Lori B. Croft

Prevalence of Metabolic Syndrome in Retired National Football League Players

The National Institute of Occupational Safety and Health mortality study of National Football League (NFL) players concluded that retired NFL linemen have an increased risk of cardiovascular death compared with both nonlinemen and the general population. Though elevated body mass index contributed to the increased cardiac risk of linemen, it could not fully account for the mortality observed, suggesting that other unmeasured cardiovascular risk factors were involved. We performed a cross-sectional prevalence study of metabolic syndrome (MS), and its individual component criteria, in 510 retired NFL players who were recruited to multicity health screenings from February 2004 through June 2006. The International Diabetes Federation criteria were used to define MS. The MS component criteria of body mass index>30 kg/m2, reduced high-density lipoprotein, and raised fasting glucose were more prevalent in linemen compared with nonlinemen (85.4% vs 50.3%, p<0.001; 42.1% vs 32.7%, p=0.04; 60.4% vs 37.6%, p<0.001, respectively). Metabolic syndrome was more prevalent in linemen compared with nonlinemen (59.8% vs 30.1%, p<0.001). In conclusion, linemen exhibited a high prevalence of MS, almost double the prevalence of their nonlinemen counterparts. These findings may partially explain the increased risk for cardiovascular death observed in retired linemen and could have significant public health implications for preprofessional training regimens and postprofessional health maintenance.

A pilot study of the clinical impact of hand-carried cardiac ultrasound in the medical clinic.

Background: Small, hand‐carried ultrasound devices have become widely available, making point‐of‐care echocardiograms (echos) accessible to all medical personnel as a means to augment and improve the increasingly inefficient physical examination. This study was designed to determine the clinical utility of hand‐carried echo by medical residents in clinical decision making. Methods: Nine residents underwent brief, practical echo training to perform and interpret a limited hand‐carried echo as an integral component of their office examination. The residents hand‐carried echo consisting of four basic views to define left ventricular (LV) function and wall thickness, valvular disease, and any pericardial effusions was compared to one performed by a level III echocardiographer. Results: Seventy‐two consecutive medical clinic patients were enrolled with an average image acquisition time of 4.45 minutes. Residents obtained diagnostic images in 94% of the cases and interpreted them correctly 93% of the time. They correctly identified 92% of the major echo findings and 78% of the minor findings. Their diagnosis of LV dysfunction, valvular disease, and LV hypertrophy improved by 19%, 39%, and 14% with hand‐carried echo compared to history and physical alone. Management decisions were reinforced in 76% and changed in 40% of patients with the use of hand‐carried echo. Conclusion: This study demonstrates that it is possible to train medical residents to perform an effective and reasonably accurate hand‐carried echo during their physical examination, which can impact clinical management.

Can hand-carried ultrasound devices be extended for use by the noncardiology medical community?

Echocardiography (echo) is a powerful, noninvasive, inexpensive diagnostic imaging technique that provides important information in a variety of cardiovascular diseases. Echo provides rapid information regarding ventricular and valvular function in the clinical management of patients. Smaller, relatively inexpensive hand‐carried cardiac ultrasound (HCU) devices have become commercially available, which can be used for diagnostic cardiac imaging. Because of their relative ease of use, portability, and affordable cost, these new hand‐held systems have made point‐of‐care (bedside) echocardiography available to all medical personnel. The rate‐limiting step to the widespread use of this technology is the lack of personnel with echo training at the immediate contact point with patients. Although extensive training and experience are needed to acquire and interpret a complete echo, training medical personnel to perform and interpret a limited echo (defined as a brief, diagnosis focused exam) may fully exploit the potential of echo as a point‐of‐care diagnostic tool and may be accomplished in a short period of time. Presently there are guidelines for independent competency in echocardiography and HCU echo established by several professional organizations and as a result of these rigorous guidelines, other noncardiology medical professionals who could practically derive the greatest benefit are discouraged and virtually precluded from utilizing echo during the initial encounter with the patient. However, there is now a growing body of literature in a diverse group of noncardiology medical personnel that demonstrates that it is possible to quickly and effectively train them to perform and interpret limited echocardiograms. Medical students, medical residents, cardiology fellows with limited experience, emergency department physicians, and surgical intensive care unit staff have all been evaluated after only brief, focused training periods, and investigators found that HCU echo provided important new information, changed therapeutic management, and was vastly superior to the physical exam alone with an acceptable overall level of accuracy. The contribution of echocardiography to the field of cardiovascular disease since its invention has been significant and the newer compact, portable, ultrasound systems have the potential to revolutionize the utilization and availability of echocardiography. To maximize integration of echo into medical practice, physicians and physician extenders could be trained to perform and interpret limited echo to complement their clinical examination and improve their diagnostic skills. The challenge is to provide practical training programs to assure competency in performing point of care echocardiograms. (ECHOCARDIOGRAPHY, Volume 20, July 2003)

Comparison of four echocardiographic techniques for measuring left ventricular ejection fraction

Accurate quantitative measurement of left ventricular (LV) ejection fraction (EF) by 2-dimensional echocardiography is limited by subjective visual endocardial border detection. Both harmonic and precision contrast microbubbles provide better delineation of endocardial borders than fundamental imaging. The aim of this study was to correlate 2-dimensional echocardiographic quantification of LVEF measured by 4 currently available techniques with radionuclide angiography. A total of 50 patients who underwent radionuclide (EF) measurement (47 of 50 had technically difficult echocardiograms by fundamental imaging) underwent echocardiography by 4 methods: fundamental alone, fundamental with contrast, harmonic alone, and harmonic with contrast. Three echocardiologists measured the biplane 2-dimensional echocardiographic LVEF independently and were blinded to radionuclide angiography. The correlation of echocardiographic EF with radionuclide EF improved incrementally with each method. However, contrast with harmonic imaging provided the closest correlation (r = 0.95, 0.96, and 0.95 as assessed by the 3 independent analysts.

Comparison of National Football League Linemen Versus Nonlinemen of Left Ventricular Mass and Left Atrial Size

Retired National Football League (NFL) linemen have higher cardiovascular mortality compared with nonlinemen. We examined echocardiographic characteristics of retired NFL linemen compared with nonlinemen to determine if position-dependent cardiac remodeling resulted in increased left ventricular (LV) mass and left atrial (LA) size. We performed echocardiography in 487 retired NFL football players. Demographic, medical, and professional career information was collected. Interventricular septal and posterior wall thickness, LV end diastolic diameter, and LA area were measured. Body mass index (BMI) and LV mass were calculated. Retired linemen had significantly higher LV mass (234.8 +/- 65.8 g) than nonlinemen (199.8 +/- 55.4 g, p <0.0001). LA area was higher in linemen versus nonlinemen (22.5 vs 20.1 cm(2), p <0.0001). Independent predictors of increased LV mass were BMI (p <0.003), linemen position (p <0.024), and systolic blood pressure (p <0.005). In former players with BMI <35 kg/m(2) there was a difference between linemen and nonlinemen in LV mass (219.9 +/- 44.3 vs 182.6 +/- 44.3 g, p = 0.004) and LV mass/height (114.3 +/- 23.5 vs 98.8 +/- 25.2 g/m, p = 0.005). In former players with BMI >35 kg/m(2), there was no difference. There was no difference in LA area between linemen and nonlinemen in both BMI groups. In conclusion, LV mass and LA area size were highest in retired linemen. Player BMI, position, and systolic blood pressure were significant predictors of LV mass. In retired linemen compared with retired nonlinemen, the persistence of these cardiac adaptations may contribute to the higher cardiovascular mortality seen in retired linemen.

Spect myocardial perfusion imaging in the morbidly obese: Image quality and hemodynamic response to pharmacological stress

Background: As little is known about the characteristics of the morbidly obese (BMI ≥ 40) undergoing stress myocardial perfusion imaging (MPI), we set out to evaluate the study quality and the hemodynamic response to pharmacological stress in this population. n nMethods: We retrospectively studied 433 consecutive morbidly obese patients without known coronary artery disease presenting for a clinically indicated Tc-99m SPECT MPI study over a 42 month period. Studies were reviewed by consensus for image quality and the contribution of attenuation correction (Vertex, Philips/ADAC, VantagePro) to image interpretation. The hemodynamic response to adenosine (23), dipyridamole (260), and dobutamine (52) in the 335 patients undergoing pharmacologic stress was determined and compared to a group of 3,443 controls of BMI 20–30 studied during the same time period. n nResults: The average age was 54 ± 11 years, 69% F and 31% M, mean BMI 47.3 ± 8 kg/m2, mean weight 278 ± 62 lbs, and 79.5% high dose studies with an average Tc99m dose of 35.6 ± 5.4 mCi. Image quality was good in 61%, adequate in 37%, and poor in 2%. By multivariate analysis, study quality was dependent (p<0.05) on weight and the stressor used (worse with dobutamine), but not BMI. Attenuation correction was used in 95% of the studies and was helpful for image interpretation in 60% of them. The utility of attenuation correction was not significantly associated with gender, stressor, weight, or BMI. Compared to control patients, heart rate response to adenosine (21 ± 12 vs 14 ± 13 bpm, p=0.02) and dipyridamole (18 ± 11 vs 14 ± 10 bpm, p<0.001) was more pronounced and the systolic blood pressure response to dipyridamole (-13 ± 20 vs -21 ± 18 mmHg, p<0.001) was less pronounced in the morbidly obese. n nConclusion: Diagnostic quality MPI imaging is feasible in the majority (98%) of morbidly obese patients with the use of a dual head camera, attenuation correction, and high stress tracer dose. Increasing weight and dobutamine were associated with worse image quality. The blood pressure drop after dipyridamole was attenuated and the heart rate response was more pronounced after dipyridamole and adenosine.