Left Ventricular Dysfunction Patients Research Articles

Evaluation Left Ventricle Performance in hypertensive patients using heart ultrasound and levels of a salt-producing brain peptide in blood

Background: we studied on 100 patients in total, with 56 in the 'LV dysfunction' group and the rest in the 'control' group to evaluate of left ventricular functioning in hypertensive patients by examining the ultrasound of the heart by tracking the scores and their association with levels of a salt-producing brain peptide in the blood. . To find relevant research, a thorough online search was conducted. Data were retrieved and synthesized from the included studies after they were evaluated for quality and risk of bias. The findings demonstrated a robust association between B-type natriuretic peptide (BNP) levels and speckle-tracking echocardiography (STE) derived indices of left ventricular (LV) performance in hypertension individuals. The findings of this review highlight the potential of STE as a valuable tool for evaluating LV performance in hypertensive patients and its association with BNP levels in Baghdad. Aim: This study aims to find out how hypertension patients' LV function, as determined by speckle-tracking echocardiography (STE), correlated with B-type natriuretic peptide BNP levels in the blood. Methods: All subjects had echocardiographic tests using a commercially available ultrasonography equipment equipped with a phased-array transducer operating at 3.5 MHz, with the following parameters measured: Biplane with a few tweaks for this study, the LVEF was calculated using Simpson's method ,the left ventricular systolic volume (SV) ,systolic volume at the end of the left ventricle (LVESV), in order to determine the LVMI, the Devereux formula was used and the filling ratio of early to late diastole (E/A ratio). They were compared with a healthy group (control) to obtain accurate results. Results: There were statistically significant differences in LVEF, LVEDV, LVESV, LVMI, E/A ratio, E/e' ratio, and global longitudinal strain (GLS) between the control and LV dysfunction groups. Diastolic dysfunction was more common in LV dysfunction patients, and they also had lower GLS values than the control group. The levels of BNP were shown to have a favorable relationship with numerous echocardiographic parameters. Hypertensive individuals had greater BNP levels than the control group. The LVH group also had greater levels of BNP than the non-LVH group.

Factors Influencing Survival Outcomes in Patients with Left Ventricular Dysfunction after Coronary Revascularization

Abstract Background Outcomes in patients with left ventricular (LV) dysfunction after coronary revascularization are influenced by multiple factors; however, it is difficult to compare a direct relationship between LV dysfunction and mortality due to the presence of confounding variables, so we attempted to observe the influence of risk factors on outcomes in severe LV dysfunction patients after revascularization and delineate if any of them have an effect on one-year mortality of such patients. Methodology This is a single center prospective study, where the studied population were severe LV dysfunction patients who underwent percutaneous transluminal coronary angioplasty (PTCA) and followed-up for one year and at the end of one year, impact of gender, age, type 2 diabetes mellitus (DM), hypertension (HTN), obesity, chronic kidney disease (CKD), cerebrovascular accident (CVA), hypothyroidism, smoking and alcohol on one-year mortality and MACE (major adverse cardiovascular events), which included reinfarction (nonfatal), recurrence of angina, repeat percutaneous intervention (PCI) or coronary artery bypass grafting (CABG) and heart failure. The above factors were analyzed and statistically approached to observe the impact of those risk factors on one-year mortality and determine whether the timing and mode of revascularization, and number of coronary arteries involved, had any influence on mortality or MACE events. By comparing different parameters of the study with respect to mortality, a regression analysis was made at the end of one year Results As many as 152 patients of severe LV dysfunction (ejection fraction < 30%) were enrolled in the study, among which 115 (75.6%) patients were males, and 37 patients were females (24.3%), with a mean age of 57.6 years; 89 (58.5%) patients were hypertensive, 80 (52.6%) patients were diabetics, 42 (27.6%) patients were smokers, 20 (13.1%) patients were alcoholics, 9 (5.9%) had CKD, one (0.6%) patient had hypothyroidism and one (0.6%) patient had a history of CVA; 46 (30.2%) patients presented with acute coronary syndrome (ACS) and 106 (69.7) patients had chronic stable angina (CSA); 144 (94.7%) patients underwent PTCA (percutaneous transluminal coronary angioplasty), while eight (5.2%) patients underwent CABG. At the end of one year, mortality was six patients (3.94%). At the end of one year, regression analysis was done for all the confounding variables by observing their influence on the MACE or mortality; none of them showed statistically significant influence (p > 0.05). Conclusion At the end of one year, after revascularization in patients with severe LV dysfunction, no significant relationship could be ascertained between the mortality or MACE events and gender, age, DM, HTN, CKD, and alcohol or smoking. MACE or mortality may be attributed directly to LV dysfunction itself, and the observed mortality was higher than that of normal LV Function. Hence, in our study, LV dysfunction is the cause of mortality in the study population but not the other confounding variables.

The impact of tissue-tracking strain on the left atrial dysfunction in the patients with left ventricular dysfunction

BackgroundThe extracellular volume (ECV) calculated by T1 mapping, and tissue-tracking strain using cardiac magnetic resonance (CMR) are useful for assessing the left ventricular (LV) function. However, those parameters are controversial for assessing left atrial (LA) function. This study aimed to investigate the usefulness of CMR to evaluate the LA function using those parameters. Furthermore, those LA function parameters were compared in each LV function. MethodsA total of 65 consecutive patients who underwent contrast CMR were prospectively enrolled (age 55.7 ± 14. 6 years, males 67.7%). Among the 65 patients, there were 15 without hypertension, diabetes, or atrial fibrillation (Healthy group). The remaining 50 patients were divided into two groups according to a left ventricular ejection fraction (LVEF) of 50%. We assessed the correlations between the LV- and LA-CMR parameters among the three groups (LVEF < 50%; n = 20, LVEF ≥ 50%; n = 30, and Healthy; n = 15). ResultsThe LA-longitudinal strain for an LVEF < 50% was lower than that for the others (LVEF < 50%; 13.6 ± 7.9%, LVEF ≥ 50%; 24. 5 ± 13.5%, Healthy; 24.5 ± 9.8%, p = 0.003). However, the LA-ECV did not significantly differ among the three groups (LVEF < 50%; 50.3 ± 3.6%, LVEF ≥ 50%; 53.1 ± 4.9%, Healthy; 53.2 ± 6.5%, p = 0.12). A multiple regression model after adjusting for the patient background revealed that a worse LA-longitudinal strain was correlated with a low LVEF and large LA-volume, but the LA-ECV was not associated with those. ConclusionsThe LA-strain in LV dysfunction patients was significantly lower. However, the LA-ECV did not significantly differ from that in those without LV dysfunction. Tissue-tracking strain is more useful for evaluating the LA dysfunction than T1 mapping.

Clinical significance of early-diastolic tissue velocity imaging of lateral mitral annulus for prognosis of nonischemic left ventricular dysfunction.

We explored the potential of tissue velocity imaging (TVI) for prognosis of nonischemic left ventricular (LV) dysfunction (LVD). We reviewed 138 nonischemic LVD patients (58 ± 14 years) who underwent both cardiac magnetic resonance (CMR) and echocardiography. Septal and lateral mitral annular TVI data were compared with late gadolinium enhancement (LGE) on CMR. During a mean follow-up of 24 months, recovery (>15%) of LV ejection fraction and clinical outcomes (cardiovascular death and heart failure hospitalization) were assessed. LGE was commonly observed in the basal anteroseptal, inferoseptal, and inferior segments, but infrequently observed in the anterolateral segment. LGE was associated with lower early diastolic, septal (Sep-e' = 5.2 ± 2.0 vs 6.9 ± 2.0 cm/s, P = .031) and lateral (Lat-e' = 7.3 ± 3.0 vs 9.5 ± 2.0 cm/s, P < .001) TVI. The relationship between Lat-e' and anterolateral LGE (area under the curve, AUC 0.834) was much better than that between Sep-e' and inferoseptal LGE (AUC 0.699). The 60 patients with LVD reversibility revealed higher Lat-e' (9.8 ± 2.0 vs 6.7 ± 2.2 cm/s, P < .001) and lower LGE burden (7.3 ± 9.0 vs 22 ± 10%, P < .001), while Lat-e' ≤ 7.8 cm/s appeared unfavorable for 31 events patients. On multivariate analyses, Lat-e' (HR 0.79, 95% CI 0.63-0.99, P = .044) and LVD reversibility (HR 0.53, 95% CI 0.16-0.90, P = .018) were still meaningful together with LGE segments and burden. Lat-e' was related with LVD reversibility and a significant predictor of clinical outcomes.

Clinical outcomes of total arterial off-pump coronary revascularization in patients with left ventricular dysfunction

Objective: To compare the advantages and disadvantages of total arterial revascularization (TAR) and conventional off-pump coronary artery bypass (OPCAB) grafting in patients with left ventricular dysfunction (LVD). Methods: Between January 2008 and March 2015, 76 patients who were scheduled to undergo selective OPCAB were selected for cardiac surgery in Zhongshan Hospital, Fudan University. The left ventricular ejection fraction of enrolled patients was less than 35%. Among those patients, 38 patients in TAR group underwent total arterial OPCAB with bilateral internal mammary artery, left and/or right radial artery, and another 38 patients in control group underwent conventional OPCAB with left internal mammary artery and great saphenous vein. The clinical data of all patients were collected. The follow-up was performed within 36 months. Results: There was no significant difference in preoperative clinical data between the two groups (all P>0.05). Additionally, there was no significant difference in the application rate of internal mammary artery, positive inotropic drugs and intra-aortic balloon pump (IABP) use between the two groups (all P>0.05). The operation time of TAR group was longer than that of control group [(278.3±31.2) min vs (196.7±19.1) min, P<0.01]. There was no significant difference in perioperative mortality between the two groups (5.3% vs 7.9%, P=0.64). The volume of operative drainage and blood transfusion in TAR group increased significantly at 24 hours after operation [(895.0±236.2) ml vs (585.4±172.5) ml, (656.3±84.4) ml vs (433.3±62.9) ml, both P<0.01]. There was no significant difference in perioperative complications such as heart, kidney and lung failure between the two groups (all P>0.05). At 12 months after operation, there were no significant differences in survival rate, cardiac death rate, angina recurrence, myocardial infarction, re-treatment rate of revascularization, re-hospitalization rate from cardiac insufficiency, graft patency rate, cardiac function and echocardiographic data between the two groups (all P>0.05). From 24 to 36 months after operation, all the above indexes in TAR group were better than those in control group except for echocardiographic data (all P<0.05). Conclusions: For LVD patients, the early clinical efficacy of the two surgical methods is similar, but for the long-term outcomes, the whole arterial OPCAB operation is obviously superior. However, the shortcomings of total arterial OPCAB are that operative drainage and the use of blood products increased significantly after operation.

Microvolt T-wave alternans profiles in patients with pulmonary arterial hypertension compared to patients with left ventricular systolic dysfunction and a group of healthy volunteers.

Objective:Microvolt T-wave alternans (MTWA) is a well-examined parameter for the risk stratification of sudden cardiac death (SCD) in patients with left ventricular dysfunction (LVD). However, the role of MTWA in pulmonary arterial hypertension (PAH) remains obscure. Consequently, the present study aimed to analyze the profile of MTWA among PAH patients in comparison with LVD patients and healthy volunteers.Methods:The prospectively study included 22 patients with PAH (mean pulmonary artery pressure ≥ 25 mm Hg and pulmonary capillary wedge pressure ≤15 mm Hg during right heart catheterization; mean age, 40±17 years); 24 with LVD [left ventricular ejection fraction (LVEF) ≤35%; mean age, 40±11 years]; and 28 healthy volunteers (mean age, 41±8 years). Patients with persistent atrial arrhythmia were excluded. The MTWA (spectral method) categories were positive, negative, or indeterminate (MTWA_pos, MTWA_neg, or MTWA_ind, respectively). MTWA_pos and MTWA_ind were qualified as abnormal (MTWA_abn). Statistical analyses (Mann–Whitney U, chi-square with Yates’s correction, Fisher’s exact test) were performed.Results:PAH patients had higher LVEF than LVD patients (61±7% vs. 27±7%; p<0.05). MTWA_abn was observed more frequently in the PAH and LVD groups than in the healthy volunteers. Patients with PAH were characterized by a considerable percentage of MTWA_pos and MTWA_abn (59% and 73%, respectively), but this did not differ from LVD patients.Conclusion:Patients with PAH are characterized by a high rate of MTWA abnormalities similar to LVD patients, despite the relevant differences in LVEF. Further research is required to elucidate the clinical significance and prognostic value of this data, particularly in the context of SCD-underlying mechanisms in PAH patients.

Trans-pulmonary physiology in patients with severe left ventricular dysfunction using ePLAR (echocardiographic Pulmonary to Left Atrial Ratio) – relationship with heart rate response to beta-blocker therapy

Background: Patients with severe left ventricular dysfunction (LVD) have post-capillary obstruction to pulmonary flow, corresponding to low ePLAR (tricuspid regurgitation maximum velocity / mitral E wave : DTI E’) values. The effect of this pathophysiology on heart rate response to beta-blocker therapy remains to be determined. Methods: 347 patients with severe LVD in sinus rhythm (EF<35%) were studied before/after beta-blocker therapy. ePLAR values were compared with a predetermined normal population (n=1000). Results: Initial ePLAR values (0.2±0.1m/s, 71±12 years, males 59%) did not change (0.19±0.09m/s, p=ns) on most recent echo (mean therapy 2.8 years). Heart rate responders (HR≤77bpm, n=285), had significantly lower initial ePLAR values (0.19±0.1m/s) than non-responders (HR>77bpm, n=62, ePLAR 0.22±0.1m/s, p=0.039). However, between groups there was no significant difference in ePLAR values (0.18±0.08m/s vs 0.20±0.13m/s, p=ns), or E:E’ values (17.6±10 vs 16.5±9.3, p=ns) on most recent echo. LVD patients had substantially reduced treated ePLAR values compared to population normals (p<0.05 for each decade). Conclusions: Patients with severe left ventricular dysfunction have low ePLAR values consistent with post-capillary obstruction to pulmonary flow. Patients achieving target heart rate have significantly lower initial ePLAR values.

Effect of Statin Treatment in Patients With Acute Myocardial Infarction and Left Ventricular Systolic Dysfunction According to the Level of High-Sensitivity C-Reactive Protein

The effects of statins on the prognosis of patients with left ventricular (LV) systolic dysfunction remain controversial. The aim of this study was to assess the effect of statin treatment on clinical outcomes in acute myocardial infarction (AMI) patients with LV systolic dysfunction. A total of 5,119 AMI patients with LV ejection fraction less than 50% on the initial echocardiogram were analyzed in the Korean Acute Myocardial Infarction Registry. The study population was divided into 4 groups according to the level of high sensitivity C-reactive protein (hs-CRP) and statin treatment: low hs-CRP (hs-CRP ≤ 2.0 mg/L) and high hs-CRP (hs-CRP > 2 mg/L) with or without statin therapy. We evaluated the incidence of major adverse cardiac events (MACEs) including cardiac death, reinfarction, target lesion revascularization, and coronary artery bypass grafting during a 12-month period in each group. Statin therapy did not significantly prevent the MACEs in the low hs-CRP groups (with statin: 10.1% versus without statin: 12.0%, P = 0.249). In the high hs-CRP groups, however, the incidence of MACEs was significantly decreased with statin treatment (with statin: 11.3%, without statin: 20.8%, P < 0.001). These findings were consistently observed in all subgroups of the high-hs CRP group, including the subgroup with an LV ejection fraction less than 40%. In a multivariable logistic regression analysis of the high hs-CRP group, lack of statin therapy was a significant predictor of MACE incidence (odds ratio: 1.573, 95% confidence interval: 1.079-2.293, P = 0.018). The statin treatment was associated with better outcome in AMI and LV dysfunction patients with hs-CRP ≥ 2 mg/dL.

Is mitral valve repair superior to replacement for chronic ischemic mitral regurgitation with left ventricular dysfunction?

BackgroundThis study was undertaken to compare mitral valve repair and replacement as treatments for ischemic mitral regurgitation (IMR) with left ventricular dysfunction (LVD). Specifically, we sought to determine whether the choice of mitral valve procedure affected survival, and discover which patients were predicted to benefit from mitral valve repair and which from replacement.MethodsA total of 218 consecutive patients underwent either mitral valve repair (MVP, n = 112) or mitral valve replacement (MVR, n = 106). We retrospectively reviewed the clinical material, operation methods, echocardiography check during operation and follow-up. Patients details and follow-up outcomes were compared using multivariate and Kaplan-Meier analyses.ResultsNo statistical difference was found between the two groups in term of intraoperative data. Early mortality was 3.2% (MVP 2.7% and MVR 3.8%). At discharge, Left ventricular end-systolic and end-diastolic diameter and left ventricular ejection fraction (LVEF) were improved more in the MVP group than MVR group (P < 0.05), however, in follow-up no statistically significant difference was observed between the MVR and MVP group (P > 0.05). Follow-up mitral regurgitation grade was significantly improved in the MVR group compared with the MVP group (P < 0.05). The Kaplan-Meier survival estimates at 1, 3, and 5 years were simlar between MVP and MVR group. Logistic regression revealed poor survival was associated with old age(#75), preoperative renal insufficiency and low left ventricular ejection fraction (< 30%).ConclusionMitral valve repair is the procedure of choice in the majority of patients having surgery for severe ischemic mitral regurgitation with left ventricular dysfunction. Early results of MVP treatment seem to be satisfactory, but several lines of data indicate that mitral valve repair provided less long-term benefit than mitral valve replacement in the LVD patients.

Abnormal myocardial insulin signalling in type 2 diabetes and left-ventricular dysfunction

Whole body and myocardial insulin resistance are features of non-insulin-dependent diabetes mellitus (NIDDM) and left-ventricular dysfunction (LVD). We determined whether abnormalities of insulin receptor substrate-1 (IRS1), IRS1-associated PI3K (IRS1-PI3K), and glucose transporter 4 (GLUT4) contribute to tissue-specific insulin resistance. We collected skeletal muscle (n = 27) and myocardial biopsies (n = 24) from control patients (n = 7), patients with NIDDM (n = 9) and patients with LVD (n = 8), who were characterized by euglycaemic-hyperinsulinaemic clamp and positron emission tomography. Comparative studies were carried out in three mouse models. We demonstrate an unrecognized reduction of IRS1 in skeletal muscle of LVD patients and an unexpected increase in cardiac IRS1-PI3K activity in NIDDM and LVD patients. In NIDDM, there was a concomitant reduction in sarcolemmal GLUT4, whereas in patients with LVD sarcolemmal GLUT4 was increased. We confirm activation of IRS1-PI3K and reduction in sarcolemmal GLUT4 in the insulin resistant ob/ob mouse heart where we also demonstrate perturbation of GLUT4 docking and fusion. A direct relationship between PI3K and GLUT4 was demonstrated in mice expressing activated PI3K in the heart and increased GLUT4 at the sarcolemma was confirmed in a mouse model of LVD. Our data show that the mechanisms of myocardial insulin resistance are different between NIDDM and LVD.

Resting muscle sympathetic nerve activity, cardiac metaiodobenzylguanidine uptake, and exercise tolerance in patients with left ventricular dysfunction

BackgroundSympathetic nerve overactivity and reduced exercise tolerance are characteristic features of patients with heart failure. However, to what extent sympathetic nerve overactivity contributes to limiting exercise tolerance has not been clearly defined. MethodsMyocardial iodine 123-metaiodobenzylguanidine (MIBG) scintigraphy, muscle sympathetic nerve activity (MSNA), and cardiopulmonary exercise testing were performed within 3 days in 30 patients with left ventricular dysfunction (LVD). Cardiac sympathetic nerve activity was estimated using H/M ratio and washout rate (WR) of 123I-MIBG imaging. MSNA was recorded by microneurography. ResultsThe patients with peak VO2 < 20 mL/minute/kg (group II, n = 15) had significantly higher MSNA and WR, and lower H/M ratio than those with peak VO2≧ 20 mL/minute/kg (group I, n = 15) (P < .05). Peak VO2 had negative correlations with MSNA and WR (r = 0.58, 0.56), and positive correlations with early H/M ratio and delayed H/M ratio (r = 0.71, 0.75) in group II. Moreover, MSNA had negative correlations with early H/M ratio and delayed H/M ratio (r = 0.78, 0.66), and a positive correlation with WR (r = 0.79) in group II. However, similar relations were not found in group I. ConclusionsA link between cardiac and peripheral sympathetic nerve activities contributed to limiting exercise tolerance in patients with LVD patients and reduced exercise tolerance.

Device Therapies in the Post-Myocardial Infarction Patient with Left Ventricular Dysfunction

The post-myocardial infarction (MI) patient with left ventricular dysfunction (LVD) is at risk for ventricular arrhythmias resulting in sudden cardiac death. In high-risk post-MI patients with a depressed left ventricular ejection fraction, prophylactic implantable cardioverter defibrillators (ICDs) may significantly improve survival. These benefits are in addition to those of optimal pharmacologic therapy, and ICD therapy should be considered the standard of care in these patients. Recent device trials have demonstrated the benefits of prophylactic ICD placement in patients who have been selected based on post-MI left ventricular systolic dysfunction alone. In addition, cardiac resynchronization therapy can improve the quality of life beyond that achievable with drug therapy alone and should be considered in patients with symptomatic heart failure with QRS prolongation. Further risk stratification studies of post-MI LVD patients will allow ICD therapy to be applied in a more cost-effective manner.

Implementing Critical Pathways and a Multidisciplinary Team Approach to Cardiovascular Disease Management

According to several medical registries, there is a need to improve the care of post-myocardial infarction (MI) patients, especially those with left ventricular dysfunction (LVD) and heart failure. This can potentially be achieved by implementing disease management programs, which include critical pathways, patient education, and multidisciplinary hospital teams. Currently, algorithms for critical pathways, including discharge processes, are lacking for post-MI LVD patients. Such schemes can increase the use of evidence-based medicines proved to reduce mortality. Educational programs are aimed at increasing patients' awareness of their condition, promoting medication compliance, and encouraging the adoption of healthy behaviors; such programs have been shown to be effective in improving outcomes of post-MI LVD patients. Reductions in all-cause hospitalizations and medical costs as well as improved survival rates have been observed when a multidisciplinary team (a nurse, a pharmacist, and a hospitalist) is engaged in patient care. In addition, the use of the "pay for performance" method, which can be advantageous for patients, physicians, and hospitals, may potentially improve the care of post-MI patients with LVD.

Pharmacologic Therapies Across the Continuum of Left Ventricular Dysfunction

Neurohormonal activation and increased sympathetic stimulation are among the factors that have been linked to the development and progression of left ventricular dysfunction (LVD) and heart failure (HF) in post-myocardial infarction (MI) patients. Various available pharmacologic therapies can target these factors and improve many aspects of the disease, depending on the degree of LVD. The American College of Cardiology/American Heart Association (ACC/AHA) guidelines recommend angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and aldosterone antagonists because of their proven favorable effects on symptoms, left ventricular function, cardiac remodeling, hospitalization rates, and survival. However, they are not being used in over two thirds of patients with post-MI LVD. This review illustrates the impact of these therapies on post-MI LVD patients using evidence from multiple clinical trials. In addition, current and emerging treatments for acute decompensated HF will be outlined.

Coronary Artery Bypass Grafting in Patients with Severe Left Ventricular Dysfunction-Early and Mid-Term Outcomes

The prevalence of patients with severe left ventricular dysfunction (LVD) referred for coronary artery bypass grafting (CABG) is increasing. The aim of the present study was to assess the outcomes of patients with severe LVD undergoing CABG. Outcomes of 115 consecutive patients with severe LVD (left ventricular ejection fraction [LVEF]</= 30%, mean 22 +/- 6%) undergoing isolated CABG between 1995 and 2000 were compared to 2335 patients with LVEF >30% (HEF). To further evaluate the LVD patients, they were divided into three subgroups base on LVEF: 0% to 10%, 11% to 20%, and 21% to 30%. Data were collected prospectively and entered into the departmental database of the Society of Thoracic Surgeons. Patients in the LVD group had increased incidence of diabetes, chronic obstructive pulmonary disease (COPD), peripheral vascular disease, prior myocardial infarction (MI), congestive heart failure, and less elective procedures compared to the HEF group. Despite this greater risk profile, operative mortality (LVD 2.6% vs. HEF 1.2%, p = 0.19), the incidence of stroke (2.6% vs. 1.0%, p = 0.13), and perioperative MI (0.9% vs. 0.7%) were not statistically different between the groups. The incidence of respiratory (14.8% vs. 1.9%, p < 0.001), renal (5.2% vs. 1.0%, p < 0.001), and vascular (5.2% vs. 0.5%, p < 0.001) complications was significantly higher in the LVD group, resulting in a longer hospital length of stay (8 +/- 8 vs. 6 +/- 4 days, p < 0.0001). In a multivariate analysis, advanced age was as an independent predictor of hospital mortality. Average follow-up in 108 (94%) LVD patients was 36 +/- 22 months (range 2 to 78 months). Twenty-one patients expired during the follow-up, for nine the causes were cardiac-related. Three- and 5-year survival rates were 91 +/- 3% and 76 +/- 6%, respectively. Independent predictors of mid-term mortality in the LVD group by a multivariate analysis included female gender, renal failure, respiratory complications, and grade I/II mitral regurgitation (MR). At the time of follow-up, 72% of LVD patients were in functional class I/II. There were no statistically significant differences in short- and mid-term outcomes among the LVD subgroups. CABG in patients with severe LVD can be performed with a low mortality, albeit with higher morbidity and longer length of hospital stay, than patients with LVEF >30%. Low ejection fraction per se was not a predictor of hospital mortality. CABG should be considered a safe and effective therapy for low ejection fraction patients with ischemic heart disease. Mitral valve repair/replacement in the presence of moderate degree of MR should be considered at the time of the initial operation.

Fractal and Complexity Measures of Heart Rate Dynamics in Patients with Normal and Left Ventricular Dysfunction: The Role of New Noninvasive Markers for Cardiac Risk Stratification

Background and Objectives:The traditional indexes of heart rate (HR) variability may lack the ability to detect subtle, but important changes in HR behavior. Nonlinear heart rate variability (HRV) analysis methods that are based on chaos theory can reveal subtle abnormalities in the HR dynamics of patients with cardiovascular diseases. Therefore, we tested the validity of nonlinear analysis methods as markers to differentiate normal and abnormal HR dynamics in the cardiovascular disease state. Subjects and Methods:One-hundred patients were studied: 70 patients with left ventricular dysfunction (LVD), including 40 post-myocardial infarct patients (PMI) and 30 di- lated cardiomyopahty patients (DCM), and 30 age and gender-matched controls. One-hour, 6-hours (day and night each) and 24 hours of R-R interval data from 24-hour Holter recordings were subjected to the conventional time and frequency-domain analysis. The ApEn, short-term (α 1) and long-term (α2) scaling exponents of the detrended fluctuation analysis (DFA) and the power-law exponent (β) were also measured. Results:Conven- tional linear measures did not show a significant difference except for the VLF, lnLF and the LF/HF ratio between the controls and the LVD patients. Among the analyzed parameters, β, β2 and α1 were the most powerful dis- criminators. The β of the normal and LVD patients was -1.10±0.29 and -0.70±0.40, respectively (p<0.001), and the α1 was 1.08±0.23 and 0.81±0.28, respectively (p<0.001). The β, β2 and α1 can discriminate the etio- logic cause of LVD. The length of the R-R interval data did not affect the result, and a significant correlation was observed. The individual values of the fractal and complexity measures were more stable than those of the con- ventional linear measures. Conclusion:We conclude that the measures derived from fractal and complexity met- hods are useful for detecting altered HR dynamics of LVD and for improving the shortcomings of the conventional measures. (Korean Circulation J 2006;36:583-592)

Pressure and time dependence of the cardiopulmonary reflex response in patients with hypertensive cardiomyopathy

The first minutes of the time course of cardiopulmonary reflex control evoked by lower body negative pressure (LBNP) in patients with hypertensive cardiomyopathy have not been investigated in detail. We studied 15 hypertensive patients with left ventricular dysfunction (LVD) and 15 matched normal controls to observe the time course response of the forearm vascular resistance (FVR) during 3 min of LBNP at -10, -15, and -40 mmHg in unloading the cardiopulmonary receptors. Analysis of the average of 3-min intervals of FVR showed a blunted response of the LVD patients at -10 mmHg (P = 0.03), but a similar response in both groups at -15 and -40 mmHg. However, using a minute-to-minute analysis of the FVR at -15 and -40 mmHg, we observed a similar response in both groups at the 1st min, but a marked decrease of FVR in the LVD group at the 3rd min of LBNP at -15 mmHg (P = 0.017), and -40 mmHg (P = 0.004). Plasma norepinephrine levels were analyzed as another neurohumoral measurement of cardiopulmonary receptor response to LBNP, and showed a blunted response in the LVD group at -10 (P = 0.013), -15 (P = 0.032) and -40 mmHg (P = 0.004). We concluded that the cardiopulmonary reflex response in patients with hypertensive cardiomyopathy is blunted at lower levels of LBNP. However, at higher levels, the cardiopulmonary reflex has a normal initial response that decreases progressively with time. As a consequence of the time-dependent response, the cardiopulmonary reflex response should be measured over small intervals of time in clinical studies.

Natriuretic peptides in assessment of left-ventricular dysfunction

The heart secrets two different natriuretic peptides, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), which have potent vasorelaxant, diuretic, and natriuretic actions. They are main tools in the body's defense against volume overload and hypertension. The natriuretic peptides (NP) are synthetized as prohormones. The C-terminal endocrinological active peptides and their N-terminal prohormone fragments are found in plasma. The NP system is maximally activated in ventricular dysfunction. However, NP:s are also increased in patients with renal failure or pulmonary hypertension, and increases may be found in arterial hypertension or liver cirrhosis. Among all NP and prohormone fragments currently BNP is the most promising candidate analyte for routine diagnosis. BNP is also superior to other neurohormones for diagnosis of left-ventricular dysfunction (LVD) or estimating prognosis in LVD or during the subacute phase of myocardial infarction. For primary care physicians BNP measurement is useful to decide which patient with suspected heart failure warrants further investigation, particularly when assessment of left ventricular function is not readily available. BNP has an excellent negative predictive value particularly in high risk patients. For the cardiologists the NP:s are helpful for monitoring therapy and disease course in LVD patients and for estimating prognosis in LVD and myocardial infarction patients. There is now sufficient evidence to encourage physicians to gain experience with NP as a supplement in the diagnosis of patients suspected of having heart failure. An increase in BNP is serious enough to warrant follow-up examinations.

Using a 6-minute walk test to predict outcomes in patients with left ventricular dysfunction.

Maximal oxygen consumption (VO2MAX) is an independent variable that predicts outcomes in patients suffering from left ventricular dysfunction (LVD). Determining VO2MAX in a rehabilitation setting is not only costly and time-consuming but it would also be beyond many patients' physical abilities. This study's goal was to show that a simpler and less costly 6-minute walk test can predict mortality in patients with LVD. Sixty-six Phase 1 cardiac rehabilitation patients with LVD performed the 6-minute walk test upon admission and at discharge from a rehabilitation hospital. Upon discharge, the group that was able to walk significantly longer distances upon discharge had a higher survival rate 3 months after discharge. The 6-minute walk test can predict longer survival in patients with LVD and can provide valuable information for determining treatment plans, future prognosis, and home disposition of deconditioned LVD patients in a rehabilitation setting.

Effects of beta blockers on ventricular dysfunction after myocardial infarction: Tolerability and survival effects

At least 44 randomized trials of β blockade in acute myocardial infarction have been reported. All of these trials excluded patients with moderate-to-severe clinical signs of acute left ventricular dysfunction (LVD). Several of the larger trials did include high-risk patients with a history of compensated heart failure or with symptoms and signs suggesting mild LVD. Data from these trials indicate that β-blocker treatment was well tolerated by patients with LVD, both in the acute phase of myocardial infarction and during longterm follow-up treatment. Further, data for LVD patients indicate that mortality in the β-blocker group was reduced by 20–30% when compared wtth the placebo group. A similar mortality reduction was obtained for the entire patient population in the trials. Because of the high mortality among patients wtth mild LVD, the absolute gain in numbers of lives saved per 100 patients treated wtth β blockers is even larger than that in patients without LVD. Data from two long-term trials indicate marked (47% and 43%) reductions in the likelihood of sudden death among LVD patients treated wtth β blockers. These results suggest that all patients wtth LVD who can tolerate β blockade may benefit from treatment wtth these agents.