Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q96S42 (nodal)
 22,877 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new protocol is described for non-invasive evaluation of electrophysiological effects of autonomic nervous system on both normal and abnormal atrio-ventricular conduction in patients with Wolff-Parkinson-White (WPW) syndrome. In 64 WPW patients with stable Kent-type ventricular preexcitation transoesophageal atrial pacing has been carried out to quantify changes in both atrioventricular (AV) node and Kent bundle refractoriness and maximal conductive capability induced by posture, physical exercise and psychophysiological activation. A significant shortening of AV nodal and accessory pathway refractory periods was found, induced by manoeuvres enhancing the sympathetic outflow, being the AV node the most sensitive structure. This finding suggests that an exhaustive investigation protocol of WPW patients should include the evaluation of the neurovegetative effects on cardiac electrophysiological parameters, under conditions which can reproduce as close as possible the individual situations a patient has to face in his real life.
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PMID:Effects of posture, effort and psychophysiological activation on atrio-ventricular node and Kent bundle refractoriness. 174 48

Since the first successful surgical intervention for Wolff-Parkinson-White syndrome by W. C. Sealy, a surgical electrophysiological intervention has been developed for every single supraventricular arrhythmia. The surgical rationale is based on the site of the mechanism of the arrhythmia and associated pathology which characterizes the "arrhythmogenic substrate". Wolff-Parkinson-White syndrome is a congenital heart disease characterized by an accessory atrioventricular connection distinct from the AV node-His bundle system. It is associated with AV reentrant tachycardia and/or atrial fibrillation with fast ventricular responses via the accessory pathway. The current surgical management is ablation of the accessory pathway using either an endocardial dissection or epicardial approach. Surgical ablation is associated with high efficacy and low morbidity. Epicardial dissection of the accessory pathway on the beating heart has helped to localize variant accessory pathways associated with Coumel's tachycardia or Mahaim's fiber electrophysiological entity. AV nodal reentrant tachycardia can be cured using direct AV nodal dissection (or perinodal cryoablation). Atrial flutter can be interrupted by cryoablation of the arrhythmogenic substrate located in the coronary sinus orifice of the region modifying atrial inputs. Chronotropic atrial function abolished by chronic or paroxysmal idiopathic atrial fibrillation can be restored using the corridor operation (sinus node-AV node insulation). Surgery is an alternative in patients with resistant atrial tachycardias. Currently surgery is indicated only after other non-invasive EP interventions have been either attempted or rejected.
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PMID:Surgery for supraventricular tachyarrhythmias. 176 6

We have investigated resting electrocardiograms from 1,299 athletic students taken in the same laboratory during the years 1973-1982 and compared them with electrocardiograms recorded in 151 age- and sex-matched sedentary controls. Fifty-two parameters were recorded for each electrocardiogram and computerized. We found that athletic students had a significant lower heart rate, longer PQ time and a prolonged QTc compared to control subjects. Athletes had higher maximal Q amplitudes in precordial leads, higher R in V1, and higher indices of right ventricular hypertrophy (RV1 + SV5) and left ventricular hypertrophy (Sokolow-Lyon and Grant indices). Furthermore, the athletes had higher maximal ST elevation and higher maximal T wave amplitudes in precordial leads. Sinus bradycardia was more frequent in athletes. All control subjects were in sinus rhythm whereas 0.9% of the athletes had other rhythms (nodal, coronary sinus or wandering pacemaker). Athletes and control subjects did not differ significantly with regard to premature beats, atrioventricular block, bundle branch block or the Wolff-Parkinson-White pattern. We conclude that training induces significant changes in heart rate, conduction times, ST elevation. QRS and T voltage, slow rhythm disturbances and atrioventricular and sinoatrial block were infrequent in the resting electrocardiogram taken in the supine position and disappeared immediately on sitting and during exercise. Training-induced electrocardiographic changes may partly be due to alterations in autonomic tone and partly to structural changes in the myocardium. Different normal criteria for left ventricular hypertrophy may be warranted in athletes.
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PMID:Electrocardiographic findings in athletic students and sedentary controls. 178 47

Ten patients (44 y), 6 with the Wolff-Parkinson-White syndrome, and none with hypertensive disease, underwent electrophysiological studies before and after intravenous infusion of a single dose of 1 mg rilmenidine administered over 15 min. The regimen produced a mean plasma rilmenidine concentration of 3.16 ng.ml-1 at the end of the infusion. There was no significant change in sinus cycle length, PR interval, QRS, QT duration or in PA, AH and HV intervals. Estimated sinoatrial conduction time and corrected sinus node recovery time did not significantly change. In one patient, however, an abnormal pause was noted after termination of rapid atrial pacing. The right atrial effective refractory period decreased from 209 to 194 ms. There was no significant change in the anterograde and retrograde block cycle length or in the refractoriness of the nodal, ventricular and accessory pathways. The cycle length of induced reciprocating tachycardia decreased slightly from 374 to 351 ms. No patient exhibited an abnormal response to the carotid sinus massage. The findings indicate that intravenous administration of 1 mg rilmenidine exerts modest effects on the electrophysiological parameters of the human heart.
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PMID:Electrophysiological effects of intravenous rilmenidine in man. 181 65

This report describes 20 consecutive patients who underwent surgical procedures for treatment of cardiac arrhythmias. 16 patients have been operated for WPW syndrome, always using the epicardial approach, without extracorporeal circulation. Three patients underwent surgery for atrio-ventricular nodal reentrant tachycardia, using a discrete perinodal cryotreatment, during normothermic extracorporeal circulation. In one case we used cryoablation of the atrial myocardium below the coronary sinus to treat atrial flutter. This operation was performed under normothermic extracorporeal circulation. In our observations, there was no early or late death; postoperative complications developed in 1 patient (5%) due to pericarditis. Ablation of the AP was completely successful in all the cases (100%) operated for WPW as well as for AVNRT syndromes and atrial flutter.
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PMID:Surgical treatment of cardiac arrhythmias. 182 Apr 5

In the recent years the approach to the patients with tachycardias due to the Wolff-Parkinson-White (WPW) syndrome has changed in relation to the favourable results obtained by the surgical treatment. In this review the significance of the pre-operative electrophysiologic study is analyzed, as to a guide to localize the accessory pathway and, in particular, to disclose the presence of complicated substrates, such as multiple accessory pathways, AV nodal reentry; these latter situations if not correctly diagnosed, are a cause of surgical failure. We report the use of the epicardial surgical approach (Guiraudon technique). With the recent modifications, this technique avoids in the most cases the use of extracorporeal circulation. This simplified and safe surgical technique is a suitable alternative to other therapeutic strategies.
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PMID:[The surgical treatment of pre-excitation syndromes]. 184 4

We studied the electrophysiologic effects of oral propafenone on induction of supraventricular tachycardia (SVT) in 10 patients with Wolff-Parkinson-White syndrome (5 manifest and 5 concealed accessory pathways). Nine patients had orthodromic SVT and one patient had atrial fibrillation with preexcited QRS (shortest RR 220 msec). Electrophysiologic studies were performed during control and 48 hours after oral propafenone administered in a dose of 300 mg every eight hours. Propafenone caused complete anterograde accessory pathway conduction block in 4 of 5 patients with manifest delta waves. Retrograde conduction through the accessory pathway was abolished in 6 of 9 patients in whom it was present during control. Sustained SVT was inducible in all 9 patients during control. Propafenone prevented induction of SVT in 8 of 9 patients (88.9%) and slowed the rate of induced SVT in one patient. In the patient with atrial fibrillation (AF) the accessory pathway was blocked and AF was not inducible. There was a significant increase in the effective refractory period (ERP) of the atrium (208 +/- 40 msec to 257 +/- 25 msec, p less than 0.01), atrioventricular (AV) node (less than or equal to 256 +/- 34 msec to greater than or equal to 324 +/- 35 msec, p less than 0.001) and ventricle (204 +/- 14 msec to 262 +/- 51 msec, p less than 0.01). The atrial paced cycle length at AV nodal block also increased from 288 +/- 51 msec to 389 +/- 51 msec (p less than 0.01) after the drug. Thus propafenone has potent inhibitory effects on accessory pathways and has additional significant effects on atrial, AV nodal and ventricular refractoriness.
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PMID:Electrophysiologic effects of oral propafenone in Wolff-Parkinson-White syndrome studied by programmed electrical stimulation. 189 3

The efficacy of verapamil and disopyramide phosphate for the termination and prevention of paroxysmal supraventricular tachycardia (PSVT) were studied electrophysiologically in 32 patients with inducible sustained PSVT (17 patients received verapamil, 15 patients received disopyramide). Twelve patients had atrioventricular nodal tachycardia, 7 had concealed and 13 had overt Wolff-Parkinson-White syndrome. Intravenous verapamil (0.15 mg/kg) terminated the sustained PSVT in 15 of the 17 patients (88%) by production of AV block in 13 patients, VA block in one, and a ventricular premature beat in one. PSVT could not be induced in any of these 15 patients after they had received verapamil. In the remaining 2 patients, PSVT could not be terminated by the use of verapamil, but the cycle lengths of PSVT were lengthened. Long-term oral dosages of verapamil of 120-240 mg/day were administered in 13 of the 17 patients. All patients except two, whose PSVT was unable to be effected by intravenous verapamil, were well controlled: PSVT disappeared in 7 patients and decreased in 4. Intravenous disopyramide (1.5 mg/kg) terminated induced PSVT in 10 of the 15 patients (67%) by production of VA block. Although PSVT could not be reinitiated in 5 of these 10 patients, non-sustained PSVT was induced in 2 and sustained PSVT was induced in 3 after having received disopyramide. PSVT was induced in all of the 5 patients who failed to respond to disopyramide. The cycle lengths of PSVT after administration of disopyramide remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Effects of verapamil and disopyramide phosphate on the termination, reinduction and long-term prevention of paroxysmal supraventricular tachycardia]. 210 70

Programmed transesophageal electrical stimulation was used to examine 733 rural inhabitants aged 16 to 70 years. Conduction dissociation along the atrioventricular node was revealed in 65 (8.8%) of the examinees, out of them 12 had induced paroxysms of atrioventricular nodal tachycardia. Atrioventricular tachycardia involving the accessory anomalous pathways was provoked in 10 subjects. Among them 2 had apparent, 1, latent, and 7, obscure forms of the Wolff-Parkinson-White syndrome. The induced paroxysms of atrioventricular tachycardias were sustained in 45.5% of the cases. Only 50% of the subjects had clinical signs of tachycardia in their medical histories.
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PMID:[Functional state of atrioventricular conduction and inducibility of atrioventricular reciprocal tachycardia]. 221 35

Antidromic circus movement tachycardia was documented in 36 of 345 consecutive patients with Wolff-Parkinson-White syndrome undergoing detailed electrophysiologic evaluation. Twenty-six patients were men and 10 were women (mean age +/- standard deviation 26 +/- 12 years [range 12 to 45]). Multiple accessory pathways were identified in 12 of these 36 patients (33%). Ten of the patients (67%) with clinically documented antidromic tachycardia had multiple accessory pathways. Dizziness and syncope occurred in 61 and 50% of patients with antidromic circus movement tachycardia. Six patients had clinical documentation of atrial fibrillation, and 4 patients (11%) were resuscitated from ventricular fibrillation. In the 36 patients, 56 distinct antidromic tachycardias were recorded and several different pathways were observed. Orthodromic tachycardia was the most frequently associated arrhythmia (72%). Dual atrioventricular nodal pathways were present in 12 patients (33%); however, atrioventricular nodal tachycardia could be initiated in only 2 of them. Interruption of the accessory pathway was successfully performed in all 20 patients undergoing surgery.
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PMID:Clinical and electrophysiologic characteristics of patients with antidromic circus movement tachycardia in the Wolff-Parkinson-White syndrome. 222 Jun 35


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