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Frequency and significance of left and right ventricular late potentials after myocardial infarction in man
Insights
Ventricular late potentials were detected in 71% of myocardial infarction patients using endocardial mapping. These signals, linked to delayed ventricular ectopic beats, indicate potential risks after heart attack.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Diagnostics
Background:
- Myocardial infarction (MI) survivors are at risk for ventricular arrhythmias.
- Identifying patients with increased arrhythmia risk is crucial for management.
- Ventricular late potentials (VLPs) are potential markers of arrhythmogenic substrate.
Purpose of the Study:
- To investigate the prevalence and characteristics of ventricular late potentials (VLPs) in patients with a history of myocardial infarction (MI).
- To assess the utility of endocardial mapping for detecting VLPs in this patient cohort.
Main Methods:
- Conducted left and right heart catheterization in 45 MI patients.
- Utilized bipolar electrode catheters for endocardial mapping and signal amplification (100-10,000x).
- Recorded and visualized unfiltered endocardial signals on an oscilloscope.
Main Results:
- Ventricular late potentials (VLPs) were detected in 32 out of 45 patients (71%).
- VLPs exhibited amplitudes from 50 to 780 microV.
- Coupling intervals ranged from 80 to 620 ms from the QRS complex onset.
Conclusions:
- Endocardial mapping effectively detects ventricular late potentials (VLPs) in a significant majority of myocardial infarction patients.
- The presence of VLPs may correlate with delayed ventricular ectopic beats, suggesting an arrhythmogenic substrate.
- These findings highlight the potential of VLPs as a biomarker for risk stratification in post-MI patients.
Abstract:
Left and right heart catheterization was conducted on 45 patients with a history of myocardial infarction in order to detect so-called ventricular late potentials by means of endocardiac mapping. The endocardiac signals were amplified 100 to 10,000 times at a low noise level using bipolar electrode catheters. The signals were stored unfiltered and visualized directly on an oscilloscope. Consistently recurring late potentials were recorded after QRS complexes in 32 patients (71%). They ranged in amplitude from 50 to 780 microV, while the coupling intervals were measured in the range of 80 to 620 ms from the beginning of the QRS complex to the beginning of the late potential. In some patients, the intracardially registered and/or Holter-monitored ventricular ectopic beats occurred with a delay, corresponding to the delayed occurrence of the ventricular late potentials.