Influence of physiologic cardiac hypertrophy on the prevalence of heart valve regurgitation

Cholecystokinin Expression in the Development of Myocardial Hypertrophy

BACKGROUND

Expression of cholecystokinin is found in myocardial tissues as a gastrointestinal hormone and may be involved in cardiovascular regulation. However, it is unclear whether there is an increase in cholecystokinin expression in myocardial hypertrophy progression induced by abdominal aortic constriction. The study is aimed at exploring the relationship between cholecystokinin expression and myocardial hypertrophy.

METHODS

We randomly divided the 70 Sprague-Dawley rats into two groups: the sham operation group and the abdominal aortic constriction group. The hearts of rats were measured by echocardiography, and myocardial tissues and blood were collected at 4 weeks, 8 weeks, and 12 weeks after surgery. Morphological changes were assessed by microscopy. The cholecystokinin expression was evaluated by immunochemistry, Western blotting, quantitative real-time polymerase chain reaction, and enzyme-linked immunosorbent assay.

RESULTS

The relative protein levels of cholecystokinin were significantly increased in the abdominal aortic constriction groups compared with the corresponding sham operation groups at 8 weeks and 12 weeks. The cholecystokinin mRNA in the abdominal aortic constriction groups was significantly higher than the time-matched sham operation groups. Changes in the left ventricular wall thickness were positively correlated with the relative protein levels of cholecystokinin and the mRNA of cholecystokinin.

CONCLUSIONS

The development of myocardial hypertrophy can affect the cholecystokinin expression of myocardial tissues.

Echocardiographic predictors of mitral regurgitation in high school and collegiate competitive athletes

Previous studies have compared cardiac morphology between strength and endurance athletes, but few studies have examined predictors of valvular regurgitation in this population. This study evaluated predictors of mitral regurgitation (MR) in high school and collegiate athletes. Athletes in 9 different sports (n = 144) underwent transthoracic echocardiography. We used 97 sedentary patients as controls. Left ventricular (LV) end-diastolic diameter, septal wall thickness, posterior wall thickness, relative wall thickness (RWT), LV mass, LV volume, and mass/volume ratio were calculated and indexed for body surface area. Valvular regurgitation was graded from 0 to 4. Using logistic regression, RWT was associated with decreased odds of MR, with each 0.07 increase in RWT accounting for a 0.52 decrease in odds of MR (95% confidence interval 0.32 to 0.85, p = 0.009). Differences were best exemplified by comparison of soccer and football players, who represent predominantly aerobic versus predominantly isometric exercise, respectively. Soccer players had a larger LV end-diastolic index (29.2 ± 3 vs 24.9 ± 2.6, p <0.001), lesser RWT (0.33 ± 0.06 vs 0.38 ± 0.08, p = 0.014), and lower mass/volume ratio (1.04 ± 0.21 vs 1.29 ± 0.3, p <0.001), with a greater prevalence of MR (45.8% vs 8.5%). Sedentary subjects were similar to football players in LV volume and soccer players in LV mass. In conclusion, RWT is a negative predictor of MR, with higher values reducing the odds of MR. MR appears to be related to the relation between wall thickness and chamber size rather than chamber size alone.