Cardiac abnormalities in children with sickle cell anemia

Abstract

Sickle cell anemia (SCA) results in chronic volume overload of the heart due to hemodilution. Previous echocardiographic studies of cardiac function in children with SCA have not accounted for these abnormal loading conditions. The objectives of this study were to (1) determine how the degree of anemia and transfusion status relate to cardiac findings and (2) evaluate cardiac function using load-independent parameters of function. We evaluated 77 patients with SCA, ages 2 to 22 years (mean ± SD = 11.7 ± 4.7), using physical examination, electrocardiography, and echocardiography. We compared two groups of patients. Group 1 consisted of 57 non-transfused patients, and Group 2 consisted of 20 patients on a chronic transfusion protocol. Group 1 patients exhibited a significantly lower hemoglobin, higher cardiac output, and larger left ventricular (LV) end-diastolic dimension and LV mass than groups 2 (P < 0.05). However, the velocity of circumferential fiber shortening-wall stress index (a load-independent measure of systolic function) was normal and not statistically different between the two groups. Conversely, the LV myocardial performance index (a measure of combined systolic and diastolic function) was significantly higher in Group 2 (P < 0.001), possibly indicating impaired myocardial diastolic function. SCA in children results in a volume-overloaded heart with a significant increase in LV dimensions and mass, both proportional to the degree of anemia. Despite these abnormal loading conditions, systolic function is preserved. Patients on a chronic transfusion protocol may develop diastolic dysfunction despite iron chelation therapy. Am.

Abnormal autonomic cardiac response to transient hypoxia in sickle cell anemia

“…Researchers have shown some degree of physiological cardiovascular adaptation in SCA patients, including elevations in heart rate and declines in cardiac output, primarily results from the associated chronic hemolytic anemia (Lester et al 1990, Batra et al 2002. Furthermore, Weiskopf et al reported linear increases in heart rates in healthy unmedicated human subjects as a result of acute isovolemic anemia (Weiskopf et al 2003).…”

“…Although acute atherosclerosis-related myocardial infarctions are rare in SCA patients, diverse cardiovascular anomalies-including heart murmur, cardiomegaly, biventricular hypertrophy and abnormalities in the cardiac conducting system-which sometimes correlate to sudden death in SCA patients, have been described by multiple researchers (James et al 1994, Assanasen et al 2003, Norris et al 1991, Pavlu et al 2007, Manci et al 2003, Batra et al 2002. Transient cardiac dysfunction and myocardial ischemia have also been reported during sickle cell crisis (Norris et al 1991, Deymann andGoertz 2003).…”

Airway and alveolar nitric oxide production, lung function, and pulmonary blood flow in sickle cell disease

“…An increased prevalence of asthma was reported in one study of SCD children (5), but other studies have indicated a similar incidence to that of non-SCD populations (6,7). Another explanation for the airways obstruction in SCD is the hyperdynamic pulmonary circulation due to a raised cardiac output resulting from chronic anemia (8). In children with SCD, we have demonstrated that pulmonary capillary blood volume is increased compared to matched controls and correlated with airflow obstruction (9).…”

“…In patients with liver cirrhosis, the enhanced NO output was shown to be of alveolar and not airway origin (17). Whether the hyperdynamic circulation in SCD patients (8) influences their F eNO levels has not been investigated.…”

Study of Pulmonary Hypertension and Left ventricular diastolic dysfunction in Patients of Sickle Cell Anaemia

“…[8] Batra et al found systolic function and contractility to be preserved in their study. [25] Taksande A et al in their prospective controlled study found that left ventricular contraction was good and systolic function was normal in study population. [26] …”