Immunization survey of non-institutionalized adults--Quebec (as of May 30, 1996).
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Adolescent↗
Biomedical subjects
R Dion
Publications and source records attributed to R Dion.
Resurgence of hepatitis A in homosexual men in Montreal Centre, Quebec.
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Adult↗
Head-to-head comparison of exercise-redistribution-reinjection thallium single-photon emission computed tomography and low dose dobutamine echocardiography for prediction of reversibility of chronic left ventricular ischemic dysfunction.
OBJECTIVES: We sought to directly compare the diagnostic value of exercise-redistribution-reinjection thallium single-photon emission computed tomography (SPECT) and low dose dobutamine echocardiography for prediction of contractile recovery after revascularization. BACKGROUND: Both thallium SPECT and dobutamine echocardiography have been proposed to predict the reversibility of left ventricular dysfunction after revascularization. Although both techniques permit differentiation of viable from nonviable myocardium, few studies have directly compared their accuracy in the same patients. METHODS: Seventy-three consecutive patients (mean [+/- SD] age 59 +/- 9 years) with coronary disease and regional left ventricular dysfunction underwent exercise-redistribution-reinjection thallium SPECT and dobutamine echocardiography before revascularization. Recovery of function was evaluated with echocardiography 5.5 +/- 2.5 months after revascularization. For analysis, the left ventricle was divided into 16 segments, in which percent thallium uptake was quantitated using circumferential profiles, and regional wall motion was graded semiquantitatively (normal = 1; akinetic = 3). RESULTS: The diagnostic performance of the two tests was investigated both for individual patients and for individual segments. Individual patient analysis showed that left ventricular ejection fraction improved > 5% after revascularization in 43 patients, whereas 30 showed no change. Receiver operating characteristic curves were used to select optimal criteria for prediction of functional recovery after revascularization. According to a mean thallium uptake > 54% at reinjection, SPECT had a sensitivity of 72%, a specificity of 73% and an overall accuracy of 73%. Similarly, according to an improvement in wall motion score > 3.5 grades during doubutamine echocardiography, echocardiography had a sensitivity of 88%, a specificity of 77% and an overall accuracy of 84% (p = NS vs. thallium). Segmental analysis showed that SPECT and dobutamine echocardiography had similar sensitivity (77% and 75%, respectively), but SPECT had lower specificity (56% vs. 86%, p < 0.01). CONCLUSIONS: Quantitative exercise-redistribution-reinjection thallium SPECT and dobutamine echocardiography have comparable accuracy for prediction of reversibility of global left ventricular dysfunction after revascularization. However, dobutamine echocardiography has greater specificity than thallium imaging for prediction of functional recovery on a segmental basis.
Cardiac Catheterization↗
Free internal mammary artery graft in myocardial revascularization.
Between August 1986 and March 1993, 124 patients (102 men; mean age of 59 years) underwent myocardial revascularization with the use of at least one free internal mammary artery (FIMA). This group represents 4.5% of the 2725 coronary bypasses performed during the same period. Seventy-six patients (61%) had suffered from at least one previous myocardial infarction. Forty-five patients (36%) had unstable angina; three-vessel disease was found in 100 cases (80.5%) and a left ventricular ejection fraction lower than 0.4 in 22 (17.7%). There were 18 (14.5%) redo procedures and 90 (72.5%) bilateral internal mammary artery (IMA) grafts. The reasons for using a FIMA were: too short an internal mammary artery pedicle in 83 patients, IMA injury at harvesting in 30 patients and post-bypass ischaemia in areas grafted with pedicled IMA (PIMA) in 11 patients. Cardiopulmonary bypass, moderate hypothermia (30 degrees C) and crystalloid anterograde and retrograde cardioplegia were used in all cases. Sixty-seven FIMA grafts were anastomosed directly to the ascending aorta; 57 were sutured via a saphenous hood using a running suture of polypropylene 7/0 and three were anastomosed end-to-end to a PIMA graft. FIMA grafts were directed to the left anterior descending (34%), the circumflex (37%) and the right coronary artery (29%). In total, 179 anastomoses were constructed using 127 FIMA, 136 using PIMA and 158 using saphenous veins (3.8 anastomoses per patient). Hospital mortality and postoperative myocardial infarction rates were 5.6% (seven patients) and 3.2% (four patients), respectively. Cardiac-related mortality was 3.2% (four patients); three of these four patients had been operated on for evolving infarction and one underwent a redo procedure. Four of the 117 survivors died later on; in two, it was cardiac-related and a result of global heart failure at 9 and 12 months. Of the 113 remaining patients, 106 are symptom free after a mean follow-up of 28.2 (range 3-84) months. Fifty-nine patients (50.4%) were restudied by angiography at a mean interval of 15 months. Patency rates of FIMA anastomosed either directly to the aorta or via a saphenous hood were 82.8 or 89.7%, respectively. Patency rates of FIMA directed to the left anterior descending, the circumflex and the right coronary artery were 85.7, 88 and 83.3%, respectively. Global FIMA patency was 86.4%, while global PIMA patency was 100%. The FIMA mid-term patency rates compare unfavourably with those of PIMA: FIMA should therefore be restricted to the cases where PIMA or other pedicled arterial grafts are unavailable.
Aged↗
Multilevel somatosensory evoked potentials (SEPs) for spinal cord monitoring in descending thoracic and thoraco-abdominal aortic surgery.
The usefulness of somatosensory evoked potential (SEP) monitoring as a means of preventing paraplegia in descending aorta surgery was evaluated in 47 consecutive cases operated on for isthmic (14 cases), thoracic (22 cases), or thoraco-abdominal (11 cases) repair. An aortic dissection was found in 11 cases (acute in 6). Somatosensory evoked potentials were obtained by unilateral left and right posterior tibial nerve (PTN) stimulation at the ankle and recordings were performed on four channels: peripheral nerve, lumbar spinal, brain-stem, and cortical recordings. Our experience led to the following current strategy: the establishment of atrio(aorto)-femoral(aortic) bypass (29 cases), proximal and distal aortic cross-clamping, aortic repair with reimplantation of the culprit artery(ies) as indicated by SEP alterations. Five types of SEP alterations were defined on the basis of the neural level involved: type I (27.7% of cases) = distal spinal ischemia due to proximal aortic cross-clamping in the absence of bypass; type II (21.3%) = PTN ischemia due to left common femoral artery cross-clamping; type III (12.8%) = segmental spinal ischemia due to the exclusion of critical feeding arteries; type IV (4.3%) = ischemia in the left carotid artery territory; type V (4.3%) = global brain hypoperfusion due to systemic hypotension. Forty-five patients survived the operation and could be tested for neurological dysfunction. Three patients presented a postoperative spinal cord deficit, but this deficit was already present preoperatively in one case, so that the actual incidence of a new paraplegia in our series was 2/45 cases (4.4%). One of the two cases was clearly a delayed paraplegia with SEP alterations appearing several hours after the operation. Somatosensory evoked potentials were evaluated on the basis of their sensitivity, specificity, and impact on the surgical strategy. Regarding SEP sensitivity, we did not encounter any unexpected immediate paraplegia, but the critical factor appeared to be the duration of SEP absence due to spinal cord ischemia, which, according to the literature, should never exceed 30 min; after a longer absence, SEP return does not guarantee neurological recovery. Somatosensory evoked potential specificity was also 100%, but only 58% of the abnormalities found were actually consequent to spinal cord ischemia, the rest of the abnormalities being consequent to peripheral nerve or brain ischemia. Finally, SEP monitoring had a significant impact on surgical strategy in 19% of the cases. It is concluded that distal aortic perfusion and multilevel SEP monitoring play a significant role in preventing paraplegia in descending aorta surgery.
Adolescent↗
Current status of the inferior epigastric artery.
The current trend is to use more arterial conduits for myocardial revascularization. The rationale for this trend is that the late patency rate of internal thoracic artery grafts has been shown to be superior to that of saphenous vein grafts. The desire to achieve complete myocardial revascularizations only with arterial conduits has led to consideration of new arteries as coronary artery bypass grafts. Recently, the inferior epigastric artery has been proposed as one of these alternative grafts. It is expected that this new conduit will provide the same advantages as the free internal thoracic artery used in similar circumstances, but this assumption has not been validated yet. This article will review the clinical experience currently gained with the use of the inferior epigastric artery as a coronary artery bypass graft.
Anastomosis, Surgical↗
Successful bridge to retransplantation with the wearable Novacor left ventricular assist system.
The wearable version of the Novacor left ventricular assist system has been implanted in a 44-year-old man as a bridge to retransplantation. Apart from a temporary right ventricular failure, the postoperative course was smooth and the patient underwent retransplantation after 95 days of support. Expected complications like infection or bleeding could be avoided or minimized.
Adult↗
Preoperative selection of patients with severely impaired left ventricular function for coronary revascularization. Role of low-dose dobutamine echocardiography and exercise-redistribution-reinjection thallium SPECT.
BACKGROUND: Both thallium imaging and low-dose dobutamine echocardiography have been proposed to predict the reversibility of left ventricular (LV) dysfunction in patients with coronary disease. The present study was designed to evaluate whether the use of these techniques during the preoperative assessment of coronary patients with depressed LV function can improve our ability to identify those likely to have improved LV function after surgery. METHODS AND RESULTS: Forty consecutive patients (age, 60 +/- 10 years) with coronary disease and an ejection fraction < or = 35% underwent dobutamine echocardiography (10 micrograms/kg per minute) and exercise-redistribution-reinjection thallium single photon emission computed tomography (SPECT) before coronary revascularization by bypass surgery (n = 33) or angioplasty (n = 7). Recovery of LV function was evaluated by echocardiography 5.3 +/- 2.4 months after revascularization. According to the changes in end-systolic volume and ejection fraction after revascularization, the patients were categorized into groups with (n = 19) and without (n = 21) postoperative functional improvement, defined as a > 5% increase in ejection fraction and > 10 mL decrease in end-systolic volume. Before revascularization, patients with improved postoperative function had smaller end-diastolic volume and less wall motion abnormalities than those with persistent dysfunction. They also showed greater improvement of wall motion score with dobutamine (6.1 +/- 2.4 versus 1.8 +/- 4.2 grades, P < .001) and smaller thallium defect score after exercise (38 +/- 12 versus 47 +/- 14 grades, P = .04). Discriminant analysis selected the improvement in wall motion score with dobutamine and baseline end-diastolic volume as independent predictors of postoperative recovery. Consideration of both parameters allowed prediction of functional outcome in 84% of the patients with and 81% of those without postoperative improvement. CONCLUSIONS: Among the parameters commonly available before surgery in coronary patients with depressed LV function, the maintenance of significant inotropic reserve, the severity of LV remodeling, and the magnitude of the perfusion defect after exercise can predict the reversal of LV dysfunction after revascularization.
Aged↗
Surgical treatment for acute native aortic valvular infective endocarditis: long-term follow-up.
During the period 1970-1993, 116 patients (63 men, 53 women) with native aortic valvular infective endocarditis were treated surgically. The mean age was 37 years. The main causative organisms were streptococci and staphylococci. Indication for surgery was cardiac failure (70 cases), uncontrolled sepsis (30), peripheral emboli (11) and overwhelming destruction of the aortic valve (five). Hospital and late mortality rates were 8% and 11% respectively. Patients who died in hospital and those who presented a paravalvular leakage had a ring abscess associated with aortic wall destruction. Among 34 patients screened for cerebral septic emboli the condition was confirmed in 15, of whom six were symptom-free. Thus, it is believed that in the presence of root abscess, surgery should be undertaken promptly, regardless of the cardiac status. It is confirmed that cerebral septic emboli should be systematically screened for in the presence of any infective endocarditis.
Acute Disease↗
Revascularization of the circumflex artery with the pedicled right internal thoracic artery: clinical functional and angiographic midterm results.
Retroaortic crossing of the pedicled right internal thoracic artery for revascularization of the circumflex artery used in combination with a pedicled left internal thoracic artery anastomosed to the left anterior descending artery and its branches is an attractive technique to achieve an extensive arterial revascularization of the left ventricle. However, there is a suspicion that pulling the right internal thoracic artery through the transverse sinus could compromise its blood flow capacity and patency. Between January 1990 and July 1994 this technique was applied in 256 patients (202 men, 54 women; average age 62 years, range 31 to 80 years). Sixty-one patients had two-vessel disease and 195 had three-vessel disease. Seventeen patients were undergoing a reoperation. Twenty-two had a left ventricular ejection fraction of 40% or less. Thirty had diabetes. Twenty-eight had morbid obesity. The right internal thoracic artery was directed to the circumflex artery (259 anastomoses) through the transverse sinus and the left internal thoracic artery was anastomosed to the left anterior descending artery and its branches (375 anastomoses) in all patients. The 195 patients with three-vessel disease received additional coronary artery bypass grafts to the right coronary artery (93 saphenous vein grafts, 89 free inferior epigastric artery grafts, 12 pedicled right gastroepiploic artery grafts). In total, the 256 patients received 833 distal anastomoses (average 3.2, maximum 5 per patient) and 634 distal anastomoses were internal thoracic artery anastomoses (average 2.4, maximum 4 per patient). Three patients died early and eight had a nonfatal myocardial infarction. Seven patients needed postoperative intraaortic balloon pump support. Six patients underwent early reoperation because of excessive bleeding. Sternal dehiscence occurred in four patients. One of these four patients died of the complication 10 months after the operation. No patient was lost to follow-up (average 33 months). During follow-up, two sudden deaths and six noncardiac deaths occurred. Two patients had a nonfatal myocardial infarction and 12 had recurrence of angina. There were no late reoperations. One patient underwent a successful percutaneous balloon angioplasty of a native left anterior descending artery. Seventy-four patients, enrolled in prospective angiographic studies, underwent a postoperative recatheterization (average 13.2 months, range 6 to 58 months). Seventy-three of the 74 right internal thoracic artery grafts were patent. In comparison, 74 of 74 of the left internal thoracic artery grafts (106/107 anastomoses) were patent. Maximal stress thallium-201 scintigraphy results, obtained in 25 of those patients, did not reveal ischemia in the area of the circumflex artery.(ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
Coronary artery bypass grafting with the inferior epigastric artery. Midterm clinical and angiographic results.
Between December 1988 and September 1993, 157 patients (141 men, 16 women, average age 60.2 years, range 37 to 78 years) underwent a complete myocardial revascularization with 157 inferior epigastric artery grafts and 285 internal mammary artery grafts (281 in situ, 4 free grafts). A total of 543 distal arterial anastomoses (average 3.4, range two to five per patient) were constructed, 376 with the internal mammary artery and 167 with the inferior epigastric artery. The inferior epigastric artery grafts were anastomosed to two left anterior descending, 5 diagonal, 34 circumflex, and 126 right coronary arteries. The indications for the use of the inferior epigastric artery were the unavailability of conventional conduits in 56 patients and a favorable anatomy or a young age in 101 selected patients. The clinical follow-up averages 31.8 months (range 6 to 62 months). Four patients died early, and there were three perioperative nonfatal myocardial infarctions. Eight patients required early reoperation for thoracic bleeding (2) or drainage of an abdominal parietal collection (6). There were four late deaths (2 sudden deaths, 2 noncardiac causes) and one nonfatal myocardial infarction. Angina recurred in nine patients, of whom one required reoperation and three underwent successful percutaneous balloon angioplasty of a native coronary artery (2) or an old saphenous vein graft (1). An early recatheterization was obtained before discharge (average 11 days) in 135 patients: 132 of 135 inferior epigastric artery grafts were patent. Seventy-seven patients underwent a second angiographic restudy 6 to 43 months after the operation. Forty-four of the 48 inferior epigastric artery grafts restudied within the first postoperative year (average 8.5 months) were patent, but eight showed a diffuse narrowing. Twenty-eight of the 29 inferior epigastric artery grafts examined angiographically between 13 and 43 months (average 25 months) were open, and among those 29, 25 were widely patent, perfectly matching the receiving coronary artery. Most of the occluded or narrowed inferior epigastric artery grafts were grafted onto coronary arteries with mild stenosis at restudy. Five patients underwent a third angiographic reexamination up to 60 months after the operation (average 39 months). All five inferior epigastric artery grafts were widely patent. The early attrition rate of the inferior epigastric artery, as for any free arterial graft, is probably the result of both the loss of a true pedicle and the need for constructing an additional proximal anastomosis. The fact that the patency rate of the inferior epigastric artery graft seems to remain stable beyond 1 year could suggest a good durability in the future.
Abdominal Muscles↗
Extension of native aortic valve endocarditis: surgical considerations.
Among 101 consecutive patients operated on for native infective aortic valve endocarditis (53 males, 48 females, mean age 39 years), 69 presented various forms of infectious extension to the surrounding areas. Twenty-six lesions were noted in the aortic roots: 18 annular abscesses, one abscess of the Valsalva sinus and seven aortic wall destructions. Among the subaortic valve pathology, 27 cases of septal lesions were noted and in one case the mitral fibrous trigone was involved. The mitral apparatus was infected in 26 cases, the tricuspid valvule in one case. Both tricuspid and mitral valvular replacements had to be performed in five cases. Among the 16 postoperative atrioventricular blocks, 14 needed a pacemaker. The most frequent causative microorganisms were Staphylococcus aureus and Streptococcus. Surgical management of the lesions consisted of extensive debridement followed by either simple repair of defects or complex reconstructions involving pericardial or synthetic patches or other more complex operations. Early and late mortality rates were 8.5% and 16%; early and late reoperation rates were 6% and 9.5%, respectively. The mean follow-up time was 148 months (12-265 months) with a survival rate of 74% (SE: +/- 0.08) at 10 years. We conclude that, although surgical correction of infective endocarditis may need a complex approach, it provides good results with an acceptable surgical risk.
Adult↗
Structural and metabolic correlates of the reversibility of chronic left ventricular ischemic dysfunction in humans.
Assessment of regional myocardial perfusion and glucose uptake with positron emission tomography (PET) identifies dysfunctional myocardium that shows improvement in function after revascularization. Yet little is known about the ultrastructural patterns of ischemic injury in myocardium with and without postoperative functional improvement in relation to residual perfusion and metabolism. Therefore dynamic PET with [13N]ammonia and 18F-labeled deoxyglucose was performed in 24 patients with coronary artery disease and anterior wall dysfunction undergoing bypass surgery. Transmural biopsies were obtained from the dysfunctional area during surgery and analyzed by optical and electron microscopy to quantify the presence of fibrosis and cardiomyocytes. As judged from the postoperative changes in contraction, left ventricular function improved in 16 patients. In myocardium that showed improved function after revascularization, preoperative flow and glucose uptake were higher by PET than in persistently dysfunctional myocardium. In tissue samples from myocardium that improved postoperatively, there were more cardiomyocytes, including a larger proportion of cells with excess glycogen stores (35 vs. 21%), and there was less fibrosis (24 vs. 49%) than in tissue samples from myocardium that did not improve functionally. Preoperative perfusion and postoperative wall motion were inversely correlated with the amount of tissue fibrosis, whereas preoperative 18F-labeled deoxyglucose uptake correlated positively with the amount of cardiomyocytes showing excess glycogen stores.
Adult↗
Immigrant and refugee children in Canada.
In view of Canada's commitment to immigration, understanding the sources of successful adaptation by immigrant and refugee children is vital. This paper reviews the literature on the mental health of migrant children and suggests an agenda for future research.
Acculturation↗
Mitral valve procedures in ischemic regurgitation.
A restrictive definition of ischemic mitral regurgitation (IMR) has allowed us to select a more uniform cohort of 41 patients having undergone mitral valve surgery for IMR between January 1993 and March 1995. Thirty-six patients (88%) presented with chronic and five with acute IMR. All patients had at least one significant stenosis in the circumflex area. Left ventricular ejection fraction averaged 35%. Transesophageal echocardiography (TEE) revealed a > or = 3+ MR in 30 patients and an intermittent, fluctuating or grade 2+ MR in 11 (27%). Annulus dilatation was found in all cases, and it was the only mechanism in 10 (24.4%). Leaflet restrictive motion was clearly seen in 17 cases (41.5%) and leaflet prolapse in 14 (34%). In doubtful cases, an intra-operative dynamic testing using TEE, and associating a loading test and an afterload test, led to the indication of a valve procedure in 11/19 patients (58%). An average of three distal coronary anastomoses per patient were constructed. Mitral valve replacement (MVR) was unavoidable in four patients (9.8%); at least the posterior leaflet subvalvular apparatus was preserved in all. Repair of the mitral valve (Mvrep) was achieved in 37 cases (90%). Ring annuloplasty alone was performed in 27 cases (73%). In the remaining 10 cases, leaflet prolapse was corrected by various artifices such as flip-over technique, quadrangular resection, papillary muscle plication or commissuroplasty. At the 10th postoperative day, a residual MR was found in 4/34 cases (11.8%), only after isolated ring annuloplasty. The four patients who have died in the ICU after MVrep belonged to the same group of isolated ring annuloplasty; this mortality of 4/27 (14.8%) illustrates the mediocre prognosis of marked annulus dilatation and impaired LV function with restrictive leaflet motion. Overall, the hospital mortality (14.6%) more reflected the mode of presentation of the patients than the type of operative technique: when a short and definitive procedure is required by a precarious general condition, one should not hesitate to prefer a rapid MVR to a complicated repair. At 4.5 months, there was no significant improvement in LV dimensions. At six months, 80.5% of the patients survived, with 88% of them being in NYHA class I or II.
Adult↗
[Implantable and portable left ventricular assistance: initial successful clinical application in Belgium].
On July 13, 1994, at the "Cliniques universities St. Luc", a wearable left ventricular assist device was successfully implanted, for the first time in Belgium, in a 44-year-old male. He had been readmitted with end-stage congestive heart failure 7 years after a first cardiac transplantation. In the absence of a suitable donor heart, the Novacor system was installed: the prosthetic ventricle is buried in the left flank and connected to the apex of the left ventricle and to the ascending aorta by means of valved conduits. The Novacor has allowed the patient to be optimally revalidated while waiting for a "ideal" donor heart. On Oct.-16, 1994, after 95 days of assistance, re-transplantation was uneventful and the patient has resumed a full-ranged activity as from January 1995.
Adult↗
Complete myocardial revascularization with arterial grafts without using the mammary artery.
We report on the case of a 60-year-old male patient who developed a crescendo angina 9 years after a coronary artery bypass procedure. Coronary angiography revealed triple vessel disease. None of the internal mammary arteries were available and the saphenous veins had previously been stripped. A complete myocardial revascularization by means of arterial grafts was still achieved by using both the epigastric arteries, and an in situ right gastroepiploic artery.
Abdominal Muscles↗
Hemodynamic effects and safety of sotalol in the prevention of supraventricular arrhythmias after coronary artery bypass surgery.
Sotalol is a beta-adrenergic blocking drug with the additional property of lengthening the cardiac action potential. These electrophysiologic properties render the drug attractive for use in the prevention of postoperative supraventricular arrhythmias (SVA), and previous studies have suggested that it was indeed effective. The hemodynamic response to sotalol and its safety early after coronary artery bypass graft (CABG) surgery were therefore studied. Forty-two patients undergoing CABG were randomly assigned either to receive sotalol to prevent postoperative SVA (25 patients) or to serve as controls (17 patients). Sotalol was started 6 hours after surgery if patients had a cardiac index > 2.8 L/min/m2 with a pulmonary capillary wedge pressure < 15 mmHg, and if they had no contraindications to the use of beta-blockers. The drug was given as a loading infusion of 1 mg/kg over 2 hours, followed by a maintenance infusion of 0.15 mg/kg/h for 24 hours. Three hours later, patients received the first oral dose of 80 mg to be repeated every 8 or 12 hours. Adverse effects necessitating discontinuation of the drug (bradycardia < 50 beats/min, systolic blood pressure < 90 mmHg, or cardiac index < 2.2 L/min/m2) occurred in six patients (24%) and were mainly related to the loading infusion. The hemodynamic data for patients who completed the study were characterized by a significant fall of the cardiac index caused by a lower heart rate without significant change of the stroke volume index. The incidence of supraventricular arrhythmias was not significantly different in the two groups (3/19 in the sotalol group, 5/17 in the control group).(ABSTRACT TRUNCATED AT 250 WORDS)
Administration, Oral↗