Plasma Nitric Oxide Level in Myocardial Disorders with Left Ventricular Diastolic Dysfunction

Journal of Clinical and Basic Cardiology 2006; 9 (1-4): 23-26

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Keywords: diastolische Dysfunktion,  Herzinsuffizienz,  Myokard,  NO,  Stickstoff,  diastolic dysfunction,  heart failure,  myocardial dysorders,  nitric oxide

Nitric oxide is a free radical that is elevated in the plasma of patients with heart failure due to contractile dysfunction. This study examines the relation between plasma NO level and left ventricular (LV) diastolic function and its aetiology in heart failure patients in the pediatric age group. We performed echocardiographic Doppler studies in 47 patients (mean age 6.16 ± 2.8 years; 31 males and 16 females) with congestive heart failure. Left ventricular diastolic dysfunction was classified as either a restrictive (RFP) or non-restrictive filling pattern (non-RFP). Same-day venous total nitrite and nitrate levels were measured by colourimetric assay. Plasma NOx levels were significantly higher in the patient group than in the control group (141 ± 54 µmol/l and 43 ± 4 µmol/l, respectively; p < 0.001). ROC curves found that the cut-off point for plasma NOx levels was 60 µmol/l to differentiate between normal children and patients with heart failure. Patients with RFP showed insignificantly higher levels of plasma NOx than the non-RFP patients (p = n. s.). Only in muscular dystrophy patients, the correlation between plasma NOx levels and LV ejection fractions (r = –0.61; p = 0.06) and LV fractional shortenings (r = –0.64; p = 0.04) was negative. On correlating the plasma NOx levels to the severity of heart failure by multiple linear regression analysis, the pulmonary artery systolic pressure was the only variable independently associated with an elevated plasma NOx level (p = 0.05). Plasma NOx levels are elevated in patients with isolated diastolic heart failure. In addition, in patients with LV systolic failure, the severity of LV diastolic dysfunction determines the amount of NO production.