Anthony Ralph-Edwards - Academia.edu (original) (raw)

Papers by Anthony Ralph-Edwards

Research paper thumbnail of Effect of Left Ventricular Outflow Tract Obstruction on Left Atrial Mechanics in Hypertrophic Cardiomyopathy

BioMed Research International, 2015

Left atrial (LA) volumes are known to be increased in hypertrophic cardiomyopathy (HCM) and are a... more Left atrial (LA) volumes are known to be increased in hypertrophic cardiomyopathy (HCM) and are a predictor of adverse outcome. In addition, LA function is impaired and is presumed to be due to left ventricular (LV) diastolic dysfunction as a result of hypertrophy and myocardial fibrosis. In the current study, we assess the incremental effect of outflow tract obstruction (and concomitant mitral regurgitation) on LA function as assessed by LA strain. Patients with HCM (50 obstructive, 50 nonobstructive) were compared to 50 normal controls. A subset of obstructive patients who had undergone septal myectomy was also studied. Utilising feature-tracking software applied to cardiovascular magnetic resonance images, LA volumes and functional parameters were calculated. LA volumes were significantly elevated and LA ejection fraction and strain were significantly reduced in patients with HCM compared with controls and were significantly more affected in patients with obstruction. LA volumes and function were significantly improved after septal myectomy. LVOT obstruction and mitral regurgitation appear to further impair LA mechanics. Septal myectomy results in a significant reduction in LA volumes, paralleled by an improvement in function.

Research paper thumbnail of coronary artery bypass surgery A phase II dose-response study of hemoglobin raffimer (Hemolink) in elective

Research paper thumbnail of Management of papillary carcinoma arising in thyroglossal-duct anlage

Canadian journal of surgery. Journal canadien de chirurgie

Cysts of the thyroglossal duct are common congenital abnormalities. They present as asymptomatic ... more Cysts of the thyroglossal duct are common congenital abnormalities. They present as asymptomatic midline cervical swellings. The risk of malignant change is low; only 103 cases have been reported in the world literature, 85% of which were papillary adenocarcinomas. The appropriate treatment for this condition remains controversial. The authors describe three patients who had papillary carcinoma contained within a thyroglossal-duct rest. All were treated by cyst resection and thyroid suppression, but without thyroidectomy and radioactive thyroid ablation. Postoperatively, all patients remained disease free, with no recurrence at follow-up ranging from 10 to 29 years. Isolated papillary carcinomas arising from primitive thyroid remnants, associated with a palpably normal thyroid gland at surgery and a negative thyroid scan, can be treated adequately by excising the thyroglossal mass.

Research paper thumbnail of Preoperative cardiac evaluation of the patient with vascular disease

Canadian journal of surgery. Journal canadien de chirurgie

To review the literature and evaluate the investigation of cardiac risk factors, by tests and int... more To review the literature and evaluate the investigation of cardiac risk factors, by tests and intraoperative predictors, that will identify patients at high risk for vascular surgery. An English-language literature review of Index Medicus articles from 1961 to 1992. Published articles that addressed preoperative risk factors, diagnostic tests and intraoperative predictors were selected by multiauthor consensus. Independent extraction by multiple authors was utilized to abstract and assess the quality of data from selected references, with consensus determining inclusion or exclusion. From evaluation of published data, a number of factors were considered to put a patient scheduled to undergo vascular surgery at higher risk: symptomatic coronary artery disease; clinical evidence of coronary artery disease, congestive heart failure, aortic stenosis and recent myocardial infarction; laboratory findings of significant disease with cardiomegaly or significant dysrhythmias; and no symptoms but two or more risk factors. The authors propose an algorithm for the investigation of patients and stratification of risk to be considered in weighing the dangers versus the benefits of vascular surgery.

Research paper thumbnail of Sudden rupture of an indirect inguinal hernial sac with extravasation in two patients on continuous ambulatory peritoneal dialysis

Canadian journal of surgery. Journal canadien de chirurgie

Continuous ambulatory peritoneal dialysis (CAPD) is commonly used to treat patients suffering fro... more Continuous ambulatory peritoneal dialysis (CAPD) is commonly used to treat patients suffering from end-stage renal failure. This method can be used on a long-term basis and in the short term for patients awaiting renal transplantation. Inguinal hernias are a potential source of morbidity for these patients. Therefore, when patients with inguinal hernias require long-term peritoneal dialysis, the hernia should be repaired if the patient's medical status will allow it. The authors report on two patients maintained on CAPD who experienced rapid enlargement and perforation of a previously undiagnosed asymptomatic inguinal hernia. The hernia was repaired successfully, without complication, in both cases.

Research paper thumbnail of Massive perirenal and intra-abdominal bleeding after shock-wave lithotripsy: case report

Canadian journal of surgery. Journal canadien de chirurgie

Complications of extracorporeal shock-wave lithotripsy are rare, with an incidence of symptomatic... more Complications of extracorporeal shock-wave lithotripsy are rare, with an incidence of symptomatic perinephric hematoma ranging from 0.2% to 0.66%. A 59-year-old man had massive symptomatic retroperitoneal and intra-abdominal bleeding 24 hours after lithotripsy. The hemorrhage was managed successfully by conservative measures, which consisted of packed red blood cells and fresh frozen plasma. The literature on the bleeding complications of lithotripsy is reviewed and the risk factors are identified.

Research paper thumbnail of Bleeding gastric and duodenal ulcers: endoscopic therapy versus surgery

Canadian journal of surgery. Journal canadien de chirurgie

From a retrospective review of 156 patients with actively bleeding peptic ulcers, 61 patients had... more From a retrospective review of 156 patients with actively bleeding peptic ulcers, 61 patients had gastric ulcers and 95 patients had duodenal ulcers. Patients presented with hematemesis or melena or a combination of the two. Forty patients with gastric ulcers and 53 patients with duodenal ulcers were in shock. Twenty-five patients with gastric ulcers underwent surgery. Bleeding was controlled in all patients, but in the postoperative period five patients died of myocardial infarction, pulmonary embolism or septic multisystem organ failure. Of 36 patients who underwent endoscopic epinephrine sclerosis of the bleeding gastric ulcer, hemorrhage was controlled in 34. Two patients required reoperation for bleeding after surgery; both survived. Fifty patients with duodenal ulcers had surgery. Bleeding was controlled in all patients, but in the postoperative period 10 died of myocardial infarction and multisystem organ failure. Of 45 patients who underwent endoscopic sclerosis, bleeding was controlled in 40. Five patients required reoperation for bleeding after surgery; all survived. The authors conclude that endoscopic sclerosis should be the initial treatment for actively bleeding gastric and duodenal ulcers. If bleeding continues or recurs then surgery should be carried out.

Research paper thumbnail of Low Operative Mortality Achieved With Surgical Septal Myectomy: Role of Dedicated Hypertrophic Cardiomyopathy Centers in the Management of Dynamic Subaortic Obstruction

Journal of the American College of Cardiology, Jan 15, 2015

Research paper thumbnail of Surgical myectomy in obstructive hypertrophic cardiomyopathy

The Canadian journal of cardiology

Research paper thumbnail of Chukwuemeka A, Ko R, Ralph-Edwards A: Short-term low-dose propofol anaesthesia associated with severe metabolic acidosis

Anaesthesia and intensive care

Propofol-induced metabolic acidosis is well recognised in the paediatric literature, but the exis... more Propofol-induced metabolic acidosis is well recognised in the paediatric literature, but the existence of such a syndrome in adults remains contentious. In most reported cases, metabolic acidosis complicated prolonged administration of propofol in critically ill patients. We present a case of severe non-fatal reversible metabolic acidosis, without ventilatory depression or hypoxia, related to short-term propofol infusion in an adult during and after coronary artery bypass grafting. We suggest that lactic acidosis occurred in a genetically susceptible patient with an abnormality of mitochondrial function. This report discusses an unusual adverse effect of propofol anaesthesia and sedation and highlights the need for further investigation to define propofol toxicity.

Research paper thumbnail of Ulcerated aortic atheromatous plaque causing amaurosis fugax

The Canadian journal of cardiology, Jan 15, 2003

Research paper thumbnail of Left atrial mass

The Canadian journal of cardiology, 2002

Research paper thumbnail of Significance of left ventricular apical-basal muscle bundle identified by cardiovascular magnetic resonance imaging in patients with hypertrophic cardiomyopathy

European heart journal, Jan 14, 2014

Cardiovascular magnetic resonance (CMR) has improved diagnostic and management strategies in hype... more Cardiovascular magnetic resonance (CMR) has improved diagnostic and management strategies in hypertrophic cardiomyopathy (HCM) by expanding our appreciation for the diverse phenotypic expression. We sought to characterize the prevalence and clinical significance of a recently identified accessory left ventricular (LV) muscle bundle extending from the apex to the basal septum or anterior wall (i.e. apical-basal). CMR was performed in 230 genotyped HCM patients (48 ± 15 years, 69% male), 30 genotype-positive/phenotype-negative (G+/P-) family members (32 ± 15 years, 30% male), and 126 controls. Left ventricular apical-basal muscle bundle was identified in 145 of 230 (63%) HCM patients, 18 of 30 (60%) G+/P- family members, and 12 of 126 (10%) controls (G+/P- vs. controls; P < 0.01). In HCM patients, the prevalence of an apical-basal muscle bundle was similar among those with disease-causing sarcomere mutations compared with patients without mutation (64 vs. 62%; P = 0.88). The presen...

Research paper thumbnail of Cardiomyopathy

A Perioperative Transdisciplinary Approach, 2012

Research paper thumbnail of A phase II dose-response study of hemoglobin raffimer (Hemolink) in elective coronary artery bypass surgery

The Journal of Thoracic and Cardiovascular Surgery, 2004

Research paper thumbnail of Prevalence of tricuspid regurgitation and pericardial effusions following pacemaker and defibrillator lead extraction

International Journal of Cardiology, 2010

Research paper thumbnail of Nucleosome DNA repeat length and histone complement in a fungus exhibiting condensed chromatin

Experimental Cell Research, 1983

Fungal chromatins are reported to exhibit unusually short nucleosomal DNA repeat lengths. To test... more Fungal chromatins are reported to exhibit unusually short nucleosomal DNA repeat lengths. To test whether this is a phylogenetic feature of fungi or rather is correlated with an apparent absence of condensed chromatin in the organisms studied, we have examined the chromatin organization and the complement of basic nuclear proteins in the fungus Entomophthora, an organism which exhibits marked chromatin condensation. Micrococcal nuclease digestion of Entomophthora chromatin revealed a nucleosomal DNA repeat length of 197 +/- 1.2 base pairs (bp). This repeat length is 20-40 bp longer than that reported for any fungus. Entomophthora nucleosomes exhibited an HI-like protein which was much less basic than the HI histones reported for higher eukaryotes but which was similar in basicity to the HI histone reported for the fungus Neurospora. However, the nucleosomal DNA repeat length of Neurospora chromatin is reported to be unusually short, whereas that of Entomophthora was found to be typical of the repeat lengths observed for chromatins of higher eukaryotes. Thus, repeat length, at least in fungi, would not appear to be directly determined by the basicity of the fungal cognate of histone HI.

Research paper thumbnail of Permanent cardiac pacing after a cardiac operation: Predicting the use of permanent pacemakers

The Annals of Thoracic Surgery, 1998

Research paper thumbnail of Infective endocarditis in patients who had replacement of the aortic root

The Annals of Thoracic Surgery, 1994

Research paper thumbnail of Successful treatment of massive pulmonary embolism after coronary artery bypass grafting due to heparin-induced thrombocytopenia

The Annals of Thoracic Surgery, 1994

Research paper thumbnail of Effect of Left Ventricular Outflow Tract Obstruction on Left Atrial Mechanics in Hypertrophic Cardiomyopathy

BioMed Research International, 2015

Left atrial (LA) volumes are known to be increased in hypertrophic cardiomyopathy (HCM) and are a... more Left atrial (LA) volumes are known to be increased in hypertrophic cardiomyopathy (HCM) and are a predictor of adverse outcome. In addition, LA function is impaired and is presumed to be due to left ventricular (LV) diastolic dysfunction as a result of hypertrophy and myocardial fibrosis. In the current study, we assess the incremental effect of outflow tract obstruction (and concomitant mitral regurgitation) on LA function as assessed by LA strain. Patients with HCM (50 obstructive, 50 nonobstructive) were compared to 50 normal controls. A subset of obstructive patients who had undergone septal myectomy was also studied. Utilising feature-tracking software applied to cardiovascular magnetic resonance images, LA volumes and functional parameters were calculated. LA volumes were significantly elevated and LA ejection fraction and strain were significantly reduced in patients with HCM compared with controls and were significantly more affected in patients with obstruction. LA volumes and function were significantly improved after septal myectomy. LVOT obstruction and mitral regurgitation appear to further impair LA mechanics. Septal myectomy results in a significant reduction in LA volumes, paralleled by an improvement in function.

Research paper thumbnail of coronary artery bypass surgery A phase II dose-response study of hemoglobin raffimer (Hemolink) in elective

Research paper thumbnail of Management of papillary carcinoma arising in thyroglossal-duct anlage

Canadian journal of surgery. Journal canadien de chirurgie

Cysts of the thyroglossal duct are common congenital abnormalities. They present as asymptomatic ... more Cysts of the thyroglossal duct are common congenital abnormalities. They present as asymptomatic midline cervical swellings. The risk of malignant change is low; only 103 cases have been reported in the world literature, 85% of which were papillary adenocarcinomas. The appropriate treatment for this condition remains controversial. The authors describe three patients who had papillary carcinoma contained within a thyroglossal-duct rest. All were treated by cyst resection and thyroid suppression, but without thyroidectomy and radioactive thyroid ablation. Postoperatively, all patients remained disease free, with no recurrence at follow-up ranging from 10 to 29 years. Isolated papillary carcinomas arising from primitive thyroid remnants, associated with a palpably normal thyroid gland at surgery and a negative thyroid scan, can be treated adequately by excising the thyroglossal mass.

Research paper thumbnail of Preoperative cardiac evaluation of the patient with vascular disease

Canadian journal of surgery. Journal canadien de chirurgie

To review the literature and evaluate the investigation of cardiac risk factors, by tests and int... more To review the literature and evaluate the investigation of cardiac risk factors, by tests and intraoperative predictors, that will identify patients at high risk for vascular surgery. An English-language literature review of Index Medicus articles from 1961 to 1992. Published articles that addressed preoperative risk factors, diagnostic tests and intraoperative predictors were selected by multiauthor consensus. Independent extraction by multiple authors was utilized to abstract and assess the quality of data from selected references, with consensus determining inclusion or exclusion. From evaluation of published data, a number of factors were considered to put a patient scheduled to undergo vascular surgery at higher risk: symptomatic coronary artery disease; clinical evidence of coronary artery disease, congestive heart failure, aortic stenosis and recent myocardial infarction; laboratory findings of significant disease with cardiomegaly or significant dysrhythmias; and no symptoms but two or more risk factors. The authors propose an algorithm for the investigation of patients and stratification of risk to be considered in weighing the dangers versus the benefits of vascular surgery.

Research paper thumbnail of Sudden rupture of an indirect inguinal hernial sac with extravasation in two patients on continuous ambulatory peritoneal dialysis

Canadian journal of surgery. Journal canadien de chirurgie

Continuous ambulatory peritoneal dialysis (CAPD) is commonly used to treat patients suffering fro... more Continuous ambulatory peritoneal dialysis (CAPD) is commonly used to treat patients suffering from end-stage renal failure. This method can be used on a long-term basis and in the short term for patients awaiting renal transplantation. Inguinal hernias are a potential source of morbidity for these patients. Therefore, when patients with inguinal hernias require long-term peritoneal dialysis, the hernia should be repaired if the patient&amp;amp;amp;amp;#39;s medical status will allow it. The authors report on two patients maintained on CAPD who experienced rapid enlargement and perforation of a previously undiagnosed asymptomatic inguinal hernia. The hernia was repaired successfully, without complication, in both cases.

Research paper thumbnail of Massive perirenal and intra-abdominal bleeding after shock-wave lithotripsy: case report

Canadian journal of surgery. Journal canadien de chirurgie

Complications of extracorporeal shock-wave lithotripsy are rare, with an incidence of symptomatic... more Complications of extracorporeal shock-wave lithotripsy are rare, with an incidence of symptomatic perinephric hematoma ranging from 0.2% to 0.66%. A 59-year-old man had massive symptomatic retroperitoneal and intra-abdominal bleeding 24 hours after lithotripsy. The hemorrhage was managed successfully by conservative measures, which consisted of packed red blood cells and fresh frozen plasma. The literature on the bleeding complications of lithotripsy is reviewed and the risk factors are identified.

Research paper thumbnail of Bleeding gastric and duodenal ulcers: endoscopic therapy versus surgery

Canadian journal of surgery. Journal canadien de chirurgie

From a retrospective review of 156 patients with actively bleeding peptic ulcers, 61 patients had... more From a retrospective review of 156 patients with actively bleeding peptic ulcers, 61 patients had gastric ulcers and 95 patients had duodenal ulcers. Patients presented with hematemesis or melena or a combination of the two. Forty patients with gastric ulcers and 53 patients with duodenal ulcers were in shock. Twenty-five patients with gastric ulcers underwent surgery. Bleeding was controlled in all patients, but in the postoperative period five patients died of myocardial infarction, pulmonary embolism or septic multisystem organ failure. Of 36 patients who underwent endoscopic epinephrine sclerosis of the bleeding gastric ulcer, hemorrhage was controlled in 34. Two patients required reoperation for bleeding after surgery; both survived. Fifty patients with duodenal ulcers had surgery. Bleeding was controlled in all patients, but in the postoperative period 10 died of myocardial infarction and multisystem organ failure. Of 45 patients who underwent endoscopic sclerosis, bleeding was controlled in 40. Five patients required reoperation for bleeding after surgery; all survived. The authors conclude that endoscopic sclerosis should be the initial treatment for actively bleeding gastric and duodenal ulcers. If bleeding continues or recurs then surgery should be carried out.

Research paper thumbnail of Low Operative Mortality Achieved With Surgical Septal Myectomy: Role of Dedicated Hypertrophic Cardiomyopathy Centers in the Management of Dynamic Subaortic Obstruction

Journal of the American College of Cardiology, Jan 15, 2015

Research paper thumbnail of Surgical myectomy in obstructive hypertrophic cardiomyopathy

The Canadian journal of cardiology

Research paper thumbnail of Chukwuemeka A, Ko R, Ralph-Edwards A: Short-term low-dose propofol anaesthesia associated with severe metabolic acidosis

Anaesthesia and intensive care

Propofol-induced metabolic acidosis is well recognised in the paediatric literature, but the exis... more Propofol-induced metabolic acidosis is well recognised in the paediatric literature, but the existence of such a syndrome in adults remains contentious. In most reported cases, metabolic acidosis complicated prolonged administration of propofol in critically ill patients. We present a case of severe non-fatal reversible metabolic acidosis, without ventilatory depression or hypoxia, related to short-term propofol infusion in an adult during and after coronary artery bypass grafting. We suggest that lactic acidosis occurred in a genetically susceptible patient with an abnormality of mitochondrial function. This report discusses an unusual adverse effect of propofol anaesthesia and sedation and highlights the need for further investigation to define propofol toxicity.

Research paper thumbnail of Ulcerated aortic atheromatous plaque causing amaurosis fugax

The Canadian journal of cardiology, Jan 15, 2003

Research paper thumbnail of Left atrial mass

The Canadian journal of cardiology, 2002

Research paper thumbnail of Significance of left ventricular apical-basal muscle bundle identified by cardiovascular magnetic resonance imaging in patients with hypertrophic cardiomyopathy

European heart journal, Jan 14, 2014

Cardiovascular magnetic resonance (CMR) has improved diagnostic and management strategies in hype... more Cardiovascular magnetic resonance (CMR) has improved diagnostic and management strategies in hypertrophic cardiomyopathy (HCM) by expanding our appreciation for the diverse phenotypic expression. We sought to characterize the prevalence and clinical significance of a recently identified accessory left ventricular (LV) muscle bundle extending from the apex to the basal septum or anterior wall (i.e. apical-basal). CMR was performed in 230 genotyped HCM patients (48 ± 15 years, 69% male), 30 genotype-positive/phenotype-negative (G+/P-) family members (32 ± 15 years, 30% male), and 126 controls. Left ventricular apical-basal muscle bundle was identified in 145 of 230 (63%) HCM patients, 18 of 30 (60%) G+/P- family members, and 12 of 126 (10%) controls (G+/P- vs. controls; P < 0.01). In HCM patients, the prevalence of an apical-basal muscle bundle was similar among those with disease-causing sarcomere mutations compared with patients without mutation (64 vs. 62%; P = 0.88). The presen...

Research paper thumbnail of Cardiomyopathy

A Perioperative Transdisciplinary Approach, 2012

Research paper thumbnail of A phase II dose-response study of hemoglobin raffimer (Hemolink) in elective coronary artery bypass surgery

The Journal of Thoracic and Cardiovascular Surgery, 2004

Research paper thumbnail of Prevalence of tricuspid regurgitation and pericardial effusions following pacemaker and defibrillator lead extraction

International Journal of Cardiology, 2010

Research paper thumbnail of Nucleosome DNA repeat length and histone complement in a fungus exhibiting condensed chromatin

Experimental Cell Research, 1983

Fungal chromatins are reported to exhibit unusually short nucleosomal DNA repeat lengths. To test... more Fungal chromatins are reported to exhibit unusually short nucleosomal DNA repeat lengths. To test whether this is a phylogenetic feature of fungi or rather is correlated with an apparent absence of condensed chromatin in the organisms studied, we have examined the chromatin organization and the complement of basic nuclear proteins in the fungus Entomophthora, an organism which exhibits marked chromatin condensation. Micrococcal nuclease digestion of Entomophthora chromatin revealed a nucleosomal DNA repeat length of 197 +/- 1.2 base pairs (bp). This repeat length is 20-40 bp longer than that reported for any fungus. Entomophthora nucleosomes exhibited an HI-like protein which was much less basic than the HI histones reported for higher eukaryotes but which was similar in basicity to the HI histone reported for the fungus Neurospora. However, the nucleosomal DNA repeat length of Neurospora chromatin is reported to be unusually short, whereas that of Entomophthora was found to be typical of the repeat lengths observed for chromatins of higher eukaryotes. Thus, repeat length, at least in fungi, would not appear to be directly determined by the basicity of the fungal cognate of histone HI.

Research paper thumbnail of Permanent cardiac pacing after a cardiac operation: Predicting the use of permanent pacemakers

The Annals of Thoracic Surgery, 1998

Research paper thumbnail of Infective endocarditis in patients who had replacement of the aortic root

The Annals of Thoracic Surgery, 1994

Research paper thumbnail of Successful treatment of massive pulmonary embolism after coronary artery bypass grafting due to heparin-induced thrombocytopenia

The Annals of Thoracic Surgery, 1994