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Results for “Ventricular Dysfunction, Left”

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PubMed1995

Dobutamine echocardiography and thallium-201 imaging predict functional improvement after revascularisation in severe ischaemic left ventricular dysfunction.

OBJECTIVES: To evaluate the concordance between thallium-201 uptake and echocardiographic wall thickening, which are both indicators of potentially reversible myocardial dysfunction, in patients with chronic ischaemic left ventricular failure and to assess their relative contribution to predicting improvement in regional function after revascularisation in a subgroup. PATIENTS AND METHODS: 45 patients with chronic ischaemic left ventricular dysfunction (mean (SD) ejection fraction 25 (8)%) underwent echocardiography before and after dobutamine infusion (10 micrograms/kg/min). Of these, 22 patients underwent rest echocardiography at a mean (SD) of 9 (1) weeks after revascularisation. 201Tl imaging was performed during dobutamine echocardiography and at rest, 1, and 4 h after treatment with sublingual glyceryl trinitrate on two separate days. Potentially reversible dysfunction was thought to be present when a myocardial segment contained a Tl score of > or = 3 (ascending score 1-4), or showed improved wall thickening of a dysynergic segment during dobutamine stimulation. RESULTS: Of the 201Tl protocols, the redistribution scan 1 h after treatment with glyceryl trinitrate best demonstrated myocardial viability. Concordance between 201Tl and dobutamine induced wall thickening was 82% (kappa = 0.59) for detecting potentially reversible myocardial dysfunction before revascularisation (n = 45). Regional function improved in 18 of 22 patients after revascularisation. There were 168 dysynergic segments before intervention. The sensitivity of echocardiography and 201Tl imaging for detecting "recoverable" or viable segments after revascularisation was 87% and 92% respectively and specificity was 82% and 78% respectively (P = NS). CONCLUSIONS: Dobutamine echocardiography and 201Tl imaging may be used to predict mechanical improvement in dysynergic segments after revascularisation in patients with chronic ischaemic left ventricular dysfunction.

Adult↗

PubMed1998

Presence of angiographic coronary collaterals predicts myocardial recovery after coronary bypass surgery in patients with severe left ventricular dysfunction.

BACKGROUND: Patients with coronary artery disease and left ventricular dysfunction (LVD) may have areas of hibernating myocardium that improve functionally after revascularization. Coronary collateral circulation may sustain ischemic, dysfunctional myocardium and favor myocardial recovery after revascularization. We evaluated the effect of angiographic coronary collaterals on myocardial functional recovery after coronary bypass graft (CABG) surgery in a group of patients with severe LVD. METHODS AND RESULTS: Forty-one patients with multivessel coronary artery disease and advanced LVD (left ventricular ejection fraction [LVEF] 25 +/- 5%) undergoing CABG were identified from a prospective database. Preoperative coronary angiograms were evaluated for collaterals, which were graded according to Rentrop's classification (0 to 3), and a collateral index was calculated (collateral sum divided by 3). Preoperative and postoperative radionuclide ventriculograms provided global LVEF and regional ejection fractions. Of 123 regions evaluated, 120 were dysfunctional at baseline. Virtually all (122 of 123) regions were subtended by an artery with > or = 70% stenosis that was bypassed. Thirty-eight (81%) of 47 dysfunctional regions with grade 2 or 3 collaterals improved regional ejection fraction after surgery versus 38 (52%) of 73 dysfunctional regions with grade 0 or 1 collaterals (P = 0.0018). Global LVEF was 34 +/- 10% after surgery (P < 0.001 versus before surgery). Among patients with a global LVEF increase > or = 10%, collateral index was 1.81 versus 0.83 in those with an LVEF increase < 10% (P = 0.005). CONCLUSIONS: In this population of patients with coronary artery disease with severe LVD, the presence of angiographic grade 2 or 3 collaterals predicted recovery of regional and global myocardial function after CABG.

Aged↗

PubMed1989

Valvular surgery in the elderly.

In previous studies from this university, advanced age was identified as an independent predictor of operative mortality for valvular surgery. Therefore, between January 1982 and December 1986, early results were compared in 469 patients greater than 70 years old (Old; 74.0 +/- 3.4 years, mean +/- SD) and in 2,040 patients less than 70 years old (Young; 53.7 +/- 12.1 years). Patients underwent single- or multiple-valve repair or replacement with or without concomitant coronary artery bypass surgery. Data consisting of 31 clinical and angiographic variables were collected prospectively and were analyzed by univariate and multivariate statistics. Old patients were characterized by having more frequent left ventricular dysfunction (left ventricular ejection fraction less than 40%: Old, 33.5%; Young, 22.4%; p less than 0.001), coronary artery disease (Old, 54.5%; Young, 24.2%; p less than 0.001), and urgent surgery (Old, 15.6%; Young, 11.8%; p = 0.02). Aortic valve procedures (Old, 59.7%; Young, 40.1%; p less than 0.001) and concomitant coronary artery bypass surgery (Old, 46.4%; Young, 20.3%; p less than 0.001) were performed more commonly in the Old patient. Operative mortality occurred in 10.0% of Old patients compared with 5.6% of Young patients (p less than 0.001), and major morbidity (low-output syndrome, perioperative myocardial infarction, intra-aortic balloon pump counterpulsation, and stroke) occurred significantly more frequently (p less than 0.001) in the Old. Stepwise logistic regression identified that urgent operation (p = 0.002), mitral or double-valve surgery (p = 0.004), coronary artery disease especially when not treated by bypass surgery (p = 0.02), female gender (p = 0.02), and left ventricular dysfunction (p = 0.05) independently predicted operative death in the Old population. The significant predictors of mortality in the Young patient were urgent operation (p less than 0.001), New York Heart Association class IV (p less than 0.001), associated tricuspid valve disease (p = 0.002), decreased left ventricular function (p = 0.01), valvular re-replacement (p = 0.02), and increasing age (p = 0.03). The predicted probability of operative mortality in Old patients ranged between 0.9 +/- 0.5% and 76 +/- 16%. Elderly patients in good risk categories should be offered surgical intervention for correction of valvular lesions. Alternative therapy may be indicated in patients with multiple risk factors.

Age Factors↗

PubMed1999

[Arterial hypertension and systolic left ventricular dysfunction: therapeutic approach].

Arterial hypertension is a cardinal precursor of congestive heart failure, and diastolic dysfunction is the most frequent mechanism for it. Systolic left ventricular dysfunction, although less frequent, has a worse prognosis. Most cases of systolic dysfunction in patients with hypertension is due to acute myocardial infarction, although other mechanisms can be involved. In some studies, non-ischemic hypertensive systolic dysfunction is the etiology of chronic heart failure in up to 10% of patients with dilated cardiomyopathy. Diastolic dysfunction and left ventricular hypertrophy are also associated with a higher risk of heart failure and systolic dysfunction. Given the poor prognosis of patients with congestive heart failure and dilated cardiomyopathy, it is fundamental to try to prevent the development of left ventricular dysfunction by means of a correct control of blood pressure, regression of left ventricular hypertrophy and prevention of coronary artery disease. When systolic dysfunction is established, angiotensin converting enzyme inhibitors are the treatment of choice; diuretics and digoxin can be added in patients with overt congestive heart failure. Recent studies suggest that other drugs, such as carvedilol and losartan, can be beneficial, but current evidence is still scarce.

Amlodipine↗

PubMed1999

Prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in general practice setting: cross sectional survey.

OBJECTIVE: To assess the prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in the general practice setting by echocardiographic assessment of ventricular function. DESIGN: Cross sectional survey. SETTING: Four centre general practice in Poole, Dorset. SUBJECTS: 817 elderly patients aged 70-84 years. MAIN OUTCOMES: Echocardiographic assessment of left ventricular systolic function including measurement of ejection fraction by biplane summation method where possible, clinical symptoms, and signs of left ventricular dysfunction. RESULTS: The overall prevalence of left ventricular systolic dysfunction was 7.5% (95% confidence interval 5.8% to 9.5%); mild dysfunction (5.0%) was considerably more prevalent than moderate (1.6%) or severe dysfunction (0.7%). Measurement of ejection fraction was possible in 82% of patients (n=667): in patients categorised as having mild, moderate, or severe dysfunction, the mean ejection fraction was 48% (SD 12.0), 38% (8.1), and 26% (7.9) respectively. At all ages the prevalence was much higher in men than in women (odds ratio 5.1, 95% confidence interval 2.6 to 10.1). No clinical symptom or sign was both sensitive and specific. In around half the patients with ventricular dysfunction (52%, 32/61) heart failure had not been previously diagnosed. CONCLUSIONS: Unrecognised left ventricular dysfunction is a common problem in elderly patients in the general practice setting. Appropriate treatment with angiotensin converting enzyme inhibitors has the potential to reduce hospitalisation and mortality in these patients, but diagnosis should not be based on clinical history and examination alone. Screening is feasible in general practice, but it should not be implemented until the optimum method of identifying left ventricular dysfunction is clarified, and the cost effectiveness of screening has been shown.

Aged↗

PubMed1993

Role of behavioral and psychological factors in mental stress-induced silent left ventricular dysfunction in coronary artery disease.

OBJECTIVES: We examined the relationship of the psychological profile to left ventricular dysfunction induced during mental stress. BACKGROUND: The contribution of psychological factors to mental stress-provoked silent myocardial ischemia has not been explored. METHODS: Thirty patients with chronic stable coronary artery disease and a reversible defect on stress thallium-201 imaging completed a psychological assessment by questionnaire and Structured Interview, serially administered mental stress and brief walking exercise. Blood pressure, electrocardiogram (ECG) and left ventricular indexes were obtained by ambulatory serial radionuclide ventriculography. Silent ventricular dysfunction was defined by a decrease > or = 0.05 in ejection fraction or > or = 1 mm in ST segment on the ECG in the absence of symptoms. RESULTS: Of the 30 patients, 15 (Group I) had evidence of silent left ventricular dysfunction during mental arithmetic. The other 15 (Group II) showed no change. In addition, 18 of 30 patients had this dysfunction during the Structured Interview. Both ischemic and nonischemic groups developed comparable and significant increases in heart rate and blood pressure. Group I patients were distinguished by higher scores on measures of aggressive responding (p < 0.001), trait anger (p < 0.0001), hostile affect (p < 0.003) and an index of behavioral reactivity (p < 0.003) and a lower score on anger control (p < 0.001). No other variables, including historical and clinical indexes, discriminated between the two groups. CONCLUSIONS: Patients with coronary artery disease and mental stress-provoked silent ventricular dysfunction were distinguished by a psychological profile consistent with emotional reactivity to social interaction and mental provocation, with anger as the predominant affective state. Patients with such a profile may be at risk of frequent silent left ventricular dysfunction.

Adult↗

PubMed1996

Transplant candidates with severe left ventricular dysfunction managed with medical treatment: characteristics and survival.

OBJECTIVES: This study sought to assess the clinical characteristics and survival of patients with symptomatic heart failure who were referred as potential heart transplant candidates, but were selected for medical management. BACKGROUND: Patients with severe left ventricular dysfunction referred for heart transplantation may be considered too well to be placed immediately on an active waiting transplant list. The clinical characteristics of this patient group and their survival have not been well defined. These patients represent a unique group that are characterized by comparatively low age and freedom from significant comorbid conditions. METHODS: We studied 116 consecutive patients with symptomatic heart failure, severe left ventricular dysfunction (left ventricular ejection fraction 20 +/- 7% [mean +/- SD]) and duration of symptoms >1 month referred for heart transplantation, who were acceptable candidates for the procedure but who were not listed for transplantation because of relative clinical stability. These patients were followed up closely on optimal medical therapy. A variety of baseline clinical, hemodynamic and exercise variables were assessed to define this patient group and used to predict cardiac death and requirement later for heart transplantation. RESULTS: During a mean follow-up period of 25.0 +/- 14.8 months (follow-up 99% complete), there were eight cardiac deaths (7%) (seven sudden, one acute myocardial infarction). Only nine patients (8%) were listed for heart transplantation. Actuarial 1- and 4-year cardiac survival rates were 98 +/- 1% and 84 +/- 7% (mean +/- SE), respectively, and freedom from listing for transplantation was 95 +/- 2% and 84 +/- 7% (mean +/- SE), respectively. Patients were mainly in New York Heart Association functional class II or III and had a preserved cardiac index (2.4 liters/min.m2), pulmonary capillary wedge pressure of 16 +/- 9 mm Hg (mean +/- SD) and maximal oxygen consumption of 17.4 +/- 4.3 ml/min per kg (mean +/- SD). By logistic regression analysis, there was no predictor for cardiac death. Longer duration of heart failure (p = 0.013) and mean pulmonary artery (p < 0.05) and pulmonary systolic (p = 0.014) and diastolic (p < 0.05) pressures correlated significantly with listing for heart transplantation by univariate logistic regression. By multivariate logistic regression, only pulmonary artery systolic pressure (p < 0.004) and duration of heart failure (p < 0.015) remained as predictors for need for later transplantation. CONCLUSIONS: In the current treatment era, prognosis is favorable in a definable group of transplant candidates despite severe left ventricular dysfunction. This patient group can be identified after intensive medical therapy by stable symptoms, a relatively high maximal oxygen uptake at peak exercise and a preserved cardiac output.

Adult↗

PubMedDate not supplied

Long-term antiarrhythmic therapy with cibenzoline.

This single-blind, placebo-controlled study evaluated long-term therapy with cibenzoline in 19 patients with chronic ventricular arrhythmias. Antiarrhythmic efficacy, defined as greater than or equal to 75% reduction in single premature ventricular complexes (PVCs), greater than or equal to 90% reduction in paired PVCs, and total abolition of ventricular tachycardia (VT), was established after dose titration in 14 of 19 (74%) patients. Mean frequency of single PVCs was reduced by 65%, mean paired PVC frequency was reduced by 68%, and mean VT event frequency was reduced by 82%. Antiarrhythmic efficacy was maintained during long-term therapy in five of the 14 (36%) short-term responders. Of the nine patients who discontinued cibenzoline during long-term follow-up, five had a loss of arrhythmia control, three failed to redevelop arrhythmias during placebo reintroduction, and one developed an adverse reaction. Three patients (16%) experienced a proarrhythmic effect. Echocardiographic evaluation did not reveal any deleterious effect of cibenzoline on left ventricular function in the group as a whole. In six patients with preexisting left ventricular dysfunction, left ventricular ejection fraction and fractional shortening improved significantly (P less than .05) during cibenzoline therapy. Adverse effects occurred in seven patients (37%) but necessitated drug discontinuation in only one patient (5%). Cibenzoline provides effective short-term therapy for patients with chronic ventricular arrhythmias. Long-term therapy must be assessed periodically to ensure continued efficacy. Drug-related adverse effects occur infrequently. Cibenzoline can be used safely in patients with compensated left ventricular dysfunction.

Adult↗

PubMed1996

Prognostic value of dobutamine echocardiography in patients with left ventricular dysfunction.

OBJECTIVES: This study sought to establish the prognostic implications of ischemic and viable myocardium identified by dobutamine echocardiography in patients with left ventricular dysfunction. BACKGROUND: Recent studies have suggested that in patients with viable myocardium identified by positron emission tomography, medical treatment is associated with recurrent cardiac events. Dobutamine echocardiography has been used to identify viable myocardium in patients with left ventricular dysfunction, but the prognostic significance of this test is undefined. METHODS: One hundred thirty-six consecutive patients (mean [+/- SD] age 67 +/- 7.9 years; 104 men) with moderate or severe left ventricular dysfunction (left ventricular ejection fraction 30 +/- 5%) undergoing dobutamine echocardiography were included in the study. Dobutamine was administered using a standard incremental protocol (5 to 40 micrograms/kg body weight per min intravenously in 3-min stages) with additional atropine (1 mg intravenously) as required. Standard body weight echocardiographic views were digitized on-line and compared using a side-by-side display. Viable myocardium was identified by enhancement of regional function at low dose (< 10 micrograms); scar was diagnosed by akinesia at rest or dyskinesia without change and ischemia as new or worsening dysfunction. One hundred thirty patients (95%) were followed up for 16 +/- 8 months after the original study for major cardiac events (cardiac death, myocardial infarction or severe unstable angina requiring late myocardial revascularization). RESULTS: No significant complications occurred during dobutamine echocardiography. Viable myocardium was detected in 26 patients (19%), ischemia in 23 (17%), both viability and ischemia in 13 (10%) and scar in 74 (54%). Of 108 patients treated medically, 46 had viable or ischemic myocardium, and 62 had scar only. There were no significant differences in age or other clinical characteristics, stress response, left ventricular dimensions and ejection fraction between the two groups. Cardiac events occurred in 26 medically treated patients (24%): 18 died of cardiac-related causes; 4 had a nonfatal myocardial infarction; and 4 had late revascularization because of unstable angina. The event rate was greater in patients with viable or ischemic myocardium than those with scar (43% vs. 8%, p = 0.01 by log-rank test). In a Cox regression model, the presence of viable or ischemic myocardium was found to predict subsequent events (relative risk 3.51, p = 0.02) independently of ejection fraction and age. CONCLUSIONS: Viable or ischemic myocardium detected at dobutamine echocardiography in patients with left ventricular dysfunction is associated with an adverse prognosis, independent of age and ejection fraction.

Aged↗

PubMed1995

Effects of long-term enalapril therapy on cardiac structure and function in patients with left ventricular dysfunction. Results of the SOLVD echocardiography substudy.

BACKGROUND: Studies of Left Ventricular Dysfunction (SOLVD) demonstrated that enalapril therapy significantly improved the clinical course of patients with left ventricular (LV) dysfunction. The goals of this substudy were to evaluate changes in LV structure and function in SOLVD patients and to test the hypothesis that enalapril inhibits remodeling in patients with LV dysfunction. METHODS AND RESULTS: Patients entering both the prevention and treatment arms of SOLVD from 5 of the 23 clinical centers were recruited for this substudy. The 301 patients who participated underwent Doppler-echocardiographic evaluation according to standard protocol before randomization to either enalapril or placebo and again after 4 and 12 months of therapy. Recorded data were analyzed in a blinded fashion at a central core laboratory. Analysis of baseline clinical characteristics showed that patients enrolled in the substudy were generally representative of the SOLVD population, although prevention arm patients were slightly overrepresented in the substudy group (69.8% compared with 61.9% of remaining SOLVD patients). The enalapril group demonstrated significant reductions in the mitral annular E-wave-to-A-wave velocity ratio (due predominantly to a reduction in E-wave velocity), and this response was different from that seen in the placebo group (P = .030). Changes in the E-to-A ratio in the enalapril group correlated significantly with changes in plasma atrial natriuretic peptide (r = .56; P < or = .01). LV end-diastolic and end-systolic volumes increased in placebo but not enalapril-treated patients, and the differences in response between the treatment groups were significant (P = .025 and .019, respectively). LV mass tended to increase in placebo patients and to be reduced in enalapril-treated patients, and the difference in response between the groups was highly significant (P < or = .001). CONCLUSIONS: These data demonstrate that enalapril attenuates progressive increases in LV dilatation and hypertrophy in patients with LV dysfunction. The results support the possibility that the favorable effects of enalapril reported in the SOLVD trials were related to inhibition of LV remodeling.

Adult↗

PubMed1996

Left ventricular dysfunction after heart transplantation: incidence and role of enhanced immunosuppression.

BACKGROUND: The purpose of this study was to examine the incidence, natural history, and outcome of left ventricular dysfunction in 102 consecutive heart transplant recipients. Left ventricular dysfunction (defined as a decline in the echocardiographic ejection fraction to < 0.45) occurred in 16 of 102 transplant recipients (16%) at a mean of 9.7 +/- 8.6 (standard deviation) months after transplantation. METHODS: Diagnostic evaluation included right heart catheterization and endomyocardial biopsy in all patients and coronary angiography in 13 patients. RESULTS: Four patients were found to have moderate cellular rejection (International Society for Heart and Lung Transplantation grade 2 or higher) and were treated with enhanced immunosuppression. Two patients had angiographically apparent coronary allograft vasculopathy; both died of electromechanical dissociation within 4 months. The remaining ten patients had no or mild cellular rejection (International Society for Heart and Lung Transplantation grade 0 or 1). Therapy in these ten patients included corticosteroids (n = 8). OKT3 (n = 5), and plasmapheresis (n = 2). Three patients died within 2 months of diagnosis, two from undetected severe coronary allograft vasculopathy and one from unrecognized constrictive pericarditis. The echocardiographic ejection fraction improved in the surviving patients after enhanced immunosuppressive therapy (0.33 to 0.53, p < 0.005). With the benefit of long-term clinical follow-up and autopsy data, the origins of left ventricular dysfunction in the 16 patients included moderate cellular rejection (n = 4), vascular rejection (n = 1), coronary allograft vasculopathy (n = 3), intercurrent cytomegalovirus infection (n = 1), constrictive pericarditis (n = 1), and either mild or no evident rejection (n = 6). Survival of the 16 patients with left ventricular dysfunction was similar to that of the 86 patients without left ventricular dysfunction. CONCLUSIONS: The cause of left ventricular dysfunction after heart transplantation includes cellular rejection, vascular rejection, coronary allograft vasculopathy, cytomegalovirus infection, constrictive pericarditis, and unexplained mechanisms. Given the improvement in left ventricular function observed after empiric therapy with enhanced immunosuppression in patients with left ventricular dysfunction, immune-mediated phenomena may play an important pathogenic role.

Biopsy↗

PubMed1998

Left bundle branch block and increased transverse:frontal plane QRS voltage ratio in severe left ventricular dysfunction.

Six patients with complete left bundle branch block and an increase in the transverse:frontal plane QRS voltage ratio are described. All these patients presented with congestive heart failure which was due to severe left ventricular dysfunction.

Aged↗

PubMed1996

Adverse effects of enalapril in the Studies of Left Ventricular Dysfunction (SOLVD). SOLVD Investigators.

In the Studies of Left Ventricular Dysfunction (LVD), enalapril or placebo was administered in a double-blind fashion to 6797 participants with ejection fraction < or = 0.35. During 40 months' average follow-up, 28.1% of participants randomized to enalapril reported side effects compared with 16.0% in the placebo group (p < 0.0001). Enalapril use was associated with a higher rate of symptoms related to hypotension (14.8% vs 7.1%, p < 0.0001), azotemia (3.8% vs 1.6%, p < 0.0001), cough (5.0% vs 2.0%, p < 0.0001), fatigue (5.8% vs 3.5%, p < 0.0001), hyperkalemia (1.2% vs 0.4%, p = 0.0002), and angioedema (0.4% vs 0.1%, p < 0.05). Side effects resulted in discontinuation of blinded therapy in 15.2% of the enalapril group compared with 8.6% in the placebo group (p < 0.0001). Thus enalapril is well tolerated by patients with LVD; however, hypotension, azotemia, cough, fatigue, and other side effects result in discontinuation of therapy in a significant minority of patients.

Aged↗

PubMed1998

Influence of the preoperative signal-averaged electrocardiogram on left ventricular function after coronary artery bypass graft surgery in patients with left ventricular dysfunction. The CABG Patch Trial.

Patients with ischemic left ventricular (LV) dysfunction often have an improved survival and life quality after coronary artery bypass grafting (CABG), in part due to an improvement in LV function. A lack of LV ejection fraction (EF) improvement postoperatively portends a worse prognosis. Recently, an abnormal preoperative signal-averaged electrocardiogram (SAECG) in patients with a severely depressed LV ejection fraction undergoing elective CABG was shown to be associated with a higher early and late postoperative mortality. The present study evaluated patients with severe LV dysfunction to identify any relation between an abnormal preoperative SAECG and postoperative changes in LV function after successful CABG. Forty-five patients with LV dysfunction (LVEF <0.36) scheduled for elective CABG underwent preoperative SAECG and both pre- and postoperative LVEF determinations using radionuclide scans. Thirty-one patients in the group had an abnormal preoperative SAECG and 14 patients had a normal preoperative SAECG. Baseline patient characteristics were similar in both groups and the mean preoperative LVEF was 0.26. Overall, LVEF improved 31% postoperatively with a significantly greater benefit noted in the group with a normal baseline SAECG (14.9+/-5.7-point vs 4.8+/-8.5-point increase, p <0.001). All patients whose LVEF did not improve or worsened postoperatively had an abnormal preoperative SAECG. No SAECG measure was altered significantly by the operation. A preoperative SAECG provides information on the postoperative functional recovery of ischemic myocardium.

Aged↗

PubMed1996

Metoprolol abolishes exercise-induced left ventricular dysfunction in patients with silent ischemia.

Left ventricular systolic function is reduced during episodes of silent ischemia in patients with coronary artery disease (CAD). Left ventricular ejection fraction (LVEF) is increased at least 5 absolute percent during exercise in most normal subjects; however, in patients with CAD, LVEF often remains unchanged or decreases. The anti-ischemic effect of beta-adrenergic receptor blockade is well documented, including a reduction of exercise-induced electrocardiographic ST depressions; however, the effect of these drugs on left ventricular volume changes during exercise in patients with silent ischemia is unknown. The aim of this study was to evaluate the effect of a cardio-selective beta-blocking agent, metoprolol, on rest and exercise LVEF in patients with silent ischemia, using radionuclide cardiography. Fifteen patients with silent ischemia completed a double-blind, placebo-controlled crossover study at rest and during submaximal exercise. LVEF remained unchanged during exercise in the placebo phase (56% to 58%; p = NS), but even though LVEF tended to decrease 56% during rest after metoprolol versus 52% after placebo (p = NS), the LVEF increase from rest to exercise resembled a normal LVEF response, 52% to 58% (p = 0.005). Exercise-induced electrocardiographic ST depressions were also reduced during metoprolol treatment. In patients with silent ischemia, the exercise-induced change in LVEF rises significantly during metoprolol treatment. The mechanism may be a reduction in myocardial ischemia as indicated by a reduction in ischemic electrocardiographic findings.

Adrenergic beta-Antagonists↗

PubMed1984

Natural history of severe left ventricular dysfunction after myocardial infarction.

The prevalence and prognosis of severe left ventricular dysfunction after infarction was prospectively analyzed in a series of 259 male patients aged 60 years or less surviving an acute myocardial infarction. All patients underwent coronary angiography 30 days after the acute event and were followed up for a mean period of 34 months (range, 15 to 55 months). Forty-five patients (17 percent) were found to have severe left ventricular dysfunction (ejection fraction less than or equal to 30 percent). Comparison of patients with and without severe impairment of left ventricular function showed the former to have a lower cardiac index (p less than 0.001), higher left ventricular end-diastolic volume index (p less than 0.001), and a higher prevalence of three-vessel disease (p less than 0.025) and of total or subtotal occlusion of at least one coronary artery (p less than 0.025). While the occurrence of congestive heart failure was higher in patients with severe left ventricular dysfunction (p less than 0.001), the probability of developing angina was similar in both groups. Cox's regression analysis showed ejection fraction to be the only independent predictor of survival in patients with severe impairment of left ventricular function. An ejection fraction of 20 percent or less identified a subset of patients with the highest mortality (62 percent at four years), significantly different from that of patients whose ejection fraction was between 21 and 30 percent (28 percent) (p less than 0.001).

Adult↗

PubMed1988

Diastolic filling in acute left ventricular dysfunction: role of the pericardium.

Patients with congestive heart failure and elevated left ventricular filling pressures demonstrate an abnormal pattern of diastolic filling that is characterized by a redistribution of diastolic filling to early diastole with reduced reliance on late diastolic filling. The diastolic filling pattern superficially resembles that which is seen with constrictive pericarditis. To examine potential mechanisms for these clinical findings, a model of ischemic left ventricular dysfunction was produced in seven dogs by repeated coronary microsphere embolization, producing a dilated left ventricle with reduced systolic function. Measurements of left ventricular systolic and end-diastolic pressures, rate of rise of left ventricular pressure (dP/dt) and echocardiographic end-diastolic and end-systolic areas were obtained at baseline, during intermediate embolization (moderate left ventricular systolic dysfunction, dilation and mild increases in left ventricular end-diastolic pressure), postembolization (further embolization resulting in severe left ventricular systolic dysfunction, dilation and marked increases in left ventricular end-diastolic pressure), after thoracotomy and after pericardiectomy. The filling fraction at 1/3 and 1/2 of diastole and the time constant of left ventricular pressure decline were also determined. Repetitive coronary microembolization caused progressive left ventricular dilation and decreasing systolic function, which did not change after opening the chest or pericardium. The filling fraction at 1/3 and 1/2 of diastole declined with intermediate embolization (12.0 +/- 5.6% and 23.1 +/- 10.8%, respectively) as compared with baseline values (29.0 +/- 11.9%, 42.9 +/- 15.6%, p less than 0.05). After embolization, there was an increase in the 1/3 and the 1/2 filling fraction (47.5 +/- 8.9%, 72.0 +/- 6.0%, respectively, p less than 0.01) as compared with baseline values.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1989

Left ventricular dysfunction in acute myocardial infarction due to isolated left circumflex coronary artery stenosis.

The characteristics of regional and global left ventricular dysfunction due to isolated left circumflex (LC) artery stenosis were determined from the contrast ventriculograms of 52 patients studied during acute myocardial infarction. In patients with a left dominant coronary circulation (35%), the severity, circumferential extent and location of hypokinesia resembled those of right coronary artery stenosis. However, in patients with a right dominant or balanced circulation (65%), the location of LC artery-related hypokinesia varied over the entire left ventricular contour, overlapping with the territories of the left anterior descending and right coronary arteries. The method for measuring the severity of hypokinesia was adjusted to take into account the wide territory of the LC artery. This enhanced the sensitivity of the method, particularly in the right anterior oblique view, as indicated by the greater severity of hypokinesia measured (-2.5 +/- 0.9 vs -1.8 +/- 1.1 standard deviations by our previously published method, p less than 0.001). However, the overlap of the artery territories may make it difficult to selectively measure the dysfunction due to stenosis of an artery of interest in patients with multiple infarctions. The circumferential extent of hypokinesia due to LC artery thrombosis was greater in the left than the right anterior oblique view. When averaged over both views, the size of the dysfunctional segment approached that due to left anterior descending coronary artery thrombosis, exceeding the size previously reported. These results suggest that current eligibility criteria for thrombolytic therapy select patients with extensive LC artery beds.

Cineradiography↗