From the Guidelines
For patients with septal hypertrophy, an exercise echocardiogram is the recommended stress test. This test combines standard exercise stress testing (typically on a treadmill or stationary bicycle) with echocardiographic imaging before, during, and after exercise 1. The exercise echocardiogram is particularly valuable because it can directly visualize the dynamic changes in the septum during physical exertion, allowing assessment of left ventricular outflow tract obstruction that may worsen with exercise. Additionally, it can evaluate exercise-induced wall motion abnormalities, changes in ejection fraction, and the development or worsening of mitral regurgitation.
Some key points to consider when selecting a stress test for patients with septal hypertrophy include:
- The ability to exercise: If a patient cannot exercise, a pharmacological stress echocardiogram using dobutamine can be considered as an alternative 1.
- The presence of abnormalities on the resting ECG: In patients with important abnormalities on their resting ECG (eg, left bundle-branch block, LV hypertrophy with “strain” pattern, or digitalis effect), stress cardiac imaging should be considered 1.
- The need for detailed anatomical information: Nuclear stress testing is generally less preferred because it doesn't provide the same detailed anatomical information about septal dynamics 1.
The test should be performed under careful medical supervision, with appropriate monitoring of blood pressure and heart rhythm, as patients with significant septal hypertrophy may be at risk for arrhythmias or hemodynamic compromise during stress testing 1.
From the Research
Septal Hypertrophy and Stress Test Recommendations
To determine the best stress test for a patient with septal hypertrophy, several factors must be considered, including the presence of symptoms, the severity of the hypertrophy, and the presence of any obstructive lesions.
- The study 2 suggests that exercise echocardiography can be useful in assessing for latent left ventricular outflow tract (LVOT) obstruction in patients with basal septal hypertrophy.
- Another study 3 found that intraoperative dobutamine stress echocardiography can be useful in unmasking occult LVOT gradients and confirming adequate myectomy in patients undergoing septal myectomy.
- The study 4 proposes criteria for diagnosing pathologic basal septal hypertrophy, including exertional symptoms, documented LVOTO gradient, and symptomatic improvement with beta-blocker therapy.
Types of Stress Tests
The following types of stress tests may be recommended for patients with septal hypertrophy:
- Exercise echocardiography: This test can help assess for latent LVOT obstruction and evaluate the patient's symptoms during exercise.
- Dobutamine stress echocardiography: This test can be useful in unmasking occult LVOT gradients and confirming adequate myectomy in patients undergoing septal myectomy.
- Orthostatic stress test: This test can help assess the patient's LVOT gradient in response to changes in posture.
Considerations
When selecting a stress test for a patient with septal hypertrophy, the following considerations should be taken into account:
- The presence of symptoms, such as exertional dyspnea or chest discomfort
- The severity of the hypertrophy and the presence of any obstructive lesions
- The patient's ability to undergo exercise or other forms of stress testing
- The need for close monitoring and supervision during the stress test to ensure the patient's safety.