Related Experiment Videos
[Late cellular potentials in patients after myocardial infarction--a result of left ventricular diastolic
L Kubik1, A Cwetsch, A Skrobowski
1Klinika Chorób Wewnetrznych i Kardyiologii CSK WAM.
Insights
This study reveals a link between late potentials (LP) and left ventricular diastolic dysfunction after myocardial infarction. LP presence correlates with impaired left ventricular filling patterns, suggesting diastolic dysfunction contributes to arrhythmogenesis.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Imaging
Background:
- Left ventricular dysfunction is linked to arrhythmogenesis, but research has focused on systolic dysfunction.
- Contradictory findings necessitate further investigation into the relationship between late potentials (LP) and diastolic dysfunction.
Purpose of the Study:
- To investigate the association between late potentials (LP) and left ventricular diastolic dysfunction in patients post-myocardial infarction.
- To determine if diastolic dysfunction parameters correlate with the presence and characteristics of LPs.
Main Methods:
- Signal-averaged electrocardiography (SAECG) and echocardiography (ECHO) were performed on 56 post-myocardial infarction patients.
- Late potentials (LP) were defined using SAECG criteria (abnormal QRS duration, low amplitude signal duration, and low root mean square voltage).
- Echocardiographic parameters assessed included E/A wave ratio, left ventricular end-diastolic volume (LVEDV), ejection fraction (EF), acceleration (AT), and deceleration times (DT).
Main Results:
- Patients with LPs (Group I) showed significantly higher E wave velocity and E/A ratio compared to those without LPs (Group II).
- No significant differences were found in age, EF, heart rate, A wave velocity, AT, isovolumetric relaxation time (IVRT), or LVEDV between groups.
- In LP-positive patients, significant correlations were observed between E wave, E/A ratio, AT, DT, and QRS duration, as well as DT and LPD, and IVRT and RMS40.
Conclusions:
- The incidence of LPs in post-myocardial infarction patients is associated with the degree of left ventricular filling patterns, particularly impaired relaxation.
- LP-positive patients exhibit a predominant restrictive left ventricular filling pattern, correlating with specific SAECG variables (filtered QRS time and RMS40 amplitude).
- These findings suggest that left ventricular diastolic dysfunction, indicated by specific filling patterns, plays a role in arrhythmogenesis in post-MI patients.
Abstract:
The link between left ventricular dysfunction and arrhythmogenesis is commonly known. However, so far, only the systolic left ventricular dysfunction has been evaluated. Because of the controversial results of those studies, we decided to assess if is there a link between late potentials (LP) and left ventricular diastolic dysfunction. Our material consisted of 56 patients: 11 women and 45 men, mean age was 61.12 +/- 10.07 years. Signal averaged ECG and ECHO were performed in each patient, 2-3 months after myocardial infarction. For high pass filter of 40 Hz, LP were defined as 2 or 3 abnormal SAECG variables (the averaged QRS > 114 ms, the low amplitude signal duration LAS > 38 ms and root mean square voltage of the terminal 40 ms RMS40 < 20 microV). During ECHO study, we assessed E and A waves E/A ratio, left ventricular end-diastolic volume (LVEDV), ejection fraction (EF), acceleration (AT) and deceleration times (DT). The patients were divided into 2 groups: group I-30 patients LP positive and group II-26 patients LP negative. There were no significant differences between the groups in terms of age, EF, and heart rate. We presented significant differences between group I and II in terms of E wave velocity (0.75 +/- 0.19 vs 0.64 +/- 0.19 p < 0.03) E/A ratio (2.13 +/- 1.56 vs 1.0 +/- 0.5 p < 0.05) respectively. We did not confirm significant differences as regards A wave velocity, AT, isovolumetric time (IVRT) and LVEDV between both tested groups. In group I we revealed a significant correlation between E wave (r = 0.45), E/A ratio (r = 0.62), AT (r = -0.42) E/A ratio (r = 0.56), DT (r = 0.55) and QRS, as well as DT and LPD (r = 0.40) and between IVRT and RMS40 (r = -0.43). The results of our study suggest that in patients after myocardial infarction: 1/incidence of LP depends on the degree of left ventricular filling pattern like in impaired relaxion, quite well correlated with filtered QRS time 3/in LP positive patients there was predominance of restrictive left ventricular filling pattern, quite well correlation with RMS40 amplitude.