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Biomedical subjects

D S Beanlands

Publications and source records attributed to D S Beanlands.

At least 19 recordsLinked to original sources
PubMed2001

Prosthetic valve fungal endocarditis due to histoplasmosis.

Fungal endocarditis is associated with severe patient morbidity and mortality. Unfortunately, fungal endocarditis is difficult to diagnose because fungal pathogens are uncommonly isolated from routine blood cultures. Histopathological examination of surgically excised cardiac valves, peripheral emboli and systemic ulcers may be useful in identifying pathogens as etiological agents of culture-negative endocarditis. The authors describe a 63-year-old man who had culture-negative endocarditis. Multiple echocardiograms showed progression of the vegetations with valve stenosis despite treatment with multiple antimicrobials. He had multiple peripheral emboli before surgery. Disseminated histoplasmosis was diagnosed by bone marrow culture. Yeast organisms consistent with histoplasma were shown in the vegetations of his excised mitral valve prosthesis. The patient was treated with amphotericin and has been doing well in the two years since his surgery. The diagnosis and management of fungal endocarditis are emphasized.

Anti-Bacterial Agents↗
PubMed2000

Isolated pulmonic valve endocarditis in healthy hearts: a case report and review of the literature.

The case of a 53-year-old man with isolated pulmonic valve endocarditis in a structurally normal heart is presented. The patient had a history of chronic obstructive pulmonary disease and was admitted to hospital with an apparent exacerbation with pneumonia. Blood cultures grew Staphylococcus aureus, and an echocardiogram identified a large vegetation on the pulmonic valve in a structurally normal heart. He was unsuccessfully treated with antibiotics and eventually required pulmonic valve replacement. The literature from 1960 to 1999 identified only 36 reported cases of pulmonic valve endocarditis in structurally normal hearts. The present report underscores the importance of suspecting pulmonic valve endocarditis in patients with multiple pulmonary lesions, and discusses the predisposing factors, clinical features, diagnostic role of echocardiography and the potential benefits of early surgical treatment.

Bacteremia↗
PubMed1998

Left anterior descending endarterectomy and internal thoracic artery bypass for diffuse coronary disease.

BACKGROUND: The risk and efficacy of using an arterial conduit to bypass an endarterectomized coronary artery remain incompletely defined. To address this question we analyzed retrospectively 74 patients from 1989 to 1994 in whom bypass grafting using the left internal thoracic artery to an endarterectomized left anterior descending artery was performed. METHODS: There were 60 men and 14 women with a mean age of 60.1 +/- 8.6 years. Of this cohort, 55 patients (74.3%) had a previous infarction, 18 (24.3%) were diabetic, and 5 (6.7%) had reoperations; 25 patients (34%) had a totally occluded left anterior descending artery and the average ejection fraction was 45%. Each patient had 2.95 +/- 0.52 grafts with 48 patients (65%) requiring multiple endarterectomies. The average length of the endarterectomized segment was 3.1 +/- 1.6 cm. Average anoxia time was 49 +/- 13 minutes. Postoperatively 19 patients (25.6%) required intraaortic balloon and 18 (24.3%) required inotropic support. Perioperative infarction in the left anterior descending artery distribution occurred in 5 patients (6.7%). RESULTS: There were 3 (4.0%) early and 4 (5.4%) late deaths at a mean follow-up of 36 +/- 16 months. Recurrent angina was present in 9 patients (14.7%). Actuarial 5-year survival was 84.5%. Angiographic follow-up obtained in 23 patients (37.4%) demonstrated 74% anastomotic patency, with good distal run-off in 13 (65%). The anterior segmental wall motion was preserved. CONCLUSIONS: The use of the left internal thoracic artery bypass and adjunctive left anterior descending artery endarterectomy to expand the scope of myocardial revascularization in carefully selected circumstances appears to be beneficial.

Coronary Artery Bypass↗
PubMed1995

Does late revascularization alter the evolution of the signal-averaged electrocardiogram in patients with a recent transmural myocardial infarction?

BACKGROUND AND OBJECTIVES: Early infarct-related artery patency associated with thrombolytic therapy decreases the incidence of signal-averaged electrocardiogram (SAECG) derived late potentials following acute Q wave myocardial infarction. The purpose of this prospective study was to follow the development of SAECG abnormalities in patients with persistent occlusion of the infarct-related artery, and to compare the course of those who subsequently had successful late percutaneous transluminal coronary angioplasty and coronary artery bypass grafting surgery with the course of those who were not revascularized. METHODS: Baseline (24 +/- 25 days after myocardial infarction) SAECG studies were acquired from 39 patients just before revascularization of the infarct-related artery (group 1) and from 32 nonrevascularized patients (group 2). Late potentials were found in 19 group 1 patients and in 13 group 2 patients (not significant). Follow-up studies were done 103 +/- 63 days after baseline acquisition. RESULTS: There were no differences between the two groups in the change in filtered QRS (fQRS), in low amplitude signal duration under 40 microV (LAS), or in the root mean square voltage of the last 40 ms (RMS). No difference was found in the frequency of resolution of late potentials (21.0% in group 1 versus 38.5% in group 2). Patients in whom late potential resolution occurred had less abnormal LAS than patients with persistent late potentials, and less abnormal RMS. In addition, the magnitude of change in the fQRS, LAS and RMS was significantly greater in patients with late potential resolution than in those with late potential persistence. CONCLUSIONS: Late revascularization of an occluded infarct-related artery does not appear to enhance resolution of late potentials compared with conservative medical therapy. Resolution occurs in patients with less severe SAECG abnormalities. This may reflect a difference in arrhythmogenic substrate.

Angioplasty, Balloon, Coronary↗
PubMed1994

Beta-blocker therapy in the Cardiac Arrhythmia Suppression Trial. CAST Investigators.

The Cardiac Arrhythmia Suppression Trial (CAST) showed antiarrhythmic drug suppression of asymptomatic or mildly symptomatic ventricular arrhythmias in survivors of myocardial infarction to be harmful. This study retrospectively searched the CAST results for evidence of mortality and morbidity reduction in patients receiving optional beta-blocker therapy. All enrolled (n = 2,611) and suppressed main study (n = 1,735) CAST patients with an ejection fraction of < or = 40% were examined using univariate analysis, Kaplan-Meier curves, and a Cox proportional-hazards multivariate analysis with respect to optional beta-blocker therapy prescribed at baseline. CAST patients receiving beta-blocker therapy had significantly enhanced survival at 30 days, and at 1 and 2 years of follow-up against all-cause and arrhythmic death or nonfatal cardiac arrest. Multivariate analysis showed beta-blocker therapy to be independently associated with a one-third reduction in arrhythmic death or cardiac arrest (p = 0.036). In CAST patients with a history of congestive heart failure, beta-blocker therapy was independently associated with longer time to occurrence of new or worsened congestive heart failure (p = 0.015). This study supports the secondary preventive benefit of beta-blocker therapy in high-risk post-myocardial infarction patients, and calls attention to the possible preventive benefit of beta-blocker therapy against proarrhythmic events experienced in the CAST.

Adrenergic beta-Antagonists↗
PubMed1994

Effects of late percutaneous transluminal coronary angioplasty of an occluded infarct-related coronary artery on left ventricular function in patients with a recent (< 6 weeks) Q-wave acute myocardial infarction (Total Occlusion Post-Myocardial Infarction Intervention Study [TOMIIS]--a pilot study).

The effect of late percutaneous transluminal coronary angioplasty (PTCA) of an occluded infarct-related artery on left ventricular ejection fraction was studied in patients with a recent, first Q-wave myocardial infarction in a prospective, randomized study. Forty-four patients (31 men and 13 women, mean age 58 +/- 12 years) with an occluded infarct-related coronary artery were randomized to PTCA (n = 25) or no PTCA (n = 19). Patients received acetylsalicylic acid, a beta blocker and an angiotensin-converting enzyme inhibitor unless contraindicated. Left ventricular ejection fraction was determined at baseline and 4 months. Coronary angiography was repeated at 4 months. Baseline ejection fraction measured 20 +/- 12 days after myocardial infarction was 45 +/- 12% in both groups. PTCA was performed 21 +/- 13 days after the event. The primary PTCA success rate was 72%. One patient in each group died before angiographic follow-up, which was completed in 37 of the remaining 42 patients (88%; 21 with and 16 without PTCA). At 4 months, the infarct-related artery was patent in 43% of PTCA patients and in 19% of no PTCA patients (p = NS). Reocclusion occurred in 40% of patients after successful PTCA. Secondary analyses showed that the change in left ventricular ejection fraction was significantly greater in patients with a patent infarct-related artery (+9.4 +/- 6.2%) than in those with an occluded artery (+1.6 +/- 8.8%; p = 0.0096). Baseline ejection fraction also independently predicted improvement in left ventricular ejection fraction (p = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Death in a catheterization laboratory.

OBJECTIVE: To assess current rates of death from diagnostic and therapeutic cardiac catheterization as well as changes in the rates, if any, from 1977 to 1991. DESIGN: A prospective descriptive study. SETTING: Catheterization laboratory, University of Ottawa Heart Institute. PATIENTS: Consecutive patients undergoing diagnostic and therapeutic procedures from 1977 to 1991. Those undergoing endomyocardial biopsy or electrophysiologic study were excluded. INTERVENTIONS: Cardiac catheterization with angiography, percutaneous transluminal coronary angioplasty (PTCA) or valvuloplasty. MAIN OUTCOME MEASURES: Rates of death within 24 hours after the procedure or later if causally related to the procedure. RESULTS: There were 32 deaths attributed to 30,838 diagnostic catheterization procedures, for a rate of 0.10%. The rate did not change significantly during the study period. Most (24 [75%]) of the 32 deaths were related to coronary angiography; all but one of these patients had left main-stem artery or triple-vessel disease. None of the cases of anaphylactoid reaction to the contrast medium resulted in death. Death from PTCA was largely confined to patients with unstable coronary syndromes, including postinfarction shock. The rate of death from elective PTCA was approximately 0.1%. CONCLUSIONS: The death rate in our catheterization laboratory has remained the same since 1977, despite changes in the patient population. Patients at highest risk of death from angiography are those with unstable and global myocardial ischemia. The universal use of low-osmolar contrast medium is not justified given the absence of fatal anaphylactoid reactions. The risk of death from elective PTCA is low, and patients at highest risk have unstable coronary artery syndromes.

Aged↗
PubMed1991

Enalapril versus digoxin in patients with congestive heart failure: a multicenter study. Canadian Enalapril Versus Digoxin Study Group.

Patients with New York Heart Association functional class II or III heart failure stabilized on furosemide therapy were entered into a randomized controlled trial comparing enalapril (n = 72) and digoxin (n = 73). End points were clinical outcome, treadmill exercise capacity and echocardiographic left ventricular dimensions. Improvement in clinical outcome was defined as a reduction of at least one functional class or withdrawal because of an adverse clinical event. After 4 weeks, 13 patients receiving enalapril showed improvement, 55 had no change and 9 manifested deterioration compared with 7, 49 and 17, respectively, in the digoxin group (p less than 0.01). After 14 weeks, 13 patients receiving enalapril showed improvement, 50 had no change and 9 manifested deterioration, compared with 14, 37 and 22, respectively, in the digoxin group (p less than 0.025). More patients in the digoxin group were withdrawn because of an adverse clinical event (p less than 0.05). Exercise time and percent fractional shortening improved in both groups (p less than 0.001 and less than 0.05, respectively), with no significant difference between groups (p greater than 0.50). Both rate-pressure product and subjectively evaluated exertion during submaximal exercise were reduced only in the enalapril group. Although the majority of patients in both groups did well, those receiving enalapril experienced fewer adverse clinical events and had less fatigue during submaximal exercise.

Adult↗
PubMed1991

Assigning priority to patients requiring coronary revascularization: consensus principles from a panel of cardiologists and cardiac surgeons.

In light of lengthy waiting lists for coronary surgery in Canada, a panel of 16 cardiologists and cardiac surgeons was convened to derive guiding principles for ranking how urgently diverse patients with angiographically proven coronary disease require revascularization. Factors likely to affect urgency were agreed upon by the panelists and incorporated into a case scenario questionnaire. Each panelist then rated 438 case scenarios with respect to maximum acceptable waiting time on a scale with seven time frames ranging from emergency surgery ('level 1') to delays of up to six months ('level 7'). The scenario rating process facilitated attainment of a panel consensus. The purpose of the principles is to assist in assigning priorities to patients according to both symptoms and risk of death or additional morbidity from ischemic events. The pattern or severity of the patient's anginal symptoms and the response of those symptoms to medical therapy emerged as the single most important determinant of the level of urgency. Anatomy and noninvasive tests of ischemic risk were the other key determinants of priority. All other factors were less important, and operated largely within a given level of urgency on the seven-point scale. The principles, including explicit ranking criteria divided according to angina class, are outlined in this final report. The panel specifically cautioned that adoption of such principles is not designed to countenance delays in treatment, but if necessary, should help form more rational queues for coronary revascularization.

Canada↗
PubMed1991

Importance of timing of treadmill predictors for risk stratification after myocardial infarction: a five year follow-up study.

The prognostic value of information derived from clinical characteristics and exercise treadmill tests performed before discharge and repeated at three months was evaluated in 205 consecutive patients followed for five years. Recurrent myocardial infarction, unstable angina and mortality were tabulated. Survival was analyzed by the Kaplan-Meier life-table method and the Cox regression model. The major difference between the predischarge and three month intervals was the failure of exercise-induced ST depression to predict mortality from the predischarge test. However, it was predictive of mortality at three months when 76% survived five years with a positive ischemic response compared to 94% with a negative response (P less than 0.0005). In contrast, resting ST depression of at least 1 mm was associated with a very poor five year survival rate of 58.3% and 50% when assessed at both predischarge and three months (P less than 0.0005 and P less than 0.004, respectively). Selected univariately at the predischarge interval, the following characteristics were ranked in descending order of predictive power for five year mortality by discriminant analysis: history of previous infarction; exercise capacity; and ST depression on resting ECG greater than 1 mm. At three months, the same characteristics were selected. However, recurrent infarction and unstable angina were not predictable at either interval by any clinical or treadmill variable. Characteristics tending to reflect poor exercise capacity are stronger predictors of five year outcome than exercise-induced ischemia. While predischarge exercise testing for ST segment response failed to predict survival, this variable showed improved predictive power with repeat testing at three months.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise Test↗
PubMed1990

Concepts in the management of congestive heart failure.

"In the realm of congestive heart failure, we've made tremendous diagnostic and therapeutic strides--yet so many crucial questions remain unanswered. An educational meeting such as this can help us share what we know and progress to new awareness."

Adrenergic beta-Antagonists↗
PubMed1989

Intravenous dipyridamole-induced myocardial ischemia during percutaneous transluminal coronary angioplasty in humans.

Percutaneous transluminal coronary angioplasty was used as a model of controlled myocardial ischemia to study the effect of intravenous dipyridamole on myocardial ischemia and coronary hemodynamics in 10 patients. All patients had 1-vessel coronary artery disease with visualized collaterals. Intravenous dipyridamole increased myocardial ischemia during inflations. ST elevation, as measured by intracoronary electrogram, increased significantly from the control inflation to the second inflation after dipyridamole injection (0.05 +/- 0.23 vs 0.44 +/- 0.43 mV, p less than 0.03). Of the 10 patients, 8 developed new or more severe angina with subsequent inflations after dipyridamole. The pulmonary artery wedge pressure increased significantly from the control inflation to the fourth inflation (15 +/- 8 vs 20 +/- 9 mm Hg, p less than 0.05). The coronary wedge pressure showed a decreasing trend with subsequent inflations after dipyridamole but did not reach statistical significance. The double product (heart rate X blood pressure) was not significantly altered by dipyridamole. The findings indicate that intravenous dipyridamole increases myocardial ischemia during balloon occlusion. The constancy of the double product and the trend toward a decrease in coronary wedge pressure suggest that dipyridamole may induce ischemia by reducing the amount of collateral flow through a coronary steal phenomenon.

Adult↗