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Left ventricular functional reserve in nonobstructive hypertrophic cardiomyopathy: evaluation by continuous left
J Taki1, K Nakajima, M Shimizu
1Department of Nuclear Medicine, Kanazawa University School of Medicine, Japan.
Insights
Patients with nonobstructive hypertrophic cardiomyopathy (HCM) often show left ventricular dysfunction during exercise. The cadmium telluride detector (CdTe-VEST) effectively monitors cardiac function in these patients.
Area of Science:
- Cardiology
- Medical Imaging
- Exercise Physiology
Background:
- Hypertrophic cardiomyopathy (HCM) can affect cardiac function.
- Nonobstructive HCM presents unique challenges in assessing exercise response.
- Evaluating left ventricular functional reserve is crucial for patient management.
Purpose of the Study:
- To assess the cardiac functional response to exercise in patients with nonobstructive HCM.
- To evaluate the utility of a continuous ventricular function monitor (CdTe-VEST) in this population.
- To identify patterns of left ventricular dysfunction during exercise and recovery.
Main Methods:
- Utilized a continuous ventricular function monitor with a cadmium telluride detector (CdTe-VEST).
- Monitored 41 patients with nonobstructive HCM and 15 healthy controls during supine ergometric exercise.
- Categorized HCM patients into two groups based on ejection fraction (EF) response at peak exercise.
Main Results:
- Left ventricular dysfunction during exercise and recovery was frequently observed in nonobstructive HCM patients.
- Patients with no EF increase at peak exercise (Group B) had higher resting EF but showed impaired recovery.
- ST-segment depression was more prevalent in Group B, suggesting exercise intolerance.
Conclusions:
- Left ventricular dysfunction during exercise in nonobstructive HCM is common and not solely related to septal hypertrophy.
- The CdTe-VEST is a valuable tool for assessing left ventricular functional reserve during exercise in HCM.
- Findings highlight the importance of monitoring cardiac function during exercise in nonobstructive HCM.
Unlabelled:
The cardiac functional response to exercise in patients with nonobstructive hypertrophic cardiomyopathy (HCM) was evaluated using a continuous ventricular function monitor with a cadmium telluride detector (CdTe-VEST).
Methods:
Supine ergometric exercise was performed under CdTe-VEST monitoring in 41 patients with nonobstructive HCM (34 men and 7 women, age 18-72 yr, mean 51 yr) and 15 patients without cardiac disease (9 men and 6 women, age 36-56 yr, mean 49 yr).
Results:
Although 20 of 41 patients with HCM maintained a LVEF above baseline at peak exercise (Group A), 21 did not show an EF increase at peak exercise (Group B). Exercise duration and work load in Group A were longer and higher, respectively, than in Group B. Resting EF in Group B (72 +/- 7.7%) was significantly higher than that in Group A (65 +/- 8.2%) and the control group (62 +/- 5.9%). The EF increase from baseline to EF overshoot during recovery and the time to EF overshoot were lower and longer, respectively, in Group B than in Group A and the control group. Septal wall thickness and the septum-to-posterior-wall-thickness ratio between Groups A and B were not different. ST-segment depression was observed in all 21 Group B patients and in 8 of the Group A patients.
Conclusion:
In patients with nonobstructive HCM, left ventricular dysfunction during exercise and during recovery was frequently observed but was not related to the degree of septal wall hypertrophy. The CdTe-VEST is a useful means to evaluate left ventricular functional reserve to exercise in patients with HCM.