Initial clinical experience of real-time three-dimensional echocardiography in patients with ischemic and idiopathic dilated cardiomyopathy

The geometry of the left ventricle in patients with cardiomyopathy is often sub-optimal for 2-dimensional ultrasound when assessing left ventricular (LV) function and localized abnormalities such as a ventricular aneurysm. The aim of this study was to report the initial experience of real-time 3-D echocardiography for evaluating patients with cardiomyopathy. A total of 34 patients were evaluated with the real-time 3D method in the operating room (n = 15) and in the echocardiographic laboratory (n = 19). Thirteen of 28 patients with cardiomyopathy and 6 other subjects with normal LV function were evaluated by both real-time 3-D echocardiography and magnetic resonance imaging (MRI) for obtaining LV volumes and ejection fractions for comparison. There were close relations and agreements for LV volumes (r = 0.98, p <0.0001, mean difference = -15 +/- 81 ml) and ejection fractions (r = 0.97, p <0.0001, mean difference = 0.001 +/- 0.04) between the real-time 3D method and MRI when 3 cardiomyopathy cases with marked LV dilatation (LV end-diastolic volume >450 ml by MRI) were excluded. In these 3 patients, 3D echocardiography significantly underestimated the LV volumes due to difficulties with imaging the entire LV in a 60 degrees x 60 degrees pyramidal volume. The new real-time 3D echocardiography is feasible in patients with cardiomyopathy and may provide a faster and lower cost alternative to MRI for evaluating cardiac function in patients.     

Changes of right ventricular size and function in neonates after valvotomy for pulmonary atresia or critical pulmonary stenosis and intact ventricular septum.

Right ventricular end-diastolic and stroke volumes were calculated from orthogonal subcostal echocardiographic images in 24 neonates (mean weight +/- SD 3.4 +/- 0.4 kg) with pulmonary atresia (n = 18) or critical pulmonary stenosis (n = 6) and intact ventricular septum before and at an average of 5 days and then 19 days after pulmonary valvotomy. The preoperative echocardiographic volume determinations were compared with the respective angiographic determinations. In addition, the endocardial area outlines of the left and right ventricles were obtained by planimetry from an end-diastolic frame taken in the apical four-chamber view. End-diastolic and stroke volumes calculated by the echocardiographic method (y) correlated closely with those calculated by the angiographic method (x); the regression equations were y = 1.02 x -0.13 (r = 0.95, SEE +/- 0.45 ml) and y = 1.16 x -0.15 (r = 0.89, SEE +/- 0.38 ml), respectively. All except one infant had right ventricular hypoplasia before valvotomy with an end-diastolic volume of 16.6 +/- 6.4 ml/m2 (44.5 +/- 17.3% of normal). Right to left ventricular area ratio was 0.56 +/- 0.09 (normal 0.95). Five days after valvotomy, right ventricular end-diastolic volume decreased to 10.6 +/- 4.6 ml/m2 (p less than 0.05) and stroke volume decreased from 8.3 +/- 3.5 to 5.5 +/- 2.8 ml/m2 (p less than 0.05). Nineteen days after valvotomy, right ventricular end-diastolic volume and right to left ventricular area ratio had increased to their respective preoperative values; right ventricular stroke volume had increased further to 10.4 +/- 3.9 ml/m2 (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of accurate measurement of left ventricular mass in patients with hypertrophied hearts by real-time three-dimensional echocardiography versus magnetic resonance imaging

To evaluate whether left ventricular (LV) mass assessed by a new real-time, 3-dimensional echocardiographic (RT-3DE) system corresponds to cardiac magnetic resonance imaging (MRI) in patients with LV hypertrophy, RT-3DE and 2-dimensional echocardiography (2DE) were performed to calculate LV mass in 21 patients (mean age 54 +/- 15 years) who underwent MRI for the evaluation of LV hypertrophy. In 20 of 21 patients, adequate 3-dimensional data for LV mass analysis were obtained, and regression analysis showed that LV mass by RT-3DE correlated with that determined by MRI (r = 0.95, y = 28.9 + 0.85x) better than with that determined by 2DE (r = 0.70, y = 43.6 + 0.81x). RT-3DE allows the accurate measurement of LV mass in patients with hypertrophied hearts.     

Volume measurement of the left ventricle in children with congenital heart defects: 3-dimensional echocardiography versus angiocardiography

BACKGROUND: Volume measurement of the left ventricle is currently done by 2-dimensional echocardiography or angiocardiography. However, for the calculation of volumes by these methods, geometrical assumptions must be made. For a precise ventricular volumetry, independent of mathematical assumptions, imaging techniques as the 3-dimensional echocardiography (3D-echo) are required, which permit the imaging of the real ventricular shape. The aim of the study was therefore to detect, whether 3D-echocardiography is suitable for left ventricular volumetry in children with congenital heart disease and whether the 3D-echocadiographically measured volumes correlate sufficiently well with angiocardiographically measured left ventricular volumes. METHODS: 102 children with congenital heart disease were investigated. For angiocardiographic left ventricular volume measurement Simpson's rule was used. Results were corrected with Lange's correction factors. The 3D-echo data sets were registered with a rotating transthoracic transducer. Ventricular volumes were calculated after manual planimetry by summation of the volumes of the single slices. RESULTS: The left ventricular volume could be calculated by 3D-echo in 83% of patients of all ages. In comparison to angiocardiography, the measured volumes were 0.6 +/- 3. 3 ml (0.9 +/- 25.8%) or 7.1 +/- 28.4 ml (7.4 +/- 12.1%) smaller during systole or diastole, respectively. The correlation coefficients r(2) were 0.89 for systolic and 0.93 for diastolic measurements after logarithmic transformation. Pressure or volume overload did not influence significantly the difference between the two methods. CONCLUSION: Transthoracic 3D-echocardiography with a rotating transmitter is feasible for volumetry of the left ventricle in most children. The volumes measured by 3D-echo were significantly smaller than those calculated from the angiocardiography by Simpson's rule. The measurements were not influenced by the kind of load of the ventricle. The correlation between the two methods is good.     

Validation of the measurement of cardiac output by acoustic quantification in patients with severe congestive heart failure

The technique of acoustic quantification (AQ), because of its automatic detection of the contours, enables left ventricular volumes to be calculated in real time using the technique of disk summation. The objective of the study was to evaluate the reliability of cardiac output (CO) measurements obtained with AQ based on left ventricle volumes in patients with severe congestive heart failure. Seventeen patients, mean age 68 +/- 11 years, NYHA stage IV, in sinus rhythm and without significant valve regurgitation were enrolled prospectively. CO, measured simultaneously by 2-dimensional echocardiography (2DE), pulsed Doppler echocardiography (DOP) and AQ, was compared to the thermodilution technique (TD) data. CO, measured by AQ, was highly correlated with TD (r = 0.875; p < 0.001) with a small bias (-0.05 l/min). DOP and 2DE were also well correlated with TD (r = 0.835 and r = 0.701, respectively). Concerning ventricular volume measurement, AQ was well correlated with 2DE (for telediastolic, r = 0.892, and telesystolic volumes, r = 0.874). However, telesystolic (bias, +36.6 +/- 35 ml) and telediastolic volumes (bias, +35.6 +/- 35 ml) were overestimated. We conclude that AQ is a reliable technique, able to estimate CO precisely in patients with severe congestive heart failure. On the other hand, both telesystolic and telediastolic volumes were overestimated.     

Left and right atrial volume by freehand three-dimensional echocardiography: in vivo validation using magnetic resonance imaging.

INTRODUCTION: Measurement of left and right atrial size is important for the management of arrhythmias, valvular and congenital heart disease. We have demonstrated that freehand three-dimensional (3D) echocardiography is more accurate and reproducible than two-dimensional (2D) echocardiography for measurement of left ventricular mass and volume. However, no prior study has validated the accuracy of freehand 3D for the determination of left or right atrial volume. METHODS: End-systolic (maximum) left and right atrial volumes were determined in 21 volunteer patients and normal subjects by one, two, and freehand 3D transthoracic echocardiography and compared to volumes obtained by gradient recalled magnetic resonance imaging. Three-dimensional echocardiographic determination of atrial volume was obtained using an acoustic spatial locator, a line-of-intersection display, and a surface reconstruction algorithm. Two-dimensional echocardiographic atrial volumes were obtained from apical biplane images of the left atrium and an apical single plane image of the right atrium using a summation of disks method. One-dimensional (ID) estimates of left atrial volume were determined by cubing the M-mode ID antero-posterior dimension obtained on the parasternal long axis view. RESULTS: An excellent correlation was Obtained between freedhand 3D echocardiography and magnetic resonce imaging (MRI) for the left atrium (r = 0.90, SEE=9.6 ml) and for the right atrium (r = 0.91, SEE = 8.8 ml) with a small bias (left atrium 5.25 ml, right atrium 12.06 ml) and narrow limits of agreement (left atrium 22.14 ml, right atrium 25.54 ml). Two-dimensional echocardiography correlated less well (left atrium r = 0.87, SEE = 10.23 ml, right atrium r = 0.79, SEE = 19.74 ml), and had a higher bias (left atrium 14.46 ml, right atrium 8.99 ml) and larger limits of agreement (left atrium 24.37 ml, right atrium 41.16 ml). One-dimensional estimates of left atrial volume correlated poorly with magnetic resonance determined left atrial volume (r = 0.80, SEE = 6.61 ml) and had unacceptably high bias (45.09 ml) and limits of agreement (35.52 ml). Interobserver variability was lowest for 3D echocardiography (left atrium 7.2 ml, 11%, right atrium 8.7 ml, 16%). CONCLUSIONS: Freehand 3D echocardiography using the line of intersection display for guidance of image positioning and a polyhedral surface reconstruction algorithm is a valid, accurate, reproducible method for determining left and right atrial volume in humans that is comparable to magnetic resonance imaging and is superior to current ID and 2D echocardiographic techniques.     

Direct assessment of right ventricular transmural pressure

Although the measurement of transmural pressure is important, calculation of transmural pressure is complicated by the difficulties in measuring pericardial pressure. Recently, flat balloons have been proposed to measure pericardial pressure. Over a wide range of volumes, right ventricular diastolic pressure and pericardial balloon pressure were similar in diastole, suggesting that the right ventricle is unstressed at physiologic volumes and that right atrial pressure can be used to estimate pericardial pressure. To evaluate these concepts and to assess indirectly the accuracy of measuring pericardial pressure using flat balloons, six canine hearts were examined postmortem. The pericardium was removed and the hearts were submerged in cold cardioplegic solution. Balloons were inserted into the right and left ventricles, and right and left ventricular pressure-volume curves were obtained. Right ventricular transmural pressures of 2.6 +/- 0.5, 3.9 +/- 0.9, 5.9 +/- 1.4, and 8.9 +/- 2.4 mm Hg were required to distend the right ventricle to 10, 20, 30, and 40 ml, respectively. For the left ventricle, transmural pressures of 3.4 +/- 0.7, 5.4 +/- 1.2, 8.6 +/- 2.1, and 14.1 +/- 3.8 mm Hg were recorded at volumes of 10, 20, 30, and 40 ml, respectively. Although the right ventricular transmural pressures were less than the left ventricular transmural pressures over the physiologic range, right ventricular transmural pressures were always positive and increased with increments in ventricular volume. Thus the right ventricle is not unstressed over the entire range of physiologic volumes, suggesting that pericardial balloon pressures may overestimate pericardial pressure and that right atrial pressure cannot be used to estimate pericardial pressure.     

Pericardial influences on right and left ventricular filling dynamics

The influence of the pericardium on right and left ventricular filling was studied using two-dimensional and Doppler echocardiography in 14 open-chest dogs. Doppler echo parameters of filling included early (E) and late (A) velocities and their ratio (E/A) for the mitral and tricuspid valves. Right and left ventricular volumes were calculated from orthogonal two-dimensional echocardiographic images. Data were compared at three levels of left ventricular end-diastolic pressure (6 +/- 2, 13 +/- 3, and 21 +/- 4 mm Hg) at matched heart rates before and after pericardiectomy. The instantaneous diastolic pressure gradient was measured in 12 of the dogs. Pericardiectomy resulted in an increase in early mitral velocity, peak early diastolic pressure gradient, and E/A but not early mitral velocity normalized for end-diastolic volume. In contrast, for the tricuspid valve flow, pericardiectomy did not change E but caused a marked increase in A and a decrease in E/A. Right ventricular end-diastolic volumes at matched left ventricular end-diastolic volumes were similar before and after the pericardium was removed. However, removal of the pericardium caused a significant decrease of the slope for the right (86.0 +/- 27.0 x 10(-4) versus 50.0 +/- 19.5 x 10(-4) mm Hg/ml, p less than 0.01), but not left, ventricular ln end-diastolic pressure-volume relation (21.2 +/- 9.2 x 10(-3) versus 21.4 +/- 5.3 x 10(-3) mm Hg/ml, p = NS), and a decrease of the pressure intercept for the left (3.0 +/- 2.0 versus 1.6 +/- 0.9 mm Hg, p less than 0.05), but not right, ventricular ln end-diastolic pressure-volume relation (2.8 +/- 1.4 versus 1.4 +/- 0.8 mm Hg, p = NS). In conclusion, filling of the two ventricles is affected by the pericardium over a wide range of physiological ventricular volumes and pressures. At matched left ventricular end-diastolic volume, pericardiectomy causes a fundamental alteration in right, but not left, ventricular filling.     

Noninvasive evaluation of global left ventricular function with use of cine nuclear magnetic resonance

Previous reports have validated the accuracy of nuclear magnetic resonance (NMR) imaging for quantitating ventricular volumes and myocardial mass. In this study, a new rapid NMR imaging method, cine NMR imaging, was used to compare left ventricular volumes determined from the transverse plane and short-axis plane in healthy volunteers and patients with dilated cardiomyopathy. With use of the short-axis plane, left ventricular mass at end-systole and end-diastole were determined and left ventricular systolic wall thickening at three different levels was assessed. For validation in the current study, cine NMR imaging and two-dimensional echocardiographic measurements of left ventricular volumes were correlated. Left ventricular volumes of the normal volunteers (end-systolic volume = 34 +/- 3.8 ml, end-diastolic volume = 90.4 +/- 7.2 ml) and patients with cardiomyopathy (end-systolic volume = 173 +/- 28.3 ml, end-diastolic volume = 219.5 +/- 29.6 ml) obtained in the transverse plane were nearly identical to those obtained in the short-axis plane (normal volunteers, end-systolic volume = 30.3 +/- 3.5 ml, end-diastolic volume = 84.7 +/- 7.0 ml and patients with cardiomyopathy, end-systolic volume = 179.1 +/- 27.8 ml, end-diastolic volume = 227 +/- 30.9 ml) and correlated highly (r = 0.91) with volumes obtained by two-dimensional echocardiography. Assessment of left ventricular mass over a broad range using cine NMR imaging in a short-axis plane was identical at end-systole (normal volunteers, 117 +/- 10 g; patients with cardiomyopathy, 202 +/- 20 g) and end-diastole (normal volunteers, 115 +/- 10 g; patients with cardiomyopathy, 194 +/- 21 g).(ABSTRACT TRUNCATED AT 250 WORDS)     

Two-dimensional echocardiographic determination of ventricular volumes in the fetal heart. Validation studies in fetal lambs

The determination of ventricular volumes in the fetal heart from two-dimensional echocardiography (2DE) may give a better estimate of fetal ventricular size than simple diameter measurements, but the accuracy of this method has not been established. In fetal lambs, we tested whether ventricular volume calculations from 2DE using a biplane Simpson's rule algorithm are accurate. Calculations of left and right ventricular end-diastolic volumes from 2DE were compared with cast volumes of these ventricles. Also, at different levels of left atrial pressure, left ventricular stroke volumes calculated from 2DE were compared with stroke volumes measured simultaneously by an electromagnetic flowmeter. There was a good correlation between volumes determined from 2DE (y axis) and from casts (x axis) for both the left (r = 0.92; y = 0.2 + 1.1x; SEE = 0.19 ml) and right ventricle (r = 0.90; y = 0.7 + 0.9x; SEE = 0.21 ml). Left ventricular stroke volumes calculated from 2DE correlated well with those measured by the electromagnetic flowmeter (r = 0.87; y = 0.2 + 0.9x; SEE = 0.27 ml). Thus, calculation of fetal ventricular volumes from 2DE images using a biplane Simpson's rule method is feasible and accurate.     

Two-dimensional contrast echocardiography in the detection and follow-up of congenital pulmonary arteriovenous malformations.

Pulmonary arteriovenous (A-V) malformation is frequently a manifestation of Osler-Weber-Rendu syndrome (hereditary hemorrhagic telangiectasia). We identified 14 patients (9 men and 5 women) with A-V malformation by contrast echocardiography; 10 patients with atrial right-to-left shunt served as control subjects. Agitated saline solution (10 ml) was injected through a peripheral vein during echocardiographic imaging. The delay in the appearance of microcavitations in the left atrium was measured (in number of frames) after right atrial appearance. The degree of left ventricular opacification was graded 1 to 4+ (where 4+ = intense left ventricular endocardial outline, and 1+ = minimal opacification). Results indicated patients with A-V malformation had a significant delay (p less than 0.001) in left atrial appearance of microcavitations compared with those with atrial right-to-left shunt (66 +/- 27 vs 21 +/- 7 frames, mean +/- 1 standard deviation). In the group with A-V malformation, abnormal blood gases were present in only 6 of 14 patients and chest x-ray was positive in 7. Pulmonary angiography was performed in 11 of 14 patients with positive contrast echocardiography, and all 11 had A-V malformation identified. In patients with 3 to 4+ left ventricular opacification (n = 8), large (greater than 5 mm feeding vessel) or multiple malformations were present, whereas patients with small or isolated malformation had 1 to 2+ left ventricular opacification. Balloon occlusion of malformations was performed in all 11 of these patients; repeat contrast echocardiography revealed significant diminution of right-to-left shunt in 9, and 2 required repeat embolotherapy for an additional previously undetected A-V malformation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Klinische Wertigkeit der intraven?sen Kontrastmittelechokardiographie zur Quantifizierung der linksventrikul?ren Volumina und Funktion bei Patienten mit reduzierter echokardiographischer Bildqualit?t

In the present study, we investigated whether the intravenous injection of air-filled albumin microspheres (Infoson) as a contrast medium improves the echocardiographic quantification of left ventricular enddiastolic and endsystolic volumes, stroke volume, ejection fraction, and regional wall motion in patients with suboptimal endocardial border definition on echocardiography. In 30 adult patients, apical two and four chamber views were performed. In comparison to biplane cineventriculography enddiastolic and endsystolic volumes, stroke volume, ejection fraction, and regional wall function were assessed for heart cycles with and without left ventricular contrast.In comparison to biplane cineventriculography echocardiography underestimates enddiastolic (167+/-64 ml, 111+/-43; p<0.0001) and endsystolic volumes (77+/-63 ml, 54+/-40 ml; p<0.0002), stroke volume (90+/-25 ml, 57+/-17 ml; p<0.0001), and ejection fraction (58+/-16%, 55+/-14%; p<0.03). By contrast echocardiography ejection fraction (58+/-16%) agreed with the angiocardiographically measured ejection fraction. Furthermore, after contrast injection correlations improved between cineventriculography and echocardiography for the assessment of left ventricular enddiastolic volumes (without contrast r = 0.90, SEE = 19 ml; with contrast r = 0.93, SEE = 19 ml), endsystolic volumes (without contrast r = 0.94, SEE = 14 ml; with contrast r = 0.95, SEE = 15 ml), stroke volume (without contrast r = 0.63, SEE = 14 ml; with contrast r = 0.67, SEE = 14 ml), ejection fraction (without contrast r = 0.84, SEE = 8%; with contrast r = 0.88, SEE = 7%), regional wall motion (p<0.01) and its reproducibility (p<0.02). In adult patients with suboptimal endocardial border delineation intravenous contrast echocardiography improves the assessment of left ventricular ejection fraction, regional wall motion, and its reproducibility without severe side effects.     

Left ventricular diastolic dysfunction in patients with so-called lone atrial fibrillation

Lone atrial fibrillation (AF) is defined by the absence of identifiable causes of AF, but its hemodynamics have not been investigated. Twenty-eight patients with lone AF were compared with 14 control patients referred for Wolff-Parkinson-White ablation. Transthoracic and transesophageal echocardiography were performed to rule out structural heart disease, followed by transseptally performed complete hemodynamic evaluation of the left heart systolic and diastolic function. There was no evidence of diastolic dysfunction according to echocardiographic criteria in AF and control patients. There was no difference in echocardiographic measurements, except for a significantly higher inferosuperior left atrial dimension seen in the four-chamber apical view in AF patients (51+/-10 vs 40+/-6 mm, P = 0.03). Hemodynamic evaluation showed that end-diastolic left ventricular pressure and the nadir of the left atrial Y descent were significantly higher in lone AF patients versus controls: 13+/-5 versus 8+/-3 mmHg (P = 0.001) and 6.7+/-3 versus 4.6+/-2.7 mmHg (P = 0.05). Our results demonstrated the presence of diastolic left heart dysfunction in patients with so-called lone AF.     

Comparison of real-time three-dimensional echocardiography to magnetic resonance imaging for assessment of left ventricular mass

This is the first study to assess the feasibility and accuracy of real-time 3-dimensional echocardiography (RT-3DE) for the measurements of left ventricular (LV) mass in patients with congenital heart disease (CHD) compared with magnetic resonance imaging (MRI). Twenty patients (60% men) with CHD were evaluated by MRI and RT-3DE on the same day. Their mean age was 29 +/- 8 years (range 19 to 49). RT-3DE was performed with a Philips Sonos 7500 echocardiographic system and LV mass analyses with the assistance of TomTec software. The results for LV mass obtained by manual tracing were compared with Signa 1.5-T MRI data. The acquisition of RT-3DE data sets was feasible in all 20 patients. Nine patients (45%) had good, 5 patients (25%) moderate, and 6 patients (30%) poor image quality of the 3-dimensional data set. The time of 3-dimensional data acquisition was 4 +/- 2 minutes. Off-line image processing and tracing required approximately 11 +/- 3 minutes. A very good correlation was observed between RT-3DE data with sufficient image quality and MRI (r = 0.98, y = 0.96x + 4.1, SEE 9.8 g), with a mean difference of 2.0 +/- 20 g. Interobserver agreement was excellent (r = 0.99, y = 0.97x + 3.81), with a mean difference of -1 +/- 11 g. In conclusion, the assessment of LV mass from RT-3DE data is feasible in patients with CHD. The mass of an abnormally shaped left ventricle can be determined with high accuracy and low interobserver variability in patients with good or moderate echocardiographic image quality.     

Direct quantitation of right and left ventricular volumes with nuclear magnetic resonance imaging in patients with primary pulmonary hypertension.

To test the utility of electrocardiographically gated spin echo nuclear magnetic resonance (NMR) imaging in quantitating right and left ventricular volumes and function in patients with primary pulmonary hypertension, right and left ventricular end-diastolic and end-systolic volumes, stroke volumes and ejection fractions were determined in 11 patients with primary pulmonary hypertension and in 10 subjects with normal echocardiographic findings. Ventricular chamber volumes were computed by summing the ventricular chamber volumes of each NMR slice at end-diastole and end-systole. This technique was verified by comparison of results obtained by this method and with the water displacement volumes of eight water-filled latex balloons and ventricular casts of eight excised bovine hearts. In the patients with primary pulmonary hypertension, right ventricular volume indexes were 121 +/- 45 ml/m2 at end-diastole and 70.1 +/- 41.6 ml/m2 at end-systole; both values were significantly greater than values in the normal subjects (67.9 +/- 13.4 and 27.9 +/- 7.5 ml/m2, respectively). Left ventricular end-diastolic volume index was significantly less in the patients (44.9 +/- 9.7 ml/m2) than in the normal subjects (68.9 +/- 13.1 ml/m2). There was no significant difference in left ventricular end-systolic volume between the two groups (24.4 +/- 8.6 and 27.1 +/- 7.8 ml/m2, respectively). Right and left ventricular ejection fractions in the patients with primary pulmonary hypertension (0.43 +/- 0.21 and 0.46 +/- 0.15, respectively) were significantly less than values in normal subjects (0.59 +/- 0.09 and 0.6 +/- 0.11, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Fate of left atrial function as determined by real-time three-dimensional echocardiography study after radiofrequency catheter ablation for the treatment of atrial fibrillation

Radiofrequency catheter ablation has been demonstrated to be effective in the treatment of patients with atrial fibrillation. However, its impact on left atrial (LA) function has not been widely studied. The purpose of the present study was to evaluate the impact of radiofrequency catheter ablation on LA function in patients with atrial fibrillation. Thirty-eight patients with symptomatic drug-refractory atrial fibrillation were treated with circumferential pulmonary vein ablation (CPVA). LA volumes and function were assessed with real-time 3-dimensional echocardiography before and 6 months after the procedure. The effectiveness of CPVA was evaluated at 6-month follow-up. Recurrence of the arrhythmia was defined as any documented (clinically or on 24-hour Holter electrocardiography) atrial tachyarrhythmia lasting>30 seconds after the first 12 weeks after the procedure. CPVA induced a reduction of maximum LA volume (from 55+/-15 to 48+/-16 ml, p<0.001), without impairment in LA function, measured as the active emptying percentage of total volume (32+/-29% vs 39+/-33%, p=NS). At follow-up, 21 patients (61.8%) had no recurrences. Maximum LA volumes were significantly larger in patients who presented with recurrences compared with those who did not (64+/-18 vs 50+/-11 ml, p=0.01). In conclusion, CPVA induces a reduction in LA volume without a deleterious impact on function, and, of importance, real-time 3-dimensional echocardiography is a useful noninvasive imaging tool to follow up LA remodeling and function in these patients.     

Acute reduction of atrial overload during vasodilator and diuretic therapy in advanced congestive heart failure

Although acute afterload reduction is known to improve cardiac output in patients with congestive heart failure (CHF), the effect of therapy on the atrial overload directly causing congestive symptoms has not been systematically studied. Atrial volumes and mitral and tricuspid regurgitation, in addition to left ventricular ejection fraction and indexes of left ventricular contractility (mean acceleration, ejection time and peak systolic pressure/end-systolic volume index), were measured using 2-dimensional and Doppler echocardiography and color flow imaging in 30 patients with advanced CHF, before and after acute vasodilator and diuretic therapy tailored to hemodynamic goals. Therapy increased stroke volume by 64% (36 +/- 10 to 55 +/- 14 cc), decreased right atrial pressure by 45% (15 +/- 5 to 8 +/- 4 mm Hg), systemic vascular resistance by 36% (1,700 +/- 400 to 1,030 +/- 300 dynes s cm-5) and pulmonary capillary wedge pressure by 37% (31 +/- 6 to 19 +/- 6 mm Hg) (all p less than 0.001). Echocardiography showed simultaneous reductions in left and right atrial volumes: 24 +/- 19 and 18 +/- 12%, respectively (p less than 0.001). Mitral and tricuspid regurgitation measured by color flow fraction both decreased by a mean of 44% (p less than 0.001). While ejection fraction increased from 15 +/- 5 to 19 +/- 7% (p less than 0.001), there were no changes in relatively load-independent indexes of contractility. Therefore, acute therapy with vasodilators and diuretics in advanced CHF causes reductions in atrial volumes and atrioventricular valve regurgitation that are evident from serial noninvasive studies and may play a major role in the improvement of congestive symptoms.     

Usefulness of right ventricular tissue Doppler imaging to predict outcome in left ventricular heart failure independent of left ventricular diastolic function

It is unknown whether right ventricular (RV) tissue Doppler (TD) predicts outcome in patients with left ventricular (LV) heart failure (HF) independently of contemporary echocardiographic Doppler variables of LV diastolic function. Comprehensive echocardiographic Doppler examination was performed before discharge in 107 patients hospitalized with LV HF. The primary end point was cardiac death or rehospitalization for HF. Follow-up was complete for 100 of 107 patients a mean of 527 days after hospital discharge. There were no significant differences in baseline clinical variables (mean age 58+/-12 years, 46% women, 77% hypertensive, 48% diabetic, 41% current smokers, and 23% known coronary artery disease) in prediction of the primary end point. Compared with patients without an event, patients with an event had a larger left atrial volume index (42+/-16 vs 33+/-13 ml/m2, p=0.001), lower LV ejection fraction (35+/-19% vs 46+/-22%, p=0.01), higher mitral peak early diastolic flow velocity/TD early diastolic velocity (19+/-7 vs 14+/-7, p=0.001), lower RV fractional area change (39+/-11% vs 43+/-10%, p=0.04), and lower RV TD systolic velocity (8+/-2 vs 10+/-3 cm/s, p=0.005). On Cox proportional hazards multivariate analysis, left atrial volume index (p=0.01), mitral peak early diastolic flow velocity/TD early diastolic velocity (p=0.03), and RV TD systolic velocity (p=0.04) were independent predictors of outcome. Even when contemporary echocardiographic Doppler measures of LV diastolic function are considered, RV TD systolic velocity is an independent predictor of cardiac death or rehospitalization for HF in patients hospitalized with HF and appears to be superior to conventional 2-dimensional parameters of RV function.     

Plasma N-terminal pro-brain natriuretic peptide: a marker of left ventricular hypertrophy in hypertrophic cardiomyopathy.

BACKGROUND: B-type natriuretic peptide is secreted mainly in the left ventricle in response to elevated wall tension. Plasma levels of the peptide correlate positively with cardiac filling pressures, making it an excellent marker for the presence of left ventricular dysfunction. In hypertrophic cardiomyopathy, enhanced production of B-type natriuretic peptide is observed. However, the relationship of the various structural and functional features present in the disease with the high plasma levels described is not yet fully clarified. In the present study, we prospectively assessed in hypertrophic cardiomyopathy the relationship of plasma NT-proBNP levels with the extent of left ventricular hypertrophy, presence of left ventricular outflow obstruction and echocardiographic parameters of left ventricular diastolic function. METHODS: The study population included 190 individuals: 53 patients with hypertrophic cardiomyopathy and well-preserved left ventricular systolic function (group A), 92 healthy relatives with no disease expression (group B), and an additional group of 46 healthy volunteers (group C) as controls for NT-proBNP levels. Groups A and B were characterized clinically and by echocardiography and compared with each other. Plasma NT-proBNP levels were measured (ECLIA-Elecsys proBNP) and compared in the 3 groups of individuals included in the study. In hypertrophic cardiomyopathy patients, correlation was sought between NT-proBNP levels, NYHA functional class and echocardiographic data. RESULTS: Groups A and B differed (p < 0.001) in septal thickness, maximal wall thickness, left ventricular hypertrophy score, left atrial size, left atrial fractional shortening, derived transmitral filling indices and plasma NT-proBNP levels (group A: 909.9 +/- 1554.2 pg/ml; group B: 40.7 +/- 45.1 pg/ml). Left ventricular diastolic size and pulmonary venous flow velocity-derived indices were similar in the 2 groups. NT-proBNP levels in group B and C (39.4 +/- 34.5 pg/ml) were similar (p = NS). In hypertrophic cardiomyopathy patients, NT-proBNP levels correlate directly with NYHA functional class (r = 0.56, p < 0.001), septal thickness (r = 0.53, p < 0.001), maximal wall thickness (r = 0.59, p < 0.001), left ventricular hypertrophy score (r = 0.63, p < 0.001), left atrial size (r = 0.32, p = 0.023) and mitral deceleration time (r = 0.46, p = 0.001) and inversely with left atrial fractional shortening (r = -0.41, p = 0.005). Functional class also correlates directly with left ventricular hypertrophy score (r = 0.39, p = 0.006), with the most symptomatic patients having the highest scores. CONCLUSIONS: In hypertrophic cardiomyopathy, plasma NT-proBNP levels depend mainly on the severity of left ventricular hypertrophy rather than on the presence of obstruction. Measurement of the peptide may help in the clinical characterization and follow-up of patients with this disease.