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[Variability of the heart rate and silent ischemia after myocardial infarction]
M C Solimene1, J A Ramires, C J Gruppi
1Instituto do Coração do Hospital das Clínicas, FMUSP.
Insights
This study found no significant relationship between heart rate changes and silent myocardial ischemia in post-heart attack patients. Arrhythmias were common but not directly linked to these ischemic events.
Area of Science:
- Cardiology
- Clinical Medicine
- Cardiovascular Research
Context:
- Silent myocardial ischemia is a critical concern in patients post-myocardial infarction.
- Asymptomatic individuals after myocardial infarction often experience ischemic episodes.
- Holter monitoring is crucial for detecting these silent events.
Purpose:
- To investigate the potential correlation between heart rate fluctuations and the occurrence of silent myocardial ischemia.
- To determine if heart rate changes precede or accompany ischemic episodes in asymptomatic patients.
Summary:
- Forty-nine silent ischemic episodes were recorded in six patients using 576-hour Holter monitoring.
- Most episodes occurred at rest, with no significant heart rate changes observed at their onset.
- Complex ventricular arrhythmias were present in all patients, but not consistently linked to silent ischemia.
Impact:
- Findings suggest heart rate and arrhythmias may not be reliable indicators for predicting silent myocardial ischemia.
- This research highlights the complex nature of silent ischemia in post-myocardial infarction patients.
- Further studies are needed to understand the triggers and management of silent myocardial ischemia.
Purpose:
To show a possible relation between heart rate and silent myocardial ischemia.
Methods:
Forty-nine ischemic episodes were registered in six patients during a total period of 576-hour Holter monitoring. Those patients were selected from a group of 40 asymptomatic individuals after a first uncomplicated myocardial infarction; 11 (27.5%) showed ischemia during daily activities or exercise, the six selected patients had myocardial ischemia on Holter monitoring.
Results:
The silent episodes consisted 92% of the total ischemic burden; they lasted from 1 min 30 s to 20 min and the ST-segment depression varied from -1.1 mm to 3.3 mm. Thirty-five (72%) episodes occurred at rest or during light physical activities; nine (18.5%) occurred between 7:00 AM and 12:00 PM; eight (16.5%), between 12:00 PM and 6:00 PM; 17 (35%) between 6:00 PM and 12:00 AM and 15 (30%), between 12:00 AM and 7:00 AM. There was no significant change (more than 20%) in heart rate at the onset of ischemic episodes in relation to the heart rate 1 minute before (94.63 +/- 9.79 bpm and 99.47 +/- 10.99 bpm, respectively). Complex ventricular arrhythmias occurred in all patients and only one of them had an episode of nonsustained ventricular tachycardia related to silent ischemia.
Conclusion:
Our results suggest that there is no relation between heart rate, arrhythmias and silent ischemia.