Grossmann G, Wieshammer S, Keck F S, Göller V, Giesler M, Hombach V
Department of Cardiology, University Hospital of Ulm, Germany.
Clin Endocrinol (Oxf). 1994 Feb;40(2):227-33. doi: 10.1111/j.1365-2265.1994.tb02473.x.
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.
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.
M-mode echocardiography of the left ventricle and pulsed-wave Doppler echocardiography of the transmitral flow velocity pattern were carried out.
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.
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.
左心室舒张功能障碍是有症状心力衰竭的重要原因。既往研究提示甲状腺功能障碍会影响左心室舒张功能，但其潜在机制仍存在争议。本研究旨在评估急性甲状腺功能减退对左心室舒张功能的影响，并通过多普勒超声心动图阐明一组甲状腺切除患者可能的潜在机制，这些患者的甲状腺状态仅依赖外源性甲状腺激素供应，因此易于控制。
11例患者（5例男性，6例女性，年龄20 - 55岁），均接受了甲状腺全切术，在轻度甲状腺功能亢进期和急性甲状腺功能减退期接受了研究。此外，11名年龄在25 - 51岁的健康对照者也纳入了本研究。
进行了左心室M型超声心动图检查及二尖瓣血流速度模式的脉冲波多普勒超声心动图检查。
急性甲状腺功能减退使左心室舒张末期内径从48±5减小至46±5mm（均值±标准差，P<0.05），舒张早期充盈峰值速度从0.52±0.10降至0.42±未0.05m/s（P<0.05），舒张晚期充盈峰值速度从0.42±0.10降至0.36±0.09m/s（P<0.05），舒张早期充盈时间速度积分降低（6.2±1.8对5.1±0.7cm，P<0.05）。其他M型和多普勒超声心动图参数在甲状腺功能亢进和甲状腺功能减退状态之间无差异。
急性甲状腺功能减退期间观察到的二尖瓣血流速度模式变化可归因于前负荷的降低。没有直接证据表明急性甲状腺功能减退会影响左心室的固有舒张特性。
