Need for a standardized protocol for stress echocardiography in provoking subaortic and valvular gradient in various cardiac conditions

Abstract

(Semi) supine exercise testing has an established role in the evaluation of patients with valvular heart disease and can help clinical decision making. Stress echocardiography has the advantages of its wide availability, low cost, and versatility for the assessment of disease severity. However, exercise-induced changes in valve hemodynamics, left ventricular outflow obstruction and pulmonary artery pressure depended on load variation. Changing position from supine to upright rapidly decreases load conditions for the ventricles. Therefore several cardiac centers have proposed exercise stress echocardiography in the upright position with gradient monitoring sometimes also in post-exercise recovery. Doppler measurement of subaortic gradient has been a very helpful and informative examination in several heart diseases (especially in hypertrophic cardiomyopathy, valve heart diseases, prosthesis dysfunction).

Troponin as ischemic biomarker is related with all three echocardiographic risk factors for sudden death in hypertrophic cardiomyopathy (ESC Guidelines 2014)

“…The patients on current pharmacotherapy were examined in the following 24-h cycle as follows: 8 a.m. echocardiography with LVOTG provocation by natural stimuli (orthostatic test and Valsalva test [ 1 , 10 – 12 ]- provocable LVOTG is more preference than resting in SCD calculator [ 1 ]) day phase physical activity with probably episodes of provocable LVOTG (unmeasurable), night phase period as a potential time for the rise of troponin, which level has been measured after night at 8 a.m. So far, no studies have used the following protocol.…”

“…This protocol seems to be reasonable because hs-TnI levels may be related to the dynamic and labile nature of LVOTG with fluctuating peaks during the day time (provoked LVOTG as a potential cause for myocardial ischemia). During the first stage of our study we did not use upright exercise stress test to provoke LVOTG [ 12 ] because previous study had reported exercise-related Tn release [ 13 ].…”

The Importance of Left Ventricular Outflow Tract and Mid-Ventricular Gradients in Stress Echocardiography: A Narrative Review

“…D—Prolonged/thickened mitral leaflet(s). E—Reduced LV preload (dehydration, diuretics, vasodilators, hemodialysis, fever, septic shock, at the end of cardiac surgery when weaning extracorporeal circulation, orthostatic position) [ 3 ].…”

“… Echocardiography before exercise in a symptomatic athlete in the left lateral decubitus position and in the orthostatic position before and at the beginning of exercise [ 3 ]. …”

“…We have been performing exercise stress echocardiography (SE) with the evaluation of cardiac function while exercising on a treadmill for more than 20 years. This method has been published [ 1 ] and is also used by other groups [ 2 , 3 ]. The assessment of exercise-induced intraventricular gradients with exercise echocardiography is increasingly used in clinical practice in the evaluation of patients with hypertrophic cardiomyopathy (HCM), in part due to the current guidelines’ recommendation to estimate the presence and increasing severity of obstruction with exercise [ 4 ].…”