Abnormal left ventricular diastolic filling in eccentric left ventricular hypertrophy of obesity

An Exploration of the Relationship Between Atrial Fibrillation and Obesity

In the past 40 years, the prevalence of atrial fibrillation and obesity have skyrocketed. It has long been established that obesity can lead to adverse cardiovascular outcomes due to its myriad of effects on cardiovascular architecture, cardiovascular hemodynamics, and electrical conduction interference. The goal of this article is to explore the pathogenesis of atrial fibrillation in obese patients and examine the role of atrial enlargement, increased adipose deposits surrounding the pericardium, interstitial fibrosis, and inflammation in the development and worsening of atrial fibrillation in obese patients.

Effect of Obesity on Left Ventricular Systolic and Diastolic Functions Based on Echocardiographic Indices

BACKGROUND

Left ventricular systolic and diastolic functions are known prognosticators for cardiovascular morbidity. One of the significant risk factors for cardiovascular diseases is obesity. The objective of this study is to determine the effect of obesity on the systolic and diastolic functions of the left ventricle on the basis of echocardiographic indices.

METHODS

75 obese and 75 averagely built subjects were studied. They had no other comorbidities. The indices of echocardiography of systolic and diastolic function were taken and assessed using recent recommendations from the European Association of Cardiovascular Imaging and the American Society of Echocardiography.

RESULTS

The volume indices of systolic and diastolic function (ejection diastolic volume (EDV) and ejection systolic volume (ESV)) and iso-volumetric relaxation time (IVRT) showed a significant increase in obese subjects (p<0.05); however, the relative thickness of the wall and internal diameter were comparable to non-obese subjects. The indices of contractility like ejection fraction, early diastolic filling velocity and late diastolic filling velocity (E/A) ratio, and mitral annular velocity were significantly lower in the obese subjects as compared to non-obese subjects. It was also found that left atrial diameter in systole and diastole had a moderate association (r=0.48, P<0.0001; r=0.35, P<0.0005) while mitral inflow E/A ratio had a negative association with body mass index (BMI) (r=-0.26, P=0.0166).

CONCLUSIONS

Volumetric changes and ejection are significantly altered by increased BMI. More comprehensive studies in the future are recommended to assess the same.

Causative Mechanisms of Childhood and Adolescent Obesity Leading to Adult Cardiometabolic Disease: A Literature Review

The past few decades have shown a worrisome increase in the prevalence of obesity and its related illnesses. This increasing burden has a noteworthy impact on overall worldwide mortality and morbidity, with significant economic implications as well. The same trend is apparent regarding pediatric obesity. This is a particularly concerning aspect when considering the well-established link between cardiovascular disease and obesity, and the fact that childhood obesity frequently leads to adult obesity. Moreover, most obese adults have a history of excess weight starting in childhood. In addition, given the cumulative character of both time and severity of exposure to obesity as a risk factor for associated diseases, the repercussions of obesity prevalence and related morbidity could be exponential in time. The purpose of this review is to outline key aspects regarding the current knowledge on childhood and adolescent obesity as a cardiometabolic risk factor, as well as the most common etiological pathways involved in the development of weight excess and associated cardiovascular and metabolic diseases.

Obesity in the absence of comorbidities is not related to clinically meaningful left ventricular hypertrophy

Obesity is associated with the development of left ventricular (LV) hypertrophy. Whether obesity in in the absence of comorbidities can cause LV hypertrophy to an extent which could create diagnostic uncertainty with pathological states (such as hypertrophic cardiomyopathy) is unknown. We used cine cardiovascular magnetic resonance imaging to precisely measure LV wall thickness in the septum and lateral wall in 764 people with body mass indices ranging from 18.5 kg/m2 to 59.2 kg/m2 in the absence of major comorbidities. Obesity was related to LV wall thickness across the cohort (basal septum r 0.30, P < 0.001 and basal lateral wall r 0.18, P < 0.001). Although no participant had hypertension, these associations remained highly significant after controlling for systolic blood pressure (all P < 0.01). Each 10 kg/m2 increase in BMI was associated with an increase in basal septal wall thickness of 1.0 mm males and 0.8 mm in females, with no statistically significant difference between genders (P = 0.1). Even in class 3 obesity (BMI > 40 kg/m2), no LV wall thickness > 13.4 mm in males or > 12.7 mm in females was observed in this cohort. We confirm that obesity in the absence of comorbidities is associated with LV hypertrophy, and establish that the magnitude of this change is modest even in severe obesity. LV hypertrophy > 14 mm cannot safely be attributed to obesity alone and alternative diagnoses should be considered.

Nutrigenetics-personalized nutrition in obesity and cardiovascular diseases

Epidemiological data support the view that both obesity and cardiovascular diseases (CVD) account for a high proportion of total morbidity and mortality in adults throughout the world. Obesity and CVD have complex interplay mechanisms of genetic and environmental factors, including diet. Nutrition is an environmental factor and it has a predominant and recognizable role in health management and in the prevention of obesity and obesity-related diseases, including CVD. However, there is a marked variation in CVD in patients with obesity and the same dietary pattern. The different genetic polymorphisms could explain this variation, which leads to the emergence of the concept of nutrigenetics. Nutritional genomics or nutrigenetics is the science that studies and characterizes gene variants associated with differential response to specific nutrients and relating this variation to various diseases, such as CVD related to obesity. Thus, the personalized nutrition recommendations, based on the knowledge of an individual's genetic background, might improve the outcomes of a specific dietary intervention and represent a new dietary approach to improve health, reducing obesity and CVD. Given these premises, it is intuitive to suppose that the elucidation of diet and gene interactions could support more specific and effective dietary interventions in both obesity and CVD prevention through personalized nutrition based on nutrigenetics. This review aims to briefly summarize the role of the most important genes associated with obesity and CVD and to clarify the knowledge about the relation between nutrition and gene expression and the role of the main nutrition-related genes in obesity and CVD.

Left ventricular myocardial deformation: a study on diastolic function in the Chinese male population and its relationship with fat distribution

Background

Obesity has become an epidemic in China with its increased prevalence, especially in the male population. Disparities in fat distribution rather than increasing body mass index (BMI) confer the risk of different diseases, including cardiac abnormalities. Therefore, early detection of cardiac abnormalities is important for treatment to reverse the progression to heart failure. Nowadays, strain analysis based on cardiac magnetic resonance (CMR) imaging has been established to assess myocardial function in diverse cardiac diseases. We aimed to assess the relationship between fat distribution and subclinical diastolic dysfunction in obese Chinese men assessed by deformation registration algorithm (DRA)-based myocardial strain rate (SR) analysis.

Methods

A total of 115 male participants with different BMI underwent CMR scanning using a 1.5T MAGNETOM Aera (Siemens Healthcare, Erlangen, Germany) and computed tomography (CT) scan. All the participants were enrolled from September 2017 to April 2018. They were classified into 3 groups according to their BMIs with 23 and 27.5 kg/m² being the cutoff values. A Trufi-Strain prototype software (version 2.0, Siemens Healthcare, Erlangen, Germany) was used to quantify SR in both early and late diastole from CMR cine images. Ratios of early and late SRs were calculated. Areas of epicardial and pericardial adipose tissue (EAT and PAT) were measured on a single 4-chamber-view slice of cine images. Volumes of visceral and subcutaneous adipose tissue (VAT and SAT) were acquired semi-automatically from CT images using the dedicated software Cardiac Risk2.0 (Siemens Healthcare). Waist and hip circumferences were manually measured (WC and HC). Analysis of variance or nonparametric tests, along with correlation and stepwise multivariate regression analysis models, was applied for statistical analysis.

Results

Peak late diastolic SRs were higher in obese men compared with their lean counterparts [-36.25±10.46 vs. -29.46±8.17, 66.97±18.58 vs. 45.62 (42.44, 55.96), and 56.81±15.07 vs. 41.40±6.41 for radial, circumferential, and longitudinal SRs, respectively; P<0.05]. All SR ratios in the obese subgroups were lower than those of lean men (3.12±1.14 vs. 4.63±1.24, 2.12±0.58 vs. 2.96±0.62 and 1.63±0.50 vs. 2.20±0.63 for radial, circumferential, and longitudinal directions, respectively; P<0.05). EAT was a significant predictor of diastolic function assessed by radial and circumferential SR ratios (β=-0.439 and -0.337 respectively; all P<0.001), while VAT was a significant predictor of circumferential and longitudinal SR ratios (β=-0.216 and -0.355, respectively, P<0.05).

Conclusions

Decreased LV diastolic function assessed by DRA-based SR analysis in obesity is associated with fat distribution. Furthermore, EAT and VAT might be better predictors of a decrease of diastolic function in obese Chinese men than BMI.

Aerobic Training Is Better Than Resistance Training on Cardiac Function and Autonomic Modulation in Female ob/ob Mice

Objective: This study evaluated the effects of aerobic, resistance, and combined exercise training on cardiac function and autonomic modulation in female ob/ob mice. Methods: Four-week-old female wild type and obese (ob/ob) mice were divided into five groups (n = 8): control (WT), obese (OB) obese + aerobic training (OBA), obese + resistance training (OBR), and obese + combined training (OBC). The exercise training was performed on treadmill and/or ladder at 40-60% maximum test during 8 weeks. Cardiac function was measured using echo machine. Heart rate variability (HRV) was evaluated in the time and frequency domain. Results: OB group presented higher body weight gain (~600%), glycemia (~44%) and glucose intolerance (~150%), reduction of cardiac vagal modulation, evidenced by a lower RMMSD (~56%), total power and high frequency band, and a higher isovolumic relaxation time (IVRT) (~24%) in relation to the WT group. Aerobic and combined training led to a lower IVRT (OBA: ~14%; OBC: ~14%) and myocardial global index (OBA: ~37%; OBC: ~44%). The OBA group presented an increased in vagal indexes of HRV than the other ob/ob groups. A negative correlation was observed between the delta of aerobic exercise capacity and MPI (r = 0.45; p = 0.002) and exercise capacity and body weight gain (r = 0.39; p = 0.002). Conclusion: Only the obese females underwent to aerobic exercise training showed improvement in cardiac function and HRV. Moreover, the aerobic exercise capacity as well as a greater responsivity to aerobic exercise training is intimately associated with these improvements, reinforcing the importance of aerobic exercise training to this population.

Short- and mid-term effects of sleeve gastrectomy on left ventricular function with two-dimensional speckle tracking echocardiography in obese patients

AIM

This study aimed to investigate left ventricular functions of obese patients with no known heart disease who underwent laparoscopic sleeve gastrectomy by speckle tracking echocardiography in their early and medium-term postoperative follow-up.

PATIENTS AND METHOD

Thirty-seven obese patients (10 M, 27 F) without coronary artery disease or heart failure who had undergone LSG were included in the study. Apical four-, three-, and two-chamber images were analyzed longitudinally by conventional methods and speckle tracking echocardiography (STE) for left ventricle functions preoperatively, at the postoperative Month 1 and at the postoperative Month 6 (QLAB 6.0), using current software.

RESULTS

No difference was found between standard echocardiography and Doppler parameters in terms of the 1-month versus 6-month follow-up values compared to baseline. Left ventricular STE longitudinal measurements demonstrated significantly higher longitudinal strain and strain velocity parameters in the follow-up values at Month 6 compared to the values at Month 1 and at baseline. Global longitudinal strain (GLS) was -17.48 ± 1.09% in 6-month follow-up, -16.16 ± 1.26% in 1-month follow-up, and -16.06 ± 1.25% at baseline (P < .001). A significant correlation was found between delta GLS, which represents patients' GLS change in 6 months, and delta weight, which represents patients' body weight change in 6 months.

CONCLUSION

Obese patients who had undergone LSG were observed to have improved left ventricular function in the mid-term.

Obesity and cardiovascular disease: revisiting an old relationship

A wealth of clinical and epidemiological evidence has linked obesity to a broad spectrum of cardiovascular diseases (CVD) including coronary heart disease, heart failure, hypertension, stroke, atrial fibrillation and sudden cardiac death. Obesity can increase CVD morbidity and mortality directly and indirectly. Direct effects are mediated by obesity-induced structural and functional adaptations of the cardiovascular system to accommodate excess body weight, as well as by adipokine effects on inflammation and vascular homeostasis. Indirect effects are mediated by co-existing CVD risk factors such as insulin resistance, hyperglycemia, hypertension and dyslipidemia. Adipose tissue (AT) quality and functionality are more relevant aspects for cardiometabolic risk than its total amount. The consequences of maladaptive AT expansion in obesity are local and systemic: the local include inflammation, hypoxia, dysregulated adipokine secretion and impaired mitochondrial function; the systemic comprise insulin resistance, abnormal glucose/lipid metabolism, hypertension, a pro-inflammatory and pro-thrombotic state and endothelial dysfunction, all of which provide linking mechanisms for the association between obesity and CVD. The present narrative review summarizes the major pathophysiological links between obesity and CVD (traditional and novel concepts), analyses the heterogeneity of obesity-related cardiometabolic consequences, and provides an overview of the cardiovascular impact of weight loss interventions.

Manifestations and mechanisms of myocardial lipotoxicity in obesity

Environmental and socioeconomic changes over the past thirty years have contributed to a dramatic rise in the worldwide prevalence of obesity. Heart disease is amongst the most serious health risks of obesity, with increases in both atherosclerotic coronary heart disease and heart failure among obese individuals. In this review, we focus on primary myocardial alterations in obesity that include hypertrophic remodelling and diastolic dysfunction. Obesity-associated perturbations in myocardial and systemic lipid metabolism are important contributors to cardiovascular complications of obesity. Accumulation of excess lipid in nonadipose cells of the cardiovascular system can cause cell dysfunction and cell death, a process known as lipotoxicity. Lipotoxicity has been modelled in mice using high-fat diet feeding, inbred lines with mutations in leptin receptor signalling, and in genetically engineered mice with enhanced myocardial fatty acid uptake, altered lipid droplet homoeostasis or decreased cardiac fatty acid oxidation. These studies, along with findings in cell culture model systems, indicate that the molecular pathophysiology of lipid overload involves endoplasmic reticulum stress, alterations in autophagy, de novo ceramide synthesis, oxidative stress, inflammation and changes in gene expression. We highlight recent advances that extend our understanding of the impact of obesity and altered lipid metabolism on cardiac function.

The associations between anthropometric measurements and left ventricular structure and function: the Echo-SOL Study

OBJECTIVE

The objective of this study is to determine associations between anthropometry and echocardiographic measures of cardiac structure and function in Hispanic/Latinos.

METHODS

A total of 1,824 participants from ECHO-SOL were included. We evaluated associations between echocardiographic measures of left ventricular structure and function and anthropometric measures using multivariable-adjusted linear and logistic regression models adjusting for traditional cardiovascular risk factors.

RESULTS

The mean age was 56 ± 0.17 years, 57% were women. The mean body mass index (BMI) was 30 ± 9.4 kg m-2, waist circumference (WC) was 100 ± 18 cm, and waist-to-hip ratio (WHR) was 0.93 ± 0.15. Adjusted analysis showed that 5-unit increment in BMI and 5-cm increase in WC was associated with 3.4 ± 0.6 and 1.05 ± 0.05 g m-2.7 (p < 0.05 for both) higher left ventricular (LV) mass index, respectively. Similarly, 0.1-unit increment in WHR was associated with 2.0 ± 0.16 g m-2.7 higher LV mass index (p < 0.01). WHR was associated with 0.22 ± 0.08% decrease in ejection fraction (p < 0.05). Concomitantly, 5-unit increment in BMI and WC was associated with increased odds of abnormal LV geometry (odds ratio 1.40 and 1.16, p = 0.03 and <0.01, respectively); 0.1-unit increment in WHR was associated with increased odds of abnormal LV geometry (odds ratio 1.51, p < 0.01).

CONCLUSIONS

Among Hispanic/Latinos, higher anthropometric measures were associated with adverse cardiac structure and function.

Management of cardiovascular diseases in patients with obesity

The management of cardiovascular diseases (CVD) in patients with obesity presents numerous challenges. Obesity has a negative effect on almost all of the major CVD risk factors, and adversely influences cardiovascular structure and function. Patients who are overweight or obese have a higher incidence of almost all CVDs compared with patients who are of normal weight. However, those who are overweight or obese seem to have a better short-term and medium-term prognosis after major CVD events and interventional procedures or cardiac surgeries than leaner patients, a phenomenon termed the 'obesity paradox'. In considering the mechanisms underlying this paradox, we review evidence of the deleterious consequences of obesity in patients with coronary heart disease, and the limited data on the benefits of weight loss in patients with CVD. Additional studies are needed on the efficacy of purposeful weight loss on cardiovascular outcomes to determine the ideal body composition for patients with CVD.

Changes in Body Weight and Composition Are Associated With Changes in Left Ventricular Geometry and Function in the General Population

Background—

The different effects of total body weight (TBW), fat-free mass (FFM), and fat mass (FM) on left ventricular (LV) geometry and function are complex. We investigated the associations of changes over time in TBW, FM, and FFM with changes in LV geometry and function.

Methods and Results—

We analyzed data from 1189 subjects (694 women), aged 44 to 86 years, from the baseline and the 5-year follow-up examination of the population-based SHIP (Study of Health in Pomerania). TBW was measured, and FFM and FM were calculated based on height-weight models derived from bioelectrical impedance studies. Echocardiographic measurements of LV geometry and function were performed according to the guidelines of the American Society of Echocardiography. Changes in body composition measures were associated with changes in LV geometry and function by multivariable-adjusted linear regression models. A 1-kg increase/decrease in TBW or FM was associated, respectively, with an increase/decrease of 0.89 g or 1.84 g in LV mass, whereas there was no such association on changes in FFM. Moreover, an increase in FM was associated with LV concentric remodeling and impairment of systolic and diastolic function parameters, whereas an increase in FFM was associated with LV eccentric remodeling and improved systolic and diastolic functional variables.

Conclusions—

Our findings indicate that changes in LV morphology and function depend on the type of body mass composition. Prospective data need to address whether specific changes in body composition over time may affect the risk for heart dysfunction more precisely than the change in TBW.

Improvement of impaired diastolic left ventricular function after diet-induced weight reduction in severe obesity

BACKGROUND/OBJECTIVES

Obesity is independently associated with left ventricular (LV) diastolic dysfunction and altered cardiac morphology. Morbidity and mortality in patients with diastolic dysfunction are similar to values observed in patients with systolic heart failure. We hypothesized that dysfunctional cardiac responses in people with obesity are reversible after weight loss. Thus, we studied the effect of dietary weight reduction on LV diastolic function as well as on cardiac structure using transthoracic echocardiography and tissue Doppler imaging (TDI).

SUBJECTS/METHODS

Thirty-two subjects with obesity underwent a 12-week low-calorie fasting phase of a formula diet. Echocardiographic tissue Doppler indices of diastolic function and measurements of cardiac size were obtained prior to and after the fasting phase.

RESULTS

A 12-week diet significantly reduced body mass index from 40.3 ± 6.6 kg/m² to 33.2 ± 6.1 kg/m² (p < 0.01). Weight loss was associated with a significant reduction in blood pressure and heart rate. Echocardiography revealed diastolic dysfunction in subjects with obesity, which was improved by dieting. After weight loss, trans-mitral Doppler echocardiography showed a significant reduction in A-wave velocity, from 65.8 ± 19.2 cm/s to 57.0 ± 16.8 cm/s, and an increase in E/A ratio from 1.2 ± 0.4 to 1.4 ± 0.5 (p < 0.01). TDI displayed a significantly lower a'-wave velocity (10.3 ± 2.3 cm/s and 8.9 ± 1.7 cm/s; p < 0.01). Left atrial and LV dimensions were normal and remained unchanged after weight loss.

CONCLUSION

Obesity is associated with diastolic dysfunction. A 12-week low-calorie diet with successful weight loss can reduce blood pressure and heart rate and partially normalize diastolic dysfunction.

Assessment of Impact of Weight Loss on Left and Right Ventricular Functions and Value of Tissue Doppler Echocardiography in Obese Patients

OBJECTIVE

In our study, we aimed to evaluate the effect of weight loss on left and right ventricular functions in obese patients.

METHODS

Thirty patients with a BMI greater than 30 kg/m(2) and without any exclusion criteria were included in the study. Left ventricular systolic and diastolic functions were assessed with conventional and tissue Doppler echocardiography (TDE). At the end of 3 months, echocardiographic examination was repeated in patients with weight loss for cardiac function evaluation and it was compared to the baseline echocardiographic parameters.

RESULTS

At the end of 3 months of weight loss period, conventional Doppler echocardiography revealed an improvement in diastolic functions with an increase in mitral E-wave, a decrease in mitral A-wave and an increase in E/A ratio. Deceleration time and isovolumetric relaxation time were ascertained shortened and Tei index decreased. TDE showed an increase in left ventricular lateral wall systolic wave (Sm) and E-wave velocity (Em). Mitral septal annular isovolumetric acceleration time (IVA), Sm and Em, were found to be increased, whereas Tei index was ascertained reduced. Right ventricular tissue Doppler examination following weight loss revealed an increase in RV- IVA, RV-Sm, and RV-Em, and a decrease in Tei index.

CONCLUSION

We disclosed that left ventricular structural changes and diastolic dysfunction occur in obese patients, and by weight loss, these abnormalities may be reversible which we demonstrated both by conventional and TDE. In addition, obesity might impair RV function as well, and we observed an enhancement in right ventricular functions by weight loss.

Long-Term Regulation of the Local Renin-Angiotensin System in the Myocardium of Spontaneously Hypertensive Rats by Feeding Bioactive Peptides Derived from Spirulina platensis

This study investigated the long-term (8 weeks) anti-hypertensive effects of 10 mg/kg tripeptides isolated from Spirulina platensis, Ile-Gln-Pro (IQP) and Val-Glu-Pro (VEP), and S. platensis hydrolysates (SH) on spontaneously hypertensive rats. The treatment period was 6 weeks, and observation continued for another 2 weeks. After treatment, weighted systolic blood pressure, weighted diastolic blood pressure, left ventricular mass index, and right ventricular mass index of groups treated with IQP, VEP, and SH were significantly lower than those of the group treated with distilled water, even when the treatments had been withdrawn for 2 weeks. Quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting showed the mRNA expression levels and protein/peptide concentrations of the main components of the renin angiotensin system in myocardium were significantly affected by treatment: angiotensin converting enzyme, angiotensin II, and angiotensin type 1 receptor were down-regulated, whereas angiotensin type 2 receptor, angiotensin converting enzyme 2, angiotensin-(1-7), and Mas receptor were up-regulated.

Obesity and heart failure: epidemiology, pathophysiology, clinical manifestations, and management

Obesity is a risk factor for heart failure (HF) in both men and women. The mortality risk of overweight and class I and II obese adults with HF is lower than that of normal weight or underweight adults with HF of comparable severity, a phenomenon referred to as the obesity paradox. Severe obesity produces hemodynamic alterations that predispose to changes in cardiac morphology and ventricular function, which may lead to the development of HF. The presence of systemic hypertension, sleep apnea, and hypoventilation, comorbidities that occur commonly with severe obesity, may contribute to HF in such patients. The resultant syndrome is known as obesity cardiomyopathy. Substantial weight loss in severely obese persons is capable of reversing most obesity-related abnormalities of cardiac performance and morphology and improving the clinical manifestations of obesity cardiomyopathy.

Weight loss and progressive left ventricular remodelling: The Multi-Ethnic Study of Atherosclerosis (MESA)

AIMS

Impact of weight loss on cardiac structure has not been extensively investigated in large, multi-ethnic, community-based populations. We investigated the longitudinal impact of weight loss on cardiac structure by cardiac magnetic resonance (CMR).

METHODS AND RESULTS

2351 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) who underwent CMR at Exam 1 (2002) and Exam 5 (2011) were included. Primary outcomes were percentage change in LV mass (indexed to height) and LV mass-to-volume ratio (concentric LV remodelling). Multivariable linear regression was used to measure the association between outcomes and weight change. At median 9.4 years' follow-up, 639 individuals (27%) experienced >5% weight loss (median 6.9 kg) and 511 (22%) had >5% weight gain (median 6.4 kg). A >5% weight gain was associated with the greatest increase in LV mass (+5.4% median) and LV mass-to-volume ratio (+12.2% median). Adjusting for medications, hypertension/diabetes (and change in these risk factors), age, race and other risk factors, every 5% weight loss was associated with a 1.3% decrease in height-indexed LV mass and 1.3% decrease in LV mass-to-volume ratio (p<0.0001). There was no effect modification/confounding by age, race, gender or baseline BMI. Change in LV mass-to-volume ratio was roughly linear, specifically for modest degrees of weight loss (-10% to +10%). Change in LV mass was linear with weight loss, suggesting no threshold of weight loss is needed for LV mass regression.

CONCLUSIONS

In a large multi-ethnic population, weight loss is associated with beneficial effects on cardiac structure, independent of age, race, gender, BMI and obesity-related cardiometabolic risk. There is no threshold of weight loss required to produce these effects.

Obesity in heart failure: impact on survival and treatment modalities

Heart failure (HF) and obesity are commonly seen in the USA. Although obesity is associated with traditional cardiovascular disease, its relationship with HF is complex. Obesity is an accepted risk factor for incident HF. However, in patients with established HF, there exists a paradoxical correlation, with escalating BMI incrementally protective against adverse outcomes. Despite this relationship, patients with HF may desire to lose weight to reduce comorbidities or to improve quality of life. Thus far, studies have shown that intentional weight loss in obese patients with HF does not increase risk, with strategies including dietary modification, physical activity, pharmacotherapy, and/or surgical intervention.

Obesity and Non-Atherosclerotic Cardiovascular Disease

Obesity is an increasing epidemic in the United States, with approximately 70% of Americans falling into either the overweight or obese categories. There also has been a global increase in the number of obese individuals worldwide, and an estimated one in ten of the world's adult population are overweight or obese. The number of overweight and obese children also has greatly increased, which likely will predispose them to earlier onset of obesity-related morbidity and mortality and further contribute to the burden obesity places on society. Obesity is a preventable and treatable cause of many systemic diseases affecting the heart, liver, lungs, endocrine, and musculoskeletal systems. Though it affects almost all organ systems, this state of over-nutrition induces abnormalities that culminate in changes in hemodynamics, heart structure, cardiac myocyte metabolism, and coronary artery disease that often lead to consequences such as systemic and pulmonary hypertension, obesity cardiomyopathy, heart failure, atrial fibrillation, and/or sudden cardiac death. Despite the prevalence of obesity in our current society, the exact effects on health are still being elucidated and, interestingly, there are some data to suggest certain populations of obese individuals may have less cardiovascular morbidity than their non-obese counterparts. Forensic pathologists should be aware of the effects of obesity, particularly on the cardiovascular system, as the number of these decedents seen at forensic autopsy increases. This review describes the non-atherosclerotic effects of obesity on the cardiovascular system.

Early myocardial deformation changes associated to isolated obesity: a study based on 3D-wall motion tracking analysis

Obesity is considered as a strong risk factor for cardiovascular morbidity and mortality. 3D-wall motion tracking echocardiography (3D-WMT) provides information regarding different parameters of left ventricular (LV) myocardial deformation. Our aim was to assess the presence of early myocardial deformation abnormalities in nonselected obese children free from other cardiovascular risk factors. Thirty consecutive nonselected obese children and 42 healthy volunteer children were enrolled. None of them had any cardiovascular risk factor. Every subject underwent a 2D-echo examination and a 3D-WMT study. Mean age was 13.9 ± 2.56 and 13.25 ± 2.68 years in the nonobese and obese groups, respectively (59.7% and 40.3% male). Statistically significant differences were found for: interventricular septum thickness, LV posterior wall thickness, LV end-diastolic volume, LV end-systolic volume, left atrium volume, LV mass, and lateral annulus peak velocity. Regarding the results obtained by 3D-WMT assessment, all the evaluated parameters were statistically significantly different between the two groups. When the influence of obesity on the different echocardiographic variables was evaluated by means of multivariate logistic regression analysis, the strongest relationship with obesity was found for LV average circumferential strain (β-coefficient: 0.74; r(2): 0.55; P: 0.003). Thus, obesity cardiomyopathy is associated not only with structural cardiac changes, but also with myocardial deformation changes. Furthermore, this association occurs as early as in the childhood and it is independent from any other cardiovascular risk factor. The most related parameter to obesity is LV circumferential strain.

Impact of orlistat-induced weight loss on diastolic function and heart rate variability in severely obese subjects with diabetes

Objective. Determine the impact of Orlistat-induced weight loss on metabolic profile and cardiovascular function in severely obese patients with type 2 diabetes. Methods. Twenty-nine patients were randomized either to a nonplacebo control group or to a treatment group with Orlistat thrice a day. Metabolic profile, anthropometric parameters, heart rate variability indices, and echocardiographic variables were measured before and after a 12-week treatment period. Results. Treatment with Orlistat induced a modest but significant weight loss compared to controls (3.7 ± 3.0 versus 0.5 ± 2.2 kg, resp.; P = .003). There was significant decrease in fasting glycemia (7.9 ± 3.0 versus 6.7 ± 2.2 mmol/L; P = .03) and significant improvements in left ventricular diastolic function (P = .03) and in the sympathovagal balance (LF/HF ratio) (P = .04) in the Orlistat group. Conclusion. These results suggest that a modest weight loss improves fasting glycemia, left ventricular diastolic function, and sympathovagal balance in severely obese patients with type 2 diabetes.

Obesity-related cardiorenal syndrome

The term obesity cardiomyopathy has previously been used to describe a clinical syndrome in obese patients typically consisting of eccentric left ventricular hypertrophy with preserved ejection fraction and diastolic dysfunction and is often associated with right ventricular dysfunction independent of the presence of the obstructive sleep apnea syndrome. Although several publications have described the early stages of this syndrome, little is known about the end stages of the disease. The authors conducted a retrospective study of a subset of edematous obese patients with multiple common medical comorbidities who present with a clinical syndrome in the setting of physiologic stress or infection. Under severe physiologic stress these patients developed pulmonary hypertension, right-sided volume overload, decreased effective arterial blood volume, and renal failure. Often, these findings were in the setting of obstructive sleep apnea. This retrospective study focuses on an obesity-related cardiorenal syndrome but also serves to provide a foreground for acknowledging the broad spectrum of cardiovascular pathology, including pulmonary hypertension, diastolic dysfunction, and sleep apnea, seen in the obese.

Obesity and preclinical changes of cardiac geometry and function

Overweight and obesity are rapidly increasing in prevalence due to adoption of the westernized life style in Korea. Obesity is strongly associated with the development of cardiovascular risk factors such as diabetes, hypertension, and dyslipidemia. In addition, accumulating evidence suggests that obesity per se has a direct effect on cardiac functional and structural changes that may not be the result of atherosclerosis. In this review, we focus on the view that obesity can influence on the structural and functional changes of the heart, drawing evidence from human and animal studies. We also review influencing factors such as physical, neurohormonal, and metabolic alterations that are associated with changes of the heart in obesity.

Obesity and cardiovascular disease: risk factor, paradox, and impact of weight loss

Obesity has reached global epidemic proportions in both adults and children and is associated with numerous comorbidities, including hypertension (HTN), type II diabetes mellitus, dyslipidemia, obstructive sleep apnea and sleep-disordered breathing, certain cancers, and major cardiovascular (CV) diseases. Because of its maladaptive effects on various CV risk factors and its adverse effects on CV structure and function, obesity has a major impact on CV diseases, such as heart failure (HF), coronary heart disease (CHD), sudden cardiac death, and atrial fibrillation, and is associated with reduced overall survival. Despite this adverse association, numerous studies have documented an obesity paradox in which overweight and obese people with established CV disease, including HTN, HF, CHD, and peripheral arterial disease, have a better prognosis compared with nonoverweight/nonobese patients. This review summarizes the adverse effects of obesity on CV disease risk factors and its role in the pathogenesis of various CV diseases, reviews the obesity paradox and potential explanations for these puzzling data, and concludes with a discussion regarding the current state of weight reduction in the prevention and treatment of CV diseases.

Evaluation of the effects of obesity on heart functions using standard echocardiography and pulsed wave tissue Doppler imaging

OBJECTIVES

This study aimed to investigate abnormalities in right and left ventricular function in older obese patients with no left ventricular (LV) hypertrophy.

DESIGN

Subjects with normal coronary angiography were included in this study. They were divided into two groups according to their body mass index (BMI): Group I = BMI > or = 27, and group II BMI = < 27. Standard echocardiography and pulsed wave tissue Doppler imaging (PW-TDI) parameters were performed in all subjects.

RESULTS

The obese patients had tachycardia (P = 0.017) and hypertension (P = 0.020). In the obese patients, there was evidence of altered LV geometry; an increase in the posterior wall thickness (P = 0.001), and larger aortic valve diameter (P = 0.007).

CONCLUSIONS

In obese patients of older ages, there is evidence of left and right ventricular dysfunction.

Role of Exercise and Metabolism in Heart Failure with Normal Ejection fraction

Left ventricular dysfunction associated with metabolic disorders has a number of features that might shed light on the integrity of heart failure with normal ejection fraction. First, although these patients may be dyspneic and have a normal ejection fraction, their diastolic dysfunction is not isolated. Both experimental models and sensitive new parameters in humans have shown abnormal systolic function, even though the less sensitive parameters (such as ejection fraction) become abnormal only with stress. Moreover, the mechanistic contributors to myocardial dysfunction, including structural changes and metabolic influences on the cardiac myocyte, interstitial fibrosis, vascular disease, and altered loading, are likely to influence systolic as much as diastolic function. The responses of systolic and diastolic heart failure to exercise training show analogies, particularly with respect to the importance of peripheral adaptation, as well as a similar training response. Together, these features are more supportive of a continuum of pathophysiology between systolic and diastolic heart failure, rather than the 2 representing discreet phenomena.

Morbid obesity is an independent determinant of death among surgical critically ill patients

OBJECTIVE

To determine whether extreme obesity (morbid obesity; body mass index > or =40 kg/m(2)) is an independent risk factor for death among critically ill patients; this objective is most salient in the subset of patients who sustain a prolonged intensive care unit stay during which the burdens of care imposed by obesity and its consequences would become most apparent.

DESIGN

Cohort analysis of data from the Project Impact database used to catalog admissions and outcomes to a surgical intensive care unit, with predetermined end point analyses of outcomes.

SETTING

Surgical intensive care unit serving Tufts-New England Medical Center, a tertiary care and university medical center in Boston.

PATIENTS

All critically ill surgical patients admitted to the Tufts-New England Medical Center surgical intensive care unit from January 1998 to March 2001.

INTERVENTIONS

Intensive care unit and hospital mortality and lengths of stay were compared with body mass index subclassified into five groups: underweight, normal weight, overweight, obese, and extremely obese. Data were examined for all admissions during the study period and for a predetermined subgroup with a prolonged intensive care unit stay (> or =4 days).

MEASUREMENTS AND MAIN RESULTS

The prevalence of obesity in the surgical intensive care unit was 26.7%; extreme obesity was observed in 6.8%. In the full cohort of patients (n = 1373), median length of stay was short (2 days) and there were no differences in mortality in patients among any of the body mass index classes. In the subgroup of prolonged stay patients (n = 406), intensive care unit and hospital mortality rates were significantly increased in extremely obese patients compared with all other patients (intensive care unit, 33.3% vs. 12.3%, p = .009; hospital, 33.3% vs. 16%, p = .045). Multivariate analysis showed that extreme obesity was an independent predictor of death in surgical critically ill patients with prolonged intensive care unit stay after controlling for age, gender, and severity of illness. The odds of death increased 7.4 times in patients with morbid obesity.

CONCLUSIONS

Morbid obesity (body mass index > or =40 kg/m(2)) is an independent risk factor for death in surgical patients with catastrophic illness requiring prolonged intensive care. The prevalence of obesity is growing, both in the intensive care unit and in the general population. The increased risk of complications and death in this population mandates that we adapt customized processes of care to specifically address this unique and very challenging subset of patients.

Influence of weight loss on myocardial performance index

Obese patients may have a phase of asymptomatic left ventricular dysfunction. A combined myocardial performance index (MPI) has been demonstrated to be a useful index to estimate left ventricular function and to predict the prognosis of patients with heart failure. The objective of the study was to determine the influence of weight loss on MPI. A total of 18 obese patients (3 men, 15 women, mean age 49.6 +/- 5.5 years, body mass index [BMI] >30 kg/m(2)) were investigated in the study. All patients were treated with a multidisciplinary approach consisting of a hypocaloric diet and orlistat therapy (120 mg three times daily), and all of them underwent two-dimensional and Doppler echocardiographic examination two times before starting the study and after a period of weight loss. Using echo-Doppler methods, ejection fraction, peak velocities of early (E) and late (A) diastolic filling, the E/A ratio, deceleration time (DT), isovolumic contraction time (IVCT), isovolumic relaxation time, ejection time, and MPI were measured. The MPI was obtained by subtraction ejection time from the interval between cessation and onset of the mitral flow. All patients lost at least 10% of their initial body weight, with a mean decrease of 10.8 +/- 3.7 kg. This was associated with significant reductions in BMI with a mean decrease 4.5 +/- 1.4 kg/m(2). Compared with baseline, after weight loss the E/A ratio of 1.01 +/- 0.22 before treatment increased to 1.17 +/- 0.26 (P = 0.012), left ventricular mass index decreased from 88 +/- 23 to 82 +/- 19 g/m(2) (P = 0.028), IVCT from 71 +/- 20 to 53 +/- 30 ms (P = 0.004), DT from 233.65 +/- 38.14 to 196.72 +/- 47.73 s (P = 0.004), and MPI from 0.63 +/- 0.13 to 0.50 +/- 0.13 (P = 0.0001). Weight loss ameliorates MPI and seems to be a clinically relevant measurement of left ventricular global function, and may prove to be a valuable tool in assessing the risk of developing heart failure.

Increased exercise capacity after surgically induced weight loss in morbid obesity

OBJECTIVE

To investigate the effects of surgically induced weight loss on exercise capacity in patients with morbid obesity (MO).

RESEARCH METHODS AND PROCEDURES

A prospective 1-year follow-up study was carried out, with patients being their own controls. A symptom-limited cardiopulmonary exercise stress test was performed in 31 MO patients (BMI > 40 kg/m2) before and 1 year after undergoing bariatric surgery.

RESULTS

At 1 year after surgery, weight was reduced from 146 +/- 33 to 95 +/- 19 kg (p < 0.001), and BMI went from 51 +/- 4 to 33 +/- 6 kg/m2 (p < 0.001). After weight loss, obese patients performed each workload with lower oxygen consumption, heart rate, systolic arterial pressure, and ventilatory volume (p < 0.001). This reduced energy expenditure allowed them to increase the duration of their effort test from 13.8 +/- 3.8 to 21 +/- 4.2 minutes (p < 0.001). Upon finishing the exercise, MO patients before surgery were able to reach only 83% of their age-predicted maximal heart rate, and their respiratory exchange ratio was 0.87 +/- 0.06. After weight loss, those values were 90% and 1 +/- 0.08, respectively (p < 0.01). When we compared the peak O2 pulse corrected by fat free mass before and after surgery, no significant differences between the groups were found.

DISCUSSION

After surgically induced weight loss, MO patients markedly improved their exercise capacity. This is due to the fact that they were able to perform the external work with lower energy expenditure and also to increase cardiovascular stress, optimizing the use of cardiac reserve. There were no differences in cardiac function before and after surgery.

Obesity and cardiovascular disease: pathophysiology, evaluation, and effect of weight loss: an update of the 1997 American Heart Association Scientific Statement on Obesity and Heart Disease from the Obesity Committee of the Council on Nutrition, Physical Activity, and Metabolism

Obesity is becoming a global epidemic in both children and adults. It is associated with numerous comorbidities such as cardiovascular diseases (CVD), type 2 diabetes, hypertension, certain cancers, and sleep apnea/sleep-disordered breathing. In fact, obesity is an independent risk factor for CVD, and CVD risks have also been documented in obese children. Obesity is associated with an increased risk of morbidity and mortality as well as reduced life expectancy. Health service use and medical costs associated with obesity and related diseases have risen dramatically and are expected to continue to rise. Besides an altered metabolic profile, a variety of adaptations/alterations in cardiac structure and function occur in the individual as adipose tissue accumulates in excess amounts, even in the absence of comorbidities. Hence, obesity may affect the heart through its influence on known risk factors such as dyslipidemia, hypertension, glucose intolerance, inflammatory markers, obstructive sleep apnea/hypoventilation, and the prothrombotic state, in addition to as-yet-unrecognized mechanisms. On the whole, overweight and obesity predispose to or are associated with numerous cardiac complications such as coronary heart disease, heart failure, and sudden death because of their impact on the cardiovascular system. The pathophysiology of these entities that are linked to obesity will be discussed. However, the cardiovascular clinical evaluation of obese patients may be limited because of the morphology of the individual. In this statement, we review the available evidence of the impact of obesity on CVD with emphasis on the evaluation of cardiac structure and function in obese patients and the effect of weight loss on the cardiovascular system.

Factors associated with mitral annular systolic and diastolic velocities in healthy adults

BACKGROUND

Measurements of systolic mitral annular velocity (S'), early diastolic mitral annular velocity (E'), and late diastolic mitral annular velocity (A') are used to assess left ventricular (LV) function.

OBJECTIVE

We sought to investigate the relationship between septal and lateral annular velocities and determine whether these velocities are related to body size (including body mass index [BMI]), heart rate (HR), blood pressure, or LV mass.

METHODS

A total of 60 healthy participants who were normotensive, between age 20 and 52 years, underwent standard echocardiography and measurement of septal and lateral S', E', and A'.

RESULTS

The lateral velocity exceeded the septal velocity for S', E', and A'. There was only weak to moderate correlation between the velocities at the two sites (r = 0.43-0.60). Septal S' was positively correlated with height and HR, and lateral S' was correlated with HR. Septal E' was negatively correlated with age, BMI, LV mass, and diastolic blood pressure, but lateral E' was only negatively correlated with age and BMI. Septal A' was positively correlated with age, HR, and BMI, whereas lateral A' was only positively associated with age.

CONCLUSIONS

S', E', and A' are not only of different magnitudes at the septal and lateral sites, but are not closely correlated. There are relationships between annular velocities and body size, HR, blood pressure, and LV mass that differ between the septal and lateral annulus, providing a possible explanation for the lack of close correlation in these velocities and suggesting that these variables may need to be considered when interpreting annular velocities.

Inspiratory Muscle Weakness in Diastolic Dysfunction

OBJECTIVES

To test the hypothesis that patients with well-documented diastolic dysfunction (DD) in the setting of normal systolic function will have inspiratory muscle weakness when compared to normal control subjects, and will experience dyspnea and tachypnea during exercise.

BACKGROUND

Respiratory muscle weakness has been described in patients with (systolic) congestive heart failure; however, whether or not patients with DD may present with the findings of congestive heart failure is not known.

METHODS

We selected for study 14 patients with DD previously referred for cardiopulmonary evaluation whose diagnosis had been confirmed by data obtained at cardiac catheterization. Seven control subjects matched for age, sex, and weight were recruited from the hospital community. Subjects performed both basic pulmonary function tests and tests of muscle strength: handgrip strength (Hgr), and maximal subatmospheric static inspiratory muscle pressure (Pimax). Subjects then performed a graded exercise test on a bicycle ergometer. Minute ventilation, oxygen consumption, carbon dioxide production, and heart rate were monitored continuously. Echocardiography was performed three times: before exercise, at a selected submaximal exercise level (20% of a predicted maximal workload), and at maximal exercise. Subjects rated their degree of dyspnea using the Borg scale at the same three time intervals.

RESULTS

Pimax was - 102 +/- 17 cm H(2)O in control subjects, and - 77 +/- 19 cm H(2)O in patients with DD (p = 0.013) [mean +/- SD]. Hgr was similar between the groups. At the selected submaximal exercise level, patients with DD rated dyspnea to be 2.6 +/- 2.2 Borg scale units (control subjects, 0.5 +/- 0.8 Borg scale units). Hey plots described a rapid, shallow breathing pattern in patients with DD during exercise. Patients with DD and control subjects achieved similar maximal work loads.

CONCLUSION

Patients with DD have diminished Pimax, adopt a rapid, shallow breathing pattern during exercise, and experience dyspnea at low work loads when compared to matched control subjects.

Obesity and cardiovascular risk: the new public health problem of worldwide proportions

Obesity could be considered a new global health epidemic above all others, especially when it is characterized by central fat distribution. This is illustrated by dramatic provisional data, indicating a continuous increase in the trend of overweight and obese individuals in several countries, including the USA and countries in Europe. Several epidemiological, pathophysiological and clinical studies clearly indicate that two of the major independent risk factors for cardiovascular disease or events are being overweight, and obesity. Accordingly, weight loss and prevention of weight gain has to be considered one of the most important strategies to reduce the incidence of cardiovascular disease.

Natriuretic peptides as markers of preclinical cardiac disease in obesity

BACKGROUND

Aim of the study was to evaluate the role of atrial (ANP) and brain natriuretic peptides (BNP) as markers of preclinical cardiac disease in obesity.

METHODS

We selected 26 obese (BMI > 29 kg m(-2)) never-treated hypertensives (24-h BP > 140 and/or 90 mmHg), 26 obese normotensives (24-h BP < 130/80 mmHg) and 25 lean (BMI < or = 25 kg m(-2)) never-treated hypertensives. Each subject underwent measurements of ANP and BNP plasma levels, 24-h ambulatory blood pressure (BP) monitoring, digitized M-mode and Doppler echocardiography.

RESULTS

Mean values of ANP and BNP were similar among the three groups. All the subjects had normal left ventricular (LV) systolic function. Within each group ANP levels were higher in patients with LV diastolic dysfunction than in patients with normal diastolic function, and BNP levels were higher in patients with LV hypertrophy and in patients with LV diastolic dysfunction. Within each group, ANP levels were inversely correlated with LV diastolic indices, whereas BNP levels were directly correlated with LV mass index and inversely correlated with LV diastolic indices. ANP and BNP levels were not correlated with other echocardiographic parameters, age, BMI or 24-h BP values.

CONCLUSION

In normotensive and hypertensive obese subjects the relationships of ANP and BNP levels with LV morpho-functional characteristics follow the same trend as in lean hypertensives, with ANP mainly influenced by diastolic dysfunction and BNP influenced by both LV hypertrophy and LV diastolic dysfunction. Therefore ANP and BNP can be considered useful markers of preclinical cardiac disease in obesity.

Effects of isolated obesity on systolic and diastolic left ventricular function

BACKGROUND

Obesity is associated with increased cardiovascular morbidity and mortality. A direct effect of isolated obesity on cardiac function is not well established.

OBJECTIVE

To determine the direct effect of different grades of isolated obesity on echocardiographic indices of systolic and diastolic left ventricular function.

METHODS

48 obese and 25 normal weight women were studied. They had no other pathological conditions. Obesity was classed as slight (n = 17; body mass index (BMI) 25-29.9 kg/m2), moderate (n = 20; BMI 30-34.9 kg/m2), or severe (n = 11; BMI > or = 35 kg/m2). Echocardiographic indices of systolic and diastolic function were obtained, and dysfunction was assumed when at least two values differed by > or = 2 SD from the normal weight group.

RESULTS

Ejection fraction (p < 0.05), fractional shortening (p < 0.05), and mean velocity of circumferential shortening (p < 0.05) were increased in slight and moderate obesity. Left ventricular dimensions were increased (p < 0.001) but relative wall thickness was unchanged. No obese patients met criteria for systolic dysfunction. In obese subjects, the mitral valve pressure half time (p < 0.01) and the left atrial diameter (p < 0.001) were increased and the deceleration slope was decreased (p < 0.01); all other diastolic variables were unchanged. No differences were found between obesity subgroups. Subclinical diastolic dysfunction was more prevalent among obese subjects (p = 0.002), being present in two with slight obesity (12%), seven with moderate obesity (35%), and five with severe obesity (45%). BMI correlated significantly with indices of left ventricular function.

CONCLUSIONS

Subclinical left ventricular diastolic dysfunction is present in all grades of isolated obesity, correlates with BMI, and is associated with increased systolic function in the early stages of obesity.

[Cardiopulmonary function and exercise capacity in patients with morbid obesity]

INTRODUCTION AND OBJECTIVES

The effect of obesity on cardiac function is still under discussion. The objective of this study was to assess cardiopulmonary capacity in morbidly obese patients. Patients and method. A symptom-limited cardiopulmonary exercise stress test was carried out in 31 morbidly obese patients (BMI 50 9 kg/m2) and 30 normal controls (BMI 24 2 kg/m2. Cardiovascular function was evaluated using the oxygen pulse (oxygen uptake/heart rate).

RESULTS

There were no differences in age, sex and height between both groups. During the effort the obese subjects presented greater oxygen uptake, heart rate, systolic arterial pressure and minute ventilation and shorter test duration than control group (14 3 vs 27 4 min; p < 0.001). Oxygen pulse values were higher in obese patients. However, after oxygen uptake indexation by fat free mass, these differences disappeared, suggesting a similar cardiovascular function. At the end of the exercise, the control group reached 96% of their age-predicted maximal heart rate and their respiratory exchange ratio was 1 0.2. Obese patients only reached 86% and 0.87 0.2, respectively.

CONCLUSIONS

Due to their need of more energy output to move total body mass morbidly obese patients have a reduced exercise capacity. They finish the test having done a submaximal exercise. However, during this effort they show a normal cardiopulmonar capacity.

Transmitral pulsed-Doppler echocardiography is a more accurate technique compared with two-dimensional echocardiography using dobutamine, in patients with one vessel coronary artery disease

To examine the effects of dobutamine on pulsed-Doppler left ventricular filling indices and its utility for evaluation of CAD we studied 14 patients with normal coronary arteries (Group 1) and 39 patients with significant CAD (>70% diameter stenosis). Patients with coronary artery disease (CAD) were divided into two groups: patients with one-vessel coronary disease (Group 2); and those with multivessel CAD (Group 3). After stopping cardioactive treatment, patients underwent incremental dobutamine stress (5, 10, 20, 30 and 40 microg/kg/min) during pulsed-Doppler interrogation of diastolic filling with simultaneous heart rate and blood pressure measurements. The following transmitral Doppler variables were measured at baseline and at peak-dose of dobutamine: peak early (E) and peak atrial (A) velocity; E/A ratio; acceleration time (AT) and deceleration time (DT) of E wave; isovolumic relaxation time (IVRT); and time-velocity integral (TVI). Two-dimensional echocardiography was performed to detect regional asinergy and analyzed using a 16 segment model.

RESULTS

Normals and CAD patients showed comparable changes in heart rate and blood pressure (P=NS between groups). Intergroup analysis of the changes of transmitral flow showed the significant changes for these indices (P<0.001): E velocity (-2.78+/-10.04, 12.4+/-9.4 and 16.47+/-10.65 cm/s); AT of E wave (1.66+/-2.47, -5.2+/-1.38 and -4.66+/-2.39 m/s(2)); DT of E wave (-0.23+/-0.18, 0.2+/-0.2 and 0.2+/-0.28 m/s(2)); and TVI of transmitral flow (-1.26+/-0.7, 3.5+/-1.75 and 4.1+/-1.66 cm), respectively for Groups 1, 2 and 3. All other transmitral Doppler variables showed insignificant changes (P=NS) to dobutamine between groups. It is important that the significance of these changes were the same for patients with one-vessel and those with multivessel coronary disease. In conclusion, during dobutamine stress testing, patients with CAD, had an abnormal response of these transmitral Doppler indices: E wave; AT of E wave; DT of E wave; and the TVI of transmitral flow. The abnormal responses of these Doppler indices of left ventricular filling are more accurate markers of significant single vessel CAD than new wall motion abnormalities during conventional DSE.