Range of tricuspid regurgitation velocity at rest and during exercise in normal adult men: implications for the diagnosis of pulmonary hypertension

Exercise Stress Echocardiography of the Right Ventricle and Pulmonary Circulation

BACKGROUND

Exercise echocardiography is used for assessment of pulmonary circulation and right ventricular function, but limits of normal and disease-specific changes remain insufficiently established.

OBJECTIVES

The objective of this study was to explore the physiological vs pathologic response of the right ventricle and pulmonary circulation to exercise.

METHODS

A total of 2,228 subjects were enrolled: 375 healthy controls, 40 athletes, 516 patients with cardiovascular risk factors, 17 with pulmonary arterial hypertension, 872 with connective tissue diseases without overt pulmonary hypertension, 113 with left-sided heart disease, 30 with lung disease, and 265 with chronic exposure to high altitude. All subjects underwent resting and exercise echocardiography on a semirecumbent cycle ergometer. All-cause mortality was recorded at follow-up.

RESULTS

The 5th and 95th percentile of the mean pulmonary artery pressure-cardiac output relationships were 0.2 to 3.5 mm Hg.min/L in healthy subjects without cardiovascular risk factors, and were increased in all patient categories and in high altitude residents. The 5th and 95th percentile of the tricuspid annular plane systolic excursion to systolic pulmonary artery pressure ratio at rest were 0.7 to 2.0 mm/mm Hg at rest and 0.5 to 1.5 mm/mm Hg at peak exercise, and were decreased at rest and exercise in all disease categories and in high-altitude residents. An increased all-cause mortality was predicted by a resting tricuspid annular plane systolic excursion to systolic pulmonary artery pressure <0.7 mm/mm Hg and mean pulmonary artery pressure-cardiac output >5 mm Hg.min/L.

CONCLUSIONS

Exercise echocardiography of the pulmonary circulation and the right ventricle discloses prognostically relevant differences between healthy subjects, athletes, high-altitude residents, and patients with various cardio-respiratory conditions. (Right Heart International NETwork During Exercise in Different Clinical Conditions; NCT03041337).

Tricuspid regurgitation and left ventricular eccentricity as a measure of heart failure in the newborn patient with a vein of Galen malformation: illustrative case

BACKGROUND

Successful management of a vein of Galen malformation (VoGM) in the newborn patient requires a highly coordinated team approach involving neonatologists, pediatric cardiologists, pediatric neurologists, neurosurgeons, and interventionalists. Indication and timing of catheter intervention are topics of ongoing debate.

OBSERVATIONS

The authors highlighted two key echocardiographic markers believed to be practical indicators regarding the need for urgent catheter embolization in neonates with a VoGM. The first and preferred parameter was the tricuspid valve regurgitation (TR) gradient, an estimate of pulmonary artery hypertension. If the TR gradient exceeds systolic blood pressure (suprasystemic pulmonary hypertension [PH], i.e., >60 mm Hg), urgent intervention should be considered in eligible newborns. The second parameter was the left ventricular end-systolic eccentricity index (EI), a newly emerging echocardiographic marker and indirect correlate of PH. As an alternative to the TR gradient, an increased eccentricity index (>1.6) suggests severe right heart compromise, requiring emergency catheter embolization of the malformation. Postoperatively, the progressive reduction of both the TR gradient and the EI correlated with recovery.

LESSONS

In eligible newborns, urgent embolization of a VoGM is recommended in the presence of suprasystemic TR gradients and/or increased EI >1.6.

Prevalence of pulmonary hypertension on echocardiogram in children with severe obstructive sleep apnea

STUDY OBJECTIVES

Pulmonary hypertension (PH) is a rare yet serious complication of obstructive sleep apnea (OSA). Echocardiographic screening for PH is recommended in children with severe OSA, but the health care burden of universal screening is high. We sought to determine the prevalence of PH on echocardiogram among children with severe OSA and identify variables associated with a positive PH screen.

METHODS

Retrospective study of 318 children with severe OSA (obstructive apnea-hypopnea index ≥ 10 events/h) and echocardiogram within 1 year of polysomnogram. PH-positive echocardiogram was defined by peak tricuspid regurgitation velocity ≥ 2.5 m/s and/or 2 or more right-heart abnormalities suggestive of elevated pulmonary artery pressure. Patient characteristics and polysomnogram data were compared to identify factors associated with PH.

RESULTS

Twenty-six children (8.2%; 95% confidence interval [CI] 5.4-11.8%) had echocardiographic evidence of PH. There was no difference in age, sex, body mass index, obstructive apnea-hypopnea index, or oxygenation indices between patients with and without PH. Sleep-related hypoventilation (end-tidal CO₂ > 50 mmHg for > 25% of total sleep time) was present in 25% of children with PH compared with 6.3% of children without PH (adjusted prevalence ratio = 2.73; 95% CI 1.18-6.35). Forty-six percent of children (12/26) with PH had Down syndrome vs 14% (41/292) without PH (adjusted prevalence ratio = 3.11; 95% CI 1.46-6.65).

CONCLUSIONS

There was a relatively high prevalence of PH on echocardiogram in our cohort of children with severe OSA. The findings of increased PH prevalence among children with sleep-related hypoventilation or Down syndrome may help inform the development of targeted screening recommendations for specific pediatric OSA populations.

CITATION

Maloney MA, Davidson Ward SL, Su JA, et al. Prevalence of pulmonary hypertension on echocardiogram in children with severe obstructive sleep apnea. J Clin Sleep Med. 2022;18(6):1629-1637.

Right Heart Pulmonary Circulation Unit Response to Exercise in Patients with Controlled Systemic Arterial Hypertension: Insights from the RIGHT Heart International NETwork (RIGHT-NET)

Background. Systemic arterial hypertension (HTN) is the main risk factor for the development of heart failure with preserved ejection fraction (HFpEF). The aim of the study was was to assess the trends in PASP, E/E’ and TAPSE during exercise Doppler echocardiography (EDE) in hypertensive (HTN) patients vs. healthy subjects stratified by age. Methods. EDE was performed in 155 hypertensive patients and in 145 healthy subjects (mean age 62 ± 12.0 vs. 54 ± 14.9 years respectively, p < 0.0001). EDE was undertaken on a semi-recumbent cycle ergometer with load increasing by 25 watts every 2 min. Left ventricular (LV) and right ventricular (RV) dimensions, function and hemodynamics were evaluated. Results. Echo-Doppler parameters of LV and RV function were lower, both at rest and at peak exercise in hypertensives, while pulmonary hemodynamics were higher as compared to healthy subjects. The entire cohort was then divided into tertiles of age: at rest, no significant differences were recorded for each age group between hypertensives and normotensives except for E/E’ that was higher in hypertensives. At peak exercise, hypertensives had higher pulmonary artery systolic pressure (PASP) and E/E’ but lower tricuspid annular plane systolic excursion (TAPSE) as age increased, compared to normotensives. Differences in E/E’ and TAPSE between the 2 groups at peak exercise were explained by the interaction between HTN and age even after adjustment for baseline values (p < 0.001 for E/E’, p = 0.011 for TAPSE). At peak exercise, the oldest group of hypertensive patients had a mean E/E’ of 13.0, suggesting a significant increase in LV diastolic pressure combined with increased PASP. Conclusion. Age and HTN have a synergic negative effect on E/E’ and TAPSE at peak exercise in hypertensive subjects.

Atrial electromechanical delay, neutrophil-to-lymphocyte ratio, and echocardiographic changes in patients with acute and stable chronic obstructive pulmonary disease

Background:

Atrial electromechanical delay (AEMD) is the time interval between the beginning of P wave on surface electrocardiography and starting of the late diastolic wave on tissue Doppler imaging. We investigated the prolongation of AEMD, echocardiographic changes, and correlation of these findings with neutrophil-to-lymphocyte ratio (NLR) in patients with chronic obstructive pulmonary disease (COPD).

Materials and Methods:

The study consisted of 105 (49 females and 56 males; mean age: 65.1 ± 9) patients with COPD exacerbation and 104 (21 females and 83 males; mean age: 64.8 ± 9.6) stable COPD outpatients. Demographics, body mass index, pulmonary function tests, and transthoracic echocardiography of the patients were evaluated. Echocardiography was performed in the first 6 h for stable COPD outpatients and in the first 24 h for COPD exacerbation patients. Diameters of right ventricle (RV), left ventricle (LV) and left atrium, aortic root diameters, left ventricular ejection fraction (LVEF), E_max, A_max, E_max/A_max, tricuspid annular plane systolic excursion (TAPSE), Ea, Aa, Ea/Aa, E_max/Ea, and tricuspid regurgitation velocity (TRV) were evaluated. AEMD measurements were obtained from lateral/tricuspid, lateral/mitral, and septal annulus from apical four-chamber views with tissue Doppler imaging and corrected for heart rate. Complete blood count including NLR was also assessed.

Results:

The mean age of patients in exacerbation period (65.1 ± 9) was higher than the stable group (64.8 ± 9.6). RV basal and mid diameters (P < 0.001), A_max (P < 0.001), Ea tricuspid (P = 0.040), Aa tricuspid (P < 0.001), TRV, and systolic pulmonary artery pressure (P < 0.001) were higher; TAPSE and tricuspid E_max/A_max (P < 0.001) were significantly lower in patients with COPD exacerbation. LV end-diastolic diameter (P = 0.002) and LVEF (P = 0.005), E_max/A_max mitral (P < 0.001), Ea/Aa mitral (P < 0.001), and Ea/Aa septal (P < 0.001) were significantly lower; A_max mitral (P = 0.002), Aa mitral (P < 0.001), Aa septal (P < 0.001), and systolic motion mitral (P = 0.011) were significantly higher in patients with exacerbation. AEMD lateral/tricuspid (P < 0.001), lateral/mitral (P < 0.001), and septal (P < 0.001) were significantly higher in patients with COPD exacerbation. Neutrophil and lymphocyte count (P < 0.001) and NLR (P = 0.003) were significantly higher in the acute group. A weak correlation of NLR with LV end-diastolic diameter (P = 0.003; r = 0.357), E_max/Ea mitral (P = 0.019; r = 0.285), E_max tricuspid (P = 0.045; r = −0.244), and systolic motion septal (P = 0.003; r = 0.352) was detected in patients with stable COPD.

Conclusion:

In COPD exacerbation patients, prolongation of AEMD intervals was determined. Acute period of COPD may trigger atrial dysrhythmias including atrial fibrillation and flutter, multifocal atrial tachycardia, premature beats, and both systolic and diastolic dysfunctions frequently.

Impact of aerobic training periodisation on global and regional right ventricular strain in coronary heart disease

Linear aerobic training periodisation (LP) is recommended for patients with coronary heart disease (CHD). However, the effects of training periodisation on the right heart mechanics in patients with CHD have never been examined. This study aimed to explore the effects of LP and non-linear periodisation (NLP) on right heart mechanics. We prospectively randomised CHD patients to 12 weeks of aerobic training with LP or NLP. While there was a weekly increase in energy expenditure with LP, there was a steeper increase during the first 3 weeks, followed by a decrease in the fourth week with NLP. Echocardiography was performed at baseline and after the training period to assess the right ventricular free wall (RVFW) and right atrial strain. Thirty patients with CHD were included (NLP, n = 16; LP, n = 14). The traditional right and left heart parameters showed no significant time effects. There was a decrease of RVFW strain with time in both groups (+1.3 ± 0.9% with NLP, and +1.5 ± 0.8% with LP; p = 0.033). Mid-ventricular RVFW strain changed significantly with time (+2.0 ± 1.3% with NLP, and from +2.3 ± 1.2% with LP; p = 0.025). There was no time effect on the right atrial strain. In stable CHD patients, LP and NLP resulted in right ventricular strain decrements with a segment-specific pattern. This study was registered at ClinicalTrials.gov (identifier number: NCT03414996). Novelty: In stable coronary heart disease patients, both linear and non-linear aerobic training periodisation programs result in right ventricular strain decrements with time, particularly in the mid-ventricular segment. Traditional right and left heart parameters and right atrial strain showed no significant time effect in both 12 weeks aerobic training periodisation programs.

Measures of Left Ventricular Diastolic Function and Cardiorespiratory Fitness According to Glucose Metabolism Status: The Maastricht Study

Background

This cross‐sectional study evaluated associations between structural and functional measures of left ventricular diastolic function and cardiorespiratory fitness (CRF) in a well‐characterized population‐based cohort stratified according to glucose metabolism status.

Methods and Results

Six hundred seventy‐two participants from The Maastricht Study (mean±SD age, 61±9 years; 17.4% prediabetes and 25.4% type 2 diabetes mellitus) underwent both echocardiography to determine left atrial volume index, left ventricular mass index, maximum tricuspid flow regurgitation, average e′ and E/e′ ratio; and submaximal cycle ergometer test to determine CRF as maximum power output per kilogram body mass. Associations were examined with linear regression adjusted for cardiovascular risk and lifestyle factors, and interaction terms. After adjustment, in normal glucose metabolism but not (pre)diabetes, higher left atrial volume index (per 1 mL/m²), left ventricular mass index (per 1 g/m^2.7), maximum tricuspid regurgitation flow (per 1 m/s) were associated with higher CRF (maximum power output per kilogram body mass; β in normal glucose metabolism 0.015 [0.008–0.023], P_interaction (pre)diabetes <0.10; 0.007 [−0.001 to 0.015], P_interaction type 2 diabetes mellitus <0.10; 0.129 [0.011–0.246], P_interaction >0.10; for left atrial volume index, left ventricular mass index, maximum tricuspid regurgitation flow, respectively). Furthermore, after adjustment, in all individuals, higher average E/e′ ratio (per unit), but not average e′, was associated with lower CRF (normal glucose metabolism −0.044 [−0.071 to −0.016]), P_interaction >0.10).

Conclusions

In this population‐based study, structural and functional measures of left ventricular diastolic function were independently differentially associated with CRF over the strata of glucose metabolism status. This suggests that deteriorating left ventricular diastolic function, although of small effect, may contribute to the pathophysiological process of impaired CRF in the general population. Moreover, the differential effects in these structural measures may be the consequence of cardiac structural adaptation to effectively increase CRF in normal glucose metabolism, which is absent in (pre)diabetes.

Stress Testing in Heart Failure with Preserved Ejection Fraction

Exertional dyspnea is the most common symptom in patients with heart failure with preserved ejection fraction; however, it is not specific to this disease. Stress testing provides crucial information about the diagnosis and prognosis of heart failure with preserved ejection before it reaches the advanced stage. Among various stress tests, noninvasive supine bicycle diastolic stress echocardiography has provided the most evidence for diagnosing and predicting the prognosis of heart failure with preserved ejection fraction. In current practice guidelines, a noninvasive or invasive diastolic stress test is recommended when a diagnosis is unclear in resting echocardiography.

Cardiac Biomarkers Following Marathon Running: Is Running Time a Factor for Biomarker Change?

PURPOSE

Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T levels show a transient increase after marathon running. The aim of this study was to investigate whether running duration influences the patterns of changes in cardiac biomarkers.

METHODS

Twenty participants with fast and slow finishing times were included in the study. Blood samples were taken before the marathon race, immediately after, and 24 hours after the race. Samples were analyzed for NT-proBNP and cardiac troponin T concentration. Furthermore, a complete blood cell count was performed.

RESULTS

After the marathon race, the fast and slow runners showed similar changes of NT-proBNP and cardiac troponin T (ie, a transient increase). Curve estimation regression analysis showed a curvilinear relationship (quadratic model) between running times and NT-proBNP increments immediately after the race, with less of an increase in the very fast and the very slow runners (r2 = .359, P = .023). NT-proBNP increments immediately after the race were correlated to the decline 24 hours after the marathon (r = -.612, P = .004).

CONCLUSIONS

This study indicates that NT-proBNP release immediately after marathon running varies in a curvilinear fashion with running time. It is speculated that low NT-proBNP release is associated with training adaptation in most elite runners and the relatively low cardiac stress in the slowest (but experienced) runners. The combination of less adaptation and relatively large cardiac wall and metabolic stress may explain the highest NT-proBNP values in runners with average running times. In addition, NT-proBNP decrements 24 hours after the race depend primarily on the values reached after the marathon and not on running time.

Prolonged Elevation of Tricuspid Regurgitation Pressure Gradient After Exercise in Patients With Exercise-induced Pulmonary Hypertension

It is necessary to measure the peak tricuspid regurgitation pressure gradient (TRPG) that is recorded at maximum exercise intensity when diagnosing exercise-induced pulmonary hypertension (ePH) on exercise stress echocardiography (ESE). However, it is difficult to measure maximum TRPG during the treadmill exercise. If ePH induced TRPG elevation continues during recovery period after exercise termination, this elevation will serve as a practical diagnostic standard. We aimed to assess whether the elevation of postexercise peak TRPG prolong soon after finishing exercise in patients with ePH. Seventy-four patients underwent symptom-limited ESE by using a semirecumbent bicycle ergometer. ePH was defined as peak TRPG > 50 mm Hg at maximum exercise. We measured peak TRPG during exercise and until 5 minutes afterward. Thirty-five patients were diagnosed with ePH; their median TRPG was 57 mm Hg [interquartile range: 52-62 mm Hg] at maximum exercise. Peak TRPG in patients with ePH was > 40 mm Hg until 2 minutes after exercise. The cut-off values of peak TRPG to detect ePH were 43 mm Hg just after exercise and 41 mm Hg at 1 minute afterward (areas under the curve: 0.98, 0.92, respectively; both p < 0.001). In conclusion, elevated peak TRPG persisted for at least 2 minutes after finishing exercise, and this time frame will therefore provide a new window for diagnosing ePH by ESE.

Reduced pulmonary vascular reserve during stress echocardiography in confirmed pulmonary hypertension and patients at risk of overt pulmonary hypertension

Noninvasive estimation of systolic pulmonary artery pressure (SPAP) during exercise stress echocardiography (ESE) is recommended for pulmonary hemodynamics evaluation but remains flow-dependent. Our aim was to assess the feasibility of pulmonary vascular reserve index (PVRI) estimation during ESE combining SPAP with cardiac output (CO) or exercise-time and compare its value in three group of patients: with invasively confirmed pulmonary hypertension (PH), at risk of PH development (PH risk) mainly with systemic sclerosis and in controls (C) without clinical risk factors for PH, age-matched with PH risk patients. We performed semisupine ESE in 171 subjects: 31 PH, 61 PH at risk and 50 controls as well as in 29 young, healthy normals. Rest and stress assessment included: tricuspid regurgitant flow velocity (TRV), pulmonary acceleration time (ACT), CO (Doppler-estimated). SPAP was calculated from TRV or ACT when TRV was not available. We estimated PVRI based on CO (peak CO/SPAP*0.1) or exercise-time (ESE time/SPAP*0.1). During stress, TRV was measurable in 44% patients ACT in 77%, either one in 95%. PVRI was feasible in 65% subjects with CO and 95% with exercise-time (p < 0.0001). PVRI was lower in PH compared to controls both for CO-based PVRI (group 1 = 1.0 ± 0.95 vs group 3 = 4.28 ± 2.3, p < 0.0001) or time-based PVRI estimation (0.66 ± 0.39 vs 3.95 ± 2.26, p < 0.0001). The proposed criteria for PH detection were for CO-based PVRI ≤ 1.29 and ESE-time based PVRI ≤ 1.0 and for PH risk ≤ 1.9 and ≤ 1.7 respectively. Noninvasive estimation of PVRI can be obtained in near all patients during ESE, without contrast administration, integrating TRV with ACT for SPAP assessment and using exercise time as a proxy of CO. These indices allow for comparison of pulmonary vascular dynamics in patients with varied exercise tolerance and clinical status.

Noninvasive Pulmonary Hemodynamic Evaluation in Athletes With Exercise-Induced Hypoxemia

BACKGROUND

Pulmonary capillary stress failure is potentially involved in exercise-induced hypoxemia (ie, a significant fall in hemoglobin oxygen saturation [Spo₂]) during sea level exercise in endurance-trained athletes. It is unknown whether there are specific properties of pulmonary vascular function in athletes exhibiting oxygen desaturation.

METHODS

Ten endurance-trained athletes with exercise-induced hypoxemia (EIH), nine endurance-trained athletes with no exercise-induced hypoxemia (NEIH), and 10 untrained control subjects underwent an incremental exercise stress echocardiography coupled with lung diffusion capacity for carbon monoxide (Dlco) and lung diffusion capacity for nitric oxide (Dlno) testing. Functional adaptation of the pulmonary circulation was evaluated with measurements of mean pulmonary arterial pressure (mPAP), pulmonary capillary pressure, pulmonary vascular resistance (PVR), cardiac output (Qc), and pulmonary vascular distensibility (alpha) mathematically determined from the curvilinearity of the multi-point mPAP/Qc relation.

RESULTS

EIH athletes exhibited a lower exercise-induced PVR decrease compared with the untrained and NEIH groups (P < .001). EIH athletes showed higher maximal mPAP compared with NEIH athletes (45.4 ± 0.9 mm Hg vs 41.6 ± 0.9 mm Hg, respectively; P = .003); there was no difference between the NEIH and untrained subjects. Alpha was lower in the EIH group compared with the NEIH group (P < .05). Maximal mPAP, Pcap, and alpha were correlated with the fall of Spo₂ during exercise (P < .01, P < .01, and P < .05). Dlno and Dlco increased with exercise in all groups, with no differences between groups. Dlno/Qc was correlated to the exercise-induced Spo₂ changes (P < .05).

CONCLUSIONS

EIH athletes exhibit higher maximal pulmonary vascular pressures, lower vascular distensibility, or exercise-induced changes in PVR compared with NEIH subjects, in keeping with pulmonary capillary stress failure or intrapulmonary shunting hypotheses.

Mild Pulmonary Hypertension Is Associated With Increased Mortality: A Systematic Review and Meta-Analysis

Background

Recent studies have demonstrated a continuum in clinical risk related to mean pulmonary artery pressure that begins at >19 mm Hg, which is below the traditional threshold used to define pulmonary hypertension (PH) of 25 mm Hg. Because of the implications on patient diagnosis and prognosis, the generalizability and validity of these data need further confirmation.

Methods and Results

Databases were searched from inception through January 31, 2018, to identify studies comparing all‐cause mortality between patients with mildly elevated mean pulmonary artery pressure near but <25 mm Hg versus the referent group. The meta‐analysis included 15 nonrandomized studies and 16 482 patients (7451 [45.2%] with measured or calculated mean pulmonary artery pressure of 19–24 mm Hg by right heart catheterization [n=6037] and echocardiography [n=1414] [mild PH]). The mean duration of follow‐up was 5.2 years. Compared with the referent group, mild PH was associated with an increased risk of mortality (risk ratio, 1.52; 95% confidence interval, 1.32–1.74; P<0.001; I²=47%). Secondary analysis using risk‐adjusted time‐to‐event estimates showed a similar result (hazard ratio, 1.19; 95% confidence interval, 1.09–1.31; P<0.001; I²=42%). The findings were consistent between subgroups of right heart catheterization and echocardiography studies (P_interaction>0.05). There was evidence of publication bias; however, this did not influence the risk estimate (Duval and Tweedie's trim and fill adjusted risk ratio, 1.34; 95% confidence interval, 1.15–1.56).

Conclusions

The risk of mortality is increased in patients with mild PH, defined as measured or calculated mean pulmonary artery pressure >19 mm Hg. These data emphasize a need for diagnosing patients with mild PH with consideration to enrollment in PH clinical studies investigating pharmacological and nonpharmacological interventions to attenuate clinical risk and improve outcomes.

Echocardiographic Pulmonary to Left Atrial Ratio (ePLAR): A Comparison Study between Ironman Athletes, Age Matched Controls and A General Community Cohort

Background: During exercise there is a proportionally lower rise in systemic and pulmonary pressures compared to cardiac output due to reduced vascular resistance. Invasive exercise data suggest that systemic vascular resistance reduces more than pulmonary vascular resistance. The aim of this study was the non-invasive assessment of exercise hemodynamics in ironman athletes, compared with an age matched control group and a larger general community cohort. Methods: 20 ironman athletes (40 ± 11 years, 17 male) were compared with 20 age matched non-athlete controls (43 ± 7 years, 10 male) and a general community cohort of 230 non-athletes individuals (66 ± 11 years, 155 male), at rest and after maximal-symptom limited treadmill exercise stress echocardiography. Left heart parameters (mitral E-wave, e’-wave and E/e’) and right heart parameters (tricuspid regurgitation maximum velocity and right ventricular systolic pressure), were used to calculate the echocardiographic Pulmonary to Left Atrial Ratio (ePLAR) value of the three groups. Results: Athletes exercised for 12.2 ± 0.53 min, age matched controls for 10.1 ± 2.8 min and general community cohort for 8.3 ± 2.6 min. Mitral E/e’ rose slightly for athletes (0.9 ± 1.8), age matched controls (0.6 ± 3.0) and non-athletes (0.4 ± 3.2). Right ventricular systolic pressure increased significantly more in athletes than in both non-athlete cohorts (35.6 ± 17 mmHg vs. 20.4 ± 10.8 mmHg and 18 ± 9.6 mmHg). The marker of trans-pulmonary gradient, ePLAR, rose significantly more in athletes than in both non-athlete groups (0.15 ± 0.1 m/s vs. 0.07 ± 0.1 m/s). Conclusions: Pulmonary pressures increased proportionally four-fold compared with systemic pressures in ironman athletes. This increase in pulmonary vascular resistance corresponded with a two-fold increase in ePLAR. These changes were exaggerated compared with both non-ironman cohorts. Such changes have been previously suggested to lead to right ventricle dysfunction, arrhythmias and sudden cardiac death.

[Physical rehabilitation of patients with pulmonary hypertension]

Pulmonary arterial hypertension (PAH) is characterized by characterized by a continuous increase in precapillary pulmonary vascular resistance with a progressive decrease in cardiac output, which leads to progressive dyspnea, fatigue, and deterioration of exercise capacity. Traditionally, the patients have been advised to limit physical exercises. Recent studies suggest that there are improvements in exercise capacity, quality of life, muscle function, and pulmonary circulation when cardiovascular and pulmonary rehabilitation programs are implemented. According to the 2015 European Society of Cardiology guidelines for the management of patients with PAH, physical rehabilitation is indicated for clinically stable patients who receive drug therapy for this disease. There are various physical rehabilitation programs, but there is no generally accepted protocol for physical exercises in patients with PAH. The review highlights the pathophysiological mechanisms for reducing exercise capacity in patients with PAH; methods for assessing the right ventricular contractile reserve, the effect of physical stress on the cardiovascular system, lungs, and muscles; the existing physical rehabilitation programs, complications and ways to overcome them are considered. Clinical trials studies are also briefly analyzed; promising areas for further development and improvement of rehabilitation programs are considered.

A review of exercise pulmonary hypertension in systemic sclerosis

In general, pulmonary vascular disease has important negative prognostic implications, regardless of the associated condition or underlying mechanism. In this regard, systemic sclerosis is of particular interest as it is the most common connective tissue disease associated with pulmonary hypertension, and a well-recognized at-risk population. In the setting of systemic sclerosis and unexplained dyspnea, the concept of using exercise to probe for underlying pulmonary vascular disease has acquired significant interest. In theory, a diagnosis of systemic sclerosis-associated exercise pulmonary hypertension may allow for earlier therapeutic intervention and a favorable alteration in the natural history of the pulmonary vascular disease. In the context of underlying systemic sclerosis, the purpose of this article is to provide a comprehensive review of the evolving definition of exercise pulmonary hypertension, the current role and methodologies for non-invasive and invasive exercise testing, and the importance of the right ventricle.

A computational multi-scale approach to investigate mechanically-induced changes in tricuspid valve anterior leaflet microstructure

The tricuspid valve is an atrioventricular valve that prevents blood backflow from the right ventricle into the right atrium during ventricular contractions. It is important to study mechanically induced microstructural alterations in the tricuspid valve leaflets, as this aids both in understanding valvular diseases and in the development of new engineered tissue replacements. The structure and composition of the extracellular matrix (ECM) fiber networks are closely tied to an overall biomechanical function of the tricuspid valve. In this study, we conducted experiments and implemented a multiscale modeling approach to predict ECM microstructural changes to tissue-level mechanical responses in a controlled loading environment. In particular, we characterized a sample of a porcine anterior leaflet at a macroscale using a biaxial mechanical testing method. We then generated a three-dimensional finite element model, to which computational representations of corresponding fiber networks were incorporated based on properties of the microstructural architecture obtained from small angle light scattering. Using five different biaxial boundary conditions, we performed iterative simulations to obtain model parameters with an overall R² value of 0.93. We observed that mechanical loading could markedly alter the underlying ECM architecture. For example, a relatively isotropic fiber network (with an anisotropy index value α of 28%) became noticeably more anisotropic (with an α of 40%) when it underwent mechanical loading. We also observed that the mechanical strain was distributed in a different manner at the ECM/fiber level as compared to the tissue level. The approach presented in this study has the potential to be implemented in pathophysiologically altered biomechanical and structural conditions and to bring insights into the mechanobiology of the tricuspid valve. STATEMENT OF SIGNIFICANCE: Quantifying abnormal cellar/ECM-level deformation of tricuspid valve leaflets subjected to a modified loading environment is of great importance, as it is believed to be linked to valvular remodeling responses. For example, developing surgical procedures or engineered tissue replacements that maintain/mimic ECM-level mechanical homeostasis could lead to more durable outcomes. To quantify leaflet deformation, we built a multiscale framework encompassing the contributions of disorganized ECM components and organized fibers, which can predict the behavior of the tricuspid valve leaflets under physiological loading conditions both at the tissue level and at the ECM level. In addition to future in-depth studies of tricuspid valve pathologies, our model can be used to characterize tissues in other valves of the heart.

Pulmonary hypertension subjects exhibit right ventricular transient exertional dilation during supine exercise stress echocardiography

Pulmonary hypertension is a condition with high morbidity and mortality. Resting transthoracic echocardiography is a pivotal diagnostic and screening test for pulmonary hypertension. The role of exercise stress echocardiography in the diagnosis of pulmonary hypertension is not well-established. We studied right ventricular size changes during exercise using exercise stress echocardiography to assess differences between normal and pulmonary hypertension patients and evaluate test safety, feasibility, and reproducibility. Healthy control and pulmonary hypertension patients performed recumbent exercise using a bicycle ergometer. Experienced echocardiography sonographers recorded the following resting and peak exercise right ventricular parameters using the apical four chamber view: end-diastolic area; end-systolic area; mid-diameter; basal diameter; and longitudinal diameter. Two cardiologists masked to clinical information subsequently analyzed the recordings. Parameters with acceptable inter-rater reliability were analyzed for statistical differences between the normal and pulmonary hypertension patient groups and their association with pulmonary hypertension. We enrolled 38 healthy controls and 40 pulmonary hypertension patients. Exercise stress echocardiography testing was found to be safe and feasible. Right ventricular size parameters were all readily obtainable and all had acceptable inter-observer reliability except for right ventricular longitudinal diameter. During exercise, healthy controls demonstrated a decrease in right ventricular end-systolic area, end-diastolic area, mid-diameter, and basal diameter (P < 0.05). Conversely, pulmonary hypertension patients demonstrated an increase in right ventricular end-systolic area, end-diastolic area, and mid-diameter (P < 0.05). These changes were unaffected by multivariate corrections. The sensitivity for pulmonary hypertension of an increase in right ventricular size was 97.2% with a negative predictive value of 95.2%. The ROC C-statistic for increase in right ventricular size was 0.93. This transient exertional dilation (TED) of the right ventricle is observed in pulmonary hypertension patients but not in healthy controls. Recumbent right ventricular exercise stress echocardiography is a feasible and safe diagnostic test for pulmonary hypertension which warrants additional study.

Non-invasive Multimodality Cardiovascular Imaging of the Right Heart and Pulmonary Circulation in Pulmonary Hypertension

Pulmonary hypertension (PH) is defined as resting mean pulmonary arterial pressure (mPAP) ≥25 millimeters of mercury (mmHg) via right heart (RH) catheterization (RHC), where increased afterload in the pulmonary arterial vasculature leads to alterations in RH structure and function. Mortality rates have remained high despite therapy, however non-invasive imaging holds the potential to expedite diagnosis and lead to earlier initiation of treatment, with the hope of improving prognosis. While historically the right ventricle (RV) had been considered a passive chamber with minimal role in the overall function of the heart, in recent years in the evaluation of PH and RH failure the anatomical and functional assessment of the RV has received increased attention regarding its performance and its relationship to other structures in the RH-pulmonary circulation. Today, the RV is the key determinant of patient survival. This review provides an overview and summary of non-invasive imaging methods to assess RV structure, function, flow, and tissue characterization in the setting of imaging's contribution to the diagnostic, severity stratification, prognostic risk, response of treatment management, and disease surveillance implications of PH's impact on RH dysfunction and clinical RH failure.

Pulmonary hemodynamic and right ventricular responses to brief and prolonged exercise in middle-aged endurance athletes

Right ventricular (RV) function is closely coupled to pulmonary arterial (PA) hemodynamics and is believed to decline with prolonged exercise. A linear pressure-flow relationship is thought to exist between PA pressures and increasing exercise intensity in athletes, yet a paucity of directly measured pulmonary hemodynamic data exists supporting this contention. We sought to describe the PA pressure, PA wedge pressure (PAWP), and RV functional responses to brief and prolonged exercise in endurance-trained athletes. Twenty-one healthy athletes (54 ± 5 yr) underwent right heart catheterization to assess pulmonary hemodynamics during graded, submaximal exercise. Measurements were made at rest and during three stages of steady-state, semiupright cycle ergometry at heart rates of 100 beats/min (EX1), 130 beats/min (EX2), and 150 beats/min (EX3). Five athletes completed an additional 34 min at 130 beats/min for a total exercise time of 60 min [prolonged exercise (PLG)]. PA pressures and PAWP increased significantly at EX1 without a further rise at EX2, EX3, or PLG. PAWP adjusted for absolute work rate demonstrated a significant decline as exercise intensity increased from EX1 to EX2. The resistance compliance time constant decreased at EX1 without further changes at EX2, EX3, and prolonged exercise. RV function did not decline during PLG. After an initial rise in PA pressure and PAWP during early, nonsteady-state exercise, values remained constant despite increases in exercise intensity and duration. These data indicate that in healthy, middle-aged endurance-trained athletes, the PA and pulmonary venous/left atrial compartments rapidly accommodate high conduit flows produced during intensive and prolonged exercise while maintaining RV function.

NEW & NOTEWORTHY The right ventricular (RV)-pulmonary arterial (PA) circulatory unit has not been well studied during prolonged exercise, and this study provides an ecological approach that reflects a typical bout of endurance training integrating a transition from rest to exercise with successive increases in intensity, progressing to steady-state, sustained exercise. We demonstrated a remarkably constant response of the PA and PA wedge pressure during incremental, steady-state exercise and that no changes occur in pulmonary pressures throughout prolonged exercise, concomitant to a preservation of RV performance.

The Right Heart International Network (RIGHT-NET): Rationale, Objectives, Methodology, and Clinical Implications

The Right Heart International Network is a multicenter international study aiming to prospectively collect exercise Doppler echocardiography tests of the right heart pulmonary circulation unit (RHPCU) in large cohorts of healthy subjects, elite athletes, and individuals at risk of or with overt pulmonary hypertension. It is going to provide standardization of exercise stress echocardiography of RHPCU and explore the full physiopathologic response.

Stressing the Cardiopulmonary Vascular System: The Role of Echocardiography

The cardiopulmonary vascular system represents a key determinant of prognosis in several cardiorespiratory diseases. Although right heart catheterization is considered the gold standard for assessing pulmonary hemodynamics, a comprehensive noninvasive evaluation including left and right ventricular reserve and function and cardiopulmonary interactions remains highly attractive. Stress echocardiography is crucial in the evaluation of many cardiac conditions, typically coronary artery disease but also heart failure and valvular heart disease. In stress echocardiographic applications beyond coronary artery disease, the assessment of the cardiopulmonary vascular system is a cornerstone. The possibility of coupling the left and right ventricles with the pulmonary circuit during stress can provide significant insight into cardiopulmonary physiology in healthy and diseased subjects, can support the diagnosis of the etiology of pulmonary hypertension and other conditions, and can offer valuable prognostic information. In this state-of-the-art document, the topic of stress echocardiography applied to the cardiopulmonary vascular system is thoroughly addressed, from pathophysiology to different stress modalities and echocardiographic parameters, from clinical applications to limitations and future directions.

Variable Hemodynamic Responses during Diastolic Stress Echocardiography in Patients Who Have Relaxation Abnormality with Possible Elevated Filling Pressure

BACKGROUND AND OBJECTIVES

The clinical characteristics of patients with diastolic dysfunction characterized by a relaxation abnormality with possible elevated filling pressure is remain to be determined. We sought to test whether diastolic stress echocardiography (DSE) is useful for characterization of these patients.

METHODS

A total of 120 patients (58 men, mean age of 64±7 years) with E/A ratio <1.0 (mean±SD, 0.7±0.1) and 10≤ E/e' <15 at rest echocardiography was enrolled prospectively for supine bicycle exercise up to 50 W.

RESULTS

During exercise, 47 patients (39%) showed high left ventricular filling pressure (E/e' >15, hLVFP) and 40 (30%) developed exercise-induced pulmonary hypertension (systolic pulomary arterial pressure >50 mmHg, EiPH) without hLVFP. The remaining 33 patients did not show hLVFP or EiPH. The incidence of EiPH with hLVFP was 21% (25/120). By multivariate analysis, age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.00-1.13; p=0.039) and systolic pulmonary artery pressure at rest (OR, 1.14; 95% CI, 1.02-1.27; p=0.02) were associated with EiPH, whereas late diastolic transmitral velocity (OR, 1.04; 95% CI, 1.00-1.08; p=0.03) and diastolic blood pressure (OR, 0.94; 95% CI, 0.90-0.99; p=0.02) were associated with hLVFP during exercise.

CONCLUSIONS

Patients with relaxation abnormality and possibly hLVFP showed markedly heterogeneous hemodynamic changes during low-level exercise and DSE was useful to characterize these patients.

Exercise training in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by a continuous increase in pre-capillary pulmonary vascular resistance (PVR) with a progressive reduction of cardiac output (CO). Similar to what occurs in left heart failure (HF), this represents the initial phase of a syndrome characterized by the progressive development of dyspnea and fatigue with increasing deterioration of exercise tolerance. Although the therapies introduced in the last two decades have determined a significant improvement of the clinical conditions of PAH patients, they have a little impact on exercise capacity and prognosis. However, as previously demonstrated for HF, recent pilot studies have reported that physical and respiratory rehabilitation may have a specific role in the management of PAH. Despite potential risks, so far all studies agree that exercise training (ET) improves exercise capacity, quality of life (QoL), muscle function and pulmonary circulation. We will review the pathophysiological mechanisms underlying the functional incompetence of PAH patients, the effects of ET on clinical and functional parameters, the selection criteria for inclusion of patients in a training program, the suggested monitoring of beneficial effects or possible side effects induced by ET. Finally, we discuss of the possible exercise induced amelioration of prognosis in PAH.

Effect of Body Position, Exercise, and Sedation on Estimation of Pulmonary Artery Pressure in Dogs with Degenerative Atrioventricular Valve Disease

Background

Severity of pulmonary hypertension (PH) in dogs is related to clinical signs and prognosis.

Hypothesis/Objectives

We hypothesized that Doppler echocardiographic (DE) indices of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) are influenced by independent factors that create clinically important variability of DE‐based estimates of PH in dogs.

Animals

Thirty‐eight client owned dogs with naturally acquired degenerative atrioventricular valve disease and tricuspid regurgitation (TR).

Methods

Dogs were prospectively enrolled, and target variables were acquired during 4 echocardiographic study periods (lateral recumbency, standing, lateral recumbency after a 6‐minute walk test [6MWT], and lateral recumbency after sedation with butorphanol 0.25 mg/kg IM). Statistical methods included repeated measures ANOVA, mixed model analysis, and Chi‐squared test of association.

Results

There was a significant increase in peak TR flow velocity (TRFV; P < 0.01) after sedation in 78% of dogs, with TRFV increasing by >0.4 m/s in 42% of dogs, independent of stroke volume. A significant effect of study period on DE‐estimated PVR was not found (P = 0.15). There were negligible effects of sonographer, body position, and 6MWT on echocardiographic variables of PH. Clinically relevant cyclic variation of TRFV was found. There was an association between estimation of right atrial pressure based on subjective assessment and estimation based on cranial vena cava collapsibility (P = 0.03).

Conclusions and Clinical Importance

The increase in TRFV observed with sedation could change assessment of PH severity and impact prognostication and interpretation of treatment response. Further studies with invasive validation are needed.

Mid-childhood outcomes after pre-viable preterm premature rupture of membranes

OBJECTIVES

Investigate cardiorespiratory outcomes in children surviving previable preterm premature rupture of membranes (PV-PPROM) before 22 weeks' gestational age (GA) with minimum 2 weeks latency.

STUDY DESIGN

Single institution, follow-up of retrospectively identified children who were born after PV-PPROM during 2000-2004, and individually matched preterm-born controls.

RESULTS

Eleven PV-PPROM and matched control children were included at mean age of 10.5 and 10.7 years. Rupture of membranes occurred at mean GA 18² and 27⁶ weeks and birth at 28³ and 28⁶ weeks, respectively. Compared to controls, the PV-PPROM group had significantly poorer lung function, findings on echocardiography indicating mild pulmonary hypertension, and lower peak oxygen consumption. Chart reviews suggested more motor difficulties and a tendency towards more problems with learning and attention.

CONCLUSION

The findings highlight a preterm-born sub-group in need of targeted long-term monitoring and possibly interventions regarding future cardiorespiratory and neurodevelopmental function.

Echocardiographic assessment of the right ventricle in the current era: Application in clinical practice

The right ventricle has unique structural and functional characteristics. It is now well recognized that the so-called forgotten ventricle is a key player in cardiovascular physiology. Furthermore, there is accumulating evidence that demonstrates right ventricular dysfunction as an important marker of morbidity and mortality in several commonly encountered clinical situations such as heart failure, pulmonary hypertension, pulmonary embolism, right ventricular myocardial infarction, and adult congenital heart disease. In contrast to the left ventricle, echocardiographic assessment of right ventricular function is more challenging as volume estimations are not possible without the use of three-dimensional (3D) echocardiography. Guidelines on chamber quantification provide a standardized approach to assessment of the right ventricle. The technique and limitations of each of the parameters for RV size and function need to be fully understood. In this era of multimodality imaging, echocardiography continues to remain a useful tool for the initial assessment and follow-up of patients with right heart pathology. Several novel approaches such as 3D and strain imaging of the right ventricle have expanded the usefulness of this indispensable modality.

Assessment of Mitral Valve Repair With Exercise Echocardiography: Artificial Chordae vs Leaflet Resection

Mitral valve (MV) repair with artificial chordae (AC) or leaflet resection (LR) is associated with good hemodynamics at rest. The aim of this study was to compare these techniques in terms of exercise capacity and echocardiographic parameters of hemodynamics at rest and peak exercise. We conducted a study in 2015 of 56 patients, who had undergone surgery for degenerative posterior mitral leaflet prolapse between 2005 and 2014 using either AC (n = 24) or LR (n = 32). Clinical data were collected, exercise capacity was measured, and resting echocardiography and peak exercise echocardiography were performed. No significant differences were detected among groups regarding exercise duration or peak exercise workload measured in Watts (W) (AC: 136 ± 43 W and LR: 131 ± 40 W; P = 0.65). The mean mitral gradient at rest was 3.0 ± 1.3 mm Hg in the AC group and 3.0 ± 1.0 mm Hg in the LR group (P = 0.90). The mean MV gradients at peak exercise did not differ significantly between groups (AC: 8.3 ± 3.4 and LR: 11.3 ± 8.7; P = 0.19). Four patients (17%) in the AC group and 1 (3%) in the LR group had systolic anterior motion, P = 0.15. We conclude that both methods of posterior MV leaflet repair were associated with good hemodynamics at rest and peak exercise. The groups had comparable exercise capacity. MV pressure gradients at rest and peak exercise were similar in both groups.

Exercise Dynamics in Secondary Mitral Regurgitation: Pathophysiology and Therapeutic Implications

Secondary mitral valve regurgitation (MR) remains a challenging problem in the diagnostic workup and treatment of patients with heart failure. Although secondary MR is characteristically dynamic in nature and sensitive to changes in ventricular geometry and loading, current therapy is mainly focused on resting conditions. An exercise-induced increase in secondary MR, however, is associated with impaired exercise capacity and increased mortality. In an era where a multitude of percutaneous solutions are emerging for the treatment of patients with heart failure, it becomes important to address the dynamic component of secondary MR during exercise as well. A critical reappraisal of the underlying disease mechanisms, in particular the dynamic component during exercise, is of timely importance. This review summarizes the pathophysiological mechanisms involved in the dynamic deterioration of secondary MR during exercise, its functional and prognostic impact, and the way current treatment options affect the dynamic lesion and exercise hemodynamics in general.

Pulmonary Hypertension in Children With β Thalassemia Major, Are Splenectomy and High-Ferritin Levels Related or Not?

We evaluated the risk of pulmonary hypertension (PH) by measuring the velocity of the tricuspid regurgitation jet velocity (TRV) on echocardiography and the associations among the TRV, ferritin, and history of splenectomy in children with β thalassemia major (TM). In total, 85 children with TM were examined with continuous Doppler flow. Patients with an abnormal TRV (>2.5 m/s) were grouped into those with a TRV of 2.5 to 2.9 m/s and TRV>2.9 m/s. A TRV of >2.5 m/s was identified in 72; 31 (36%) of these patients had a TRV of >2.9 m/s, suggesting a risk for significant PH. The ferritin concentration was significantly higher in patients with a TRV of >2.9 m/s and showed a positive correlation with a TRV. The TRV was significantly correlated with markers of diastolic function: the tricuspid peak early diastolic wave (E) was higher in patients with a TRV of >2.9 m/s and showed a significant correlation with the TRV (R=0.315). The ratio of the TRV over the velocity-time integral (VTI) at the right ventricular outflow tract (TRV/VTI RVOT), which is correlated with the pulmonary vascular resistance, was higher in patients with a TRV of >2.9 m/s. In total, 27 patients had splenectomy. Splenectomized patients had a higher TRV and splenectomy was correlated with the TRV (R=-0.221). A risk of PH as defined by a TRV of >2.9 m/s was common in our patients with TM. Screening with Doppler flow indices on echocardiography can detect PH in early stages.

Readdressing the entity of exercise pulmonary arterial hypertension

Exercise pulmonary hypertension (EPH) indicates an abnormally elevated pulmonary artery pressure (PAP) during exercise. The physiological range of PAP during exercise remains poorly defined and, therefore, a universally accepted definition of EPH remains elusive. Nevertheless, previous data concerning the distribution of PAP in normal populations and more recent retrospective clinical data enhanced our ability to define EPH. EPH can impair exercise capacity and cause dyspnea. The underlying pathophysiology of the arterial form of EPH (EPAH) appears to be similar to that seen in resting pulmonary arterial hypertension (PAH), and EPAH individuals are at risk of developing resting PAH. Patients with collagen vascular disease, especially scleroderma, are at risk for EPAH and its presence indicates a relatively poor prognosis. The prevalence of EPAH in scleroderma may be as high as 50%. The utility of pulmonary vasodilator therapy for EPAH is not well defined; however, a sizable subgroup of EPAH patients will achieve an improvement in symptoms.

Relationship Among Pulmonary Hypertension, Autoimmunity, Thyroid Hormones and Dyspnea in Patients With Hyperthyroidism

OBJECTIVE

Previous studies have reported conflicting results regarding the mechanisms underlying the pathophysiology of pulmonary hypertension (PHT) in patients with hyperthyroidism. Therefore, in this study, we investigated the association between PHT and thyroid-stimulating hormone (TSH) receptor antibody, thyroid peroxidase antibody, thyroglobulin antibody, TSH, fT3, fT4 and dyspnea during daily activities in a large population of patients with hyperthyroidism.

METHODS

A total of 129 consecutive patients with hyperthyroidism, 37 with hypothyroidism and 38 euthyroid controls were enrolled in this study. The modified medical research council scale was used for the assessment of dyspnea in daily activities. All the patients and euthyroid controls underwent transthoracic echocardiography for the assessment of PHT.

RESULTS

Mild PHT was present in 35%, 36%, 13.5% and 5% of the patients with Graves׳ disease, toxic multinodular goiter, hypothyroidism and euthyroid controls, respectively. Pulmonary vascular resistance (PVR) was higher in hyperthyroid patients with PHT than in those without PHT. Moreover, a significant positive correlation was found between modified medical research council scale and pulmonary artery systolic pressure as well as PVR in patients with hyperthyroidism. No association was found between PHT and serum TSH receptor antibody, thyroid peroxidase antibody, thyroglobulin antibody, TSH, fT3 and fT4 levels.

CONCLUSIONS

Mild PHT is present in a significant proportion of patients with hyperthyroidism, regardless of etiology. PVR appears to be the main cause of PHT in patients with hyperthyroidism, and neither autoimmunity nor thyroid hormones are associated with PHT in these patients. Mild dyspnea during daily activities in patients with hyperthyroidism may be related to PHT; however, severe dyspnea requires further evaluation.

Global Deformation Parameters Response to Exercise in Adolescents with Repaired Tetralogy of Fallot

Exercise stress echocardiography is rarely used in the follow-up of children with congenital heart disease following surgical repair. There are no data on global longitudinal strain (GLS) and global circumferential strain (GCS) during exercise in adolescents with repaired tetralogy of Fallot (TOF). The purpose of this prospective study was to investigate GLS and GCS using speckle tracking two-dimensional echocardiography (2D-STE) at rest and during exercise in adolescents with repaired TOF. Twenty patients with repaired TOF and 20 controls were included. The subjects exercised on a semi-supine cycle ergometer using a two-staged 3-min step protocol of 20-40 W at 60-75 rpm. Exercise images with 2D-STE measurements were available for all 40 subjects. In the study group, the GLS values changed significantly between the baseline and third and sixth minute of exercise (-18.10 ± 2.20, -16.23 ± 4.47, -14.22 ± 2.63, respectively, p < 001). GCS did not vary significantly from baseline to end of the exercise testing (-17.49 ± 5.14, -17.15 ± 9.20, -15.66 ± 3.59, respectively, p > 0.05). There was a statistically significant difference between the Stage I longitudinal strain values of the study and control groups (-14.26 ± 9.13 and -20.22 ± 2.88, respectively, p = 0.02) but no significant difference between the Stage II values of these groups (-14.22 ± 2.63 and -15.11 ± 2.45, respectively, p > 0.05). The results revealed significant changes in GLS during exercise in patients with repaired TOF. Data gathered from deformation analysis of 2D-STE during exercise testing can enhance the ability to detect subtle ventricular dysfunction in the follow-up of children with repaired TOF.

Echocardiography in pulmonary hypertension

PURPOSE OF REVIEW

Pulmonary hypertension is a progressive disease of the pulmonary vasculature characterized by increased vascular resistance and pressure overload of the right ventricle. This review aims to describe the diagnostic and prognostic role of echocardiography in pulmonary hypertension with particular consideration of relative strengths, weaknesses and new advances.

RECENT FINDINGS

Although right heart catheterization (RHC) remains the gold standard, echocardiography represents an accessible and feasible real-world tool for screening, differential diagnostic, follow-up assessments and risk stratification in pulmonary hypertension. In the context of clinical scenario and multimaging approach, echocardiography provides accurate measurements of pulmonary haemodynamics, either at rest and/or during exercise, and is particularly useful in ruling out secondary causes of pulmonary hypertension and/or detecting preclinical stages. The use of advanced noninvasive imaging techniques may provide additional information in assessing right heart structure and function.

SUMMARY

Advances in echocardiography and the multimodality imaging approach continue to provide new understandings and opportunities for the study of the right heart-pulmonary circulation unit in pulmonary hypertension.

The Burden of Pulmonary Hypertension in Patients with Degenerative Mitral Valve Disease in Enugu South-East Nigeria: An Echocardiographic Based Study

Background:

Pulmonary hypertension is a common complication of degenerative mitral valve disease, and contributes significantly to both morbidity and mortality. The use of medications for reduction of pulmonary pressure in patients is not a common practice by most physicians in this part of the world because of the absence of data on pulmonary hypertension.

Aim:

The authors set out to find the prevalence of pulmonary hypertension in patients with degenerative mitral valve disease and to determine if there are gender differences in affectation. This will form a basis for future research on the management of pulmonary hypertension in sub-Saharan Africa.

Subjects and Methods:

The echocardiographic records of 1390 patients carried out over a period of 4 years were retrospectively reviewed. The examinations were done with a Logic 500 MD echocardiographic machine. Tricuspid valve regurgitation velocity above 250 cm/s defined pulmonary hypertension. Data obtained included presence of degenerative mitral valve disease, pulmonary hypertension, age, and gender.

Results:

A total of 1390 echocardiogram reports done at Conquest Medical Imaging, Enugu, from July 2009 to August 2013 were retrospectively reviewed. Degenerative mitral valve disease was noted in 18.7% of the patients, (259/1390) made up of 149 males and 110 females with a mean age of 68.3 (14.4) years. Pulmonary hypertension was present in 30% of the patients (78/259) and affected males more than females.

Conclusion:

Pulmonary hypertension is common in patients with degenerative mitral valve disease in Enugu, and affects males more than females.

Impact of age on pulmonary artery systolic pressures at rest and with exercise

AIM

It is not well known if advancing age influences normal rest or exercise pulmonary artery pressures. The purpose of the study was to evaluate the association of increasing age with measurements of pulmonary artery systolic pressure at rest and with exercise.

SUBJECTS AND METHODS

A total of 467 adults without cardiopulmonary disease and normal exercise capacity (age range: 18-85 years) underwent symptom-limited treadmill exercise testing with Doppler measurement of rest and exercise pulmonary artery systolic pressure.

RESULTS

There was a progressive increase in rest and exercise pulmonary artery pressures with increasing age. Pulmonary artery systolic pressures at rest and with exercise were 25±5mmHg and 33±9mmHg, respectively, in those <40 years, and 30±5mmHg and 41±12mmHg, respectively, in those ≥70 years. While elevated left-sided cardiac filling pressures were excluded by protocol design, markers of arterial stiffness associated with the age-dependent effects on pulmonary pressures.

CONCLUSION

These data demonstrate that in echocardiographically normal adults, pulmonary artery systolic pressure increases with advancing age. This increase is seen at rest and with exercise. These increases in pulmonary pressure occur in association with decreasing transpulmonary flow and increases in systemic pulse pressure, suggesting that age-associated blood vessel stiffening may contribute to these differences in pulmonary artery systolic pressure.

Right ventricular and pulmonary vascular reserve in asymptomatic BMPR2 mutation carriers

BACKGROUND

Non-invasive estimates have suggested that asymptomatic BMPR2 mutation carriers may have an abnormal pulmonary vascular response to exercise and hypoxia. However, this has not been assessed with "gold standard" invasive measures.

METHODS

Eight controls and 8 asymptomatic BMPR2 mutation carriers underwent cardiac magnetic resonance imaging with simultaneous invasive pressure recording during bicycle exercise in normoxia, hypoxia and after sildenafil administration. Abnormal pulmonary vascular reserve was defined as an increase in mean pulmonary artery pressure relative to cardiac output (P/Q slope) >3 mm Hg/liter/min.

RESULTS

During normoxic exercise, BMPR2 mutation carriers had a similar P/Q slope when compared with healthy subjects. Only 1 of 8 BMPR2 mutation carriers had a P/Q slope >3 mm Hg/liter/min. During exercise in hypoxia, 3 of 8 BMPR2 mutation carriers had P/Q slopes >3 mm Hg/liter/min compared with none of the controls. Sildenafil decreased the P/Q slope both in controls and BMPR2 mutation carriers. The exercise-induced increase in right ventricular ejection fraction was similar between groups. None of the BMPR2 mutation carriers developed pulmonary arterial hypertension within 2 (range 1.3 to 2.8) years.

CONCLUSIONS

The presence of a BMPR2 mutation, per se, is not associated with an abnormal pulmonary vascular and right ventricular functional response to exercise in asymptomatic individuals. Longer follow-up will be required to determine whether a P/Q slope of >3 mm Hg/liter/min during exercise in normoxia or hypoxia is a sign of pre-clinical disease expression.

The Evolving Landscape of Exercise-Induced Pulmonary Hypertension

OPINION STATEMENT

Normal pulmonary artery pressures at rest, with an exaggerated rise during exercise, characterize exercise-induced pulmonary hypertension. Exercise itself as it relates to this condition is not deleterious, nor does it cause or induce disease. However much like any classical stress test, it is a physiologic probe that aids in disease unmasking. Although more work is required to establish criteria for defining this clinical entity, the phenomenon is real. It remains unknown whether it represents a nascent form of cardiopulmonary disease and whether its genesis predicts fulminant cardiopulmonary disease. Incremental cardiopulmonary exercise testing and the construction of pressure-flow plots to describe the pulmonary vascular response to exercise will be essential in defining this disease. The critical first step remains a consensus definition that will allow for further prospective study focused by a common language.