Related Experiment Videos
[Treadmill exercise test in patients with hypertrophic cardiomyopathy with and without coronary artery disease]
1Department of Medicine, Kawasaki Medical School.
Insights
The treadmill exercise test effectively distinguishes hypertrophic cardiomyopathy (HCM) patients with coronary artery narrowing. The delta ST/delta HR index showed high sensitivity and specificity for diagnosing significant coronary artery stenosis in HCM patients.
Area of Science:
- Cardiology
- Exercise Physiology
- Diagnostic Imaging
Background:
- Hypertrophic cardiomyopathy (HCM) can present with chest pain, mimicking ischemic heart disease.
- Coronary artery abnormalities are found in a subset of HCM patients.
- Differentiating true coronary artery narrowing from HCM-related changes is clinically important.
Purpose of the Study:
- To evaluate the diagnostic utility of the treadmill exercise test in patients with hypertrophic cardiomyopathy (HCM) and chest pain.
- To compare the extent of exercise-induced myocardial ischemia between HCM patients with normal versus stenotic coronary arteries.
- To identify specific exercise test parameters that can differentiate these two groups.
Main Methods:
- Thirty-one patients with HCM were divided into two groups: normal coronary arteries (n=21) and significant coronary artery narrowing (n=11).
- All patients underwent a treadmill exercise test.
- Key parameters including treadmill time, systolic blood pressure changes (delta SBP), ST depression (delta ST), and the ratio of ST depression to heart rate change (delta ST/delta HR) were analyzed.
Main Results:
- Patients with coronary stenosis exhibited shorter treadmill times (338 vs 542 seconds, p<0.05).
- Significant delta ST depression (0.17 vs 0.05 mV, p<0.05) and higher delta ST/delta HR values (3.3 vs 0.7 microV.min/beats) were observed in the coronary stenosis group.
- A delta ST/delta HR ratio ≥ 2.0 demonstrated 90% sensitivity and specificity for diagnosing significant coronary artery narrowing in HCM patients.
Conclusions:
- Treadmill exercise elicits more severe myocardial ischemia in HCM patients with significant coronary artery narrowing compared to those with normal coronary arteries.
- The delta ST/delta HR index is a highly effective parameter for diagnosing significant coronary artery narrowing in the context of HCM.
- Exercise testing can aid in differentiating coronary artery disease in HCM patients presenting with chest pain.
Abstract:
We studied whether the treadmill exercise test can discriminate between normal and significant narrowing of coronary arteries in patients with hypertrophic cardiomyopathy (HCM) accompanied with chest pain, and we compared the extent of myocardial ischemia during exercise. Thirty one patients with HCM were divided into two groups; 21 with normal coronary arteries and 11 with significant narrowing of coronary arteries. The treadmill exercise test was carried out in both groups. The following parameters were more frequently seen in the group with coronary stenosis. (1) short treadmill time (338, sec vs 542, p less than 0.05). (2) delta SBP less than or equal to 60 mmHg (delta: end point minus rest, 10 cases vs 12, 0.05 less than p less than 0.1). (3) significant delta ST depression (0.17 mV vs 0.05, p less than 0.05). (4) large delta ST/delta HR (3.3 microV.min/beats vs 0.7). delta ST/delta HR greater than or equal to 2.0 was the most useful for differentiating the two groups, and it was 90% in index both sensitivity and specificity for diagnosis of HCM with significant narrowing of the coronary arteries. It was concluded that treadmill exercise induced more severe myocardial ischemia in patients with HCM who had significant narrowing of the coronary arteries than in patients with HCM who had angiographically normal coronary arteries. The delta ST/delta HR was the most useful index for diagnosis of HCM with significant narrowing of the coronary arteries.