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M J Metcalfe

Publications and source records attributed to M J Metcalfe.

36 records · Page 2Linked to original sources
PubMed1993

Management of paroxysmal atrial fibrillation.

Paroxysmal atrial fibrillation is a common, poorly understood and difficult-to-treat arrhythmia. Although it tends to be treated in a similar fashion to chronic atrial fibrillation, its pathophysiology is different, and drugs commonly used for chronic atrial fibrillation may have only limited value in treating paroxysmal atrial fibrillation. A broad range of presenting clinical symptoms may be associated with this arrhythmia, and even in the asymptomatic patient, there may be a risk of serious thromboembolic events. In symptomatic patients, effective control of paroxysms with antiarrhythmic therapy can often be difficult, and the role of anticoagulation remains controversial. This review attempts to clarify these issues, by surveying the range of therapies available.

Anti-Arrhythmia Agents↗
PubMed1993

Improved detection of abnormal left ventricular wall motion using tomographic radionuclide ventriculography compared with planar radionuclide and single plane contrast ventriculography.

Tomographic radionuclide ventriculography is a technique which could have major advantages over conventional planar imaging, such as better assessment of ventricular wall motion abnormalities. This possibility was therefore investigated in 100 consecutive patients undergoing routine cardiac catheterization. Following angiography, planar blood pool images were conventionally acquired and tomographic imaging performed using the Aberdeen Section Scanner. All derived wall motion data were subsequently analysed in an objective and blinded manner. The mean age was 56 (range 33-71) and 79% were male. 67 patients had experienced prior myocardial infarction, 27 were categorized as having significant and six insignificant coronary artery disease. The detection rates for patients with prior myocardial infarction were 95% for angiography, 57% for planar imaging and 90% for tomography. Even taking patients with only prior anterior myocardial infarction, the detection rates were 94%, 63% and 91% respectively. For those residual patients with significant coronary artery disease, the rates were 7%, 0% and 59% respectively. Overall for the detection of patients with significant coronary artery disease, the sensitivity was 70%, 40% and 81% respectively. Patients with insignificant coronary artery disease did not demonstrate any abnormalities using any method. These results demonstrate that tomography and angiography have similar detection rates in the presence of significant coronary artery disease and both are superior to planar imaging.

Adult↗
PubMed1992

Dipyridamole.

Explore the source record for details and available documents.

Dipyridamole↗
PubMed1990

Association of patient delay with symptoms, cardiac enzymes, and outcome in acute myocardial infarction.

The delay between the onset of symptoms and the call for help is the longest single component of the time taken for patients with acute myocardial infarction to come under coronary care and receive thrombolytic therapy. In order to investigate factors influencing patient delay, visual analogue scores for pain, shortness of breath, and anxiety were obtained retrospectively from 250 patients with acute myocardial infarction, for the time of onset of symptoms, and for the time of the call for help. The predominant symptom was chest pain, followed by anxiety and breathlessness. Although all symptoms increased in severity after their onset, the initiation of a call was largely unexplained in terms of worsening symptoms. Patient delay had a skewed distribution with modal, median and mean values of up to 1 h, 1.5 h, and 11 h respectively. Patient delay was negatively correlated with the pain score at the time of calling, but most of the variance of patient delay could not be explained in terms of symptom scores. However, patient delay was independently and negatively related to maximum serum aspartate aminotransferase. During acute myocardial infarction, patients with higher cardiac enzyme levels experience more pain and delay less. This tendency for patients with more severe infarction and a greater risk of death to call for help sooner is an added reason for administering thrombolytic treatment at the first opportunity: those patients who call early have most to gain from prompt therapy.

Adult↗
PubMed1990

Time of occurrence, duration, and ventricular rate of paroxysmal atrial fibrillation: the effect of digoxin.

One hundred and thirty nine episodes of atrial fibrillation were identified from Holter recordings in 72 patients with paroxysmal atrial fibrillation. Paroxysms occurred more often by day than by night, suggesting that attacks are more closely associated with sympathetic than with vagal activity. In 41 patients who were not taking digoxin there were 79 episodes, and in 31 patients who were taking digoxin there were 60 episodes. Significantly more of the episodes that lasted for 30 minutes or more occurred in patients taking digoxin (13/17); the relative risk of a prolonged paroxysm associated with taking digoxin was 4.3 (95% confidence intervals 1.6-11.9). The mean (SD) ventricular rate at the onset of the paroxysms was not significantly different in those taking digoxin (140 (25) beats/min) and in those who were not (134 (22) beats/min). In paroxysmal atrial fibrillation, pretreatment with digoxin does not seem to reduce the frequency of paroxysms, or the ventricular rate when paroxysms occur, but it is associated with longer attacks.

Adult↗
PubMed1990

Six year follow up of a consecutive series of patients presenting to the coronary care unit with acute chest pain: prognostic importance of the electrocardiogram.

In a retrospective 6 year follow up data were obtained for 536 of 566 (95%) consecutive patients admitted to a coronary care unit with acute chest pain. Their diagnoses were acute myocardial infarction in 290 (54%), myocardial ischaemia in 164 (31%), pericarditis in 16 (3%), and non-cardiac in 66 (12%). Six year mortality was 36%, 24%, 0%, and 16% respectively. In patients with acute myocardial infarction a higher mortality rate during follow up was associated with a higher than average age, a higher than average creatine kinase, previous myocardial infarction, Q wave infarction, and the presence of reciprocal changes. The presence of reciprocal changes was associated with higher than average concentration of serum creatine kinase, indicating more extensive infarction. Infarction complicated by ventricular fibrillation or left bundle branch block was associated with a higher death rate. The electrocardiogram recorded at the time of acute myocardial infarction contains much useful prognostic information.

Adult↗
PubMed1989

Stroke distance in acute myocardial infarction: a simple measurement of left ventricular function.

Stroke distance was measured by means of doppler ultrasound in 100 consecutive patients with acute myocardial infarction. Mean stroke distance on days 1-5 after infarction was 72% of the predicted normal value for age and rose to 77% of normal by days 6-10. Stroke distance was lower after anterior (65%) than inferior infarction (75%), and was negatively correlated with peak serum aspartate aminotransferase (r = 0.47, p less than 0.001). Of 16 patients whose stroke distance on days 1-5 was below 50% of normal for age, 4 died, all within the first week. Of 84 patients whose stroke distance was 50% of normal or higher, only 1 died (at 13 days). The simple bedside measurement of stroke distance offers a practical method of monitoring left ventricular function in acute myocardial infarction: the measurement may have prognostic value.

Adult↗
PubMed1989

The effects of treatment with felodipine as a single agent in coronary artery disease.

In an earlier study one dose of the vasodilator felodipine improved haemodynamic function in patients with angina without having a negative inotropic effect. The haemodynamic response of sustained treatment with felodipine as a single agent in stable angina was investigated in a double blind crossover study of 25 patients. The dosage of felodipine was increased from 5 mg twice daily to 10 mg twice daily after two weeks. Twenty one patients completed the study, two were withdrawn because of acute myocardial infarction, and a further two because of symptoms of vasodilatation. Felodipine reduced both supine and erect blood pressure and increased the resting heart rate. Median exercise time was increased by 10% at two weeks and 7% at four weeks. There was a sustained reduction in the number of angina attacks and use of sublingual nitrate on active treatment. Felodipine has antianginal effects but these are limited and seem less than those of other related compounds. This finding is unexpected and possibly related to increased heart rate.

Adult↗
PubMed1989

Low-field cine magnetic resonance imaging in aortic valve disease.

Cine magnetic resonance imaging (MRI) holds considerable promise as a means of detecting abnormal blood flow patterns with the heart and great vessels. To date, the majority of techniques employed have required moderate to high field strengths. We describe a novel, low-field-strength approach that is technically undemanding and faster than conventional methods, which we have applied to the detection of aortic valve disease. A series of 26 patients with aortic stenosis or aortic regurgitation was compared with 21 normal subjects. All 20 patients with aortic stenosis and 15 of 16 patients with aortic regurgitation were identified. There were four false positives in the aortic stenosis group; all these patients had significant aortic regurgitation. There were no false positives in the aortic regurgitation group. Low-field cine MRI is a practical and useful technique for the detection of aortic valve disease.

Adolescent↗
PubMedDate not supplied

Have we identified the factors affecting prognosis following coronary artery bypass surgery?

Although coronary artery bypass graft (CABG) surgery has been an established therapeutic alternative for more than 20 years in the palliation of symptoms of ischaemic heart disease, the associated risk factors for subsequent mortality and morbidity in these patients remain unclear. This is pertinent, as CABG surgery does not affect the underlying pathological process and different factors affect the early and late postoperative outcomes. As one objective of CABG surgery is to provide symptomatic relief of angina, it is desirable to identify (and perhaps modify) the factors affecting prognosis and outcome. An awareness of these factors will allow better patient selection and the development of better screening and therapeutic interventions.

Adult↗