title: The pathophysiological relationship and clinical significance of left atrial function and left ventricular diastolic dysfunction in β-thalassemia major.
abstract: Iron deposition in combination with inflammatory and immunogenetic factors is involved in the pathophysiology of cardiac dysfunction in β-thalassemia major. We investigated the mechanical and endocrine function of the left atrium and ventricle to identify early signs of dysfunction. We studied 90 patients (mean age: 29 ± 11 years) with β-thalassemia and normal left ventricular function and 90 age and sex-matched healthy controls. Patients and controls underwent a thorough cardiac echocardiographic study and measurements of the b-type (NT-proBNP) and atrial natriuretic peptides (proANP). Patients underwent 24-hr Holter recordings for arrhythmia monitoring. In the patient group, atria were affected early during the course of the disease, prior to diastolic and systolic left ventricular dysfunction. The E/E'ratio (E Doppler mitral fast inflow to the corresponding tissue Doppler E) continually increased with age (P < 0.05) and reached levels indicating left ventricular diastolic dysfunction (E/E' > 15) in the third decade whereas indexes of active and passive atrial function decreased gradually throughout life. In controls, the E/E' ratio continually increased with age but with later (fifth decade) appearance of diastolic dysfunction and a compensatory increase in atrial active function. Both natriuretic peptides were significantly increased in patients compared to controls (558 ± 141 and 2,580 ± 1,830 fmol/mL for NT-proBNP and proANP versus 332 ± 106 and 1,331 ± 1,134 fmol/mL, respectively). Atrial fibrillation was found in a subgroup of 23 (26%) patients, older in age with mild diastolic function and enlarged, depressed atria. In conclusion, atrial mechanical depression seems to be a very early sign of cardiac damage. It may become echocardiographically evident even before diastolic and systolic dysfunction and is associated to supraventricular arrhythmias.
authors.affiliation: Department of Cardiology, Onassis Cardiac Surgery Center, Athens, Greece.
authors.forename: Anna G
authors.initials: AG
authors.lastname: Kostopoulou
authors.forename: Dimitrios P
authors.initials: DP
authors.lastname: Tsiapras
authors.forename: Antigoni S
authors.initials: AS
authors.lastname: Chaidaroglou
authors.forename: Dimitrios E
authors.initials: DE
authors.lastname: De Giannis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Farmakis
authors.forename: Dimitrios Th
authors.initials: DT
authors.lastname: Kremastinos
mesh_terms: D000293:Adolescent; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism; D016279:Atrial Function, Left; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D045265:Natriuretic Peptides / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D012189:Retrospective Studies; D012307:Risk Factors; D020107:Troponin T / Q000097:blood; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D055815:Young Adult; D017086:beta-Thalassemia / Q000150:complications*
chemical_list: D045265:Natriuretic Peptides; D010446:Peptide Fragments; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain