The role of echocardiography in the evaluation of cardiac damage in hypertensive obese patient

Association Between Elevated Body Mass Index and Cardiac Organ Damage in Children and Adolescents: Evidence and Mechanisms

INTRODUCTION

Although a number of pathophysiological aspects of childhood obesity have been reported, few information are available on obesity-related cardiac organ damage.

AIM

The present study was aimed at assessing the impact of anthropometric, blood pressure (BP) and metabolic variable on cardiac structure and function in youth.

METHODS

In 78 subjects aged 5-16 years attending the outpatient clinic of cardiovascular risk (Valencia, Spain) anthropometric and metabolic variables, clinic and ambulatory BP and echocardiographic parameters were assessed. Subjects were also classified according to the presence of insulin resistance.

RESULTS

Subjects mean age (± SD) amounted to 12.03 ± 2.4 years and males to 53.8%. Ten subjects were normoweight, 11 overweight, 39 obese, and 18 severely obese. No significant difference in office and ambulatory BP was detected among different bodyweight groups. A significant direct correlation was observed between left ventricular mass index (LVMI) and obesity markers [body mass index (BMI): r = 0.38, waist circumference (WC): r = 0.46, P < 0.04 for both]. Left ventricular hypertrophy, relative wall thickness and left atrial diameter were significantly related to BMI and WC. In contrast, office and ambulatory BP were unrelated to other variables, and differences in LVMI among different BP phenotypes were not significant. When partitioning the population by insulin resistance, LVMI, adjusted for confounders, was significantly greater in the insulin-resistant group.

CONCLUSIONS

In children and adolescents characterized by different body weight patterns, weight factors "per se" and the related insulin resistance state appear to represent the main determinants of LVMI and left ventricular hypertrophy, independently on BP values and BP phenotypes.

Cardiovascular Imaging in Obesity

Obesity represents one of the most challenging public health problems of our century. It accounts for approximately 5% of deaths worldwide, mostly owing to cardiovascular disease and its associated complications. Cardiovascular noninvasive imaging may provide early accurate information about hypertrophy and ischemia/fibrosis in obese subjects. Echocardiography and nuclear cardiology have serious limitations in obese subjects owing to poor acoustic window and attenuation artifacts, respectively. Coronary computed tomography angiography can provide information about obstructive coronary disease; however, the use of radiation is a serious disadvantage. Finally, cardiac magnetic resonance (CMR) holds the promise of an "all in one" examination by combining evaluation of function, wall motion/thickness, stress rest/perfusion, replacement and diffuse fibrosis without radiation. Future studies are required to document the cost/benefit ratio of the CMR in the evaluation of cardiovascular risk in overweight/obese children and adolescents.

Role of Cardiovascular Ultrasound in the Evaluation of Obese Subjects

Obesity represents a worldwide increasing health problem. Obesity, through complex and not fully understood pathogenetic mechanisms, induces different structural and functional changes of left heart chambers, right heart chambers, and arteries. Ultrasound techniques are the first choice for a comprehensive assessment of the cardiovascular adaptation to obesity. This review summarizes the up-to-date literature on the topic, with particular focus on the main clinical studies, which range over different cardiovascular adaptations to obesity, namely left ventricular mass, diastolic function, right ventricle structure and function, arterial stiffness, and intima-media thickness. Also, the importance of epicardial fat and of the degree of obesity is described. Finally, the role of weight loss and bariatric surgery and the study of cardiovascular obesity-induced abnormalities in children and adolescent are discussed.

Left Atrium: Still a Neglected Chamber?

It is widely recognized that an effective cardiovascular system is based upon both a good ventricular-vascular interplay and a good ventricular-atrial interaction in all the phases of cardiac cycle. Moreover, left atrial dysfunction has been identified to be contributory in several common cardiovascular conditions, such as heart failure, atrial fibrillation and valvular heart disease; for instance, a good anatomical and functional assessment of this cardiac chamber is mandatory. For this purpose a multimodality imaging approach – including two-dimensional and three-dimensional echocardiography, speckle tracking technique, cardiac computed tomography (CT) and cardiac magnetic resonance (CMR) – is the most suitable one to achieve the best functional and anatomical evaluation of this cardiac chamber.