Search PubMed⌕ Search

Biomedical subjects

J G Sloman

Publications and source records attributed to J G Sloman.

At least 37 records · Page 2Linked to original sources

Chronic recurrent ventricular tachycardia--an electrophysiological study.

Electrophysiological techniques were used to study 17 patients with chronic recurrent ventricular tachycardia. Twelve of the patients had coronary disease, while eight had pre-existing intraventricular conduction defects. The site of origin of the tachycardia as deduced by analysis of the QRS morphology correlated well with the electrocardiographic evidence of the site of the old infarction. Ventricular tachycardia was induced by pacing techniques in eight patients while it occurred spontaneously during the study in two others. In only four of the eight patients in whom tachycardia was induced, could the arrhythmia be reinduced; the arrhythmia could not be reproduced in one, while reproducibility was not assessed in the remaining three. Tachycardia was terminated by pacing techniques in six patients and by DC cardioversion in four. Ventricular tachycardia was initiated with a run of "torsade de pointes" in four patients. Ventricular tachycardias with varying morphology were observed in three patients. Electrophysiological study was of significant benefit in patient management in 14 of the 17 patients, particularly those with pre-existing intraventricular conduction defects, undocumented tachycardia or undocumented syncope.

Adult↗

The use of balloon-tipped electrodes for permanent cardiac pacing.

A new balloon-tipped ventricular endocardial electrode for permanent artificial cardiac pacing is described. Following transvenous insertion of the electrode to the right ventricular apex, the distal balloon is inflated with contrast material in order to wedge the electrode tip between or beneath trabeculae and prevent displacement. fifty-nine electrodes were implanted, including a second generation type incorporating a wedge tip as well as the balloon. The incidence of displacement was 17% with 10% of cases being early, and 7% late. Early in the series, 50% Urografin was used to inflate the balloon and this resulted in premature deflation and early electrode displacement in two of the nine patients. When the concentration of Urografin was reduced, the balloon remained inflated for a longer period and the incidence of early displacement was reduced to 8%. However, there was still a late displacement of 8%. Only one wedge-tipped balloon electrode displaced. This electrode had a faulty sealing mechanism and the balloon could not be adequately inflated. There was a 3% incidence of early and a 3% incidence of late threshold problems with the electrode. However, name of the wedge-tipped balloon electrodes exhibited this problem. It was concluded that this new electrode did not fulfill its objectives. The total electrode failure rate, including displacements and episodes of high threshold was approximately 24%.

Aged↗

Similar QRS morphology in sinus rhythm and ventricular tachycardia.

A 74-year-old man with coronary artery disease and bifascicular block suffered recurrent tachycardia. Although the similarity of QRS morphology in tachycardia and sinus rhythm suggested a supraventricular origin, His bundle electrocardiography and programmed stimulation showed a ventricular origin. Digitalis toxicity was not an etiological factor and there was no evidence to suggest a His bundle tachycardia. The case illustrates that in occasional circumstances the onset of ventricular tachycardia may produce no change in QRS morphology thus making the diagnosis by conventional electrocardiographic criteria difficult.

Aged↗

Sinus arrhythmia in acute myocardial infarction.

Sinus arrhythmia, defined by means of a calculation of variance of the R-R interval on admission to hospital, was present in 73 of 176 patients admitted to a coronary care unit with acute myocardial infarction. These patients had a lower hospital mortality. They tended to have a higher incidence of inferior infarction, and a lower incidence of anterior infarction, and to have smaller infarcts as measured by the Norris index. The main difference between patients with sinus arrhythmia and without sinus arrhythmia related to heart rates on admission to hospital, the patients with the former having slower heart rates at that time.

Acute Disease↗

Acute myocardial infarction in women. The influence of age on complications and mortality.

The prognostic implications of a past history of ischaemic heart disease, site of infarction, ectopic ventricular dysrhythmias (ventricular premature beats (VPB) more than one in 10 sinus beats, and/or ventricular tachycardia (VT), ventricular fibrillation (VF), atrioventricular blocks (AVB), bundle branch blocks (BBB)) and the occurrence of electrical and/or mechanical complications during stay in the Coronary Care Unit (CCU) were analysed in 154 women with definte (WHO Class 1) acute myocardial infarction, admitted sequentially to the CCU over a four-year period. The prognosis in these women was then compared with the prognosis in a group which represented the general male population in the CCU and an age-matched group of men. The results showed that the long-term prognosis in women with acute myocardial infarction is remarkably similar to age-matched groups of men.

Acute Disease↗

The prognostic value of the HV interval in patients with acute myocardial infarction and bundle branch block.

HV intervals were measured in 42 of 119 patients in the acute phase of myocardial infarction associated with bundle branch block (BBB). The mean HV intervals of patients with right, left and incomplete bilateral BBB were similar. The hospital and subsequent mortality of patients with prolonged HV intervals did not differ significantly from that of patients with normal HV intervals. The HV interval appeared to remain stable over the following months in most patients in whom it was remeasured. We conclude that the HV interval cannot be used to select patients who might benefit from prophylactic long term pacing.

Bundle-Branch Block↗

Thyroid hormone levels and protein binding in patients on long-term diphenylhydantoin treatment.

The effect of long-term diphenylhydantoin (DPH) treatment on thyroid hormone concentrations and protein binding was determined in a randomized controlled trial. As has been demonstrated previously, total thyroxine (T4) concentrations were significantly depressed in patients on DPH. There was no significant effect on indirect indices of protein binding of thyroid hormones, and the free thyroxine index (FTI) was also significantly depressed. Triiodothyronine (T3) and thyrotrophin (TSH) concentrations were either unaffected, or only very slightly affected by DPH. Significant effects on the FTI were still apparent 4 weeks after discontinuing treatment. It is concluded that the depression of total T4 levels observed in vivo is not due solely to diminished protein binding, but may instead be largely explained by reports suggesting enhanced degradation of T4 following DPH therapy.

Adult↗

Cardiac arrest.

Cardiac arrest is easily recognized clinically and requires immediated cardiopulmonary resuscitation (CPR) by well trained personnel. The importance of prophylaxis is emphasized in high risk patients. The ABC regime of CPR and the technique of blind defibrillation are recommended in the management of cardiac arrest. Good results may be expected with ventricular fibrillation associated with some correctable factor or myocardial infarction. With a satisfactory CPR technique and prompt resuscitation, the incidence of complications is low.

Adult↗

Primary oxalosis with myocardial involvement and heart block.

An unusual case is described of primary oxalosis with renal failure and cardiac involvement with complete heart block. Although cardiac involvement rarely occurs, it nevertheless requires evaluation because of the therapeutic implications.

Heart Block↗

Changing results of treatment of infarction in a coronary case unit.

A comparison has been made between the first 300 patients admitted from 1963 to 1967 to the Coronary Care Unit (CCU) of The Royal Melbourne Hospital with transmural cardiac infarction, and two groups of similar numbers admitted in 1969 and 1974. While the age spectrum and duration of stay of survivors in the Unit has remained similar, there has been a reduction in mortality, most marked in the most recent group of patients. The improvement was seen in all age groups, but was statistically significant only in the patients under 50 years and over 70 years. The reduction occurred in both sexes and was most evident in the patients admitted with severe cardiac infarction. The improvement in results of treatment is due in part, at least, to improvements in management introduced since 1963.

Age Factors↗

Cardiac effects of different tricyclic antidepressant drugs.

The effects of tricyclic antidepressants on the heart are reviewed. Statistically significant increases in heart rate and in atrioventricular conduction times were found following the administration of tricyclic drugs to 32 depressed patients. The method of His bundle electrocardiography was used to study atrioventricular conduction in ambulant patients and in patients admitted after an overdose of tricyclic antidepressant drugs. Distal conduction defects were frequently found in patients following tricyclic overdosage, but these were not seen with doxepin overdosage. Impaired distal conduction was also found in occasional patients on therapeutic doses of tricyclic drugs. Some animal experiments giving similar results to the above clinical findings are also described. The clinical implications of these findings are discussed.

Amitriptyline↗