Methods
136 patients over the age of 18, who admitted to Akdeniz University
Hospital Cardiology Department between March 2017 and March 2018 and
were scheduled to undergo right heart catheterization(RHC) for any
reason were included the study. Patients with congenital heart disease,
who had undergone surgery due to congenital heart disease in childhood,
whose echocardiographic evaluations could not be made due to poor
echogenicity and patients with missing RHC data were excluded from the
study.
Each individual included in the study was informed about the study and a
written consent form was read and signed. The study protocol was
approved by the local ethics committee and was performed in accordance
with the Declaration of Helsinki.
RAP, RV end-diastolic pressure, RV systolic pressure, PA pressures
(systolic, mean, diastolic) and pulmonary capillary wedge pressure
(PCWP) were measured by RHC. Measurements were evaluated at the end of
expiration.
Echocardiographic examinations of the patients were performed by an
experienced specialist at the Echocardiography Laboratory of the Akdeniz
University Cardiology Department. The patients were placed in the left
lateral decubitus position. Echocardiographic evaluations were performed
in the presence of electrocardiographic rhythm monitoring. Standard
two-dimensional echocardiography, M-mode echocardiography and doppler
examinations were performed through apical, parasternal and subcostal
windows in accordance with the recommendations of the American
Echocardiography Society. Parameters were taken in accordance with these
guideline recommendations and relevant measurements were calculated
according to these guideline recommendations (10). The CS diameter was
visualized in the posterior region between LA and LV, with a slight
posterior tilting of the probe at the level of the mitral annulus in
apical 4-chamber window. Maximum and minimum diameter of CS was measured
by M-Mode echocardiography method (Figure-1). CS collapse index (CSCI)
was calculated by the following formula:
= % [(CSDmax – CSDmin)] / CSDmax x 100
CSDmax: Maximum CS diameter, CSDmin: minimum CS diameter
IVC measurements were made through a standard subcostal
echocardiographic window. The intrahepatic region where IVC joins to the
RA was visualized. After expiration, IVC’ s maximum diameter, minimum
diameter and respiratory change were measured 1-2 cm near the point
where the IVC joins the RA. IVC collapse index (IVCCI) was calculated by
the following formula:
= % [(IVCDmax – IVCDmin)] / IVCDmax x 100
IVCDmax: Maximum IVC diameter, IVCDmin: minimum IVC diameter
Body surface areas (BSA) of the patients were calculated and CS and IVC
parameters were also analyzed by indexing with BSA.
Descriptive statistics are presented with mean, percentage and standard
deviation values. Fisher’s Exact Test or Pearson’s chi-square test was
used in the analysis of the relationships between categorical variables.
In the analysis of the difference between the measurement values of the
two groups, Mann-Whitney U test was used when the distribution of the
data did not comply with the normal distribution and Student’s t test
was used if it did. Spearman correlation test was used for continuous
variables not conforming to ordered or normal distribution and Pearson
correlation test was used for continuous variables that conforming to
normal distribution. p values less than 0.05 were considered
statistically significant. In order to estimate the increase in RAP
measured by catheterization, ”Receiver-Operating Characteristic (ROC)”
curves were created for each IVC and CS parameter and optimal cut-off
values were determined from them. In addition, sensitivity, specificity,
positive and negative predictive values were found for the increased RAP
value. Study data were analyzed in ”MedCalc” and ”SPSS 25.0 for Windows”
programs.