-free HM: Gl ≡ No VTns (n = 70), G2 ≡ g0 to l0.25 runs/h (n = 190). G3 ≡ ≥0.25 to l1 runs/h (n = 109), G4 ≡ ≥ 1 runs/h (n = 117). There were no significant differences (p g 0.05) between groups with respect to age, ejection fraction, functional class, presenting arrhythmia, prior exposure to antiarrhythmic drugs or guidance method. Data are presented in order of group number (Gr1, 2, 3, 4, respectively). Significant differences were observed for sex (29, 8, 13, 15%female; p = 0.0008), previous myocardial infarction (6%, 10%, 22%, 23%; p = 0.0002), PVC/h (136, 146, 300, 735; p l 0.0001), pairs/h (1, 3,12, 60; p l 0.0001), and mean heart rate (77, 74, 74, 80 bpm; p = 0.0008). Because the significance of VTns may vary in pts with different disorders, an analysis was restricted to pts with ischemic heart disease (IHD, n = 414). Significant differences were observed for age (63, 65, 64, 67 yr; p = 0.01). sex (23, 6, 10,9%female, p = 0.0028). years since last myocardial infarction (MI) (3.7, 8.9, 9.1, 7.9yr; p l 0.0001), history of operative revascularization (8%, 29%, 30%, 38%; p = 0.0003), for PVC/h (151, 149,286, 769 PVC/h; p l 0.0001). mean pairs/h (1, 3, 12,62; P l 0.0001). mean heart rate (76, 74, 76, 81 bpm; p = 0.004), but not for ejection fraction, functional class, presenting arrhythmia, previous exposure to antiarrhythmic drugs, number of Mis, or angina since last MI. Variables based on presence/absence, on continuous and on stratified frequency measures of VTns events and the above variables were entered into a Cox proportional hazards regression model for: 1) pts discharged on a drug predicted to be effective, 2) all randomized pts (intention-to-treat), 3) pts with IHD. None of the VTns variables were significant independent predictors of arrhythmia recurrence or all-cause mortality. We conclude that significant clinical differences exist between groups of pts with different frequencies of VTns events. However, measures of VTns event frequency were not predictors of arrhythmia recurrence or mortality in this group of patients with known ventricular tachyarrhythmias.

Administration of adenosine (Ad) frequently terminates reentrant supraventricular tachycardias and may precipitate atrial fibrillation. We characterized the electrophysiologic effects of incremental doses (1, 3, 6 mg) of Ad in 8 pts (age 24–60) during elective electrophysiologic study. Ad was administered via a central catheter during pacing at cycle lengths (CU of 800, 600 and 500 msec. Monophasic action potentials (MAP) were simultaneously recorded from the RA and RV and analyzed off-line. Results Ad decreased atrial MAP at 90% repolarization (CL 600 msec) by 14, 28 and 35% (1, 3, 6 mg respectively). Ad's atrial effects were rate-dependent (graph A) and dissipated with a mean time constant of 3.2 ± 0.58 msec (graph B). Download : Download high-res image (72KB) Download : Download full-size image In conclusion, Ad causes marked shortening of human atrial action potential at doses even lower than those used clinically. These effects are ratedependent and may account for induction of atrial fibrillation by Ad.