Search PubMed⌕ Search

Biomedical subjects

G Sloman

Publications and source records attributed to G Sloman.

At least 55 records · Page 3Linked to original sources
PubMed1976

Changes in heart dipole moment after surgical correction of atrial septal defect.

Spatial dipole moment of the heart (M) was measured in patients before and 1 to 2 weeks after repair of atrial septal defect. In normals three peaks of M were found, corresponding to excitation of the septum (M1), ventricular walls (M2), and basal portion of ventricles (M3). Most of the patients also had an M2a peak at 52 to 56 per cent of QRS duration. The patients with secundum defects were divided into two groups, A and B, depending on whether right ventricular pressure was less than or greater than 30 mm. Hg. M1 was smaller for the Group B patients than for the normals for Group A and decreased slightly after surgery. M2 was about half normal for Group A and one third normal for Group B. After surgery M2 increased for both Groups but was still below normal. There were small mean clockwise rotations of the M2 vector in the horizontal plane PO. The M2a vector pointed to the right anterior or posterior and generally downward. In three Group A patients the M2a peak disappeared PO but in two others it increased in magnitude with a counterclockwise rotation in the horizontal plane. In the Group B patients, M2a increased in all cases. The M3 vectors generally increased slightly in magnitude postoperatively. M3 pointed posteriorly in the normals but to the right in the patients, with little change in direction after surgery. Both P and T curves dropped in magnitude after surgery. The changes observed may be due in part to restoration of right ventricular blood volume towards normal after surgery. The remaining VCG abnormalities should be due to right ventricular hypertrophy.

Adolescent↗
PubMed1976

Wenckebach phenomenon in the exit area from a transvenous pacing electrode.

An unusual type of exist block from a transvenous pacing electrode was recorded in a 63-year-old man with an acute inferior infarct and cardiogenic shock. The pacemaker artefact to QRS interval increased gradually till there was loss of capture. A gradual change from I:I pacing rhythm to 4:3 and 3:2 Wenckebach cycles was recorded. This was followed by a fixed 2:I pacemaker artefact to QRS block.

Electrocardiography↗
PubMed1976

Inhibition of demand pacemakers caused by potentials associated with inspiration.

A 69-year-old man with a permanent demand pacemaker and a unipolar electrode system had intermittent failure of pacing during deep inspiration. Pacing was not interrupted when the unit was switched to fixed rate mode by an external magnet. Thus, the problem was not caused by a change in electrode position or to a loose connexion. The likely cause was inhibition by non-cardiac potentials, possibly myopotentials associated with respiration.

Aged↗
PubMed1975

Clinical experience with verapamil.

Verapamil administered by the intravenous route restored sinus rhythm in 33 out of 40 episodes of supraventricular tachycardia. The drug was also effective in reducing ventricular rate in patients with atrial fibrillation. Intracardiac conduction studies using His bundle electrograms showed prolongation of atrioventricular nodal conduction in eight out of nine cases after 5 mg of verapamil were given. The distal conduction was unaffected. Bradycardia and hypotension occurred in two cases and responded promptly to intravenous administration of atropine. Verapamil is an effective antiarrhythmic agent which is, in general, free from significant side effects.

Arrhythmias, Cardiac↗
PubMed1975

Establishment of the Melbourne mobile intensive care service.

As the majority of deaths after infarction occur in the first hour, a mobile intensive care ambulance service has been instituted in Melbourne to enable adequate care and early monitoring facilities. Initially the service was manned by doctors and ambulance officers, but currently each ambulance is manned by two specially trained officers. Over a 27-month period 52 patients have been resuscitated from ventricular fibrillation or ventricular standstill. Half of the patients had sustained a definite acute myocardial infarction and another 16 had probable but not proven myocardial infarction. Of the 52 patients, 31 survived to leave hospital and all patients known to be alive are leading active and useful lives. In spite of an initial fear that medical treatment might be overused or misused by the officers, this has not been the case, and only about 13% of patients have received drugs from the officers. This paper deals with the setting up, staffing and training of the ambulance service and reviews its results.

Adult↗
PubMed1975

Haemodynamic effect of intravenous verapamil in controlled atrial fibrillation.

The haemodynamic effect of intravenous verapamil was assessed in eight digitalised patients with atrial fibrillation, at rest and on exercise. The reported regularisation of the ventricular rate in atrial fibrillation with verapamil, was also examined. The only significant haemodynamic effect attributable to the drug was an increased stroke volume which was in accordance with significant heart rate slowing which occurred at rest and both during and after exercise. There was no significant change in cardiac output. Although the heart rate slowed in all studies, regularisation of the R-R interval did not occur.

Adult↗
PubMed1975

Assessment of cardiovascular side effects of therapeutic doses of tricyclic anti-depressant drugs.

An assessment of the side effects of therapeutic doses of tricyclic anti-depressant drugs was attempted in 32 patients with depressive illness. The patients studied had no evidence of clinical heart disease or hypertension and were not receiving any other drugs. Moderate increase in heart rate and mild prolongation of atrioventricular conduction occurred. No significant effect on the corrected QT interval or blood pressure was found. There was no correlation between the increased heart rate, prolongation of the atrioventricular conduction time (PR interval) and plasma nortriptyline levels measured in 20 out of 32 patients.

Adult↗
PubMed1975

The floppy mitral valve syndrome--a review of fourteen patients requiring valve surgery.

The correlation of clinical features with the operative findings in 14 patients with a floppy mitral valve is discussed. The clinical course is typified by rapidly progressive disability. An abrupt deterioration was present in five of our subjects and this may be due to rupture of chordae tendinea or stretching of the valve apparatus. The redundancy of the anterior cusp in 13 of our series may explain the absence of mid systolic clicks in all except one patient. The diagnosis of prolapse can be difficult to make prior to surgery because the prolapsed cusp may be masked by the regurgitant contrast medium. Hypokinesis and prominent inflow sacculation of the left ventricular inflow tract suggest an associated myocardial abnormality. Calcium was present in one valve and thus mitral valve calcification does not exclude the possibility of a floppy valve in patients with mitral regurgitation.

Adolescent↗
PubMed1975

His bundle electrogram in patients with acute myocardial infarction complicated by atrioventricular or intraventricular conduction disturbances.

Seventy-two patients with acute myocardial infarction complicated by atrioventricular or bundle-branch block or a combination of both had His bundle electrogram studies performed during their stay in the coronary care unit. In 19 of the 72 patients a repeat His bundle electrogram was performed before discharge from hospital. These studies demonstrated that 30 of the 32 patients with atrioventricular block and narrow QRS complexes had a block above the origin othe His spike (proximal block). Eleven patients in this group had repeat His bundle electrograms performed before discharge and in 3 patients there was evidence of residual atrioventricular nodal dysfunction. Both the hospital and follow-up mortality in this group was low and there was no evidence to suggest that permanent pacing would benefit these patients. Of the 18 patients with bundle-branch block and a normal PR interval, 9 had prolongation of the HV interval, but there was no difference in mortality in patients with normal or prolonged HV intervals. Twenty-two patients with bundle-branch block also developed atrioventricular block. In 5 of these patients the site of the AV block was proximal and in 14 it was distal, while 3 patients had both proximal and distal block. The hospital mortality in those patients who progressed to second- or third-degree atrioventricular block was considerably higher than in those patients who remained in first-degree atrioventricular block.

Acute Disease↗
PubMed1975

Successful surgical resection of a chronic false aneurysm of the left ventricle.

The case of a patient with a chronic false aneurysm of the left ventricle diagnosed three years after a documented myocardial infarction is reported. The patient presented with a mass seen on the chest x-ray examination. The correct diagnosis was made by ventriculography and the aneurysm was successfully resected.

Chronic Disease↗
PubMed1975

Intracardiac conduction defects following overdose of tricyclic antidepressant drugs.

Atrioventricular and intraventricular conduction were assessed in 4 patients with tricyclic antidepressant overdosage. The proximal or A-V nodal conduction (A-H) was normal, but 3 patients showed a drug-related increase in the QRS duration and His-Purkinje (H-V) conduction time. One patient with a normal H-V interval had a normal width QRS. The findings were independent of the heart rate and suggested a "quinidine-like effect" of the tricyclic drugs when ingested in suicidal doses. All 4 patients had normal intracardic conduction when restudied 8 days later. Procainamide and quinidine have similar effects on the intracardiac conduction and would appear undesirable in the treatment of cardiac arrhythmias in patients with tricyclic overdosage. Practolol in a dose of 20 mg by intravenous injection reduced the heart rate and caused a relative increase in the A-H interval but did not affect either the distal atrioventricular or intraventricular conduction. Although there was a slight drop in blood pressure, it may be a safer drug to use.

Aged↗
PubMed1975

The effect of toxic and therapeutic doses of tricyclic antidepressant drugs on intracardiac conduction.

Intracardiac conduction studies using His bundle electrography (HBE) were performed in 14 patients admitted to hospital following an overdosage of one of the tricyclic antidepressant drugs and in another 12 patients before and during administration of therapeutic doses of nortriptylline. Amongst the former group, 7 of 8 patients showed impaired distal intracardiac conduction (H-V interval) following overdosages of nortriptyline, imipramine or amitriptyline but none of the 6 patients with doxepin overdosage. The prolonged H-V interval had returned to normal at a repeat study 7 days later. In the therapeutic dose study, 5 of 12 patients showed an increase in the H-V interval by more than 10 msec during treatment with nortriptyline. Four of these 5 patients had plasma nortriptyline levels of over 200 ng/ml. Tricyclic antidepressant drugs show a quinidine-like effect in toxic, and in some patients, in therapeutic doses. This finding may having a bearing on the treatment of cardiac arrhythmias in patients following overdosage with these drugs and may provide a clue to the reported increase in the incidence of sudden deaths in 'cardiac patients' following therapeutic doses of such agents.

Antidepressive Agents, Tricyclic↗