Methods
This cross-sectional study was conducted in National Center for Cardiovascular Diseases and a university hospital from November 2019 to January 2020. Seventy-two Patients (mean age: 40.90 ± 13.28), )21 patient :29.1 % male gender) who underwent right heart catheterization (RHC) were enrolled in this study. This study was approved by the Ethical Committee of the University of Medical Sciences .
Exclusion criteria were poor image quality, history of liver disease, tricuspid stenosis, equal or more than moderate TR, pericardial disease and presence of any type of arrhythmia or heart block. Patients were divided in two groups with PHTN and with normal PAP .Patients with PHTN were subdivided in two sub-groups based on the presence or absence of significant RV dysfunction. Significant RV dysfunction was defined as RV fraction area change(FAC)<20% and by visual assessment(10, 11). All patients had LVEF > 50% and were in sinus rhythm.
RHC was performed in the cardiac catheter laboratory under radiographic guidance (Siemens Medical Solutions, Erlangen, Germany). PHTN was defined as mPAP greater than or equal to 25 mmHg in RHC (12).
All subjects underwent transthoracic echocardiography (TTE) using Phillips iE33 ultrasound device equipped with an S5-1 transducer by an expert echocardiologist who was blinded to RHC results the day after RHC. An electrocardiogram and spirogram were recorded during TTE. After a complete conventional TTE, the spectral Doppler of the MHV was obtained via subcostal view. A 2-mm Pulse Wave sample volume was placed 1 to 2 cm into the MHV, proximal to its junction with the IVC. Color Doppler flow was used to obtain good alignment of ultrasound beam to the MHV flow. The velocity filter was adjusted to optimize the quality of the spectral display and to allow visualization of low-velocity waveforms. Data derived from recording of several respiratory cycles using speed of 25 mm/s. To obtain accurate morphology and measurements of HV waveform, Doppler data were traced at the speed of 75 mm/s (6,7). The measured parameters in spectral Doppler of the HV included maximal S ,V ,D and A wave velocities, the systolic velocity time integral (S VTI), diastolic VTI (D DVTI) and atrial reversal VTI (A AVTI) waves. Furthermore, time to peak and duration of all the waves were measured separately. All parameters were obtained in several respiratory cycle and averaged in five cardiac cycles during end inspiration. Furthermore, the hepatic venous systolic filling fraction [S/(S+D)], S/D and A/S ratios were also calculated.