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Biomedical subjects

L A Mercier

Publications and source records attributed to L A Mercier.

At least 19 recordsLinked to original sources

Prospective multicenter study of pregnancy outcomes in women with heart disease.

BACKGROUND: The maternal and neonatal risks associated with pregnancy in women with heart disease receiving comprehensive prenatal care have not been well defined. METHODS AND RESULTS: We prospectively enrolled 562 consecutive pregnant women with heart disease and determined the outcomes of 599 pregnancies not ending in miscarriage. Pulmonary edema, arrhythmia, stroke, or cardiac death complicated 13% of pregnancies. Prior cardiac events or arrhythmia, poor functional class or cyanosis, left heart obstruction, and left ventricular systolic dysfunction independently predicted maternal cardiac complications; the cardiac event rate can be predicted using a risk index incorporating these predictors. Neonatal complications (20% of pregnancies) were associated with poor functional class or cyanosis, left heart obstruction, anticoagulation, smoking, and multiple gestations. CONCLUSIONS: Pregnancy in women with heart disease is associated with significant cardiac and neonatal complications, despite state-of-the-art obstetric and cardiac care. Maternal cardiac risk can be predicted with the use of a risk index.

Adolescent↗

Prolonged distress and clinical deterioration before pericardial drainage in patients with cardiac tamponade.

OBJECTIVE: To determine whether patients with cardiac tamponade are subject to delays and clinical deterioration before undergoing echocardiography and pericardial drainage. DESIGN: Retrospective study. SETTING: The Montreal Heart Institute, Montreal, Quebec, a cardiology referral centre. PATIENTS: The charts of 50 patients who presented with tamponade were reviewed. Intervals between the appearance of symptoms, consultation, echocardiography and drainage were noted. The presence of clinical deterioration before drainage was evaluated. Causes for delays were investigated. RESULTS: Previous cardiac surgery (74%) was the most common etiology of tamponade. Symptoms were present 6.6+/-5.8 days before consultation. The delay between consultation and echocardiography was 1.2+/-2.0 days (range 0 to 12), and that between echocardiography and drainage was 0.8+/-0.9 days (range 0 to four). Patients underwent drainage 1. 9+/-2.5 days (range 0 to 16) after the initial consultation. Deterioration of the clinical status was noted in 34% of patients before pericardial drainage. An error in the initial diagnosis was present in 36% of patients; the majority of these were incorrectly diagnosed with heart failure. Another 44% of patients had no mention of either a working diagnosis in the chart at admission or the desire to rule out tamponade on the request for echocardiography. CONCLUSION: The proper diagnosis does not appear to be initially considered in up to 80% of patients who present with cardiac tamponade. Clinical deterioration occurs in approximately a third of patients during the interval between consultation and pericardial drainage.

Adult↗

Outcome of children with atrial septal defect considered too small for surgical closure.

There are few studies providing information on the natural course of hemodynamically insignificant atrial septal defect (ASD). To review the outcome of patients with secundum ASD, we retrospectively reviewed the charts of patients who had initially not been considered for surgical closure after age 1 year, and who had either a follow-up of at least 10 years or documented closure. Thirty patients, 22 females and 8 males, fulfilled our inclusion criteria. Mean age at diagnosis was 1.3 year and mean follow-up duration was 11.5 years. Seventeen patients had spontaneous closure of the ASD at a mean age of 8.4 years. There were 7 asymptomatic patients whose ASD was still patent at the last visit (mean age 14.1 years, mean follow-up 13.2), with defect dimensions on echocardiography ranging from 1 to 6 mm. The remaining 6 patients were considered to require surgical closure on the basis of an apparent increase in size of the ASD and secondary clinical and hemodynamic manifestations. These results (1) confirm that not all secundum ASDs need to be treated surgically because they can still spontaneously close past the age of 5, and (2) suggest that in a minority of cases the size of the defect could increase.

Cardiac Surgical Procedures↗

Idiopathic dilatation of the pulmonary artery: report of four cases.

Idiopathic dilatation of the pulmonary artery (IDPA) is a rare congenital disease which is usually detected fortuitously on chest x-ray, thus radiologists must be aware of this clinical entity. This report describes four cases to which Magnetic Resonance Imaging (MRI) played a major role in diagnosing IDPA and in detecting the concomitant findings observed in this disease. MRI is a non-invasive procedure with many advantages for the accurate and reproducible measurement of artery structures, which makes it the preferred option for combined use with echocardiography in the diagnosis and follow-up of patients with IDPA.

Adolescent↗

Transthoracic echocardiographic assessment of periprosthetic mitral regurgitation using intravenous injection of sonicated albumin.

Mechanical prostheses induce artifacts that decrease the accuracy of conventional transthoracic echocardiographic imaging for the detection and quantitation of periprosthetic mitral regurgitation. In 15 patients undergoing transthoracic echocardiography, injection of sonicated albumin significantly enhanced the assessment of periprosthetic mitral regurgitation with an accuracy similar to that of transesophageal echocardiography.

Adult↗

Anterior margin adaptation for implant-retained auricular prostheses.

Adaptation of the anterior margin of implant-retained auricular prostheses may be compromised during mandibular movement. Loss of contact between prostheses and underlying skin in an esthetic area is of great concern. This article describes an impression procedure that addresses the problem of anterior margin adaptation.

Acrylic Resins↗

Simultaneous determination of aortic valve area by the Gorlin formula and by transesophageal echocardiography under different transvalvular flow conditions. Evidence that anatomic aortic valve area does not change with variations in flow in aortic stenosis.

OBJECTIVES: The purpose of this study was to determine the impact of changes in flow on aortic valve area (AVA) as measured by the Gorlin formula and transesophageal echocardiographic (TEE) planimetry. BACKGROUND: The meaning of flow-related changes in AVA calculations using the Gorlin formula in patients with aortic stenosis remains controversial. It has been suggested that flow dependence of the calculated area could be due to a true widening of the orifice as flow increases or to a disproportionate flow dependence of the formula itself. Alternatively, anatomic AVA can be measured by direct planimetry of the valve orifice with TEE. METHODS: Simultaneous measurement of the planimetered and Gorlin valve area was performed intraoperatively under different hemodynamic conditions in 11 patients. Left ventricular and ascending aortic pressures were measured simultaneously after transventricular and aortic punctures. Changes in flow were induced by dobutamine infusion. Using multiplane TEE, AVA was planimetered at the level of the leaflet tips in the short-axis view. RESULTS: Overall, cardiac output, stroke volume and transvalvular volume flow rate ranged from 2.5 to 7.3 liters/min, from 43 to 86 ml and from 102 to 306 ml/min, respectively. During dobutamine infusion, cardiac-output increased by 42% and mean aortic valve gradient by 54%. When minimal flow was compared with maximal flow, the Gorlin area varied from (mean +/- SD) 0.44 +/- 0.12 to 0.60 +/- 0.14 cm2 (p < 0.005). The mean change in Gorlin area under different flow rates was 36 +/- 32%. Despite these changes, there was no significant change in the planimetered area when minimal flow was compared with maximal flow. The mean difference in planimetered area under different flow rates was 0.002 +/- 0.01 cm2 (p = 0.86). CONCLUSIONS: By simultaneous determination of Gorlin formula and TEE planimetry valve areas, we showed that acute changes in transvalvular volume flow substantially altered valve area calculated by the Gorlin formula but did not result in significant alterations of the anatomic valve area in aortic stenosis. These results suggest that the flow-related variation in the Gorlin AVA is due to a disproportionate flow dependence of the formula itself and not a true change in valve area.

Adrenergic beta-Agonists↗

Remnants of the right valve of the sinus venosus presenting as a right atrial mass on transthoracic echocardiography.

Three patients were referred for suspicion of intracardiac tumour on transthoracic echocardiography. In all patients, the mass appeared as a nonobstructive oval structure measuring approximately 12 x 4 mm, located near the posterior third of the interatrial septum in the right atrium in the apical four-chamber view. The characteristics of the mass were not those of a Eustachian valve or a Chiari network. Multiplane transesophageal echocardiography performed in each of these patients did not reveal a tumour but rather a fibrous band in the right atrium, extending from the inferior to the superior vena cava. These findings are consistent with remnants of the right valve of the sinus venosus. Inclusion of a persistent right valve of the sinus venosus in the differential diagnosis of a right atrial mass can alleviate concern and spare an unnecessary transesophageal examination when the typical transthoracic echocardiographic characteristics are identified.

Adult↗

[Tricuspid valve replacement: long-term clinical and echocardiographic follow-up].

Long term results of tricuspid valve replacement, were evaluated by echocardiographic and clinical means retrospectively on 55 patients hospitalized at the Montreal Heart Institute between 1969 and 1993. Twenty seven percent were male and 73% female. Taking into account differences in means of myocardial protection the whole population was divided in 2 groups. Group 1: 19 patients from 1969 to 1980. Group 2: 36 patients - from 1981 to 1994. Forty seven patients (85%) received a bioprosthesis and 8 (15%) a mechanical valve. Forty one (74%) had another surgical procedure and 60% (33 patients) were re-operations. Mortality at 30 days is 23% (13 patients) -15% group 1 and 27% group 2. Twenty six patients (72%) of group 2 were re-operations compared with 7 (36%) for group 1 (p = 0.026). Risk factors of operative mortality were: high systolic pulmonary pressure (0.051), bypass time (0.012) and abnormal ejection fraction (0.025). Mean time of follow up is 113.8 months completed at 95%. Six patients were re-operated; 4 for failure of bioprosthesis 11.5 years (mean) after initial surgery. Forty three percent of patients presented with an amelioration of NYHA class. 26% in class I and 50% in class II. Mean gradient across the tricuspid valve was 4.1 +/- 1 mm Hg. Twenty two over 42 patients (50%) died during follow up: 75 months after surgery.

Actuarial Analysis↗

Is cardiac migraine a clinical entity?

Chest pain because of a disorder of the coronary circulation is assumed to be ischemic in nature. Irrespective of the underlying pathophysiological mechanism, it is accepted that all routes lead to myocardial ischemia in the pathway to anginal pain. The authors describe a patient with a history of vasoactive disorders including migraine, asthma, documented variant angina with prolonged episodes of chest pain, and scintigraphic evidence of inferior and posterior wall ischemia during exercise and ergonovine testing in the absence of significant underlying stenoses. Remarkably, severe retrosternal chest pain, ST segment depression in multiple leads, and relative increased uptake in the inferior and posterior walls on Tc-99m sestamibi tomographic images developed during pharmacologic coronary vasodilatation with dipyridamole, leading the authors to speculate as to the possible existence of a nonischemic chest pain syndrome caused by coronary vasodilatation either in association with variant angina or as a separate entity.

Angina Pectoris, Variant↗

[Patients with heart valve prostheses: dental care, dental procedures and prevention].

Patients with birth or rheumatic heart defects, or wearing prosthetic cardiac valves, are at high risk of developing bacterial endocarditis following dental treatment. Two hundred patients with cardiac valves were surveyed with respect to both their oral hygiene habits and their last visit to the dentist. More than half of the respondents (112) were fully edentulous, and most of them had not seen a dentist for many years. Of the 88 respondents who had natural teeth, 23 had not been to a dentist since surgery. For the purpose of this study, focus was placed primarily on the answers given by the 65 patients who reported having been to a dentist after surgery. Only 41 of them (63 per cent) reported having received a prophylactic antibiotic therapy while being treated with a risk of bacteremia. Of the 24 others who did not receive prophylactic antibiotic therapy, 20 were given dental treatments with a risk of bacteremia. In light of this study, there should be recommendations to improve the health care given to patients predisposed to bacterial endocarditis.

Antibiotic Prophylaxis↗

[Is the quantification of mitral valve involvement by transesophageal echography useful before percutaneous mitral commissurotomy?].

The aims of this study were to determine the value of quantifying mitral valve disease by transoesophageal echocardiography before percutaneous mitral commissurotomy (PMC) and to analyse the incidence of embolic complications during PMC since the introduction of transoesophageal echocardiography. From March 1987 to December 1991, 317 patients with pure or dominant mitral stenosis were selected by Doppler echocardiography to undergo PMC at the Montreal Institute of Cardiology. The clinical features of the first 138 patients (Group I) were the same as those of the last 179 patients (Group 2) who also underwent routine transoesophageal echocardiography the day before the procedure. A thrombus in the left atrial appendage was observed in 8 patients in Group 2 (4.4%). No embolic complications have occurred since the protocol was changed to include routine transoesophageal echocardiography, whereas 4 embolic episodes, 3 of which were fatal, occurred in patients in group 1. The indication of PMC was turned down because of angiographically severe mitral regurgitation which was underestimated by transthoracic echocardiography in 2 patients in Group 1 (1.4%) and in 3 patients in group 2 (1.6%). The mobility, thickness and degree of calcification of the valves were attributed a score from 0-4 at transthoracic and transoesophageal echocardiography. No difference was observed in the scores of mobility (2.3 +/- 0.5 versus 2.3 +/- 0.05, NS) or valve thickness (2.1 +/- 0.4 versus 2.1 +/- 0.4, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Clinical relevance of the low correlations between Doppler and hemodynamic measurements before and after balloon mitral commissurotomy.

The aim of this study was to evaluate the clinical consequences of the poor correlations between Doppler and hemodynamic measurements before and after balloon mitral commissurotomy (BMC). From March 1987 to December 1991, 317 patients with symptomatic mitral stenosis were selected for BMC at the Montreal Heart Institute. Despite the low correlation coefficients between Doppler and hemodynamic measurements before BMC (transmitral gradient: r = 0.57, mitral valve area: r = 0.35, mitral regurgitation: r = 0.33), the positive predictive value of Doppler echocardiography to select patients for BMC was 96%. Hemodynamic success, defined as a final mitral valve area greater than 1.5 cm2 and an increase in mitral valve area of more than 25% was obtained in 204 (80%) of the 253 patients who completed the procedure without complications. Doppler and hemodynamic mitral valve area increase were poorly correlated (r = 0.2) but the sensitivity and specificity of Doppler in the diagnosis of hemodynamic success were 86% and 63% respectively. A prospective six month echocardiography and hemodynamic re-examination was performed in our 50 patients first treated by BMC. Hemodynamic restenosis, defined as a loss of more than 50% of the gain achieved in mitral valve area and a mitral valve area of less than 1.5cm2 were diagnosed in 12 (26%) of the 46 patients with initially successful BMC. Despite a low correlation between Doppler and hemodynamic mitral valve area measurements (r = 0.28), the sensitivity and specificity of echocardiography in the diagnosis of hemodynamic restenosis were 66% and 88% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Doppler echocardiographic predictors of recurrence of atrial fibrillation after cardioversion.

To determine if the return of atrial contraction as evidenced by progressive return of the A wave on the Doppler atrial profile could better predict long-term success of cardioversion than other clinical and echocardiographic parameters, 50 patients were studied 4 hours, 24 hours and, if sinus rhythm persisted, up to 180 days after cardioversion. Recurrence of atrial fibrillation (AF) was 64% at 6 months. Age, sex, prior episodes of AF, presence of mitral valve disease or magnitude of mitral valve gradient did not predict recurrence, but duration of AF was significantly longer in the failure group (p less than 0.01). Left atrial dimension greater than or equal to 45 mm had a positive predictive value of 66%, with a sensitivity of 59% and a specificity of 61%. Presence or magnitude of the A wave at 4 hours did not predict long-term success of cardioversion. Percent increase of the A wave from 4 to 24 hours less than 10% had the highest positive predictive value (80%) for recurrence of AF (sensitivity 71% and specificity 71%) and can be obtained in the immediate post-cardioversion period to better establish prognosis and adjust therapeutic regimens.

Adult↗