D. Burstow

Effects of Age on Left Ventricular Dimensions and Filling Dynamics in 117 Normal Persons

OBJECTIVE To determine standard left ventricular Doppler measurements in a large reference group of various ages to reflect the senescence process. DESIGN We prospectively studied the influence of aging on left ventricular diastolic filling by performing Doppler echocardiography in 117 normal healthy volunteers. MATERIAL AND METHODS Transthoracic pulsed-wave Doppler echocardiographic studies of pulmonary venous flow and left ventricular inflow were done in the 53 male and 64 female study subjects. For analysis, the study subjects were arbitrarily classified into two groups: those younger than 50 years of age (group 1; N = 61) and those 50 years old or older (group 2; N = 56). RESULTS A striking difference was found in pulmonary venous flow and left ventricular inflow between group 1 and group 2 subjects. Group 2 had increased pulmonary venous peak systolic flow velocity (71 +/- 9 versus 48 +/- 9 cm/s), decreased peak diastolic flow velocity (38 +/- 9 versus 50 +/- 10 cm/s), increased peak atrial reversal flow velocity (23 +/- 4 versus 19 +/- 4 cm/s), and increased percentage of forward flow in systole (65 +/- 7 versus 55 +/- 8%) in comparison with group 1. In group 2, peak early filling velocity (62 +/- 14 versus 72 +/- 14 cm/s) and ratio of early filling to atrial filling (1.1 +/- 0.3 versus 1.9 +/- 0.6) were lower and peak atrial filling velocity (59 +/- 14 versus 40 +/- 10 cm/s) was higher than in group 1. Deceleration time (210 +/- 36 versus 179 +/- 20 ms) and isovolumic relaxation time (90 +/- 17 versus 76 +/- 11 ms) were prolonged in group 2 in comparison with group 1. CONCLUSION This study confirms the major influence of the aging process on left ventricular diastolic function in a large series of normal subjects. This physiologic factor should be considered in Doppler assessment of left ventricular diastolic filling in future studies.

Doppler characterization of left ventricular diastolic function in cardiac amyloidosis

Sixty-four patients with primary systemic amyloidosis-53 with two-dimensional echocardiographic features of cardiac involvement (Group I) and 11 without cardiac involvement (Group II)--underwent Doppler echocardiographic assessment of left ventricular diastolic function. Pulsed wave Doppler recordings of left ventricular inflow velocities and pulmonary vein flow velocities with respiratory monitoring in these patients were compared with findings in a normal group. Patients in Group I showed striking abnormalities of left ventricular diastolic filling when classified into subgroups by mean left ventricular wall thickness: early greater than 12 but less than 15 mm; advanced greater than or equal to 15 mm. In early amyloidosis, relaxation was abnormal, with decreased peak early velocity (75 +/- 20 versus 86 +/- 16 cm/s; p less than 0.01), increased late velocity (71 +/- 22 versus 56 +/- 13 cm/s; p less than 0.01), decreased early to late velocity ratio (1.2 +/- 0.6 versus 1.6 +/- 0.5; p less than 0.01) and prolonged isovolumic relaxation time (87 +/- 15 versus 73 +/- 13 ms; p less than 0.01) compared with normal values. In advanced amyloidosis, there was a restrictive filling pattern with a markedly shortened deceleration time (148 +/- 50 versus 199 +/- 32 ms; p less than 0.001), decreased pulmonary vein peak systolic flow velocity (34 +/- 16 versus 54 +/- 12 cm/s; p less than 0.01) and increased diastolic flow velocity (55 +/- 20 versus 44 +/- 12 cm/s; p less than 0.01) compared with normal values. Group and the subgroup with early amyloidosis had similar flow velocity patterns. Thus, this study documents that in cardiac amyloidosis, a spectrum of diastolic filling abnormalities exists; the restrictive filling pattern is seen only in the advanced stages.

Age-related Prevalence of Valvular Regurgitation in Normal Subjects: A Comprehensive Color Flow Examination of 118, Volunteers

We prospectively assessed the influence of aging on the prevalence of valvular regurgitation by using color flow imaging. One hundred eighteen healthy volunteers (21 to 82 years old) had a two-dimensional Doppler echocardiographic study that included color flow imaging to assess valvular regurgitation and that was semiquantitated by mapping the dimensions of the color flow regurgitant jet in orthogonal views. The subjects were divided into two groups: group 1 consisted of subjects who were younger than 50 years old (n = 61), and group 2 consisted of subjects who were at least 50 years old (n = 57). Mitral regurgitation was detected in 57 (48%) of the 118 subjects: 24 subjects (39%) in group 1 and 33 subjects (58%) in group 2. The severity of mitral regurgitation was trivial to mild. Aortic regurgitation was detected in 13 (11%) of the 118 subjects, all in group 2. The severity was trivial to mild. Tricuspid regurgitation was detected in 77 (65%) of the 118 subjects: 35 (57%) in group 1 and 42 (74%) in group 2. The severity was trivial to mild. Pulmonary regurgitation was detected in 24 (31%) of 78 subjects: nine (22%) in group 1 and 15 (41%) in group 2. The severity was trivial. These findings suggest that valvular regurgitation of a trivial or mild degree is a frequent finding in normal subjects and that it increases with age.

Continuous wave Doppler echocardiographic measurement of prosthetic valve gradients. A simultaneous Doppler-catheter correlative study.

Studies correlating prosthetic valve gradients determined by continuous wave Doppler echocardiography with gradients obtained by cardiac catheterization have, to date, been limited to patients with mitral and tricuspid prostheses or have compared nonsimultaneous measurements. Simultaneous Doppler and catheter pressure gradients in 36 patients (mean age, 63 +/- 13 years) with 42 prosthetic valves (20 aortic, 20 mitral, one tricuspid, and one pulmonary) were studied. Catheter gradients were obtained using a dual-catheter technique. The simultaneous pressure tracings and Doppler flow velocity profiles were digitized at 10-msec intervals to derive the corresponding maximal and mean gradients. The correlation between the maximal Doppler gradient and the simultaneously measured maximal catheter gradient was 0.94 (SEE = 6), and that between the Doppler gradient and the simultaneously measured mean catheter gradient was 0.96 (SEE = 3). There were no significant differences in correlation between gradients for the 32 mechanical valves (maximal gradients: r = 0.95, SEE = 6; mean gradients: r = 0.96, SEE = 3) and the 10 bioprosthetic valves (maximal gradients: r = 0.89, SEE = 6; mean gradients: r = 0.93, SEE = 3). In patients with mitral prostheses, Doppler gradients correlated well with the corresponding catheter gradients obtained with direct measurement of left atrial pressure (maximal gradients: r = 0.96, SEE = 2; mean gradients: r = 0.97, SEE = 1.2). A close correlation between corresponding Doppler and catheter gradients also was found in patients with aortic prostheses (maximal gradients: r = 0.94, SEE = 6; mean gradients: r = 0.94, SEE = 3). Thus, continuous wave Doppler echocardiography can accurately predict the pressure gradient across prosthetic valves.

Lack of effect of coenzyme Q on left ventricular function in patients with congestive heart failure.

OBJECTIVES This study evaluated the effects of oral therapy with coenzyme Q on echocardiographic and hemodynamic indexes of left ventricular function and on quality of life in patients with chronic left ventricular dysfunction. BACKGROUND Coenzyme Q a coenzyme for oxidative phosphorylation and an antioxidant and free radical scavenger. It has been claimed to improve symptoms, quality of life, left ventricular ejection fraction and prognosis in patients with cardiac failure. METHODS Thirty patients with ischemic or idiopathic dilated cardiomyopathy and chronic left ventricular dysfunction (ejection fraction 26 +/- 6%) were randomized to a double-blind crossover trial of oral coenzyme Q versus placebo each for 3 months. Right heart pressures, cardiac output and echocardiographic left ventricular volumes were measured at baseline and after each treatment phase, and quality of life was assessed using the Minnesota Living With Heart Failure questionnaire. It was calculated that to demonstrate an increase in left ventricular ejection fraction from 25% to 30% with a standard deviation of 5% using 95% confidence intervals with a power of 80% we would require 17 patients. RESULTS Twenty-seven completed both treatment phases. There was no significant difference in left ventricular ejection fraction, cardiac volumes or hemodynamic and quality of life indices after treatment with coenzyme Q placebo, although plasma coenzyme Q levels increased from 903 +/- 345 nmol/l(-1) to 2,029 +/- 856 nmol/l(-1). CONCLUSIONS Inpatients with left ventricular dysfunction, treatment for three months with oral coenzyme Q failed to improve resting left ventricular systolic function or quality of life despite an increase in plasma levels of coenzyme Q to more than twice basal values

Comprehensive Doppler assessment of right ventricular diastolic function in cardiac amyloidosis

To assess right ventricular diastolic function in cardiac amyloidosis, pulsed wave Doppler ultrasound measurements of right ventricular inflow velocities and superior vena cava and hepatic vein flow velocities with respiratory monitoring were performed in 41 patients with primary systemic amyloidosis and two-dimensional echocardiographic features of cardiac involvement. Right ventricular diastolic function was abnormal in 31 (76%) of these patients, the major abnormality being a short deceleration time (less than 150 ms) in 21 (68%), suggesting restriction. In contrast, 7 (23%) of the 31 patients had a decreased ratio of early (E) and late (A) diastolic peak flow velocities and a prolonged deceleration time (greater than 240 ms), suggesting abnormal relaxation. The patients were classified into two groups on the basis of right ventricular free wall thickness: group 1, less than 7 mm and group 2, greater than or equal to 7 mm. Compared with normal values, group 1 showed an increased peak late flow velocity (44 +/- 19 versus 39 +/- 6 cm/s; p less than 0.01) and a decreased E/A velocity ratio (1.1 +/- 0.4 versus 1.5 +/- 0.3; p less than 0.01). Group 2 showed a markedly shortened deceleration time (151 +/- 37 versus 225 +/- 28 ms; p less than 0.01), characteristic of restriction. In the overall group, superior vena cava peak flow velocity was decreased in systole and increased in diastole and flow reversals during inspiration were increased compared with normal values. Hepatic venous flow velocities were similar to those in the superior vena cava except for larger flow reversals in the hepatic vein. Thus, in cardiac amyloidosis, right ventricular diastolic function is abnormal. There is a spectrum of right ventricular filling abnormalities and the restrictive filling pattern is seen only in the advanced stages of the disease.

Two-dimensional echocardiographic findings in systemic sarcoidosis

The records of 88 patients with systemic sarcoidosis who underwent 2-dimensional echocardiography were reviewed to define the typical echocardiographic abnormalities in patients with clinical evidence of cardiac involvement. Twelve patients (14%) had echocardiographic evidence of left ventricular systolic dysfunction attributed to cardiac sarcoidosis (segmental hypokinesis in 8 patients and global hypokinesis in 4 patients). A high incidence of congestive heart failure (9 of 12) and conduction system disease (7 of 12) was characteristic of these patients. The remaining 76 patients had normal echocardiograms or abnormalities attributed to nonsarcoid sources. In 8 (11%) of these 76 patients, there were significant clinically unexplained conduction abnormalities likely related to sarcoidosis.

Arg389Gly-[beta]1-adrenergic receptors determine improvement in left ventricular systolic function in nonischemic cardiomyopathy patients with heart failure after chronic treatment with carvedilol

Objective Administration of the &bgr;-adrenergic receptor blocker carvedilol to patients with chronic heart failure leads to clinically significant benefits, including improvement in left ventricular systolic function in some, but not all, patients. We sought to determine the basis of the variable effect obtained with carvedilol in patients with heart failure. Carvedilol blocks both &bgr;1-adrenergic and &bgr;2-adrenergic receptors, and both receptors exist as polymorphisms. We aimed to determine whether these polymorphisms contribute to variability in response to carvedilol in patients with chronic heart failure. Methods We retrospectively and prospectively investigated 135 patients with nonischemic cardiomyopathy and chronic stable heart failure (New York Heart Association class II, III) treated with carvedilol. Baseline echocardiography was obtained before introduction of carvedilol and repeated after stabilization of a maximally tolerated dose of carvedilol (50–100 mg/day) for at least 1 year. Polymerase chain reaction and restriction fragment length polymorphism analysis were used to genotype &bgr;1-adrenergic and &bgr;2-adrenergic receptor polymorphisms. Results When grouped according to receptor polymorphisms patients were well matched for severity of heart failure, comorbidity and treatment. No significant difference was observed in baseline left ventricular ejection fraction (LVEF) between groups (P>0.05). After 1.5 years of treatment with carvedilol patients with Arg389Arg-&bgr;1-adrenergic receptors had a significantly greater improvement in LVEF compared with Gly389 carriers (Arg389Arg 18.8%; Arg389Gly 9.4%; Gly389Gly 6.0%; P<0.001) whereas there were no differences attributable to other &bgr;1-adrenergic and &bgr;2-adrenergic receptor polymorphisms (P>0.05). Conclusion In patients with nonischemic dilated cardiomyopathy, carvedilol leads to a significantly greater improvement in LVEF in patients with the Arg389Arg-&bgr;1 adrenergic receptor phenotype.

The Role of Echocardiography in the Management of Patients Supported by Extracorporeal Membrane Oxygenation

Extracorporeal life support can be viewed as a spectrum of modalities based on modifications of a cardiopulmonary bypass circuit to provide cardiac and respiratory support, which can be used for extended periods, from hours to several weeks. Extracorporeal membrane oxygenation (ECMO) is among the most frequently used forms of extracorporeal life support. It can be configured for venovenous blood flow, to provide adequate oxygenation and carbon dioxide removal in isolated refractory respiratory failure, or in a venoarterial configuration, when support is required for cardiac and/or respiratory failure. Echocardiography plays a fundamental role throughout the entire journey of a patient supported on ECMO. It provides information that assists in patient selection, guides the insertion and placement of cannulas, monitors progress, detects complications, and helps in determining cardiac recovery and the weaning of ECMO support. Although there are extensive published data regarding ECMO, particularly in the pediatric population, there is a paucity of data outlining the role of echocardiography in guiding the management of adult patients supported by ECMO. ECMO is likely to become an increasingly used form of cardiorespiratory support within the critical care setting. Hence, clinicians and sonographers who work within echocardiography departments at institutions with ECMO programs require specific skills to image these patients.

Cardiac Tamponade: Characteristic Doppler Observations

Abnormal respiratory variation in diastolic filling has been reported in patients with cardiac tamponade. To determine the characteristic diastolic filling abnormalities in this disorder, we recorded left ventricular isovolumic relaxation time and transvalvular and hepatic venous flow velocities by pulsed-wave Doppler echocardiography in 28 patients with pericardial effusion (16 with and 12 without cardiac tamponade) and 20 normal control subjects. The phase of respiration was recorded simultaneously with all profiles. In 13 of the 16 patients with cardiac tamponade, Doppler examination was repeated after pericardiocentesis. In patients with cardiac tamponade, respiratory variations in transvalvular flow velocities and isovolumic relaxation time were substantially increased in comparison with values in normal subjects, patients without tamponade, and those who had undergone pericardiocentesis. An exaggerated expiratory decrease in diastolic forward flow and increase in reverse flow in the hepatic vein also were characteristic of patients with cardiac tamponade. Thus, Doppler echocardiography is an additional noninvasive means of detecting hemodynamic compromise in patients with pericardial effusion.