ABC | Volume 113, Nº5, November 2019

Original Article Gouveta et al. cTEE in pulmonary artery dilation in HSS Arq Bras Cardiol. 2019; 113(5):915-922 Methods Patients Twenty-nine patients with diagnosis of HSS without pulmonary hypertension were first evaluated for the presence of HPS, including the detection of IPVD by cTTE. All patients met epidemiological, clinical (hepatosplenomegaly), laboratorial (Schistosomiasis mansoni eggs in feces or rectal biopsy) and ultrasonographic criteria (periportal fibrosis) for HSS. Liver function was relatively preserved in all patients, and only one patient had ascites at clinical examination. Seven patients were excluded – two for previous splenectomy, two for pulmonary disease, one for hepatic cirrhosis, one for portal vein thrombosis and one for poor echocardiographic image quality. After the cTEE, another three patients were excluded for PFO, and the final study group was composed of 19 patients (HSS group). Seventeen (89%) patients had esophageal varices at endoscopy and previous sclerotherapy. No patient had left ventricular dysfunction, heart valve disease, suspected or proven coronary artery disease, or congenital heart disease. Demographic and clinical characteristic of HSS patients are described in Table 1. Nineteen patients who underwent cTEE for detection of embolic events were selected as control of enhancement degree of the microbubble contrast agent. Control subjects were matched for age and sex with the HSS group. No patient of the HSS group had hepatic, cardiac or pulmonary disease, or PFO at cTEE. All individuals of the HSS group and the control group had stable sinus rhythm, with normal left ventricular ejection fraction (>0.55), tricuspid regurgitation velocity (TRV) slower than 2.8 m/s 13 and absence of indirect signs of pulmonary hypertension. All subjects signed the informed consent form and the study protocol was approved by the local ethics committee. Clinical evaluation Laboratory tests were performed on blood samples from the HSS group patients for assessment of liver function, arterial blood gas analysis (sitting position, at rest and in environmental air), abdominal ultrasound, upper digestive endoscopy, chest radiography and spirometry were performed within three weeks after the cTTE. A-aO 2 was calculated using the formula: A-aO 2 = [FiO 2 x (atm-P)-PACO 2 /R] - PaO 2, where FiO 2 is the fraction of inspired oxygen; atm is the atmospheric pressure in São Paulo city (690 mmHg); P is the vapour pressure of water at 37°C = 47mmHg; PACO 2 is the alveolar pressure of carbon dioxide, assumed to be equivalent to the PaCO 2 ; R is the respiratory exchange rate (V’CO 2 /V’O 2 ), considered to be 0.8. Oxygen saturation was also measured (SatO 2 ). The diagnosis of HPS was defined as A-aO 2 greater than 15 mmHg and/or PaO 2 lower than 80 mmHg, 14 combined with the presence of IPVD detected by microbubble cTTE. Echocardiography All participants of the HSS and the control groups underwent cTTE followed by cTEE, using an HDI 7 device with 4 MHz transducer (Phillips Health Care) and a 3-7 MHz multiplane esophageal transducer, respectively. cTTE was used for structural and functional evaluation of the heart, following the American Society of Echocardiography (ASE) recommendations. 15-17 Left ventricular ejection fraction was calculated using the Simpson’s biplane method. Pulmonary arterial pressure was estimated from the tricuspid regurgitation. A contrast-enhanced test was performed by injection of saline after its manual agitation with air to create microbubbles. In the presence of IPVD, saline microbubbles appeared in the left chambers 4-6 heartbeats after their appearance in the right ventricle. An early appearance (< 3 heartbeats) was associated with intracardiac shunt, generally due to PFO, and the diagnosis was optimized by the Valsalva maneuver. The effect of the contrast agent was observed in the apical four chamber view and classified as present (positive contrast echocardiogram) or absent (negative contrast echocardiogram), without graduating the intensity (Figure 1). None of the control subjects showed a positive contrast test at cTTE. In the cTTE, midazolam and fentanyl were used for sedation with continuous monitoring of SatO­ 2 , heart rhythm, and systemic blood pressure during the procedure, following well-established methods. 18 Valsalva maneuver was performed whenever possible. Esophageal varices were not considered contraindications to cTTE, except in the presence of active or evidence of recent bleeding (<15 days). After injection of agitated saline, contrast in the left atrium was quantified according to the classification proposed by Vedrinne et al. 10 and modified by us: grade 0: no microbubbles; grade I (minimal) = occasional and punctiform microbubbles; grade II (mild) = the microbubble signal was unclear and diffuse, with incomplete opacification of the left atrium; grade III (moderate) = many microbubbles with homogeneous opacification of the left atrium, but with lower intensity than the right atrium; and grade IV (significant) = homogeneous distribution of the microbubbles between the two atria (Figure 2). Statistical analysis Continuous variables were described as mean and standard deviation, or median and interquartile ranges. Categorical variables were described as proportions. The Student’s t-test was used for comparison of continuous variables between the groups, and the chi-square test, the Pearson’s test and the Fisher’s exact test used to compare the frequencies of categorical variables when necessary. A p < 0.05 was set for statistical significance. Results Patients with HSS showed normal parameters of cardiac structure (chamber size, left ventricular mass and thickness), preserved systolic and diastolic functions (ejection fraction of 0.67 ± 0.04) and pulmonary systolic pressure of 27 ± 3 mmHg (TRV= 2.34 ± 0.14 m/s) at cTTE, which was performed without complications in all HSS patients. There was no case of hypoxia, arrythmia, neurological complications or upper gastrointestinal bleeding. 916