PubMed Health⌕ Search

Biomedical subjects

R A Spurrell

Publications and source records attributed to R A Spurrell.

At least 55 records · Page 3Linked to original sources
PubMed1980

Haemodynamic effects of oral salbutamol alone and in combination with sublingual isosorbide dinitrate in patients with severe congestive cardiac failure.

To examine possible augmentation of the effects of isosorbide dinitrate by salbutamol, haemodynamic measurements were made in 10 patients with severe chronic congestive cardiac failure who received isosorbide dinitrate 2.5 to 25 mg sublingually and salbutamol 4 to 12 mg orally, alone and in combination. Isosorbide dinitrate reduced mean left ventricular filling pressure from 29 to 18 mmHg and increased mean cardiac index from 1.7 to 2.0 1/min per m2, with no significant change in mean heart rate. Systemic arterial mean pressure fell from 85 to 72 mmHg. Salbutamol increased cardiac index from 1.8 to 2.2 1/min per m2. There was no significant change in left ventricular filling pressure, heart rate, or systemic arterial pressure. Compared with control, combined isosorbide dinitrate and salbutamol reduced left ventricular filling pressure from 27 to 19 mmHg and increased cardiac index from 1.8 to 2.7 1/min per m2, with no significant change in heart rate. Systemic arterial pressure fell from 82 to 75 mmHg. The reduction in left ventricular filling pressure by combined treatment was similar to that produced by isosorbide dinitrate alone, but the increase in cardiac index was significantly greater than that produced either by isosorbide dinitrate alone or salbutamol alone. Combined sublingual isosorbide dinitrate and oral salbutamol have an additive effect in improving left ventricular performance in patients with severe chronic congestive cardiac failure.

Aged↗
PubMed1980

Clinical antiarrhythmic effects of amiodarone in patients with resistant paroxysmal tachycardias.

Oral amiodarone, an iodine-containing antiarrhythmic agent, was administered to 72 patients with recurrent paroxysmal tachycardias. Thirty-nine patients had tachycardias associated with the Wolff-Parkinson-White syndrome, 15 patients had paroxysmal atrial fibrillation unassociated with the Wolff-Parkinson-White syndrome, and 18 patients had ventricular tachycardia. In all patients, the frequency of symptomatic attacks had not been reduced by at least three other antiarrhythmic agents alone or in combination. The response to amiodarone treatment was graded according to the patients' subjective response (total suppression, partial suppression, and no effect). Overall, 57 per cent of patients had total abolition of attacks and another 22 per cent had a partial suppression of attacks. Side effects, the most common of which were photosensitivity and gastrointestinal upsets, occurred in 44 per cent and were sufficiently severe to warrant withdrawal of treatment in 15 per cent. These results confirm that amiodarone is of considerable value in the treatment of recurrent paroxysmal arrhythmias resistant to other drugs.

Adolescent↗
PubMed1980

Radionuclide and hemodynamic assessment of left ventricular functional reserve in patients with left ventricular aneurysm and congestive cardiac failure. Response to exercise stress and isosorbide dinitrate.

The hemodynamic response to exercise stress was assessed in 17 patients with left ventricular (LV) aneurysm, demonstrated by contrast left ventriculography, and congestive cardiac failure (CCF) before and after sublingual isosorbide dinitrate (ISDN). Radionuclide ventriculography was performed at rest and during exercise in 14 patients. ISDN increased mean exercise LV stroke work index (LVSWI) from 31 to 39 g-m/m2 (p less than 0.001) and reduced mean exercise LV filling pressure from 38 to 25 mm Hg (p less than 0.001). Using the combined criteria of LVSWI and ejection fraction of the contractile section of the left ventricle (EFCS), no patient with rest EFCS of less than 40% achieved a good absolute response to exercise in LV performance with or without ISDN. Of the six patients with rest EFCS greater than or equal to 40% only three achieved a good response. While rest EFCS less than 40% indicates poor LV functional reserve, good LV functional reserve is not always indicated by rest EFCS greater than or equal to 40%.

Adult↗
PubMed1980

A microcomputer-based tachycardia termination system--a preliminary report.

A microprocessor-based system is described which employs the autodecremental mode of atrial pacing. Preliminary experience suggests that this modality of pacing retains the advantages of rapid asynchronous atrial pacing but reduces the risk of provoking resistant atrial tachyarrhythmias. If the technique continues to prove successful it is suitable for incorportation into a fully implantable pacemaker.

Cardiac Pacing, Artificial↗
PubMed1979

Atrial bigeminy with block associated with bradycardia and paroxysmal atrial fibrillation -- an important variant of the tachycardia-bradycardia syndrome.

Serial 2-channel 24 h dynamic ECGs in 7 patients who were referred with the "tachy-brady" syndrome for consideration for permanent cardiac pacing revealed: 1. atrial premature beats (APBs) which were conducted to the ventricles normally or aberrantly; 2. intermittent atrial bigeminy with block towards the ventricles (this rhythm mimicked sinus bradycardia with ventricular rates of 38-45 beats/min and the ectopic P waves were visible on only one of the ECG channels); 3. paroxysms of atrial fibrillation initiated by closely coupled APBs. These findings suggested that both the ventricular bradycardia and the atrial fibrillation were caused by frequent APBs and that pacing therapy was unnecessary. Disopyramide was given to 5 patients resulting in suppression of the arrhythmia and relief of symptoms. In one patient there was spontaneous resolution and one patient refused treatment. This variant of the "tachy-brady" syndrome can be successfully treated by suppression of abnormal atrial impulse formation without recourse to pacemaker implantation.

Adult↗
PubMed1979

The acute cardiac electrophysiological effects of intravenous sotalol hydrochloride.

The cardiac electrophysiological effects of sotalol were studied in ten patients (pts) aged 20--65 years undergoing intracardiac stimulation studies for palpitations (7 pts) or dizzy spells (3 pts). The following measurements were made: 1. basic sinus cycle length (SCL): 2. SINUS NODE RECOVERY TIME (SNRT) following overdrive pacing; 3. intra-atrial (PA), atrio-His (AH) and His-ventricular (HV) conduction intervals during regular atrial pacing; 4. effective refractory periods of the atria (AERP), AV node (AVERP) and ventricular myocardium (VERP). AV nodal functional refractoriness (AVFRP) was also determined. All measurements were repeated 10--15 min after i.v. administration of 0.4 mg/kg of sotalol. Results were analysed by the Wilcoxon Signed Rank test. Significant increases in SCL (p less than 0.01), AH (p less than 0.01). SNRT (p less than 0.01), AVERP (p less than 0.02) and AVFRP (p less than 0.01) were observed. These effects are consistent with the beta-blocking action of sotalol. The acute increase in AERP (p less than 0.01) is, however, not a common property of other beta-blockers and may be related to the 'class III' cellular effect of sotalol. These results are discussed in relationship to the electrophysiological effects of other beta-blocking drugs.

Adult↗
PubMed1979

Cardiac emission tomography in patients using 201thallium. A new technique for perfusion scintigraphy.

The distribution of 201thallium (Tl) in the myocardium has been studied by the new technique of emission tomography, and compared with standard gamma camera images in 5 patients. Tomographic imaging was carried out using a dual-detector scanner operated under the single-photon technique. Initial results have been promising, with visualisation of resting perfusion defects in patients with recent infarction and those with ventricular aneurysms. Emission tomography has also been performed at exercise, and has shown tracer deficits in the distribution of significant coronary stenoses. This new approach to myocardial perfusion scintigraphy may lead to improved sensitivity for detecting apical and inferior wall abnormalities by providing depth information not available from a conventional two-dimensional image.

Coronary Disease↗
PubMed1979

Ebstein's anomaly in association with anomalous nodoventricular conduction. Pre-operative and intra-operative electrophysiological studies.

A 13 year old girl with Ebstein's anomaly was investigated for refractory paroxysmal tachycardias and ventricular pre-excitation. Intracardiac electrophysiological studies demonstrated that ventricular pre-excitation was due to conduction in an anomalous nodo-ventricular pathway. Tachycardia occurred as a result of re-entry within the A-V node with pre-excitation during tachycardia due to conduction in the nodo-ventricular pathway. These tachycardias were controlled initially by medical therapy but because of increasing frequency of attacks, occasionally requiring D.C. conversion, further electrophysiological studies and epicardial mapping were undertaken. The epicardial surface of the right ventricle and right atrium were mapped during tachycardia. The results of the studies confirmed that a direct anomalous atrio-ventricular pathway was not present and that re-entrant tachycardia did not involve an accessory pathway of this type. A rapid atrial pacing system was implanted and paroxysmal tachycardias have been successfully controlled.

Action Potentials↗
PubMed1979

The effect of intravenous disopyramide phosphate on recurrent paroxysmal tachycardias.

1 Reccurent paroxysmal atrial, atrioventricular and ventricular tachycardias in 50 patients without acute coronary insufficiency, heart failure or metabolic abnormlity were treated with disopyramide phosphate in a dose of 2 mg/kg body weight infused over 5 min. 2 Conversion to sinus rhythm within 10 min of the completed infusion occurred in 10 of 14 (71%) patients with paroxysmal 'lone' atrial fibrillation, 3 of 7 (43%) patients with paroxysmal atrial flutter, 6 of 9 (67%) patients with paroxysmal atrial tachycardia, 5 of 9 (56%) patients with paroxysmal atrioventricular tachycardia associated with the Wolff-Parkinson-White syndrome and 8 of 11 (73%) patients with paroxysmal ventricular tachycardia. 3 Side effects: significant systemic hypotension in 3, high grade AV block in 1, an increased ventricular response producing symptoms in 4, post conversion asystole in 1 land sinus bradycardia in 2. 4 The anti-arrhythmic effect and arrhythmogenic side effects may be related to both the direct membrane stabilizing effect and the anticholinergic effect of disopyramide.

Atrial Fibrillation↗
PubMed1979

The response of regular re-entrant supraventricular tachycardia to right heart stimulation.

The study was designed to assess the effect of various forms of right atrial or ventricular stimulation on the termination of re-entrant "supraventricular" tachycardias. Standard electrophysiological techniques were used in 81 patients to study 86 stable tachycardias. All tachycardias were initiated by single or double atrial or ventricular premature stimuli or incremental atrial pacing. Eight groups of tachycardia circuit were defined in terms of the anterograde and retrograde pathways. Termination of each tachycardia was studied by atrial underdrive, ventricular underdrive, rapid atrial stimulation and single or double atrial and ventricular premature extrastimuli. Intranodal re-entrant tachycardias formed 33% of the total and WPW tachycardias as a whole formed 55% of the total number of arrhythmias. The remainder were comprised of atrial tachycardia (5%), tachycardias in association with a partial AV nodal bypass (3%) and pre-excited tachycardias (5%). A single atrial extrastimulus was most effective where the circuit involved the right atrium. Atrial underdrive was consistently less successful than a single atrial extrastimulus in all groups. Rapid atrial pacing was effective in all groups, but caused transient atrial flutter or fibrillation in a proportion of each group except one. Ventricular underdrive stimulation was most effective in those groups where the right ventricle was involved in the circuit, but tended to be less effective than programmed single or double ventricular extrastimuli. Pacemakers designed to deliver appropriately timed single or double extrastimuli may offer an important alternative to other pacing modalities.

Adolescent↗
PubMed1979

Intravenous disopyramide phosphate and ventricular overdrive pacing in the termination of paroxysmal ventricular tachycardia.

Both antiarrhythmic drugs and bursts of rapid ventricular pacing provide alternatives to DC cardioversion for the treatment of paroxysmal ventricular tachycardia. This report considers the individual and combined success of burst ventricular pacing and intravenous disopyramide phosphate in the tretment of 11 examples of paroxysmal ventricular tachycardia. Rapid ventricular pacing, at a rate of up to 50 beats/min faster than the tachycardia rate terminated 7 of the tachycardias. Intravenous disopyramide resulted in increased tachycardiac cycle length (342 +/- 34 ms-385 +/- 56 ms), increased QRS complex width (147 +/- 42 ms-180 +/- 41 ms) and termination of 8 the tachycardias. The remaining 3 tachycardias could be terminated by bursts of ventricular pacing following the infusion of disopyramide. Of these, 2 could not be terminated prior to disopyramide. The use of both techniques allowed the extinction of all 11 tachycardias and prevented the need to proceed to DC conversion.

Adult↗
PubMed1979

Detection of postinfarction left ventricular aneurysms by first pass radionuclide ventriculography using a multicrystal gamma camera.

Eighteen patients with a history of previous anterior myocardial infarction and suspected left ventricular aneurysms were studied both by contrast left ventriculography and by first pass radionuclide ventriculography using Technetium99m and a computerised multicrystal gamma camera. The radionuclide study successfully identified all 14 patients with aneurysms and all 4 with diffusely hypo-kinetic ventricles. Ejection fraction calculated from the change in radioactive counts in the left ventricle correlated well with that calculated from the area-length method from the contrast angiogram (r = 0.83). Ventricular volumes calculated from the area-length formula for both contrast and radionuclide angiograms correlated closely (r = 0.85 and r = 0.89 for end-systolic and end-diastolic volumes, respectively). In the patients with aneurysms, there was a close correlation between the extent of akinesis, as assessed by the two methods (r = 0.94). The ability of the radionuclide ventriculogram to provide accurate information on global and segmental ventricular function, and to differentiate between segmental and diffuse ventricular dysfunction, enables the method to act as a screening procedure in the investigation of patients with suspected left ventricular aneurysms.

Adult↗
PubMed1979

Sinus node dysfunction associated with absence of right superior vena cava.

A 41-year-old man presented with dizziness associated with sinus bradycardia and sinus arrest. An attempt to implant a transvenous pacing lead was frustrated by absence of the right superior vena cava. The left superior vena cava persisted and drained via the coronary sinus into the right atrium. Absence of the right superior vena cava may present with symptomatic sinus node dysfunction and may require an epicardial demand pacing system.

Adult↗