Why the study?
Does preexisting hypothyroidism worsen left ventricular function and remodeling after myocardial infarction in rats?
Does preexisting hypothyroidism worsen left ventricular function and remodeling after myocardial infarction in rats?
Preexisting hypothyroidism exaggerates post-MI remodeling and worsens LV diastolic function in a rat model.
May worsen post-MI remodeling and diastolic dysfunction in rats; leaves open translation to human hypothyroidism.
It has been shown that hypothyroidism may lead to delayed wound healing after experimental myocardial infarction (MI) in rats and increased infarct size in dogs. However, the long-term effect of hypothyroidism on left ventricular (LV) remodeling after MI has not been determined. Adult female Sprague-Dawley rats with and without surgical thyroidectomy (TX) were used in the study. Four weeks after TX, MI or sham MI was performed on TX and non-TX rats. Rats from all groups were examined 4 wk later. Four weeks after TX, hypothyroid-induced LV dysfunction was confirmed by echocardiography. In terminal experiments 4 wk after MI, TX sham-MI rats showed smaller hearts and impaired LV function compared with non-TX sham-MI controls. TX + MI rats showed smaller hearts with bigger infarct areas, higher LV end-diastolic pressures, and greater impairment of relaxation (-dP/dt) compared with non-TX MI rats. Relative changes after MI between TX and non-TX rats for most other hemodynamic and echocardiographic indexes were similar. These results suggest that preexisting hypothyroidism exaggerates post-MI remodeling and worsens LV function, particularly diastolic function.
No takes yet. Share an insight, caveat, or question.
Chen et al. (2009) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: