title: Evaluation of P-Wave Dispersion, Diastolic Function, and Atrial Electromechanical Conduction in Pediatric Patients with Subclinical Hypothyroidism.
abstract: OBJECTIVE
  This study aimed to evaluate ventricular diastolic dysfunction, inter- and intraatrial conduction delay, and P-wave dispersion in pediatric patients with subclinical hypothyroidism.
  
  
  METHODS
  The study comprised a total of 30 pediatric patients with subclinical hypothyroidism (SH) (mean age 7.8 ± 3.2 years) and 30 healthy children (mean age 8.4 ± 3.6 years) as the control group. A SH diagnosis was made in the event of increased serum thyroid-stimulating hormone (TSH) and decreased serum free triiodothyronine (T3 ) and free thyroxine (T4 ) concentrations.
  
  
  RESULTS
  Conventional Doppler imaging (TDI) showed low mitral early diastolic E-wave velocity and E/A ratio (P < 0.001) and significantly higher mitral late diastolic A-wave velocity (P = 0.001) in hypothyroidism patients. Moreover, patients with hypothyroidism had significantly lower left ventricular (LV) septal Em velocity and Em /Am ratios compared with the control group (P < 0.001), whereas Am velocity was higher in hypothyroidism patients (P = 0.018). LV lateral Em velocity and Em /Am ratio were significantly lower in patients with hypothyroidism compared with the control group (P < 0.001). With regard to atrial electromechanical conduction, atrial electromechanical delay (PA) lateral, PA septum, PA tricuspid, and each of interatrial and intraatrial conduction delay were significantly prolonged in hypothyroidism patients as compared with the control group (P < 0.001, P < 0.001, P = 0.023, P = 0.002, and P = 0.003, respectively). P-wave dispersion was significantly different in the pediatric patients with hypothyroidism (P < 0.001).
  
  
  CONCLUSIONS
  This study demonstrated atrial electromechanical conduction delay, abnormal P-wave dispersion, and ventricle diastolic dysfunction in pediatric patients with hypothyroidism.
authors.affiliation: Pediatric Cardiology Department, Okmeydani Education and Training Hospital, Istanbul, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Irdem
authors.affiliation: Pediatric Cardiology Department, Suleymaniye Gynecology, Obstetrics and Children Training and Research Hospital, Istanbul, Turkey. deryaaydin01@mynet.com.
authors.forename: Derya
authors.initials: D
authors.lastname: Aydın Sahin
authors.affiliation: Division of Pediatric Cardiology Department, Gaziantep University Faculty of Medicine, Gaziantep, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kervancioglu
authors.affiliation: Division of Pediatric Cardiology Department, Gaziantep University Faculty of Medicine, Gaziantep, Turkey.
authors.forename: Osman
authors.initials: O
authors.lastname: Baspinar
authors.affiliation: Division of Pediatric Cardiology Department, Gaziantep University Faculty of Medicine, Gaziantep, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Sucu
authors.affiliation: Division of Pediatric Endocrinology and Metabolism, Gaziantep University Faculty of Medicine, Gaziantep, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Keskin
authors.affiliation: Division of Pediatric Cardiology Department, Gaziantep University Faculty of Medicine, Gaziantep, Turkey.
authors.forename: Metin
authors.initials: M
authors.lastname: Kilinc
mesh_terms: D058070:Asymptomatic Diseases; D002648:Child; D015150:Echocardiography, Doppler / Q000379:methods*; D056966:Excitation Contraction Coupling; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007037:Hypothyroidism / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D009200:Myocardial Contraction; D009203:Myocardial Infarction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology*
keywords: P-wave dispersion; atrial electromechanical conduction; children; diastolic function; subclinical hypothyroidism