Doppler flow velocity profile of the left anterior descending in a patient with hypertrophic cardiomyopathy and markedly elevated left ventricular end-diastolic pressure: a novel observation.

Abstract

Left anterior descending (LAD) coronary artery blood flow predominantly occurs in diastole and depends on the pressure differential across the myocardium, referred to as the coronary perfusion pressure (CPP). LAD flow can be visualized using two-dimensional/Doppler echocardiography. Restrictive diastolic filling patterns were previously described in the coronary artery Doppler profile as the ‘Doppler square root sign’ [EHJ CVI. 2017; 18(9):1067. doi: 10.1093/ehjci/jex061]. We present a case of a 44-year-old male with hypertrophic cardiomyopathy and no left ventricular outflow tract obstruction. The echocardiogram demonstrated septal wall thickness of 35 mm (Panel A), normal left ventricular ejection fraction (75%), impaired global longitudinal strain (−10%) (Panel B), and grade II diastolic dysfunction with a left atrial volume index of 56 mL/m2, E/A ratio 1.9 (Panel C), and septal e’ velocity 0.05 m/s. Further assessment of diastology revealed a mitral A wave duration of 120 ms (Panel D) and a pulmonary venous A wave duration of 220 ms (Panel E). The difference between the venous and transmitral A wave durations was 100 ms (normal < 30 ms). This degree of difference in the duration of flows is consistent with and indicative of a marked increase in left ventricular end-diastolic pressure (LVEDP). The LAD pulsed wave doppler flow (Panel F) profile (Panel G, see Supplementary data online, Video S1) demonstrated a transient reduction in end-diastolic velocity (‘a’ dip), which correlated with a decrease in CPP secondary to elevated LVEDP from a powerful atrial contraction, indeed a novel observation. Also noted is a small systolic flow reversal.