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[Late ventricular potentials and ventricular arrhythmia in patients with stable ischemic heart disease]
W Zareba1, H Pracka, S Oszczygieł
1I Klinika Kardiologii I.K. AM w Katowicach.
Insights
Signal-averaged electrocardiograms (SA-ECG) can identify late potentials (LP) in patients with ischaemic heart disease. Abnormal SA-ECG results, particularly prolonged QRS duration, correlate with previous myocardial infarction and complex ventricular arrhythmias.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Diagnostics
Context:
- Ischaemic heart disease, especially post-myocardial infarction, increases risk of life-threatening ventricular arrhythmias.
- Late potentials (LP) are established predictors of sudden cardiac death in ventricular arrhythmia mechanisms.
- Noninvasive body surface registration of LP via signal-averaged electrocardiograms (SA-ECG) is a key diagnostic tool.
Purpose:
- To analyze SA-ECG findings in patients with stable ischaemic heart disease.
- To correlate SA-ECG results with clinical indicators like previous myocardial infarction and left ventricular function.
- To assess the relationship between SA-ECG parameters and the occurrence of ventricular arrhythmias.
Summary:
- SA-ECG was performed on 86 patients with stable ischaemic heart disease using Simson technique and quantitative criteria.
- Late potentials were detected in 19% of patients, while 20% showed abnormal SA-ECG results (often prolonged filtered QRS duration).
- Higher incidence of previous Q-wave myocardial infarctions was observed in patients with LP and abnormal SA-ECG (63% and 71% vs. 43%). Complex ventricular arrhythmias were more frequent in these groups (56% and 53% vs. 49%).
Impact:
- Abnormal SA-ECG findings, including LP, are associated with a history of myocardial infarction.
- These electrophysiological markers may indicate a higher risk for complex ventricular arrhythmias in ischaemic heart disease patients.
- SA-ECG provides valuable prognostic information for patients at risk of sudden cardiac death.
Abstract:
Ischaemic heart disease especially after previous myocardial infarction can predispose to the life-threatening ventricular arrhythmias. Late potentials (LP) are confirmed parameters predicting patients prone to sudden cardiac death in ventricular arrhythmias mechanism. Late potentials registered noninvasively from the body surface were analysed in 86 patients with stable ischaemic heart disease (67 males and 19 females aged 35-67, mean 53 years). Registration of signal average electrocardiograms (SA-ECG) were performed by Simson technic (X, Y, Z orthogonal leads) using identical analysing systems and quantitative SA-ECG criteria in all three participating centers. In all patients ventricular arrhythmias detected on 24-hour ecg Holter monitoring were assessed. The localisation of previous myocardial infarction and echocardiographic assessment of left ventricular function were also analysed in each case. The results of SA-ECG were correlated with these clinical findings. Late potentials were detected (according to two or three accepted criteria) in 16 pts (19%), in 53 pts (61%) SA-ECG were normal but in other 17 pts (20%) abnormal SA-ECG (according to only one criterium) were registered. Out of these 17 pts with abnormal SA-ECG, 14 pts had prolonged filtered QRS duration as the only incorrect SA-ECG parameter. Comparative analysis between studied groups shows higher incidence of previous Q-wave myocardial infarctions in patients with LP and with abnormal SA-ECG than in patients with normal SA-ECG (63% and 71% vs 43% respectively; p less than 0.01). Ventricular arrhythmias observed in studied patients occurred with similar frequency in all groups however in patients with LP and with abnormal SA-ECG complex ventricular arrhythmias were more common than in group with normal SA-ECG (56% and 53% vs 49% respectively: NS).(ABSTRACT TRUNCATED AT 250 WORDS)