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Biomedical subjects

R G Charles

Publications and source records attributed to R G Charles.

At least 37 records · Page 2Linked to original sources
PubMed1987

Holter monitoring in patients with mitral stenosis and sinus rhythm.

To determine the type and frequency of supraventricular arrhythmias in patients with mitral stenosis and sinus rhythm we studied 63 such patients, mean (sd) age 48.8 (8.2) years, by 24 hour ambulatory ECG monitoring. Thirty-five patients (55.6%) had supraventricular tachyarrhythmias. Twenty-five (39.7%) had paroxysmal atrial tachycardia, 14 (22.2%) atrial fibrillation, 8 (12.7%) multifocal atrial tachycardia and 5 atrial flutter. Ninety-five per cent (101) of episodes were asymptomatic and 96% non-sustained. Supraventricular premature beats occurred in 59 patients with couplets and triplets in 40 (63.5%) and 28 (44.4%), respectively. Frequent supraventricular premature beats, couplets, triplets and episodes of paroxysmal arrhythmias were commoner in patients greater than 50 years. Ectopic atrial rhythms with varying P wave morphology occurred in 12 patients (19%). Nine patients (14.3%) had suffered systemic embolic episodes. We conclude that supraventricular ectopic and tachyarrhythmias occur frequently in patients with mitral stenosis and sinus rhythm and that most paroxysms are non-sustained and asymptomatic.

Adult↗
PubMed1985

Rate-responsive ventricular pacing: clinical experience with the RS4-SRT pacing system.

Eighteen patients (11 men and 7 women) with symptomatic second or third degree atrioventricular block underwent implantation of the rate-responsive RS4-SRT pacing system. Exercise tolerance in RS4 mode was compared to that in VVI mode by randomized double-blind treadmill stress testing. Following hospital discharge, RS4 function was assessed by repeat exercise testing and 24-hour Holter monitoring. Difficulty in obtaining satisfactory P-wave amplitudes at implantation (mean 3.1 +/- 1.5 mV) resulted in prolonged implantation times (mean 79.4 +/- 26.4 minutes). Following implantation, 10 patients (58%) showed a significant ventricular rate response to exercise, seven did not, and one remained in sinus rhythm. For responders, peak ventricular paced rate and double product were significantly greater in RS4 than in VVI mode, being 101.8 +/- 5.8 vs. 74.3 +/- 0.4 beats per minute and 20.1 +/- 2.9 vs. 15.5 +/- 3.7 beats per minute X mmHg X 10(-3), respectively (p less than 0.001). However, treadmill times (10.5 +/- 2.6 vs. 9.7 +/- 3.3 minutes) and work done (5.51 +/- 2.01 vs. 4.97 +/- 2.33 joules X 10(-5] were not significantly different (p = 0.22). Following hospital discharge, repeat exercise testing and 24-hour Holter monitoring demonstrated RS4 function in 11 of 16 and 15 of 18 patients, respectively. We conclude that, due to unreliable atrial sensing, the RS4-SRT pacing system does not provide the reliable rate-responsiveness required to improve exercise tolerance.

Aged↗
PubMed1984

Antibiotic prophylaxis for pacemaker implantation: a prospective randomized trial.

Prophylactic antibiotics are frequently prescribed for patients undergoing permanent pacemaker implantation even though data confirming their effectiveness are limited. Five hundred patients requiring elective permanent pacemaker implantation or generator replacement were prospectively randomized either to receive or not receive prophylactic antibiotic treatment at the time of implantation. The implantation site was treated with 10% povidone-iodine solution and 0.5% alcoholic chlorhexidine preoperatively. The wound were inspected for evidence of infection at 3 days and 1, 3, 6 and 12 months postimplantation. Three patients (two receiving prophylactic antibiotics and one no antibiotics) developed pacemaker pocket infection; Staphylococcus aureus was the pathogenic organism in each case (P = 0.56). Eighteen patients developed clinical evidence of superficial wound inflammation requiring antibiotic treatment but not pacemaker removal. Six had received prophylactic antibiotics and 12 had not (P = 0.27). We conclude that pacemaker pocket infection is unusual with careful preoperative skin preparation and close postoperative follow-up. Under these circumstances prophylactic antibiotic treatment is of no practical value.

Adult↗
PubMed1983

Diagnosis of coronary embolism: a review.

Coronary embolism is an uncommon but distinct clinical entity. It can be diagnosed clinically, and should be suspected when acute myocardial infarction occurs in association with an underlying condition which predisposes to embolism. The most common are valvular heart disease, a prosthetic heart valve, infective endocarditis, cardiomyopathy with mural thrombus and arrhythmia. The diagnosis may be obscured by atypical symptoms and transient ECG changes. The diagnosis is supported by the demonstration of normal coronary arteries by selective coronary arteriography. Treatment with long-term anticoagulants may prevent further emboli. Additional antiplatelet drugs are also necessary in patients with prosthetic heart valves.

Adult↗
PubMed1982

The assessment and selection of patients for heterotopic heart transplantation.

In the 2-year period 1979-1980, 34 patients were assessed at Groote Schuur Hospital as candidates for heterotopic heart transplantation. Ischaemic heart disease was the most common underlying cause (19 patients), with cardiomyopathy (9), rheumatic heart disease (2), failed transplants (3), and endomyocardial fibrosis (1) as the other causes of myocardial disease. Five patients were not accepted into the transplant programme, 2 declined after being accepted, and in 3 the initial decision of acceptance was later reversed. Nine patients died while awaiting suitable donors, the mean survival time from the date of acceptance being only 26 days. Fifteen patients underwent heterotopic heart transplantation, 11 remaining alive at the end of the period of study; 8 had normally functioning donor hearts but 3 had suffered irreversible rejection and awaited a second transplant.

Adolescent↗
PubMed1982

Coronary embolism in valvular heart disease.

Coronary embolism is considered to be rare but recent evidence suggests that it may be underdiagnosed, and implicated in acute myocardial infarction associated with angiographically normal coronary arteries. Twenty-six patients were studied. In six, coronary embolism was a primary cause of death confirmed at autopsy. In 20 patients, 23 episodes of coronary embolism were diagnosed clinically. The left coronary system was occluded in 65 per cent, transient electrocardiographic changes occurred in 30 per cent, and either no history or an atypical history of acute myocardial infarction occurred in 29 per cent. Other systemic emboli occurred in 25 per cent. Aortic valve lesions were present in 70 per cent and combined mitral and aortic valve disease in 55 per cent of the patients. The incidence of coronary risk factors was low. Sequelae included increased dyspnoea (35 per cent), ventricular aneurysm (25 per cent) and cardiac failure (12 per cent). Angina rarely followed acute myocardial infarction.

Adult↗
PubMed1981

Myocardial sarcoidosis. A case report.

A 63-year-old man with sarcoidosis developed recurrent ventricular tachyarrhythmias, intermittent heart block and congestive cardiac failure. Transvenous endomyocardial biopsy demonstrated sarcoid infiltration of the myocardium. Ventricular tachyarrhythmias were abolished with amiodarone and prednisone.

Cardiomyopathies↗
PubMed1981

The importance of ergonovine maleate provocation in the diagnosis of coronary artery spasm. A case report.

Ergonovine maleate produced transient vasospastic occlusion of the entire left anterior descending coronary artery in a young woman with atypical angina pectoris and normal coronary arteries. Electrocardiographic evidence of extensive anterior subendocardial ischaemia persisted for days after an episode of spontaneous pain, suggesting that the patient was at risk of developing completed infarction due to coronary spasm.

Adult↗
PubMed1980

Long-term survival after orthotopic and heterotopic cardiac transplantation.

Five long-term survivors of heart transplantation were reinvestigated. Two patients had undergone orthotopic heart transplantation over 11 and 9 years earlier and constitute two of the world's longest-surviving patients after this procedure. Three patients had undergone heterotopic heart transplantation (one left heart bypass alone and two biventricular bypass) four to six years earlier. Four of the five patients had had only one or no documented acute rejection episodes. Three had been given blood transfusions. None had had particularly good tissue matching in relation to the donor on HLA typing. All five patients were leading full and active lives. At review two patients had significant coronary artery disease, one severe, presumably due to chronic immune-complex deposition. Heart transplantation remains a major undertaking, but it can offer the patient many years of good-quality life.

Adult↗
PubMed1978

Spontaneous mid-oesophageal rupture.

The clinical presentation and management of spontaneous rupture of the middle third of the oesophagus is described in two patients. Early presentation and treatment in one case led to uncomplicated recovery. In the other patient late presentation and diagnosis resulted in delayed surgical intervention with an unsuccessful outcome. The nature of this rare lesion is discussed and nine previously described cases are reviewed.

Adult↗
PubMed1977

Endocardial pacing electrode design and rate of displacement.

In a series of 184 patients with a permanent endocardial pacing system the rate of electrode displacement was 3-0 per cent using the Devices L120SR electrode, and 23-1 per cent using the Devices S120 electrode. The technique and pacing team were unchanged during the period of study. It is suggested that the design and mechanical characteristics of the elctrodes were responsible.

Electrodes, Implanted↗
PubMed1977

Polyradiculoneuritis and Mycoplasma pneumoniae infection.

A patient with severe Mycoplasma pneumonia developed polyradiculoneuritis and respiratory failure. The acute phase of the illness was complicated by a myocarditis, and recovery of neurological function was slow. Residual left hemidiaphragmatic paralysis was present 1 year after onset of the illness.

Acute Disease↗