Korean Circ J.  1981 Dec;11(2):41-52. 10.4070/kcj.1981.11.2.41.

Apexcardiogram in Hyperthyroidism: With Particular Reference to Fractional Systolic and Diastolic Time Intervals

• Kwon YJ
• Park HM

• KMID: 2229761
• DOI: http://doi.org/10.4070/kcj.1981.11.2.41

Abstract

For the non-invasive evaluation of cardiac performance in hyperthyroidism, fractional systolic and diastolic time intervals were determined in 96 female patients with hyperthyroidism from the mechanocardiograms which included apexcardiograms together with electrocardiograms, phonocardiograms and carotid arterial pulse tracings. The observed values of the time intervals inversely related to heart rate, i.e., ejection period, mechanical systole, isovolumic relaxation time and active ventricular filling period, were significantly shortened in proportion to the severity of the disease in general, as determined by the rate of the radioactive iodine uptake of the thyroid glands. However, these values were not significantly different from those of the predicted for heart rate, except for one of mechanical systoles which is a time interval from the onset of the systolic upstroke in the apexcardiogram to the second aortic sound. This suggests that the shortening of these observed values is promarily due to tachycardia associated with hyperthyroidism. One the other hand, the observed values of the time intervals unrelated to heart rate, i.e., electromechanical delay, isovolumic contraction time together with one of its components, namely ventricular pressure elevation time, and rapid ventricular filling period, were significantly shorter than those in the controls, although the degree of the shortening was not related to the degree of the radioactive iodine uptake of the thyroid gland. It appears that the shortening of these time intervals is related to the altered cardiac function caused by hyperthyroidism and, in particular, that of the isovolumic contraction time and ventricular pressure elevation time reflects enhancemet by the thyrotoxic myocardial contractility.

MeSH Terms

Electrocardiography
Female
Hand
Heart Rate
Humans
Hyperthyroidism*
Iodine
Relaxation
Systole
Tachycardia
Thyroid Gland
Ventricular Pressure
Iodine