Thyrotoxicosis was associated with a significantly shortened cardiac pre-ejection period compared to expected normal values (mean deviation -33.8; P<0.001), which normalized with treatment.
Observational (n=17)
Does thyrotoxicosis alter the pre-ejection period (PEP) compared to expected normal values?
A shortened pre-ejection period is characteristic of uncomplicated thyrotoxicosis and may serve as a useful noninvasive index of therapeutic response.
Mean Difference: -33.8
p-value: p=<0.001
Systolic time intervals (STI) were determined from simultaneous records of the electrocardiogram, carotid pulse and phonocardiogram in 17 consecutive patients with thyrotoxicosis and sinus rhythm. None of the patients had clinical evidence of congestive heart failure. Intervals measured included electromechanical systole (Q-S 2 ), heart sound interval (S 1 -S 2 ) and left ventricular ejection time (LVET). From these, the pre-ejection period (PEP), isovolumetric contraction time (ICT) and Q-S 1 intervals were derived. Deviations (ΔSTI) of observed values from expected values (Weissler equations) for the same heart rate were obtained by subtraction. The mean deviation of the thyrotoxic patients ± sem from the normal population were ΔQ- S 2 * = –37.8 ± 4.2; ΔLVET = –4.0 ± 4.1; ΔPEP * = –33.8 ± 1.8. The shortening of PEP was due largely to a shortened ICT (ΔICT * = –27.2 ± 1.1). In eight patients studied serially during treatment the short PEP returned to the normal range concurrently with serum T 4 measurements. This study indicates that the PEP is a unique noninvasive measurement of biological end organ responsiveness with thyroid dysfunction; a short PEP is characteristic of uncomplicated thyrotoxicosis and serial changes in PEP may be a useful index of therapeutic response. * P < .001.
Parisi et al. (Wed,) conducted a observational in Thyrotoxicosis (n=17). Thyrotoxicosis vs. Expected normal values was evaluated on Deviation of pre-ejection period (ΔPEP) from expected normal values (MD -33.8, p=<0.001). Thyrotoxicosis was associated with a significantly shortened cardiac pre-ejection period compared to expected normal values (mean deviation -33.8; P<0.001), which normalized with treatment.