Effects of exercise on transmitral gradient and pulmonary artery pressure in patients with mitral stenosis or a prosthetic mitral valve: a Doppler echocardiographic study

Doppler echocardiography was used to determine changes in transmitral gradient and pulmonary artery pressure after exercise in 12 patients with mitral stenosis and 11 patients with a prosthetic mitral valve. The mean transmitral gradient in the mitral stenosis group was 9 +/- 7 mm Hg at rest and increased to 17 +/- 8 mm Hg after exercise. In patients with a prosthetic mitral valve, exercise resulted in an increase in mean transmitral gradient from 5 +/- 2 to 8 +/- 3 mm Hg. Calculated pulmonary artery systolic pressure increased with exercise from 41 +/- 19 to 70 +/- 32 mm Hg in the mitral stenosis group and from 28 +/- 8 to 39 +/- 15 mm Hg in patients with a prosthetic valve. Exercise Doppler echocardiographic evaluation of changes in transmitral gradient and pulmonary artery systolic pressure was found to be technically simple and an important addition to the noninvasive evaluation of patients with mitral valve disease.     

The use of stress echocardiography in the assessment of mitral valvular disease

Stress echocardiography plays an important role in evaluating asymptomatic patients with significant mitral stenosis and symptomatic patients with only mild disease at rest, as it correlates the exercise-induced symptoms with changes in transmitral gradients, pulmonary pressures, and mitral valve area. In patients with mitral regurgitation (MR), exercise or dobutamine protocols assess for the change in the degree of regurgitation and the pulmonary artery pressure (PAP) in response to high flow states, and detect underlying left ventricular (LV) dysfunction prior to valvular surgery. Exercise echocardiography also helps in the prognostic assessment of patients with mitral valve prolapse as new MR, or latent LV dysfunction may be provoked to identify a group of high risk individuals with normal resting echocardiographic parameters. Finally, it evaluates the proper functioning of prosthetic mitral valves and helps on the monitoring of transmitral gradients and PAPs after mitral valve surgery.     

Cor Triatriatum Sinister in an Adult: Management Guided by Real Time Three‐Dimensional Transesophageal Echocardiography and Stress Echocardiography

A 39‐year‐old female had cor triatriatum (CT) detected as an incidental finding on transthoracic echocardiography performed to evaluate chest pain. By conventional two‐ and real time three‐dimensional transesophageal echocardiography, the CT membrane had a communicating orifice connecting the accessory and main left atrial chambers that measured 1.3 × 0.8 cm. The resting mean transmembrane gradient was 2 mm Hg. The postexercise mean transmembrane gradient and pulmonary artery pressure were 6 and 40 mm Hg. Extrapolating from cutoff values for postexercise gradients and pulmonary pressures in patients with mitral stenosis, we advised deferring surgery and close clinical and echocardiographic follow up. (Echocardiography 2010;27:E132‐E136)     

Detection of Early Cardiac Dysfunction in Patients with Beta Thalassemia by Tissue Doppler Echocardiography

Backgrounds: In this study we tried to evaluate the prognostic significance of several echocardiographic parameters on the occurrence of heart failure or arrhythmias in patients with beta thalassemia. Methods: We investigated possible differences in myocardial function between a population of 37 asymptomatic patients with beta thalassemia and 25 age‐matched healthy controls, all of whom underwent an echocardiographic study, including tissue Doppler imaging (TDI), moreover plasmatic levels of N‐terminal pro‐BNP (NT‐pro BNP) were measured in all patients. We followed the patients for 22 ± 8 months to evaluate adverse cardiac events. Results: Conventional echocardiographic parameters of left ventricle were comparable in both groups. Whereas TDI peak systolic velocity (Sm) and diastolic parameter (E/Em ratio) were significantly abnormal in patients with thalassemia. Moreover eleven adverse cardiac events were observed during follow‐up. Baseline systolic velocity (Sm) <7.9 cm/s was significantly associated with cardiac complications (P < 0.05). We also demonstrated that systolic velocity is inversely related to NT‐proBNP plasmatic levels (P < 0.001). Conclusions: Our study suggests that mitral annular systolic velocity <7.9 cm/s is associated to the onset of adverse cardiac events. (Echocardiography 2011;28:175‐180)     

二尖瓣球囊扩张术对患者血浆B型利钠肽水平的影响

目的:观察二尖瓣球囊扩张术(PBMV)对二尖瓣狭窄患者血浆B型利钠肽(BNP)水平的影响。方法:检测30例成功施行PBMV的二尖瓣狭窄患者(窦性心律21例,心房颤动9例)术前、术后20 min及术后24 h的血浆BNP浓度,与8例对照者比较,并将BNP浓度与血流动力学参数作相关分析。结果:术前30例二尖瓣狭窄患者血浆BNP水平显著高于对照者(P<0．01);且与平均左心房压(r=0．441,P< 0．05)和肺动脉压(r=0．488,P<0．01)呈正相关。心房颤动患者与窦性心律患者BNP浓度无明显差异。术后20 mim及术后24 h窦性心律患者BNP浓度较术前显著下降(P均<0．05),术后24 h左心室舒张末容量(P<0．01)和每搏输出量(P<0．05)较术前相应增加,左心室舒张末压不变;术后20 min的BNP浓度变化与平均左心房压变化(r=0．696,P <0．01)及肺动脉压变化(r=0．456,P<0．05)呈正相关。术后心房颤动患者BNP浓度较术前无明显改变,左心室舒张末容量和每搏输出量相应不变,左心室舒张末压术后20 min较术前增加(P<0．01)。结论:二尖瓣狭窄患者血浆BNP浓度升高和左心房压及肺动脉压升高相关。心脏节律对球囊扩张术后血浆BNP的变化起重要作用,BNP是反映窦性心律患者球囊扩张术后左心房压及肺动脉压变化的敏感指标,但这一指标不适用于心房颤动患者。     

Is the left atrial v. wave the determinant of peak pulmonary artery pressure in patients with pure mitral stenosis?

A large left atrial (LA) v. wave can be observed in patients with pure mitral stenosis (MS) because of decreased LA compliance. Few data are available regarding the relation between the magnitude of the LA v wave and pulmonary artery pressure in MS. We hypothesized that pulmonary artery pressure may be higher in patients with decreased LA compliance and thus a large v. wave. We analyzed the right-sided cardiac and transseptal catheterization data in 113 patients (16 men and 97 women, mean age 39 years) with pure rheumatic MS in sinus rhythm. Peak systolic, diastolic, and mean pulmonary artery pressures were measured with right-sided cardiac catheterization. The magnitude of LA a and v. waves were measured through transseptal catheterization. Two-dimensional and Doppler echocardiography were also performed to measure LA size, mitral valve area, mean mitral gradient, and valvular regurgitation. Multiple regression analysis was performed to identify the most important factor in the determination of pulmonary artery pressure. A large v wave, defined if peak v wave height exceeded the mean LA pressure by > or =10 mm Hg, was observed in 43 of 113 patients (38%). Increased pulmonary artery systolic pressure (> or =50 mm Hg) was observed in 38 patients (34%). Univariate analysis showed that the factors associated with increased pulmonary artery systolic pressure were smaller mitral valve area, higher mean mitral gradient, higher mean LA pressure, and higher LA v. wave; among them, LA v wave (p <0. 001) and mean mitral gradient (p<0.001) were significant independent factors for pulmonary artery systolic pressure in multivariate analysis. In conclusion, in patients with pure MS and sinus rhythm, the magnitude of the LA v. wave is strongly associated with pulmonary artery pressure. This finding may suggest that LA compliance is a major contributing factor determining pulmonary artery pressure in pure MS.     

The Effect of Cardiac Fibrosis on Left Ventricular Remodeling,Diastolic Function,and N‐Terminal Pro‐B‐Type Natriuretic Peptide Levels in Patients with Nonischemic Dilated Cardiomyopathy

Background: Cardiac fibrosis is common and associated with poor prognosis in patients with heart failure. We investigated the effect of cardiac fibrosis on the left ventricular (LV) diastolic function, functional capacity, LV remodeling, and biochemical parameters in patients with nonischemic dilated cardiomyopathy (NIDC). In addition, we investigated the biochemical and echocardiographic predictors of cardiac fibrosis in this group. Methods and Results: Forty patients with NIDC were enrolled. Cardiac fibrosis was evaluated according to the presence of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging. Nineteen patients had cardiac fibrosis (Group I) and 21 patients did not have cardiac fibrosis (Group II). LV systolic and diastolic parameters were assessed with conventional and tissue Doppler echocardiography. N‐terminal pro‐B‐type natriuretic peptide (NT‐pro BNP) levels of each patient were recorded. Patients with cardiac fibrosis had impaired diastolic function, higher functional class and NT‐pro BNP levels, and significant LV remodeling than the patients without cardiac fibrosis. A correlation analysis revealed that the cardiac fibrosis severity was associated with functional class, cardiac chamber sizes, NT‐pro BNP levels, diastolic parameters such as E/Se. A linear regression analysis demonstrated that NT‐pro BNP and E/Se were the independent predictors of cardiac fibrosis. Conclusion: Cardiac fibrosis correlates with impaired LV diastolic function and functional capacity, elevated NT‐proBNP levels, and adverse cardiac remodeling in patients with NIDC. Therefore, the assessment of cardiac fibrosis can be useful in the management of these patients. (Echocardiography 2010;27:954‐960)     

经皮球囊二尖瓣成形术后房颤患者ANP和BNP水平变化研究

目的探讨房颤患者行经皮球囊二尖瓣成形术（PBMV）后心房利钠肽（ANP）和脑钠肽（BNP）变化及与血流动力学参数的关系。方法选择因风湿性二尖瓣狭窄伴持续性房颤成功行PBMV患者38例,术前、术后1d及半年分别用放射免疫法和酶链免疫法测定血浆中ANP、BNP值,由超声心动图测左房内径（LAD）、二尖瓣口面积（MVA）、二尖瓣跨瓣压差（MPG）及肺动脉压（PAP）。结果PBMV术后患者血流动力学参数明显改善;术后1d及半年ANP水平较术前明显下降,BNP变化不明显。术后半年与术前比较,LAD与ANP下降相关（r=0．774,P〈0．05）,△BNP与△MPG相关（r=0．574,P〈0．05）。结论房颤患者PBMV术后半年血中ANP逐步下降,BNP降低不明显。房颤律时△ANP和△BNP仍是反映LAD和MPG变化的有效指标。     

Left Atrial Compliance and Pulmonary Venous Flow Velocities Are Related to Functional Status in Patients with Moderate‐to‐Severe Mitral Stenosis

Aim: In mitral stenosis (MS), left atrial (LA) compliance plays a crucial role in the occurrence of symptoms and pulmonary arterial hypertension and can alter pulmonary venous flows (PVF). The aim of present study is to compare LA compliance (net atrioventricular compliance‐Cn) and PVF velocities in patients with different functional status despite similar mitral valve area (MVA). Additionally, the relationships of the same variables with each other and other echocardiographic parameters showing the hemodynamic severity of mitral stenosis were investigated. Methods: Thirty‐one patients with moderate to severe mitral stenosis were studied. The patients were divided into two groups according to their NYHA functional classes (FC). The patients with lower FC (NYHA FC1 and FC2) were included in Group I(n = 15), and those with FC ≥ 3 included in Group II (n = 16). All patients underwent comprehensive transthoracic and transesophageal echo Doppler examination. Results: Despite similar LA size, MVA, and transmitral diastolic pressure gradients, systolic pulmonary artery pressure (SPAP) was significantly higher and LA compliance was significantly lower in Group II as compared to group I. Also, systolic PVF velocity (PVs), diastolic PVF velocity (PVd), and PVs/PVd ratio were significantly lower in Group II as compared to Group I. In whole group, significant positive correlations between LA compliance and PVs (r = 0.38, P = 0.035), as well as PVd (r = 0.40, P = 0.023) and, significant negative correlation between LA compliance and SPAP (r =– 0.36, P = 0.047) were noted. Conclusion: Our findings suggested that in patients with MS, when there is inconsistency between symptomatic status and conventional echocardiographic variables, simple and noninvasive Doppler parameters, LA compliance, and PVF could be measured before cardiac catheterization for more accurate and complete evaluation of patients. (ECHOCARDIOGRAPHY, Volume 26, November 2009)     

Determinants of brain natriuretic peptide levels in patients with lone atrial fibrillation.

BACKGROUND: Although brain natriuretic peptide (BNP) is increasingly being used for screening and monitoring of congestive heart failure, its utility in patients with lone atrial fibrillation (AF) is unclear. METHODS AND RESULTS: Plasma BNP levels were measured and comprehensive transthoracic echocardiography was performed in 96 subjects (47: sinus rhythm, 49: AF). Patients with structural heart disease were excluded. Potential determinants of BNP levels were identified by univariate and multivariate analyses. Individuals with AF had higher BNP levels than those with sinus rhythm (150 +/- 114 vs 49 +/- 61 pg/ml, p<0.001) The left atrial (LA) volume index (r=0.63, p<0.001), the pulmonary artery systolic pressure (r=0.45, p=0.006), and the early mitral inflow velocity (E)/mitral annular velocity (E') (r=0.36, p=0.04) were found to be independently correlated with BNP level. The correlations between BNP level and LA volume index (p=0.001) or E/E' (p=0.03) were unaltered when subjects with sinus rhythm were removed from the analysis. CONCLUSIONS: BNP levels significantly correlated with LA volume index and E/E' in patients with lone AF, which indicates that the BNP level may reflect early left ventricular dysfunction and LA enlargement in this patient population.     

The correlation of left atrial volume index to the level of N-terminal pro-BNP in heart failure with a preserved ejection fraction

Background: Patients with heart failure with a preserved ejection fraction (HFPEF) have high N‐terminal pro‐B‐type natriuretic peptide (NT‐pro‐BNP) level and a high ratio of early transmitral inflow to diastolic velocity of the mitral annulus (E/E′) derived from tissue Doppler imaging (TDI). Because left atrial volume indexed to body surface area (LAVI) is believed to reflect chronic diastolic dysfunction, we assessed the ability of LAVI and E/E′ ratio to predict NT‐pro‐BNP level in patients with HFPEF. Methods: One hundred forty‐eight patients with HFPEF (ejection fraction ≥ 50%, NT‐pro‐BNP ≥ 100 pg/ml) underwent conventional echocardiography including LAVI and E/E′ ratio, which were compared with NT‐pro‐BNP level. Results: In the overall patient population, modest correlations were found between NT‐pro‐BNP level and peak systolic TDI (S′) (P = 0.009), LAVI (P = 0.009), and E/E′ ratio (P = 0.017). However, in patients with E/E′ ratio ≥13, LAVI was the most important predictor of NT‐pro‐BNP level (P < 0.001), whereas in those with E/E′ ratio <13 it was S′ (P < 0.001) in multivariate analysis. Conclusion: In patients with HFPEF evidenced by high NT‐pro‐BNP level, LAVI correlates with NT‐pro‐BNP level in the setting of elevated E/E′ ratio. However, in the setting of low E/E′ ratio, LAVI does not seem to be associated with NT‐pro‐BNP level.     

Clinical and echocardiographic correlates of plasma B-type natriuretic peptide levels in patients with aortic valve stenosis and normal left ventricular ejection fraction

Background: Several studies suggest that BNP testing may help define the timing of aortic valve surgery in patients with aortic valve stenosis (AVS) prior onset of overt LV systolic dysfunction. The aim of this study was to identify clinical and echocardiographic correlates of plasma BNP levels in a large cohort of patients with AVS and preserved LV ejection fraction. Method and results: One hundred thirty‐five consecutive patients were prospectively included in the present study (Mean age 73 ± 13 years old, 66 (49%) male). Eighty‐nine patients (66%) had severe AVS (aortic valve area <0.6 cm²/m² BSA). Plasma BNP levels, clinical and comprehensive Doppler echocardiography evaluation was performed in all patients. Independent clinical correlates of plasma BNP levels (R²= 0.19) were older age (P < 0.0001) and presence of AVS symptoms (P = 0.004). Independent echocardiographic correlates of plasma BNP levels (R²= 0.38) were E/Ea ratio (P = 0.01), LV mass index (P = 0.018), left atrial surface (P < 0.0001) and systolic pulmonary artery pressure (sPAP; P = 0.004). Overall, independent correlates of plasma BNP levels (R²= 0.47) were older age (P = 0.001), known coronary artery disease (P = 0.047), increased LV mass index (P = 0.001), left atrial enlargement (P = 0.002), and increased sPAP (P = 0.003). Conclusions: In patients with AVS and normal LV ejection fraction, plasma BNP predominantly reflects the clinical and echocardiographic consequences of afterload burden imposed on the left ventricle rather than the severity of valve stenosis, per se. (Echocardiography 2011;28:695‐702)     

Observations suggesting a high incidence of exercise-induced severe mitral regurgitation in patients with mild rheumatic mitral valve disease at rest

Objectives. The aim of this study was to determine the hemodynamic effects of upright bicycle ergometry in symptomatic patients with mild, mixed mitral stenosis and regurgitation.Background. Patients with seemingly mild rheumatic mitral valve disease often complain of exertional dyspnea or fatigue. These symptoms are usually ascribed to flow-dependent increases in the gradient across the stenotic mitral valve. Although catheterization studies in these patients may demonstrate an increase in mitral valve gradient proportional to an increase in cardiac output, this approach does not specifically address the underlying mechanism of any observed increases in mitral gradient or left atrial (i.e., pulmonary capillary wedge) pressure. Exercise echocardiography is uniquely suited to the dynamic assessment of exercise-induced hemodynamic changes.Methods. Fourteen symptomatic patients with exertional dyspnea and mild mitral stenosis and regurgitation at rest performed symptom-limited upright bicycle ergometry with quantitative two-dimensional, Doppler and color Doppler echocardiographic analysis.Results. Average pulmonary artery systolic pressure in the 13 patients with adequate spectral signals of tricuspid regurgitation increased from 36 ± 5 mm Hg (mean ± SD) at rest to 63 ± 14 mm Hg at peak exercise (p < 0.001). The mean transmitral pressure gradient in all patients increased from 4.5 ± 1.4 mm Hg at rest to 12.7 ± 2.7 mm Hg at peak exercise (p < 0.001). Five patients developed severe mitral regurgitation during exercise.Conclusions. Patients with exertional dyspnea and mild mitral stenosis and regurgitation at rest demonstrate a marked increase in pulmonary artery systolic pressure and mean transmitral pressure gradient during dynamic exercise. In a subset of these patients, marked worsening of mitral regurgitation appears to be the underlying mechanism of this hemodynamic deterioration. Because of the small sample size, this novel observation must be considered preliminary with respect to the true prevalence of exercise-related development of severe mitral regurgitation. If additional studies confirm the importance of this phenomenon, it has important implications for the management of patients with rheumatic mitral valve disease.     

Simultaneous echocardiographic and catheterisation gradients and mitral valve area during balloon mitral valvuloplasty.

This study was aimed at estimating mean transmitral gradients by simultaneous Doppler echocardiography and cardiac catheterisation and determining mitral valve area by pressure half time, Gorlin's formula and two-dimensional echocardiography so as to assess the relative accuracy of these methods before and after balloon mitral valvuloplasty in patients with rheumatic mitral stenosis. Left atrium-left ventricular, pulmonary artery wedge-left ventricular and echo gradients were simultaneously recorded in 18 patients undergoing balloon mitral valvuloplasty. Mitral valve area was estimated by pressure half time, Gorlin's equation and two-dimensional echocardiography. The correlation between left atrium-left ventricular and echo mean gradient before balloon mitral valvuloplasty was 0.96 (p < 0.03). Between pulmonary artery wedge-left ventricular and echo mean gradient, it was 0.95 (p < 0.04). The correlations between left atrium-left ventricular and pulmonary artery wedge-left ventricular mean gradient were also good. After balloon mitral valvuloplasty, similar good correlations were seen. On subgrouping the patients into those with high and low pulmonary artery pressure, good correlation persisted both before and after balloon mitral valvuloplasty. Mitral valve area by all the methods were similar before balloon mitral valvuloplasty. After balloon mitral valvuloplasty, mitral valve area by pressure half time was the least and by two-dimensional echocardiography, the maximum. All the three methods are equally accurate in estimating transmitral gradients and mitral valve area in mitral stenosis before balloon mitral valvuloplasty. Two-dimensional echocardiography is the best to estimate mitral valve area after balloon mitral valvuloplasty. Echocardiography can replace haemodynamic measurement of gradients and mitral valve area before and after balloon mitral valvuloplasty. But pressure half time is not recommended for measuring mitral valve area immediately after balloon mitral valvuloplasty where two-dimensional echocardiography mitral valve area is to be employed.     

Serum N-terminal pro-BNP levels correlate with symptoms and echocardiographic findings in patients with mitral stenosis

This study is designed to evaluate the N-terminal pro-BNP (NTproBNP) levels in patients with mitral stenosis (MS) and its possible correlation with clinical and echocardiographic parameters of the disease. The study group consisted of 29 patients with isolated MS (patients with greater mild regurgitation were excluded) and 20 normal control subjects of similar age and gender distribution. Blood samples for NTproBNP were collected at the time of clinical and echocardiographic examination. NTproBNP levels were elevated in patients with MS compared to controls (325 +/- 249 pg/dL [19.9-890] versus 43 +/- 36 pg/dL [5.76-193.3], P < 0.001). Patients with atrial fibrillation had significantly higher NTproBNP levels compared to those with sinus rhythm (561 +/- 281 pg/dL versus 254 +/- 194 pg/dL, P = 0.044). MS patients with sinus rhythm also had higher NTproBNP levels compared to controls (254 +/- 194 pg/dL versus 43 +/- 36 pg/dL, P = 0.00011). NT pro BNP levels correlated to the LA (R = 0.73, P < 0.0001) and RV (R = 0.41, P = 0.042) diameters, mitral valve area (R =-0.45, P = 0.025), mean mitral gradient (R = 0.57, P = 0.003), peak PAP (R = 0.7, P = 0.03), and NYHA functional class (R = 0.61, P = 0.007). In conclusion, serum NTproBNP levels correlate well with echocardiographic findings and functional class in patients with MS and can be used as a marker of disease severity. Additionally, it may have a potential use as an additional noninvasive and relatively cheap method in monitoring disease progression especially in patients with poor echocardiographic windows.     

Comparison of usefulness of high-dose dipyridamole echocardiography and exercise electrocardiography for detection of asymptomatic restenosis after coronary angioplasty

The present study compares the relative usefulness of the maximal treadmill exercise electrocardiography test with the high-dose dipyridamole echocardiography test (echocardiographic monitoring during dipyridamole infusion up to 0.84 mg/kg in 10 minutes) in detecting severe restenosis or coronary artery disease progression (>70% stenosis) in asymptomatic patients 12 months after a primary successful coronary angioplasty. Criteria of positivity were: for the exercise electrocardiography test, an ST-segment shift ≥0.1 mV from baseline, 0.08 second from the J point; for the dipyridamole echocardiography test, a transient dyssynergy of contraction, absent or of a lesser degree than that in the baseline examination. The exercise electrocardiography and dipyridamole echocardiography tests revealed a similar feasibility (91 vs 87%, difference not significant). Both tests could be performed in 75 patients. For detection of restenosis or disease progression, or both, the exercise electrocardiography test revealed a sensitivity similar to the dipyridamole echocardiography test (71 vs 71%, difference not significant), but a lower specificity (61 vs 90%). It is concluded that the high-dose dipyridamole echocardiogrphy test is equally feasible but more accurate than the exercise electrocardiography test for noninvasive detection of severe asymptomatic restenosis or disease progression at 1 year after successful coronary angioplasty.     

Isolated chronic mitral regurgitation with preserved systolic left ventricular function and severe pulmonary hypertension

Pulmonary hypertension in chronic mitral valve disease has been related most commonly to left ventricular dysfunction or mitral stenosis; its association with chronic, isolated mitral regurgitation and preserved left ventricular systolic function is unclear. In 41 catheterized patients with chronic mitral regurgitation (known history of mitral regurgitation for greater than 18 months) and preserved left ventricular systolic function (ejection fraction greater than 0.55), historic, electrocardiographic, echocardiographic and hemodynamic variables were analyzed. Ten patients (Group I) had normal pulmonary artery systolic pressure (less than 30 mm Hg), whereas 31 patients had pulmonary hypertension. Pulmonary artery systolic pressure was mildly increased (30 to 49 mm Hg) in 13 patients (Group II) and was greater than or equal to 50 mm Hg in 18 patients (Group III). Univariate analysis showed the more frequent occurrence of male gender and ruptured chordae tendineae in the groups with pulmonary hypertension. Mean pulmonary capillary wedge pressure, size of the V wave in pulmonary capillary wedge pressure and pulmonary arteriole resistance were higher, whereas cardiac index was lower in the hypertension groups. Multivariate stepwise analysis revealed higher mean pulmonary capillary wedge pressure and pulmonary arteriole resistance as the only variables independently differing among groups. In conclusion, pulmonary hypertension occurs frequently (76% of cases) in patients with chronic, isolated mitral regurgitation with preserved left ventricular systolic function. In these patients, a severe increase in pulmonary capillary wedge pressure is associated with elevation in pulmonary artery resistance, a finding similar to that in mitral stenosis.     

Cardiopulmonary exercise testing and exhaled nitric oxide in the assessment of patients with mitral stenosis

AIM: In patients with mitral stenosis, symptoms do not always correlate with echocardiographic data. The aims of the study were to evaluate the role of cardiopulmonary exercise testing in the assessment of patients with mitral stenosis and to quantify nitric oxide production at rest and at the end of exercise. METHODS: We evaluated 43 patients with moderate to severe mitral stenosis with a discrepancy between echocardiographic data and symptoms. Nitric oxide output was calculated by measuring nitric oxide concentration in the exhaled air at rest and at the end of exercise test. RESULTS: Patients were divided in 2 groups: group 1 with a functional capacity <75% at cardiopulmonary exercise test (VO2max in % of the predicted one) and group 2 with functional capacity >75%. Transvalvular gradient and pulmonary artery pressure were significantly higher in group 1 than in group 2 (respectively 9.07 +/- 2.11 mmHg vs 6.01 +/- 1.08 mmHg, p<0.001 and 42.8 +/- 7.2 mmHg vs 33.1 +/- 4.7 mmHg, p<0.001). Patients of group 1 had a lower nitric oxide output at the end of exercise compared to group 2 (231.4 +/- 96.6 nl/min vs 326.3 +/- 74.0 ml/min, p=0.01) and to normal subjects (511.15 +/- 180.1 nl/min, p<0.001). CONCLUSION: Cardiopulmonary exercise testing provides objective non invasive information in the evaluation of patients with discrepancy between symptoms and echocardiographic data. Different levels of nitric oxide output during exercise suggest the role of nitric oxide in regulating pulmonary vascular tone.     

Left atrial function preserves pulmonary circulatory pressure during pacing-tachycardia and contributes to exercise capacity in patients with idiopathic dilated cardiomyopathy in sinus rhythm, whose exercise is limited by dyspnea.

The aim of this study was to determine whether left atrial (LA) function contributes to pulmonary circulatory pressure during pacing-tachycardia and exercise capacity in patients with idiopathic dilated cardiomyopathy (DCM). Thirty-two patients with DCM and in sinus rhythm had limited exercise capacity because of dyspnea. The correlation between peak oxygen consumption (VO2) and the variables of cardiac function by cardiac catheterization and 2-dimensional, Doppler echocardiography, and plasma neurohumoral factor levels was tested, as was the correlation between non-invasive LA functional parameters and pulmonary circulatory pressure during pacing-tachycardia. A significant correlation was observed between VO2 and LA dimension (r = -0.45, p < 0.01), the peak velocities of LA appendage empty flow during atrial systole (r = 0.63, p < 0.0001) and the pulmonary venous forward flow in early ventricular systole (PVS1; r = 0.74, p < 0.0001), as well as plasma brain natriuretic peptide (BNP) concentrations. The predictable equation to VO2 with the multiple regression analysis was: VO2 = -0.01 BNP+0.21 PVS1+15.4 (r = 0.81, p < 0.0001). Furthermore, LA functional variables derived from pulmonary venous flow, especially PVS1, but not plasma BNP concentration, were useful for predicting the degree of the increase in pulmonary circulatory pressure during pacing-tachycardia. Therefore, it is suggested that LA function contributes to exercise capacity through its influence on pulmonary hemodynamic reserve in patients with DCM with sinus rhythm whose exercise is limited by dyspnea.     

Left atrial volume and N-terminal pro-B type natriuretic peptide are associated with elevated pulmonary artery pressure in patients with systemic sclerosis

Early detection of pulmonary hypertension (PH) in patients with systemic sclerosis (SSc) is essential as it leads to substantial morbidity and mortality irrespective of its etiology. The aim of our study was to determine whether noninvasive biochemical and/or echocardiographic indices can predict the presence of PH in these patients. We prospectively studied 66 patients (mean age of 57.7?±?12.1 years, 63 women) with SSc without clinical manifestations of heart failure. All patients underwent standard and tissue Doppler echocardiography. Plasma N-terminal pro-B type natriuretic peptide (NT-proBNP) and asymmetric dimethylarginine (ADMA) levels were also measured. In 24 (36%) patients, the diagnosis of PH was established by echocardiography (systolic pulmonary artery pressure value ≥40 mmHg). Left atrial (LA) volume, NT-proBNP, ADMA, ratio of early transmitral filling velocity to early diastolic velocity of the mitral annulus (mitral E/E _m), and right ventricular myocardial performance index (MPI) were univariate predictors of PH. In multivariate analysis, NT-proBNP, LA volume, and right ventricular MPI were independent predictors of PH in SSc patients. LA volume and NT-proBNP may be useful noninvasive markers for the prediction of elevated pulmonary artery pressure in patients with SSc. These parameters should be considered when assessing this population for risk stratification and for identification of patients demanding further investigation and institution of specific therapy for the disease at the time when it is most likely to be effective.