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Predictive value of changes in R-wave amplitude after exercise in coronary heart disease
Insights
Changes in R-wave amplitude during exercise predict coronary events in heart disease patients. An abnormal response indicates a higher risk of myocardial infarction and cardiovascular death over six years.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Coronary heart disease (CHD) poses significant risks for cardiovascular events.
- Predictive markers for future cardiac events are crucial for risk stratification in CHD patients.
Purpose of the Study:
- To evaluate the predictive capability of R-wave amplitude changes during exercise for coronary events.
- To determine if abnormal R-wave responses correlate with increased risk in patients with documented CHD.
Main Methods:
- 146 patients with angiographically confirmed CHD were monitored for 6 years.
- Exercise-induced changes in R-wave amplitude were categorized as normal (decrease) or abnormal (no change/increase).
- Incidence of myocardial infarction and cardiovascular death was compared between groups.
Main Results:
- Patients with an abnormal R-wave response had a significantly higher incidence of coronary events (45.8%) compared to those with a normal response (23%) (p < 0.01).
- An abnormal R-wave response was associated with higher event rates in specific subgroups, including those with prior myocardial infarction and abnormal left ventricular function.
Conclusions:
- Exercise-induced R-wave amplitude changes are a valuable, noninvasive predictor of future coronary events in CHD patients.
- Incorporating R-wave amplitude assessment into risk evaluation can improve prognostication for patients with coronary heart disease.
Abstract:
To assess the predictive value of coronary events reflected by changes in R-wave amplitude after exercise, 146 patients with angiographically documented coronary heart disease were studied. All patients were followed up for 6 years, during which time myocardial infarction and death of cardiovascular origin were considered endpoints. The incidence of events in patients in whom R-wave amplitude decreased (normal response) and in those in whom R-wave amplitude did not change or increase (abnormal response) were compared. The incidence of coronary events in patients with a normal response was 23% and in those with an abnormal response, 45.8% (p less than 0.01). Correlating the results with several noninvasive and angiographic variables, an abnormal R-wave response showed a significantly higher rate of events in the subsets of patients with prior myocardial infarction, absence of cardiomegaly, maximal functional capacity lower than 4 METs, maximal heart rate higher than 140 beats/min and abnormal left ventricular function. Thus, the changes in R-wave amplitude after exercise is a variable that should be taken into account when assessing the risk of future events in patients with coronary heart disease.