The aim of this study was to estimate the impact and prevalence of left ventricular geometric alterations and systolic and diastolic dysfunction in hemodialysis patients, as well as the relationship with cardiac troponin as a marker of myocardial damage.
Methods: 31 patients (pts), 19 males and 12 females, age 58.1+/-16.4 (26 on hemodialysis, 5 on peritoneal dialysis) and 31 healthy normal controls were enrolled. Echocardiography measurements were carried out according to the American Society of Echocardiography recommendations. Left ventricular mass was calculated, according to the Devereux formula and indexed to height and weight 2.7. Doppler echocardiography was performed to study diastolic function by measurements of isovolumetric relaxation period (IVRT), E wave deceleretion time (DTE) and E/A ratio. Cardiac troponin was measured by a third generation electro-chemiluminescence immunoassay. Statistical analysis was performed using the t-test for between-group comparisons and the Pearson and Spearman's tests to investigate correlations; p values of <0.05 were considered statistically significant.
Results: Eccentric hypertrophy was the most frequent pattern (n=17; 55%), followed by normal cardiac geometry (n=7; 23%), and concentric hypertrophy (n=5; 16%). Only 6% of pts (n=2) showed concentric remodelling. Systolic dysfunction was present in terms of endocardial parameters in 3 pts (9%) (fractional shortening <25%, EF<50%), but in terms of midwall myocardial shortening in 51% (n=16). Diastolic dysfunction was present in 87% (n=27) with a pattern of impaired relaxation (in 5 without left ventricular hypertrophy). E/A was negatively correlated with age (r=-0.41, p=0.02); DTE was positively correlated with posterior wall thickness (r=0.36, p=0.05) and interventricular septum thickness (r=0.45, p=0.01); cardiac troponin was positively correlated with age (r=0.50, p=0.00), left ventricular mass (r=0.41, p=0.02), posterior wall thickness (r=0.41; p=0.02) and interventricular septum thickness (r=0.39, p=0.03) but not with diastolic dysfunction parameters. No significant difference was found in terms of duration of dialysis between patients with normal left ventricular geometry and those with left ventricular hypertrophy, but a significant difference in age was found (p=0.03). Pts with diastolic dysfunction had more frequent hypotensive episodes during dialysis (p<0.01).
Conclusion: Impaired geometry and cardiac function is frequently observed in pts undergoing hemodialysis. Diastolic dysfunction is associated to a geometric pattern of left ventricular hypertrophy, although it can be an isolated initial manifestation of myocardial damage. Depressed midwall myocardial shortening can discriminate left ventricular dysfunction better than traditional endocardial systolic indexes.