[The prognostic significance of late potentials in patients with chronic coronary disease]
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M Almeida1, J Ferreira, L Bronze
1Serviço de Cardiologia, Hospital de Santa Cruz, Carnaxide, Portugal.
Insights
Late potentials (LP) on signal-averaged ECG (SAECG) did not predict cardiac events in long-standing coronary disease (LSCD). However, LPs were linked to a higher incidence of ventricular arrhythmias in patients with prior myocardial infarction (MI).
Area of Science:
- Cardiology
- Electrophysiology
- Diagnostic ECG
Background:
- Late potentials (LP) are established prognostic markers in the subacute phase of myocardial infarction (MI).
- The prognostic significance of LPs in patients with long-standing coronary disease (LSCD) remains unclear.
- Signal-averaged electrocardiography (SAECG) is used to detect LPs.
Purpose of the Study:
- To investigate the prognostic value of LPs detected by SAECG in patients with LSCD.
- To determine the association between the presence of LPs and the incidence of cardiac events in this population.
Main Methods:
- A case-control study involving 50 patients with LSCD and LPs, and a control group without LPs, identified from hospital records.
- Patients underwent SAECG prior to cardiac catheterization; none had recent ischemic events or revascularization.
- Follow-up data collected on ventricular arrhythmias, cardiac death, revascularization procedures, MI, and unstable angina.
Main Results:
- No statistically significant difference in the overall incidence of cardiac events was observed between groups during a mean follow-up of 20.1 months.
- A higher incidence of ventricular arrhythmic events, specifically ventricular tachycardia, was noted in the LP group (4 patients vs. 0).
- All patients experiencing ventricular tachycardia had a history of previous MI.
Conclusions:
- LPs detected by SAECG do not appear to have the same prognostic value in LSCD as in the subacute phase of MI.
- The presence of LPs in patients with LSCD and a history of MI may be associated with an increased risk of arrhythmic events.
- Further research is warranted to clarify the role of LPs in risk stratification for LSCD patients.
Objective:
The prognostic value of late potentials (LP) in the subacute phase of myocardial infarction (MI) is well known, but its prognostic value in long-standing coronary disease (LSCD) has not yet been established. In a population with LSCD we searched for a relation between the presence of LP in signal-averaged ECG (SAECG) performed before cardiac catheterization, and the incidence of cardiac events.
Methods:
Based on our department's casuistics, we selected 50 consecutive patients with coronary disease confirmed by an angiogram and LP, and a control group without LP, in SAECG. We selected 91 men and nine women with an average age of 59 +/- 8 years. None of the patients had had ischemic events or revascularization procedures, in the 3 month period before catheterization. The follow-up was made between the time of the SAECG and the last medical visit. The events recorded were: ventricular arrhythmia, cardiac death, coronary angioplasty, coronary artery by-pass graft, MI or unstable angina.
Results:
During a follow-up period of 20.1 +/- 8 months, we found no statistically significant difference between the two groups, regarding the incidence of such events. However, there was a higher incidence of ventricular arrhythmic events in the group with LP (four patients with ventricular tachycardia against none in the control group). All patients with ventricular tachycardia had had a previous MI.
Conclusions:
In this study, the presence of LP in SAECG did not have the same prognostic value found in the subacute phase of MI, but a higher incidence of arrhythmic events was observed in the group with LP and a previous MI.