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Circadian Rhythm of Infarct Size and Left Ventricular Function Evaluated with Tissue Doppler Echocardiography in ST
Hatem Arı1, Osman Sonmez2, Fatih Koc3
1Suleyman Demirel University, Faculty of Medicine, Cardiology Department, Isparta/Turkey.
Insights
The timing of ST-elevation myocardial infarction (STEMI) onset influences left ventricular (LV) function and infarct size. Poor LV function and larger infarcts were observed in patients with STEMI onset between midnight and noon.
Area of Science:
- Cardiology
- Circadian Biology
- Medical Imaging
Background:
- ST-elevation myocardial infarction (STEMI) is a critical cardiovascular event.
- Understanding factors influencing STEMI outcomes is crucial for patient management.
- The role of circadian rhythms in STEMI pathophysiology requires further investigation.
Purpose of the Study:
- To investigate the influence of circadian rhythm on left ventricular (LV) function and infarct size.
- To analyze these effects based on the time of STEMI onset.
- To correlate echocardiographic findings with STEMI timing.
Main Methods:
- Retrospective analysis of 252 STEMI patients.
- Patients grouped by 6-hour intervals of daily onset.
- Echocardiography, including tissue Doppler imaging (TDI), performed within 48 hours.
- Calculation of LV ejection fraction (LVEF) and peak systolic myocardial velocities (Sm).
Main Results:
- A negative correlation was found between CK-MB levels and Sm.
- Circadian variation in average Sm was observed.
- Lowest Sm and largest infarct size occurred in the 06:00-noon period.
- LVEF and Sm were significantly lower in the midnight-noon group compared to the noon-midnight group.
Conclusions:
- A circadian rhythm affects infarct size and LV function following STEMI.
- The largest infarct size and poorest LV function are associated with STEMI onset between midnight and noon.
- Specifically, the 06:00-noon period showed the most adverse outcomes.
Background:
We aimed to investigate the circadian rhythm on left ventricular (LV) function and infarct size, according to the onset of ST elevation myocardial infarction (STEMI), with echocardiography in patients with first STEMI successfully revascularised with primary percutaneous coronary intervention (PCI).
Methods:
We conducted a retrospective analysis of 252 STEMI patients. Patients were divided into the four, six-hour periods of the day. Conventional and tissue Doppler imaging (TDI) echocardiography were performed within 48hours after onset of chest pain. The average of peak systolic myocardial velocities (Sm) in each of the four myocardial segments and LV ejection fraction (LVEF) were calculated.
Results:
A negative linear correlation was shown between CK-MB levels and Sm (r= -0.209, p=0.001). There was an oscillation between time of day and average of Sm. The lowest Sm and largest infarct size were in the period of 06:00-noon compared with period of noon-18:00 and 18:00-midnight (p=0.029 and p=0.031, respectively). A secondary analysis showed that both LVEF and Sm were lower in the midnight-noon group compared with the noon-midnight group (44.9±7.3% versus 47.3±7.9%, p=0.018, and 7.6±1.4cm/s versus 8.2±1.6cm/s, p=0.003, respectively).
Conclusions:
This study has shown that there was a circadian rhythm of infarct size and LV function evaluated by echocardiography according to time of STEMI onset. The largest infarct size and poor LV function occurred in the midnight-noon period, in particular in the 06:00-noon period.
