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Biomedical subjects

D E Ward

Publications and source records attributed to D E Ward.

At least 235 records · Page 13Linked to original sources
PubMed1979

Ectopic ventricular tachycardia in association with a concealed accessory pathway.

Ventricular tachycardia may result in retrograde atrial depolarization. In all previous examples studied by intracardiac recording techniques retrograde conduction to the atria has been thought to occur via the normal conduction system. In the patient reported here, 1 : 1 retrograde conduction with atrial preexcitation during ventricular tachycardia indicated the presence of a concealed accessory pathway. This was confirmed by the phenomenon of exact atrial capture. The achievement of atrioventricular dissociation during tachycardia by atrial overdrive pacing excluded a reentrant tachycardia involving such a pathway. The widely variable H--V interval in the presence of a constant V--A interval during tachycardia suggested anterograde His bundle depolarization following atrial activation over the accessory pathway. This hypothesis was supported by the long V--H interval during tachycardia and the relationship of the ventricular, atrial and His bundle electrograms of the first and least beat of the tachycardia. This report illustrates the value of careful electrophysiological investigation in evaluating the relationship of an accessory pathway to the tachycardia mechanism.

Electrophysiology↗
PubMed1979

Ventricular preexcitation due to anomalous nodo-ventricular pathways: report of 3 patients.

3 patients with paroxysmal palpitations had surface electrocardiographic evidence of type B preexcitation with a small positive delta wave in lead V1. At study all patients had an abnormally short H-V interval. Programmed atrial premature stimuli at progressively shorter coupling intervals resulted in prolongation of AV conduction time and increasing preexcitation. In 2 patients early atrial premature stimuli elicited atrial echo beats or sustained tachycardia with preexcited QRS complexes. In these patients the accessory pathway did not appear to be involved in the tachycardia circuit. It is postulated that the site of reentry is within the AV node with preexcitation occurring as the result of conduction in an anomalous node-ventricular pathway. In the 3rd patient, preexcitation occurred within a restricted range of coupling intervals of an atrial premature stimulus. The electrophysiological responses of nodo-ventricular and His-ventricular pathways to atrial stimulation are compared and contrasted.

Adult↗
PubMed1978

Gaps in anterograde conduction in patients with the short PR interval, normal QRS complex syndrome.

Of 8 patients with the short PR interval, normal QRS complex syndrome studied recently, 3 reported here displayed gaps in anterograde conduction. Atrial premature beats at decreasing coupling intervals conducted with minimal AH prolongation until a zone within the cardiac cycle was reached where conduction failed at a supra-Hisian level. Conduction resumed at earlier atrial coupling intervals and was associated with a sudden increase in the AH interval and the appearance of atrial echo beats with earliest atrial activation on the proximal coronary sinus electrogram. It is suggested that the failure of anterograde conduction at relatively late atrial coupling intervals was caused by a short AH functional refractoriness produced by the pre-excitation of the lower AV junction by a partial AV nodal bypass. Conduction resumed only when early atrial premature beats found the extranodal pathway refractory and were transmitted with decremental delay through the AV node.

Adult↗
PubMed1978

Re-entrant tachycardia using two bypass tracts and excluding AV node in short PR interval, normal QRS syndrome.

In patients with the short PR interval, normal QRS complex syndrome, paroxysmal tachycardias are usually the result of circus movement involving the AV node and a partial or complete AV nodal bypass. We report 2 patients with this syndrome who suffered distressing rapid paroxysms of tachycardia but in whom there was evidence of a concealed direct VA connection. In both patients, tachycardia was initiated with critical AV prolongation distal to the His bundle, in response to programmed atrial premature stimuli. The constancy of the timing of the atrial echo from the onset of the QRS complex in the presence of a varying HV interval is evidence for involvement of the ventricles in the re-entry pathway. In addition, in both patients the appearance of left bundle-branch block during tachycardia was associated with appropriate prolongation of tachycardia cycle length consistent with the presence of a direct VA connection. The short AH interval during tachycardia and the absence of critical AH prolongation suggests the participation of a rapidly conducting pathway in the anterograde limb of the tachycardia circuit.

Adult↗
PubMed1978

Arrhythmias in ambulatory persons. A review and experience of 1,000 consecutive recordings.

The value of 24-hour ambulatory monitoring of the ECG for the diagnosis of symptoms of dizziness, palpitations and syncope is controversial. In this study results from a hospital-based, clinical service have been analysed. Of 1,000 consecutive dynamic electrocardiograms (DCG), 678 were performed for assessment of dizziness, syncope or palpitations in 405 patients. 36 of the patients had pacemakers. 60 DCGs were technically inadequate. The recordings were classified according to the correspondence between DCG findings and symptoms noted in the patient diary: (I) Completely diagnostic: significant arrhythmias (SA) corresponding to diary symptoms - 99 recordings. (II) Incompletely diagnostic: (a) absence of SA in the presence of diary symptoms - 90 recordings; (b) presence of SA but no diary symptoms - 197 recordings; (c) presence of SA corresponding to symptoms other than that for which the DCG was indicated - 52 recordings. (III) Non-diagnostic: absence of both SA and diary symptoms - 180 recordings. Incompletely diagnostic categories were regarded as clinically valuable in that they either excluded a cardiac arrhythmia as a cause of symptoms (group IIa) or they revealed SA which did not correspond to diary symptoms (group IIc). The absence of symptoms corresponding to SA was ascribed to poor diary keeping in 54 of 197 recordings. These results are discussed in the context of the findings in normal and symptomatic patients. A clinical 24-hour ambulatory ECG monitoring service provided useful diagnostic information in 65% of recordings and 74% of patients.

Adolescent↗
PubMed1977

Ambulatory monitoring of the electrocardiogram: an important aspect of pacemaker surveillance.

Of the 353 patients followed in the pacemaker surveillance clinic between July 1976 and July 1977, 25 patients complained of episodes of dizziness and faintness. 20 of these had normal pacing function and pacemaker parameters at routine clinic testing. 18 patients had 'demand' units and 2 had fixed-rate pacemakers. The indication for permanent pacing was complete heart block in 16 patients and sinoatrial disease in 5 patients. At clinic follow-up, there was unequivocal evidence of vertebrobasilar insufficiency in 5 patients and postural hypotension in 4 patients. In 11 patients, the cause of presyncope was not evident at the clinic. All patients were monitored by 24-hour tape recording until an episode of pre-syncope occurred. In 8 patients, there was evidence of intermittent failure to pace associated with the episodes of presyncope. In 2 patients, an additional cause for presyncope was found at clinic examination. Ambulatory 24-hour tape monitoring of the electrocardiogram is an important adjunct to pacemaker follow-up especially when other methods such as transtelephone monitoring are not available in the United Kingdom. Routine electronic testing of pacemaker function does not always reveal intermittent abnormalities related to changes in threshold or unstable electrode positions.

Ambulatory Care↗
PubMed1976

An artificial anterior chamber.

Corneas for penetrating keratoplasty that have been excised from the globe for storage ordinarily require punching of the donor tissue from the posterior surface. They may be trephined from the anterior surface when they are mounted on an instrument that forms a seal around the scleral rim of the excised cornea, allowing the endothelium to be supported physically by the liquid storage medium. The artificial anterior chamber protected the endothelial cells from damage as if they were still in the intact globe. The instrument allowed trephination to any desired depth and facilitated the cutting of corneal buttons with a rim of Descemet's membrane and endothelium. Sutures may be preplaced in the donor button before the button is seperated completely from the rest of the cornea. Iris prolapse did not interfere with the procedure.

Anterior Chamber↗
PubMed1970

Buruli ulcer.

Explore the source record for details and available documents.

Child, Preschool↗
PubMedDate not supplied

Rapid ventricular pacing to control resistant neonatal atrioventricular re-entrant tachycardias.

A 3-week-old baby presented with recurrent supraventricular tachycardias unresponsive to medical treatment. Several DC shocks were required to terminate tachycardia. An abbreviated electrophysiological study was undertaken to determine the cause of the tachycardia. Rapid ventricular burst pacing successfully terminated repeated attacks of tachycardia until successful therapy with amiodarone was established. This patient demonstrates the value of pacemaker treatment of a resistant atrioventricular tachycardia in a neonate.

Amiodarone↗