Effort angina, normal coronary angiogram, and dynamic left ventricular obstruction

Area of Science:

• Cardiology
• Cardiovascular Physiology
• Diagnostic Imaging

Background:

• Dynamic left ventricular outflow tract obstruction (DLVOTO) is infrequently reported in patients without hypertrophic cardiomyopathy.
• The clinical significance and underlying mechanisms of DLVOTO during exertion remain unclear.
• Effort-induced angina with normal coronary arteries presents a diagnostic challenge.

Purpose of the Study:

• To investigate the occurrence of DLVOTO during exercise in patients presenting with angina and unobstructed coronary arteries.
• To identify potential mechanisms and clinical predictors associated with DLVOTO in this specific patient cohort.
• To analyze the relationship between LVOT dimensions and the development of DLVOTO.

Main Methods:

• Exercise echocardiography was performed on 23 patients (mean age 60.7 years) experiencing effort angina and having normal coronary arteries.
• Patients were monitored for the development of DLVOTO and associated pressure gradients during exercise.
• Statistical analysis was employed to determine predictive factors for DLVOTO, focusing on LVOT size.

Main Results:

• DLVOTO was observed in 7 patients (30.4%), with exercise-induced gradients ranging from 31.1 to 67.2 mm Hg.
• Patients with DLVOTO reported significantly more exertional angina symptoms compared to those without (100% vs 47.3%, P = .014).
• A smaller left ventricular outflow tract (LVOT) size (9.1 +/- 0.5 mm/m(2)) was the sole significant predictor of DLVOTO (P = .017).

Conclusions:

• DLVOTO during exercise can occur in patients with angina and normal coronary arteries.
• A reduced LVOT size is a key factor associated with the development of DLVOTO in this population.
• These findings suggest a potential mechanism for exertional symptoms in patients with seemingly normal coronary arteries.