MATERIALS AND METHODS
Patient Data. This prospective study included 73 adult
patients referred clinically indicated left heart catheterization who
also had transthoracic echocardiography (TTE) immediately before
catheterization. ST-elevation and non-ST elevation myocardial infarction
(MI), EF< %50, moderate to severe aortic and mitral
regurgitation, and moderate to severe aortic and mitral stenosis were
excluded. The medical histories, including all clinical and demographic
data, were obtained from the electronic medical records. Laboratory
results received within 24hrs before catheterization were obtained. The
study protocol was reviewed and approved by the ethical committee.
Transthoracic Echocardiography. Two-dimensional
echocardiographic imaging was performed in 73 patients who met the
clinical criteria for study inclusion at Ankara University Cardiology
Department Two-dimensional, color flow, continuous-pulse wave, and
tissue Doppler TTE were performed by two experienced physicians using
Vivid E9 imaging system (with an M5Sc-D transducer; GE Medical Systems,
Chicago, USA) within 24hrs before left heart catheterization and
measurements obtained in a standard manner as recommended by the
American Society of Echocardiography. LV dimensions were measured in the
parasternal long-axis view at end-systole and end-diastole. LV ejection
fraction was calculated from 4 chamber view using the modified Simpson
method.
TTE parameters assessed LV diastolic function. Diastolic filling
periods, including rapid filling, diastasis, and atrial contraction,
were assessed by pulsed wave (PW) Doppler. Mitral inflow at the level of
mitral valve leaflet tips was used to measure the peak early (E-wave)
and late (A-wave) diastolic flow velocities and calculate the E/A ratio.
Besides, tissue Doppler imaging (TDI) using PW was performed with the
sample volume at the lateral and septal mitral annulus to obtain lateral
e’ and medial e’ velocities. The arithmetic mean of lateral and medial
e’ were defined as average e’, which was used to calculate the E/e’
ratio. Peak velocity of the tricuspid regurgitation (TR) jet was
measured using continuous-wave Doppler. Left atrial volume was measured
using a 4-chamber view and divided body surface area (BSA) to calculate
the left atrial volume index (LAVi).
Speckle tracking 2D LV longitudinal strain . Speckle tracking 2D
LV longitudinal average and the regional strain was measured using
automated functional imaging (AFI). AFI was performed in 73 patients
using an E9 imaging system (with a 4V-D transducer; GE Medical Systems,
Chicago, USA) and transferred to Echo Pac imaging workstation (Echo Pac
imaging system). LV longitudinal strain was performed according to
standardized measurements recommended by the 2015 ASE Cardiac Chamber
Quantification guideline.
LV catheterization. Left heart catheterization was performed
according to the standard procedure by an interventional cardiologist
blinded to the echocardiographic data. Invasive LV systolic and
diastolic pressure measurements were performed using a 6-Fr pigtail
catheter (Boston Scientific, Marlborough, MA) placed in the left
ventricle through the femoral or radial artery before the evaluation of
coronary artery visualization. The measurements were obtained after the
fluid-filled transducer was balanced with the zero level at the
mid-axillary line. Continuous pressure tracings were acquired at least
three consecutive respiratory cycles. LV pre-A pressure, which
corresponds to the mean left atrial pressure(LAP) used as LV filling
pressure recommended in the 2016 ASE/EACVI algorithm, and Pre-A pressure
>12 mm Hg confirmed as elevated LV filling pressure.