title: Doppler echocardiographic evaluation of left ventricular diastolic function in acute hypothyroidism.
abstract: OBJECTIVE
  Left ventricular diastolic dysfunction is an important cause of symptomatic heart failure. Previous studies suggest that thyroid dysfunction affects left ventricular diastolic function but the underlying mechanisms remain controversial. The study was undertaken to asses the influence of acute hypothyroidism on left ventricular diastolic function and to elucidate possible underlying mechanisms by means of Doppler echocardiography in a group of athyreotic patients, whose thyroid state depended only on external thyroid hormone supply and could therefore easily be controlled.
  
  
  METHODS
  Eleven patients (5 men, 6 women, aged 20-55 years), who had had total thyroidectomy, were investigated during mild hyperthyroidism and during acute hypothyroidism. Additionally, 11 healthy control subjects aged 25-51 years were included in the study.
  
  
  METHODS
  M-mode echocardiography of the left ventricle and pulsed-wave Doppler echocardiography of the transmitral flow velocity pattern were carried out.
  
  
  RESULTS
  Acute hypothyroidism produced a decrease of left ventricular end-diastolic diameter from 48 +/- 5 to 46 +/- 5 mm (mean +/- SD P < 0.05), of peak velocity of early diastolic filling from 0.52 +/- 0.10 to 0.42 +/- 0.05 m/s (P < 0.05), of peak velocity of late diastolic filling from 0.42 +/- 0.10 to 0.36 +/- 0.09 m/s (P < 0.05), and a decreased time-velocity integral of early diastolic filling (6.2 +/- 1.8 vs 5.1 +/- 0.7 cm, P < 0.05). The other M-mode and Doppler echocardiographic parameters did not differ between the hyperthyroid and the hypothyroid states.
  
  
  CONCLUSIONS
  The observed changes of the trans-mitral flow velocity pattern during acute hypothyroidism can be attributed to a reduction of pre-load. There is no direct evidence that acute hypothyroidism affects the intrinsic diastolic properties of the left ventricle.
authors.affiliation: Department of Cardiology, University Hospital of Ulm, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Grossmann
authors.forename: S
authors.initials: S
authors.lastname: Wieshammer
authors.forename: F S
authors.initials: FS
authors.lastname: Keck
authors.forename: V
authors.initials: V
authors.lastname: Göller
authors.forename: M
authors.initials: M
authors.lastname: Giesler
authors.forename: V
authors.initials: V
authors.lastname: Hombach
mesh_terms: D000208:Acute Disease; D000328:Adult; D003971:Diastole; D015150:Echocardiography, Doppler; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006980:Hyperthyroidism / Q000503:physiopathology; D007037:Hypothyroidism / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D013965:Thyroidectomy; D016277:Ventricular Function, Left / Q000502:physiology*