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Biomedical subjects

P Morton

Publications and source records attributed to P Morton.

16 recordsLinked to original sources
PubMed1992

Hemodynamic effects of different temporary pacing modes for the management of bradycardias complicating acute myocardial infarction.

Twelve patients requiring temporary pacing following acute myocardial infarction (AMI) (10 heart block, 2 junctional bradycardia) had hemodynamic measurements taken with ventricular demand pacing at 80 ppm (VVI80), ventricular demand pacing at the atrial rate (VVIa), physiological pacing (DDD), and spontaneous (intrinsic) rhythm. VVI80 mode did not improve any hemodynamic parameter compared with spontaneous rhythm. VVIa mode improved diastolic and mean arterial pressures only. DDD mode improved most hemodynamic parameters compared with spontaneous rhythm (cardiac output by 29% [P less than 0.0001]; blood pressure: diastolic by 24% [P less than 0.01], systolic by 19% [P less than 0.01], mean by 21% [P less than 0.005]; pulmonary wedge pressure by 10% [P = 0.057] and right atrial pressure by 24% [P less than 0.005]) and also significantly improved some parameters compared with VVIa (cardiac output by 20% [P less than 0.001], systolic blood pressure by 11% [P less than 0.01] and right atrial pressure by 15% [P less than 0.01]). Physiological pacing is hemodynamically superior both to ventricular pacing and spontaneous rhythm for patients requiring temporary pacing following AMI. Ventricular pacing at 80 ppm has little hemodynamic advantage over spontaneous rhythm.

Adult↗
PubMed1990

Management of acute coronary occlusion during percutaneous transluminal coronary angioplasty: experience of complications in a hospital without on site facilities for cardiac surgery.

OBJECTIVE: To determine whether percutaneous transluminal coronary angioplasty may be safely performed in cardiology centres in the United Kingdom without immediate on site cardiac surgical cover for complications arising at angioplasty. DESIGN: Retrospective review of coronary angioplasties and complications in a hospital without on site cardiac surgical cover. SETTING: All angioplasties were performed in the catheterisation laboratory of the Belfast City Hospital. Revascularisation surgery for complicated coronary angioplasty was performed in the cardiac surgical unit of the Royal Victoria Hospital, 2.4 km away from the catheterisation laboratory. PATIENTS: 540 Coronary angioplasties were performed on 512 patients between late 1982 and November 1988. Indications included stable angina, unstable rest angina, and suitable coronary disease at coronary arteriography after myocardial infarction. MAIN OUTCOME MEASURES: In hospital mortality after complicated coronary angioplasty and delay to surgical revascularisation after acute coronary occlusion at angioplasty. RESULTS: Coronary angioplasty was successful in 444 cases (82%). Acute coronary occlusion occurred in 35 cases (6.5%). Twelve patients required urgent revascularisation surgery and were transferred safely to the surgical unit; none of these patients died. A mean delay of 268 minutes (range 180-390 minutes) occurred before revascularisation compared with 273 minutes (range 108-420 minutes) in the Royal Victoria Hospital, where on site surgical cover was available. The principal cause of delay was the wait for a cardiac operating theatre to become available and not the transfer time between hospitals. Five deaths occurred after coronary angioplasty, a mortality of 0.9%. Three deaths were related to acute coronary occlusion. The absence of immediate surgical help did not influence the outcome in any patient. CONCLUSION: With careful selection of patients coronary angioplasty may be safely performed in a hospital without on site cardiac surgical facilities, provided that these are available at a nearby centre.

Acute Disease↗
PubMed1990

Intravenous streptokinase for acute myocardial infarction reduces the occurrence of ventricular late potentials.

The occurrence of ventricular late potentials in survivors of acute myocardial infarction treated with intravenous streptokinase was compared with that in a conservatively treated group and the relation between ventricular late potentials and patency of the infarct related artery was examined. Of 115 patients admitted with a first infarct, 55 were treated with intravenous streptokinase (streptokinase group) and 60 were treated conservatively (non-streptokinase group). A signal averaged electrocardiogram was recorded in all patients and coronary angiography was performed in 45 (81.8%) of the streptokinase group and in 21 (35%) of the non-streptokinase group. At a 40 Hz filter setting ventricular late potentials were significantly less common in patients treated with streptokinase (9 (16.4%) of 55) than in those who were not (26 (43.3%) of 60). A total of 66 patients underwent angiography. Of the 26 who had closed infarct-related arteries, 17 had ventricular late potentials at a 40 Hz filter setting (sensitivity 65.4%, specificity 95%) and 38 of the 40 patients with a patent infarct-related artery did not have ventricular late potentials (sensitivity 80.9%, specificity 89.5%). Patients with acute myocardial infarction treated with intravenous streptokinase were significantly less likely to have ventricular late potentials than conservatively treated patients and the absence of ventricular late potentials at 40 Hz filter setting was a good non-invasive predictor that the infarct-related artery was patent.

Arrhythmias, Cardiac↗
PubMed1989

Oral acyclovir in the treatment of herpes zoster in general practice.

A double-blind, randomised trial evaluated the efficacy of oral acyclovir, 800 mg 5 times daily for 7 days, in acute herpes zoster and postherpetic neuralgia. Forty patients aged 16 years or over, presenting to their general practitioners within 3 days of rash onset, received acyclovir, while 43 patients received placebo. Acyclovir reduced the extent and duration of the rash, the spread of the rash to adjacent dermatomes and the incidence of disseminated lesions. It shortened the period of new lesion formation and reduced the incidence of ulceration. The weekly prevalence of pain was reduced on acyclovir by the fourth week, with a reduction in the monthly prevalence of chronic pain in the second and third months and a reduction in associated local neurological symptoms between months 3-6. Total analgesic use in the first 4 weeks was reduced by acyclovir, but during follow up there was no difference in the prevalence of analgesic use between groups. There were slightly fewer medical events on acyclovir in the second week, but the frequency was the same in each group for the rest of the 6 months. Biochemical and haematological tests showed no adverse effects of treatment.

Acute Disease↗
PubMed1989

Pathological changes after intravenous streptokinase treatment in eight patients with acute myocardial infarction.

At necropsy five of eight patients (mean age 57 years) who died after intravenous streptokinase treatment for severe acute myocardial infarction (mean Peel index = 18) were found to have a patent infarct related coronary artery. Coronary artery stenoses were caused by fibrofatty atheromatous plaques; there were no residual thrombi in the lumen or acute intimal lesions. Three of these infarcts were of partial thickness (less than two thirds wall width) with sparing of the outer third of the myocardium and subendocardial zones. In the other three patients the infarct related coronary arteries remained histologically closed with residual lumen thrombi and underlying intimal lesions. Two infarcts were transmural. Six of the eight infarcts were noticeably haemorrhagic. Myocardial haemorrhage was confined to areas of necrotic myocardium and did not affect viable regions. These findings suggest that thrombus overlying a complex lesion may be more difficult to lyse than thrombus overlying a simple fibrofatty plaque. They also suggest that myocardial haemorrhage outside the infarct area, which might lead to cardiac rupture or delayed healing, does not usually occur.

Acute Disease↗
PubMed1988

Relation of coronary arterial patency and left ventricular function to electrocardiographic changes after streptokinase treatment during acute myocardial infarction.

One hundred and eighty-eight patients with evolving acute myocardial infarction were treated with intravenous streptokinase. Serial 12-lead electrocardiograms were recorded for 3 hours after treatment and inspected for rapid repolarization changes of the ST segment and T wave. Abrupt electrocardiographic repolarization changes were observed in 106 patients (56%) and were strongly predictive for an open infarct-related coronary artery at a mean of 6 days after treatment (predictive value = 0.92, sensitivity = 0.67). Abrupt electrocardiographic changes were not observed in 82 patients (44%). This absence was not a good predictor of an occluded infarct-related coronary artery (predictive value = 0.4). There was no relation between the presence or absence of abrupt electrocardiographic changes and global or regional left ventricular function after streptokinase treatment. Abrupt repolarization changes after thrombolytic treatment indicate a high probability of an open infarct-related artery. When abrupt repolarization changes do not occur, the patency of the infarct-related coronary artery cannot be predicted with accuracy. Serial electrocardiographic recordings do not provide sufficient information about coronary patency to eliminate the need for coronary arteriography.

Aged↗
PubMed1987

Topical benzyl alcohol reduces cataract surgery need: two long-term double blind studies.

Substances derived from biotransformation of non-steroid antiinflammatory drugs (NSAID) produced by patients responsive to the biological liquid oxidant activity (BLOA) test, have been shown to have anticataract activity. They are all aromatic alcohols with physico-chemical properties similar to benzyl alcohols (BA); they were very efficacious in preventing in vitro (cyanate, heat) cataracts and in vivo (uveitis, radiation, selenite) cataracts but had no effect on sugar cataracts. The mechanism underlying this effect seems to be mainly antioxidant together with a stabilizing effect on lens membrane integrity and a stimulating effect on Na-K ATPase and membrane sodium pump. The well balanced lipo- and hydro-solubility of these compounds makes them very suitable for topical application to the eye as lipid solubility is the major factor governing transcorneal penetration of drugs. In the two long-term double blind studies on humans described here, comparing BA, placebo and Catalin in the topical treatment of progressive cataract rapid (2-3 weeks treatment) reversal of incipient cataract was obtained accompanied by a marked improvement of vision and by a significantly lower percentage of eyes requiring surgery after 22 months treatment with BA than with placebo and Catalin. In conclusion, further studies on the effect on the eye of BA and similar compounds such as phenyl-ethanol are advisable especially because they are already used as preservatives in eye-drop formulations.

Administration, Topical↗
PubMed1987

Coronary artery surgery and myxoedema.

A patient with a preoperative diagnosis of myxoedema had triple vessel coronary artery bypass surgery. The perioperative and postoperative course was essentially uneventful. The most appropriate management of a patient with coronary artery disease who has concomitant myxoedema is first to improve myocardial blood flow by relieving coronary obstruction and then to treat the thyroid deficiency.

Adult↗
PubMed1987

Pathology of the heart and conduction system in lymphoma and leukaemia.

The clinical and pathological findings in two patients with non-Hodgkin's lymphoma and two patients with T helper cell prolymphocytic leukaemia affecting the heart are described. All four patients had extensive malignant disease, with infiltration of multiple organs. Cardiac infiltration varied from microscopic foci in one case, to grossly identifiable tumour deposits destroying and replacing normal heart structures in three cases. Two patients with infiltration of the conduction system had abnormal electrocardiograms and cardiac dysfunction: one died suddenly, and the other died in heart failure. A third patient with widespread cardiac lymphoma did not show any electrocardiographic abnormalities or dysfunction. Clinicians should be aware of the possibility of cardiac and conduction system disease, particularly in the light of the evolution of specific antitumour chemotherapeutic agents.

Aged↗
PubMed1986

Comparison of transdermal nitrate and isosorbide dinitrate in chronic stable angina.

The effects of transdermal nitrate (TN) (Transiderm-Nitro TTS, Geigy Pharmaceuticals, one 10 cm2 patch daily) and oral isosorbide dinitrate (ISDN) (Sorbitrate, Stuart Pharmaceuticals, 10 mg three times daily) were compared in a group of 20 patients with chronic stable angina pectoris. Treadmill exercise duration was prolonged from a median time of 365 s to 428 s after ISDN (P less than 0.05), but was unchanged after TN. The difference between the active treatments was not significant. Weekly consumption of glyceryl trinitrate (GTN) increased during treatment with TN from a median value of 5.5 to 6.3 (P less than 0.05). A decrease was observed after ISDN (7.8 to 3.9, P = NS), and the difference between the drugs was significant (P less than 0.01). Systolic arterial pressure was significantly lower during the ISDN than during the TN treatment period in both the supine (135 +/- 5 vs 128 +/- 5 mm Hg; P less than 0.05) and standing positions (134 +/- 5 vs 122 +/- 5 mm Hg; P less than 0.05). No change in weekly attack rate, the degree of ST depression at angina on treadmill testing, or the number of episodes of ST depression recorded during a 24 h period by Holter monitoring was observed after either drug. In this study, an antianginal effect was demonstrated for ISDN but not for TN. It is suggested that the dose of TN may have been inadequate to demonstrate such an effect, and further studies using a higher dose schedule will be required.

Administration, Oral↗
PubMed1986

Acute haemodynamic effects of pinacidil in man.

The acute haemodynamic effects of i.v. pinacidil 0.2 mg kg-1 infused over 8 min were studied in 10 normotensive patients undergoing cardiac catheterisation. Mean arterial pressure fell from 94 +/- 3 mmHg (mean +/- s.e. mean) before infusion to 74 +/- 3 mmHg at 10 min after commencing infusion (P less than 0.001) and during this time heart rate increased from 75 +/- 4 to 106 +/- 7 beats min-1 (P less than 0.001). Significant changes were recorded until the end of the observation period (70 min after commencing infusion). Cardiac index increased from 3.2 +/- 0.2 to 4.0 +/- 0.2 l min-1 m-2 (P less than 0.001) and systemic vascular resistance fell from 16 +/- 1 to 10 +/- 1 units (P less than 0.001) at 10 min after commencing infusion. By the end of the observation period, the values had returned to pre-infusion levels. Only small changes in pulmonary haemodynamics were observed. These results indicate that pinacidil acts as a peripheral arteriolar vasodilator, and as such may have a role in the treatment of arterial hypertension and of cardiac failure.

Adult↗
PubMed1979

Gastrointestinal mucormycosis.

Mucormycosis is an acutely malignant fungal disease causing local thrombosis and infarction. Gastrointestinal infection most commonly occurs in diabetics or in the immunologically compromised. This case demonstrates the radiological appearances of the gastrointestinal lesion and prolonged survival with amphotericin-B therapy.

Adult↗
PubMed1979

Dextranomer: a review of its general properties and therapeutic efficacy.

Dextranomer is a hydrophilic dextran polymer advocated as a 'cleansing agent' for various types of exudating wounds or ulcers, including stasis (venous) ulcers and decubitus ulcers. It appears to exert its effect by a capillary action which absorbs wound exudate, as well as wound debris and micro-organisms, into the dextranomer beads or into the spaces between the beads, thus removing such products from the wound surface. Dextranomer is an aid to wound or ulcer management, and does not directly affect tissue repair in such ulcers, but as with other 'cleansing' agents or techniques, removal of debris (and possibly micro-organisms) from the wound could be expected to promote natural healing. Reports of its effectiveness in open studies, often in patients with seemingly resistant lesions, have been encouraging. Similarly, in comparative trials results have usually favoured dextranomer, but a clear indication of the relative efficacy and benefits as compared with other treatments used for exudating lesions has not yet emerged. Further well designed comparative studies are needed to provide such information.

Animals↗