Background: Patients with hypertrophic cardiomyopathy (HCM) have been shown to exhibit abnormal diastolic vessel flow; however, flow pattern profiles and their possible association with different grades of diastolic dysfunction have not been studied. Color Doppler 2D echocardiography permits visualization of the septal perforator arteries, and pulsed-wave Doppler allows recording of diastolic septal artery flow (SAF). Through routine visualization of the septal perforator arteries and acquisition of SAF, we noticed three patterns of SAF in patients with HCM. In this study, we aimed to assess the feasibility of the acquisition of SAF and to describe types of SAF in an HCM cohort and their associations with diastolic function.

Methods: We reviewed 2D echocardiograms and the electronic records of 108 patients with HCM in whom septal artery color and spectral Doppler had been performed. The peak diastolic and end-diastolic velocities, diastolic slope, diastolic flow time velocity integral, and systolic flow reversal of the septal perforator arteries were recorded with pulsed-wave Doppler. Echocardiographic and clinical characteristics were analyzed.

Results: A reproducible pulsed-wave Doppler tracing was recorded in 54% of patients with HCM. Three distinct patterns of SAF were identified: Type 1-smooth, linear holodiastolic velocity decrease, Type 2-with presence of an atrial dip, and Type 3-biphasic velocity decrease with an early, rapid diastolic slope and a mid-to-late gentle slope. These three SAFs correlated with different grades of diastolic dysfunction.

Conclusion: SAF could be detected in more than 50% of patients with HCM. Three distinct types of SAF were identified, correlating with different grades of diastolic dysfunction. These three types of SAF can provide additional information about left ventricular end-diastolic pressure and diastolic function in patients with HCM in whom diastolic function may be difficult to determine.