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Biomedical subjects

D Dymond

Publications and source records attributed to D Dymond.

16 recordsLinked to original sources
PubMed1999

Platelet IIb/IIIa antagonists followed by delayed stent implantation. A new treatment for vein graft lesions containing massive thrombus.

The percutaneous treatment of saphenous vein graft lesions containing angiographically massive thrombus is associated with a high risk of distal embolisation and no-reflow. The optimal management for these lesions remains unclear and a challenge to the interventional cardiologist. Five cases are described in whom the risks of percutaneous angioplasty were felt to be excessive owing to a high thrombus load. Each case was treated with a bolus and infusion of abciximab (ReoPro; Eli Lilly-a platelet glycoprotein IIb/IIIa receptor antagonist) at least 24 hours before further angiography. Repeat angiography of the culprit vein graft, following treatment with abciximab alone, demonstrated a major reduction in the thrombus score and the presence of TIMI 3 flow in each case. Immediately following repeat angiography, angioplasty with stent insertion was performed successfully with no distal embolisation or no-reflow phenomenon. This staged approach, with abciximab used alone to reduce thrombus load, is a new treatment for vein graft lesions containing massive thrombus.

Abciximab↗
PubMed1990

A randomized dose-ranging study of rt-PA in acute myocardial infarction. Effects on coronary patency and fibrinolytic parameters.

This study was designed to examine the relationships between dose of Wellcome two-chain recombinant tissue type-plasminogen activator (BW rt-PA) and coronary patency and fibrinolytic parameters in acute myocardial infarction (AMI). In an open randomized study, patients with AMI (determined by ECG) and symptoms of less than 4 h duration without contraindications for fibrinolytic therapy were treated with rt-PA in nominal doses of 20 (7.7 MU), 50 (14.8-29.6 MU) or 100 mg (29.6-48.2 MU) administered over 90 min followed by intravenous heparin. Coronary patency was determined by coronary arteriography of the infarct-related artery and haematological parameters (fibrinogen, plasminogen, alpha 2-antiplasmin and fibrin(ogen) degradation products) measured at 90 min. Coronary patency increased in a dose-related manner to 53% (95% C.I. 37-69%) in the 100 mg/90 min group. Logistic regression demonstrated a relationship between dose (in MU kg-1) and coronary patency. Fibrinogen at 90 m was reduced to 74 (61.5-86.4%) of the pooled plasma standard in the nominal 100 mg group. Patients with a higher predose fibrinogen had higher reductions of fibrinogen. Serious bleeding occurred in three (3%) patients, and no intracranial bleeds were reported. BW rt-PA produces dose-related patency of the coronary arteries with moderate, dose-related reduction in fibrinogen.

Aged↗
PubMed1980

Suppression of long-standing incessant ventricular tachycardia by amiodarone.

A 25 year old man had experienced virtually incessant ventricular tachycardia since the age of 16 years, and complained of increasing lethargy and shortness of breath over the past 5 years. Despite medical therapy with numerous conventional antiarrhythmic agents, no single drug or combination of drugs had successfully controlled the tachycardia. Isotope and contrast angiography revealed an enlarged left ventricle with poor function. Electrophysiological studies demonstrate earliest endocardial activation at the left ventricular apex. No electrical procedure terminated tachycardia. Following institution of amiodarone, continuous ECG monitoring revealed periods of sinus rhythm alternating with periods of ventricular bigeminy. Repeat isotope angiography indicated a considerable improvement in L.V. function. There was a corresponding reduction in heart size on the chest radiograph. Clinical improvement was evidenced by disappearance of lethargy and shortness of breath. This report demonstrates that amiodarone, a new antiarrhythmic agent, may suppress long standing incessant ventricular tachycardia resistant to other antiarrhythmic agents. The marked reduction in heart size on amiodarone may suggest that the associated cardiomegaly is secondary to tachycardia.

Adult↗
PubMed1980

Dual isotope stress testing in congenital atresia of left coronary ostium. Applications before and after surgical treatment.

A 38-year-old women presented with an 11-year history of angina pectoris. Coronary arteriography disclosed a large right coronary artery which filled the entire left coronary tree retrogradely. The left main coronary artery ended blindly and was not connected to the aortic root. There were no atherosclerotic lesions in any vessel. Exercise thallium-20l scintigrams showed a perfusion defect in the anterior region of the left ventricle and exercise first pass radionuclide ventriculography showed anterior hypokinesis of the left ventricle with an ejection fraction of 54 per cent, compared with 60 per cent at rest. An aortocoronary saphenous vein graft was constructed to the left coronary artery. Four months after operation the patient is free from symptoms. Repeat thallium scintigrams were normal. Exercise radionuclide ventriculography after operation disclosed no wall motion abnormality, and ejection fraction on exercise was 70 per cent. The mechanism of angina in this patient is unclear but may have been related to the abnormal timing of delivery of blood to the left ventricular myocardium. Dual radionuclide stress testing showed abnormalities after operation. This non-invasive approach may be useful in the assessment of the physiological significance of coronary anomalies and of the value of corrective surgery.

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↗
PubMedDate not supplied

Is the waiting list a safe place for outpatients awaiting coronary bypass surgery?

This study was undertaken to identify the safety of outpatients awaiting coronary bypass surgery. An audit of the outcome of 92 such outpatients at one Regional centre was undertaken by a retrospective review of medical records. Outcome measures were: time on the waiting list, anti-ischaemic medications, readmission for unstable angina, myocardial infarction and death. Almost half of the patients underwent surgery within three months, and three-quarters waited less than six months. No outpatient death occurred. However, 4 of the 7 adverse events occurred within this period. Despite advanced disease, the safety of outpatients awaiting coronary surgery within such a short time frame appeared to be acceptable, the only adverse events being non-fatal and occurring unpredictably.

Adult↗