Long axis electromechanics during dobutamine stress in patients with coronary artery disease and left ventricular dysfunction

OBJECTIVE—To dissociate the effect of inotropy from activation change during dobutamine stress on left ventricular long axis function in patients with coronary artery disease (CAD).
METHODS—25 patients with CAD and normal left ventricular cavity size and 30 with cavity dilatation—18 with normal activation (DCM-NA) and 12 with left bundle branch block (DCM-LBBB)—were compared with 20 controls. 12 lead ECG and septal long axis echograms were assessed at rest and peak dobutamine stress. Amplitude, shortening and lengthening velocities, postejection shortening, Q wave to onset of shortening (Q-OS), and A2 to onset of lengthening (A2-OL) were measured. Inotropy was evaluated from peak aortic acceleration.
RESULTS—In controls, amplitude, shortening and lengthening velocities, and peak aortic acceleration increased with stress; QRS, Q-OS, and A2-OL shortened (all p < 0.001); and contraction remained coordinate. In the group of patients with CAD and normal left ventricular cavity size, shortening velocity and peak aortic acceleration increased with stress (p < 0.005). However, amplitude and lengthening velocity did not change, QRS, Q-OS, and A2-OL lengthened (p < 0.01), and incoordination appeared. Results were similar in the group with DCM-NA. In the DCM-LBBB group, shortening velocity and peak aortic acceleration increased modestly with stress (p < 0.01) but amplitude, lengthening velocity, QRS, Q-OS, A2-OL, and incoordination remained unchanged. Overall, change in shortening velocity correlated with that in peak aortic acceleration (r² = 0.71), in amplitude with that in lengthening velocity (r² = 0.74), and in QRS with both Q-OS (r² = 0.69) and A2-OL (r² = 0.63).
CONCLUSION—The normal long axis response to dobutamine reflects both inotropy and rapid activation. In CAD, inotropy is preserved with development of ischaemia but the normal increase in amplitude is lost and prolonged activation delays the time course of shortening, causing pronounced incoordination. Overall, shortening rate uniformly reflects inotropy while lengthening rate depends mainly on systolic amplitude rather than primary diastolic involvement, even with overt ischaemia.


Keywords: stress echocardiography; activation; inotropy; incoordination     

Different effects of abnormal activation and myocardial disease on left ventricular ejection and filling times

BACKGROUND—Ventricular activation is often abnormal in patients with dilated cardiomyopathy, but its specific effects on timing remain undetermined.
OBJECTIVE—To investigate the use of the ratio of the sum of left ventricular ejection and filling times to the total RR interval (Z ratio) to dissociate the effects of abnormal activation from those of cavity dilatation.
METHODS—Subjects were 20 normal individuals, 11 patients with isolated left bundle branch block (LBBB, QRS duration > 120 ms), 17 with dilated cardiomyopathy and normal activation, and 23 with dilated cardiomyopathy and LBBB. An additional 30 patients (nine with normal ventricular systolic function and 21 with dilated cardiomyopathy) were studied before and after right ventricular pacing. Left ventricular ejection and filling times were measured by pulsed wave Doppler and cavity size by M mode echocardiography.
RESULTS—Z ratio was independent of RR interval in all groups. Mean (SD) Z ratio was 82 (10)% for normal subjects, 66 (10)% for isolated LBBB (p < 0.01 v normal), 77 (7)% for dilated cardiomyopathy without LBBB (NS v normal), and 61 (7)% for dilated cardiomyopathy with LBBB (p < 0.01 v normal). In the nine patients with normal left ventricular size and QRS duration, Z ratio fell from 88 (6)% in sinus rhythm to 77 (10)% with right ventricular pacing (p = 0.26). In the 21 patients with dilated cardiomyopathy and LBBB, Z ratio rose from 59 (10)% in sinus rhythm to 74 (9)% with right ventricular DDD pacing (p < 0.001).
CONCLUSIONS—Z ratio dissociates the effects of abnormal ventricular activation and systolic disease. It also clearly differentiates right ventricular pacing from LBBB. It may thus be useful in comparing the haemodynamic effects of different pacing modes in patients with or without left ventricular disease.


Keywords: dilated cardiomyopathy; pacemaker; left bundle branch block; echocardiography.     

Relation between right ventricular enlargement, QRS duration, and right ventricular function in patients with tetralogy of Fallot and pulmonary regurgitation after surgical repair

OBJECTIVE—In patients with repaired tetralogy of Fallot, to examine (1) a possible relation between right ventricular enlargement and QRS prolongation, and (2) the effect of right ventricular enlargement caused by pulmonary regurgitation on the right ventricular ejection fraction, evaluated by three dimensional echocardiography, and global function, evaluated by the myocardial performance index.
DESIGN AND PATIENTS—40 patients with repaired tetralogy were studied. Right ventricular volumes were derived from three dimensional echocardiographic data after this method had been validated by comparison with magnetic resonance imaging in 21 patients. Ejection fraction was calculated from end diastolic and end systolic volumes. The Doppler derived myocardial performance index was measured in all patients. Measured data were correlated with QRS duration.
SETTING—Tertiary cardiac centre for congenital heart disease.
RESULTS—There was good agreement between three dimensional echocardiographic and magnetic resonance assessment of right ventricular volumes and ejection fraction. The z score of the right ventricular end diastolic volume and ejection fraction of all patients was 1.35 and −4.15, respectively. Patients with severe pulmonary regurgitation had a lower right ventricular ejection fraction (p < 0.01) and an increased myocardial performance index (p < 0.01) compared with patients with mild to moderate pulmonary regurgitation. The correlation between ejection fraction and right ventricular end diastolic volume was r = −0.35 (p < 0.05). The mean (SD) QRS duration was 131.89 (25.69) ms, range 80-180 ms. The correlation between QRS duration and right ventricular end diastolic volume was r = 0.6 (p < 0.01).
CONCLUSIONS—There is a correlation between the right ventricular size obtained by three dimensional echocardiography and QRS duration on the surface ECG, indicating mechanoelectrical interaction. The severity of pulmonary regurgitation has a negative influence on right ventricular ejection fraction and combined systolic and diastolic global function, as assessed by myocardial performance.


Keywords: tetralogy of Fallot; pulmonary regurgitation; right ventricular enlargement; QRS prolongation     

Long axis excursion in aortic stenosis

OBJECTIVES—To examine long axis excursion in patients with all grades of aortic stenosis and preserved transverse systolic function, and to compare long axis excursion in symptomatic with that in asymptomatic severe aortic stenosis.
DESIGN—Prospective comparative study.
SETTING—Regional cardiothoracic centre.
PATIENTS—78 patients with all grades of aortic stenosis and normal fractional shortening and ejection fraction were studied. There were two comparison groups, 10 age matched normal subjects and 14 patients with aortic stenosis and fractional shortening < 26%.
METHODS—Aortic valve function and left ventricular mass were assessed echocardiographically. M mode measurements of long axis excursion at the septal and lateral sides of the mitral annulus were taken.
RESULTS—There were significant differences between the groups in long axis excursion at both the septal (p < 0.0001) and lateral sides of the mitral annulus (p = 0.002 by analysis of variance). Long axis excursion was independently related to both left ventricular mass index (p = 0.001) and the grade of aortic stenosis (p = 0.002). Comparing patients with severe aortic stenosis with and without symptoms, there were significant differences in effective orifice area (p = 0.02 ) and long axis excursion at the lateral side of the mitral annulus (p = 0.04), but not in fractional shortening, ejection fraction, or peak or mean pressure difference.
CONCLUSION—In patients with aortic stenosis, long axis excursion is reduced even in the presence of normal fractional shortening or ejection fraction. It is lower in patients with symptomatic compared with asymptomatic severe aortic stenosis and may be of use in predicting the onset of symptoms.


Keywords: aortic stenosis; long axis excursion; symptoms     

N-terminal proatrial natriuretic peptide correlates with systolic dysfunction and left ventricular filling pattern in patients with idiopathic dilated cardiomyopathy

OBJECTIVE—To investigate the diastolic Doppler filling pattern in patients with idiopathic dilated cardiomyopathy and its relation to N-terminal pro-atrial natriuretic peptide (NT-pro-ANP).
METHODS—32 patients (26 male, six female) with idiopathic dilated cardiomyopathy were investigated. All were in sinus rhythm. Conventional M mode echocardiography and Doppler echocardiography was done in each patient. Pulsed wave Doppler inflow signals were obtained and the following variables were measured: maximum E wave, maximum A wave, E/A ratio, E wave deceleration time, A wave deceleration time. NT-pro-ANP was measured using radioimmunoassay.
RESULTS—Mean (SD) left ventricular ejection fraction was 34 (7)% and mean left ventricular end diastolic diameter on M mode echocardiography was 69 (7) mm. Left ventricular filling indices were as follows: maximum E wave velocity, 0.86 (0.22) m/s; maximum A wave velocity, 0.71 (0.24) m/s; E/A ratio, 1.41 (0.65). Mean E wave deceleration time was 140 (50) ms; mean A wave deceleration time was 100 (20) ms. In a stepwise forward regression model, NT-pro-ANP correlated significantly with left atrial diameter (r = 0.603; p < 0.001), left ventricular ejection fraction (r = −0.758; p < 0.001), and Doppler derived E/A ratio (r = 0.740; p < 0.001).
CONCLUSIONS—In patients with idiopathic dilated cardiomyopathy there is a relation between NT-pro-ANP and both systolic and diastolic variables. In a multivariate model NT-pro-ANP correlated with left atrial diameter, left ventricular ejection fraction, and Doppler derived E/A ratio on transmitral inflow.


Keywords: idiopathic dilated cardiomyopathy; transmitral Doppler filling; N-terminal pro-ANP; atrial natriuretic factor     

Abnormal ventricular activation and repolarisation during dobutamine stress echocardiography in coronary artery disease

Objective—To assess possible ECG changes caused by dobutamine stress and their relation to wall motion disturbances in patients with coronary artery disease.
Design—Prospective recording and analysis of 12 lead ECG at rest and during each stage of dobutamine stress echocardiography, and correlation with wall motion changes.
Setting—A tertiary referral centre for cardiac disease equipped with non-invasive facilities for pharmacological stress tests.
Subjects—27 patients, mean (SD) age 60 (8) years, with documented evidence of coronary artery disease in whom dobutamine stress echo was clinically indicated, and 17 controls of similar age.
Results—In controls, all ECG intervals shortened with increasing heart rate but in the patient group only PR and QT intervals shortened while QRS duration broadened and QTc interval prolonged progressively. In the 27 patients, 16 developed chest pain, 15 with reduced left ventricular long axis systolic excursion (p < 0.001), and all showed reduced peak lengthening rate; ST segment shift appeared in 16, 13 of whom developed chest pain, but did not correlate with reduction of either systolic long axis excursion or peak lengthening rate; QRS duration broadened in 20, 16 with reduction of long axis excursion (p < 0.02) which was more often seen at the septum (p < 0.005); QTc interval prolonged in 19, all of whom had associated reduction of peak long axis lengthening rate (p < 0.02).
Conclusions—QRS duration and QTc interval both normally shorten with dobutamine stress, while in coronary artery disease they both lengthen: changes in QRS duration correlate with systolic and QTc interval with diastolic left ventricular wall motion disturbances. ST segment shift also occurred in most patients, but without consistent correlation with wall motion abnormalities. It was thus less discriminating than the other two abnormalities in this respect.

Keywords: long axis;  QRS duration;  QTc interval;  stress echocardiography;  coronary artery disease     

Incidence and prognostic significance of atrial fibrillation in acute myocardial infarction: the GISSI-3 data

OBJECTIVE—To assess the relations between early filling deceleration time, left ventricular remodelling, and cardiac mortality in an unselected group of postinfarction patients.
DESIGN AND PATIENTS—Prospective evaluation of 131 consecutive patients with first acute myocardial infarction. Echocardiography was performed on day 1, day 2, day 3, day 7, at three and six weeks, and at three, six, and 12 months after infarction. According to deceleration time on day 1, patients were divided into groups with short (< 150 ms) and normal deceleration time ( 150 ms).
SETTING—Tertiary care centre.
RESULTS—Patients with a short deceleration time had higher end systolic and end diastolic volume indices and a higher wall motion score index, but a lower ejection fraction, in the year after infarction. These patients also showed a significant increase in end diastolic (p < 0.001) and end systolic volume indices (p = 0.007) during the follow up period, while ejection fraction and wall motion score index remained unchanged. In the group with normal deceleration time, end diastolic volume index increased (p < 0.001) but end systolic volume index did not change; in addition, the ejection fraction increased (p = 0.002) and the wall motion score index decreased (p < 0.001). One year and five year survival analysis showed greater cardiac mortality in patients with a short deceleration time (p = 0.04 and p = 0.02, respectively). In a Cox model, which included initial ejection fraction, infarct location, and infarct size, deceleration time on day 1 was the only significant predictor of five year mortality.
CONCLUSIONS—A short deceleration time on day 1 after acute myocardial infarction can identify patients who are likely to undergo left ventricular remodelling in the following year. These patients have a higher one year and five year cardiac mortality.


Keywords: deceleration time; left ventricular remodelling; acute myocardial infarction     

Four year follow up of aortic valve replacement for isolated aortic stenosis: a link between reduction in pressure overload, regression of left ventricular hypertrophy, and diastolic function

OBJECTIVE—To evaluate changes in left ventricular function and the impact of ventricular hypertrophy and pressure gradient early and late after aortic valve replacement in patients with isolated aortic stenosis.
DESIGN—41 patients with isolated aortic stenosis and normal systolic function underwent cross sectional and Doppler echocardiography two months before and two weeks and four years after aortic valve replacement.
RESULTS—Early after the operation, left ventricular mass index (mean (SD)) decreased from 187 (44) g/m² to 179 (46) g/m², because of a reduction in end diastolic diameter (p < 0.05). Aortic pressure gradients were reduced, as expected. Isovolumic relaxation time was reduced from 93 (20) ms to 78 (12) ms, and deceleration time from 241 (102) ms to 205 (77) ms (p < 0.05). At four years, left ventricular mass index was further reduced to 135 (30) g/m² (p < 0.01) as a result of wall thickness reduction in the interventricular septum (from 14 (1.6) mm to 12 (1.4) mm, p < 0.01) and the posterior wall (from 14 (1.6) mm to 12 (1.3) mm, p < 0.01). Diastolic function, expressed by a reduction in isovolumic relaxation time from 93 (20) ms to 81 (15) ms (p < 0.01) and deceleration time from 241 (102) ms to 226 (96) ms (p < 0.05), remained improved. Prolonged isovolumic relaxation time was associated with significant septal and posterior wall hypertrophy (wall thickness > 13 mm) (p < 0.05), whereas prolonged deceleration time was related to high residual gradient (peak gradient > 30 mm Hg ) (p < 0.01).
CONCLUSIONS—Left ventricular diastolic function improves early after surgery for aortic stenosis in parallel with the reduction in the aortic gradient. However, prolongation of Doppler indices of myocardial relaxation and ventricular filling is observed in patients with significant left ventricular hypertrophy and a residual pressure gradient early after surgery. At four years postoperatively, diastolic function remains improved.


Keywords: diastolic function; hypertrophy regression; aortic valve replacement; aortic stenosis     

Circadian rhythm of the signal averaged electrocardiogram and its relation to heart rate variability in healthy subjects

Objective—To examine the circadian variation in the signal averaged electrocardiogram (saECG) and heart rate variability and investigate their relations in healthy subjects.
Methods—24 hour ECGs were obtained with a three channel recorder using bipolar X, Y, and Z leads in 20 healthy subjects. The following variables were determined hourly: heart rate, filtered QRS (f-QRS) duration, low and high frequency components of heart rate variability (LF and HF), and the LF/HF ratio.
Results—Heart rate, f-QRS duration, HF, and the LF/HF ratio showed significant circadian rhythms, as determined by the single cosinor method. Heart rate and the LF/HF ratio increased during daytime, and f-QRS duration and HF increased at night. f-QRS duration was negatively correlated with heart rate (r = 0.95, p < 0.001) and the LF/HF ratio (r = 0.94, p < 0.001) and positively with HF (r = 0.93, p < 0.001).
Conclusions—f-QRS duration has a significant circadian rhythm in healthy subjects and is closely related to the circadian rhythm of autonomic tone.

Keywords: signal averaged ECG;  f-QRS duration;  circadian rhythm;  heart rate variability     

Early changes in longitudinal performance predict future improvement in global left ventricular function during long term beta adrenergic blockade

OBJECTIVE—Contraction of longitudinal and subendocardial myocardial muscle fibres is reflected in descent of the atrioventricular (AV) plane. The aim was therefore to determine whether β blocker treatment with prolongation of diastole might result in improved function as reflected by AV plane movements in patients with chronic heart failure.
DESIGN—Double blind, randomised, placebo controlled and open intervention study.
SETTING—University hospital.
PATIENTS—Patients with congestive heart failure: placebo controlled (n = 26) and an open protocol (n = 15).
INTERVENTIONS—12 months of metoprolol treatment.
MAIN OUTCOME MEASURES—Short axis and long axis echocardiography, invasive haemodynamics, radionuclide angiography.
RESULTS—Recovery of systolic and diastolic function during metoprolol treatment was reflected by early changes in mean (SD) AV plane amplitude, from 5.3 (2.0)% to 7.1 (3.2)% and 7.8 (3.1)% (at 3 and 12 months, respectively; p < 0.05). In a multivariate analysis, only the change in AV plane amplitude by three months was independently associated with improvement in pulmonary capillary wedge pressure by six months (r = 0.80, p = 0.017). Change in AV plane amplitude by three months was also a better predictor of improvement in ejection fraction by 12 months (r = 0.78, p < 0.001) than changes in radionuclide ejection fraction by three months (r = 0.34, p = 0.049).
CONCLUSIONS—Improvement in longitudinal contraction was closely associated with a decrease in left ventricular filling pressure during metoprolol treatment. This association was stronger than changes in short axis performance or radionuclide ejection fraction, emphasising the importance of AV plane motion for left ventricular filling and systolic performance in patients with heart failure.


Keywords: diastolic function; metoprolol; dilated cardiomyopathy; echocardiography     

Relaxation in hypertrophic cardiomyopathy and hypertensive heart disease: relations between hypertrophy and diastolic function

AIM—To determine the relation between the extent and distribution of left ventricular hypertrophy and the degree of disturbance of regional relaxation and global left ventricular filling.
METHODS—Regional wall thickness (rWT) was measured in eight myocardial regions in 17 patients with hypertrophic cardiomyopathy, 12 patients with hypertensive heart disease, and 10 age matched normal subjects, and an asymmetry index calculated. Regional relaxation was assessed in these eight regions using regional isovolumetric relaxation time (rIVRT) and early to late peak filling velocity ratio (rE/A) derived from Doppler tissue imaging. Asynchrony of rIVRT was calculated. Doppler left ventricular filling indices were assessed using the isovolumetric relaxation time, the deceleration time of early diastolic filling (E-DT), and the E/A ratio.
RESULTS—There was a correlation between rWT and both rIVRT and rE/A in the two types of heart disease (hypertrophic cardiomyopathy: r = 0.47, p < 0.0001 for rIVRT; r = −0.20, p < 0.05 for rE/A; hypertensive heart disease: r = 0.21, p < 0.05 for rIVRT; r = −0.30, p = 0.003 for rE/A). The degree of left ventricular asymmetry was related to prolonged E-DT (r = 0.50, p = 0.001) and increased asynchrony (r = 0.42, p = 0.002) in all patients combined, but not within individual groups. Asynchrony itself was associated with decreased E/A (r = −0.39, p = 0.01) and protracted E-DT (r = 0.69, p < 0.0001) and isovolumetric relaxation time (r = 0.51, p = 0.001) in all patients. These correlations were still significant for E-DT in hypertrophic cardiomyopathy (r = 0.56, p = 0.02) and hypertensive heart disease (r = 0.59, p < 0.05) and for isovolumetric relaxation time in non-obstructive hypertrophic cardiomyopathy (n = 8, r = 0.87, p = 0.005).
CONCLUSIONS—Non-invasive ultrasonographic examination of the left ventricle shows that in both hypertrophic cardiomyopathy and hypertensive heart disease, the local extent of left ventricular hypertrophy is associated with regional left ventricular relaxation abnormalities. Asymmetrical distribution of left ventricular hypertrophy is indirectly related to global left ventricular early filling abnormalities through regional asynchrony of left ventricular relaxation.


Keywords: hypertrophic cardiomyopathy; hypertensive heart disease; isovolumetric relaxation; diastolic function     

Prognostic value of left ventricular diastolic function and association with heart rate variability after a first acute myocardial infarction

OBJECTIVE—To study the prognostic value of left ventricular (LV) diastolic function and its relation with autonomic balance expressed by heart rate variability (HRV) in patients after a first acute myocardial infarction.
DESIGN—The study population consisted of 64 consecutive patients with first acute myocardial infarction and 31 control subjects. Long and short term HRV indices were evaluated by 24 hour Holter monitoring, and LV systolic and diastolic function were assessed by two dimensional and Doppler echocardiography before discharge. Patients were divided into two groups: those with restrictive LV filling characteristics (deceleration time  140 ms) and those with non-restrictive LV filling characteristics (deceleration time > 140 ms).
RESULTS—Both long and short term HRV indices were significantly reduced in patients with restrictive LV filling compared with the non-restrictive group and control subjects. Mitral deceleration time and isovolumetric relaxation time correlated weakly but significantly with all indices of HRV whereas ejection fraction correlated weakly with the long term HRV indices. The mean follow up time was 14.9 (8.7) months. Multivariate analysis showed that mitral deceleration time (χ² = 6.4, p < 0.001) and ejection fraction  40% (χ² = 4.4, p < 0.05) were independent predictors of cardiac death and readmission to hospital with congestive heart failure.
CONCLUSIONS—A restrictive LV filling pattern was found to be the strongest predictor of adverse outcome independent of HRV and ejection fraction during follow up after a first acute myocardial infarction. Patients with restrictive LV filling characteristics had more reduced HRV than those with non-restrictive diastolic filling.


Keywords: diastole; infarction; autonomic balance     

Operator independent left ventricular function monitoring during pharmacological stress echo with the new peak transcutaneous acceleration signal

BACKGROUND—As the myocardium contracts isometrically, it generates vibrations that can be measured with an accelerometer. The vibration peak, peak endocardial acceleration (PEA), is an index of contractility.
OBJECTIVE—To evaluate the feasibility of PEA measured by the cutaneous precordial application of the accelerometer sensor; and to assess the usefulness of PEA monitoring during pharmacological stress echocardiography.
DESIGN—Feasibility study.
SETTING—Stress echo laboratory.
PATIENTS—34 consecutive patients underwent pharmacological stress (26 with dipyridamole; 8 with dobutamine) and PEA monitoring simultaneously.
INTERVENTIONS—A microaccelerometer was positioned in the precordial region and PEA was recorded. Dipyridamole was infused up to 0.84 mg/kg in 10 minutes, and dobutamine up to 40 µg/kg/min in 15 minutes.
RESULTS—A consistent PEA signal was obtained in all patients. Overall mean (SD) baseline PEA was 0.26 (0.15) g (g = 9.8 m/s²), increasing to 0.5 (0.36) g at peak stress (+0.24 g, 95% confidence interval (CI) 0.14 to 0.34 g; p < 0.01). PEA increased from 0.26 (0.16) to 0.37 (0.25) g in the dipyridamole group (+0.11 g, 95% CI 0.08 to 0.16 g; p < 0.01), and from 0.29 (0.1) to 0.93 (0.37) g in the dobutamine group (+0.64 g, 95% CI 0.37 to 0.91 g; p < 0.01).
CONCLUSIONS—Using precordial leads this method offers potential for diagnostic application in the short term monitoring of myocardial function. PEA monitoring is feasible during pharmacological stress and documents left ventricular inotropic response quantitatively in a non-invasive and operator independent fashion.


Keywords: ventricular function; contractility; peak endocardial acceleration; stress echo     

Left ventricular function in adults with mild pulmonary insufficiency late after Fallot repair

OBJECTIVE—To assess left ventricular function in adult Fallot patients with residual pulmonary regurgitation.
SETTING—The radiology department of a tertiary referral centre.
PATIENTS—14 patients with chronic pulmonary regurgitation and right ventricular volume overload after repair of tetralogy of Fallot and 10 healthy subjects were studied using magnetic resonance imaging.
MAIN OUTCOME MEASURES—Biventricular volumes, global biventricular function, and regional left ventricular function were assessed in all subjects.
RESULTS—The amount of pulmonary regurgitation in patients (mean (SD)) was 25 (18)% of forward flow and correlated significantly with right ventricular enlargement (p < 0.05). Left ventricular end diastolic volume was decreased in patients (78 (11) v 88 (10) ml/m²; p < 0.05), ejection fraction was not significantly altered (59 (5)% v 55 (7)%; NS). No significant correlation was found between pulmonary regurgitation and left ventricular function. Overall left ventricular end diastolic wall thickness was significantly lower in patients (5.06 (0.72) v 6.06 (1.06) mm; p < 0.05), predominantly in the free wall. At the apical level, left ventricular systolic wall thickening was 20% higher in Fallot patients (p < 0.05). Left ventricular shape was normal.
CONCLUSIONS—Adult Fallot patients with mild chronic pulmonary regurgitation and subsequent right ventricular enlargement showed a normal left ventricular shape and global function. Although the left ventricular free wall had reduced wall thickness, compensatory hypercontractility of the apex may contribute to preserved global function.


Keywords: left ventricular function; pulmonary insufficiency; tetralogy of Fallot; magnetic resonance imaging     

Ventricular mass and diastolic function in patients infected by the human immunodeficiency virus

OBJECTIVE—Echocardiographic and Doppler analysis of myocardial mass and diastolic function in patients infected with HIV.
DESIGN—Case-control study.
SETTING—Tertiary referral centre, Huelva, Spain.
PATIENTS—61 asymptomatic patients with HIV infection and 32 healthy controls.
MAIN OUTCOME MEASURES—Time motion, cross sectional, and Doppler echocardiographic studies were performed, and left ventricular mass and diastolic function variables determined (peak velocity of early and late mitral outflow and isovolumic relaxation time).
RESULTS—Left ventricular mass index (LVMI) was decreased in patients compared with healthy controls (mean (SD): 76.7 (23.6) v 118.8 (23.5) g/m², p < 0.001). Linear regression analysis showed a correlation between LVMI and brachial fat and muscle areas. The ratio of peak velocities of early and late mitral outflow was decreased in HIV infected patients compared with controls (1.19 (0.44) v 1.58 (0.38), p < 0.001). This ratio was exclusively related to haemodynamic variables (heart rate, systolic and diastolic blood pressures). HIV infected patients had a prolonged isovolumic relaxation time (103.0 (10.5) v 72.9 (12.9) ms, p < 0.001). Isovolumic relaxation time was correlated only with brachial muscle area on multivariate analysis.
CONCLUSIONS—HIV infected patients had a reduced left ventricular mass index and diastolic functional abnormalities. These cardiac abnormalities are predominantly related to nutritional status.


Keywords: HIV infection; cardiac function; nutrition     

Clinical and patho-anatomical factors affecting expansion of thoracic aortic aneurysms

OBJECTIVE—To examine the expansion of aneurysmal aortic segments ( 35 mm) and to assess the impact of clinical and patho-anatomical factors on aneurysm expansion.
DESIGN—87 consecutive patients (mean age 63.6 years, range 22-84 years) were studied using serial (six month intervals) computed tomographic or magnetic resonance imaging to monitor progression of thoracic aortic aneurysms. Aortic diameter was measured at seven predetermined segments and at the site of maximum aortic dilatation (MAX).
RESULTS—780 segment intervals were identified. The median overall aneurysm expansion rate was 1.43 mm/year. This increased exponentially with incremental aortic diameter (p < 0.01) and varied by anatomical segment (p < 0.05). The presence of intraluminal thrombus (p < 0.01) but not dissection or calcification was associated with accelerated growth. Univariate analysis identified thrombus (p < 0.001), previous stroke (p < 0.002), smoking (p < 0.01), and peripheral vascular disease (p < 0.05) as factors associated with accelerated growth in MAX. Dissection, wall calcification, and history of hypertension did not affect expansion. β Blocker treatment was not associated with protection. Multivariate analysis confirmed the positive effect of intraluminal thrombus and previous cerebral ischaemia, and the negative effect of previous aortic surgery on aneurysm growth. These findings translated into a mathematical equation describing exponential aneurysm expansion.
CONCLUSIONS—Aneurysmal thoracic aortic segments expand exponentially according to their initial size and their anatomical position within the aorta. The presence of intraluminal thrombus, atherosclerosis, and smoking history is associated with accelerated growth and may identify a high risk patient group for close surveillance.


Keywords: thoracic aortic aneurysm; expansion rate     

Neuroendocrine prediction of left ventricular function and heart failure after acute myocardial infarction

Objective—To determine the relations of plasma levels of brain natriuretic peptide (BNP), atrial natriuretic factor (ANF), N-terminal ANF (N-ANF), cyclic guanosine monophosphate (cGMP; the cardiac peptide second messenger), and plasma catecholamines to left ventricular function and to prognosis in patients admitted with acute myocardial infarction.
Design—Plasma hormones and ventricular function (radionuclide ventriculography) were measured 1-4 days after myocardial infarction in 220 patients admitted to a single coronary care unit. Radionuclide scanning was repeated 3-5 months after infarction. Clinical events were recorded over a mean period of 14 months.
Results—Both early and late left ventricular ejection fraction (LVEF) were most closely related to plasma BNP (r = −0.60, n = 220, p < 0.001; and r = −0.53, n = 192, p < 0.001, respectively), followed by ANF, N-ANF, cGMP, and the plasma catecholamines. Early plasma BNP concentrations less than twofold the upper limit of normal (20 pmol/l) had 100% negative predictive value for LVEF < 40% at 3-5 months after infarction. In multivariate analysis incorporating all the neurohormonal factors, only BNP remained independently predictive of LVEF < 40% (p < 0.005). Survival analysis by median levels of candidate predictors identified BNP as the most powerful discriminator for death (p < 0.0001). No early deaths (within 4 months) occurred in patients with plasma BNP concentrations below the group median (27 pmol/l), and over follow up only three of 26 deaths occurred in this subgroup. Of all episodes of left ventricular failure, 85% occurred in patients with plasma BNP above the median (p < 0.001). In multivariate analyses, BNP alone gave additional predictive information beyond sex, age, clinical history, LVEF, and plasma noradrenaline for both subsequent onset of LVF and death.
Conclusions—Plasma BNP measured within 1-4 days of acute myocardial infarction is a powerful independent predictor of left ventricular function, heart failure, or death over the subsequent 14 months, and superior to ANF, N-ANF, cGMP, and plasma catecholamines.

Keywords: cardiac natriuretic peptides; noradrenaline; myocardial infarction; heart failure     

Troponin T measurement after myocardial infarction can identify left ventricular ejection of less than 40%

Aim—To determine whether measurement of serum troponin T concentration after first acute myocardial infarction can be used to identify patients with a left ventricular ejection fraction of < 40%, who have an adverse prognosis.
Methods—Troponin T concentration was measured, and coronary and left ventriculography performed in 50 consecutive patients with acute myocardial infarction. Angiographic left ventricular ejection fraction was compared with serum troponin T concentration. Patients with previous myocardial infarction were excluded.
Results—There was a strong negative correlation between left ventricular ejection fraction and troponin T concentration. Spearman's rank correlation coefficient (corrected for ties) was −0.72 (95% confidence intervals (CI) −0.55 to −0.83; p < 0.0001). Analysis by receiver operator characteristic curve produced an area under the curve of 0.9773 (95% CI 0.9409 to 1.0136). A troponin T concentration of > 2.8 µg/l predicted a left ventricular ejection fraction of < 40% with a sensitivity of 100% (CI 84.6 to 100.0) and specificity of 92.9% (CI 76.5 to 99.1). Exclusion of patients who did not receive thrombolytic treatment did not significantly affect the results.
Conclusion—Serum troponin T concentration measured 12-48 hours after admission for first myocardial infarction is a reliable, simple, quick, inexpensive, non-invasive method for identifying patients with a left ventricular ejection fraction of < 40% for whom there is a poor prognosis.

Keywords: troponin T;  acute myocardial infarction;  angiotensin converting enzyme inhibitors;  left ventricular function     

The left ventricular dysfunction questionnaire (LVD-36): reliability, validity, and responsiveness

OBJECTIVE—To examine the reliability, validity, and responsiveness of a new health status measure (LVD-36) for patients with left ventricular dysfunction which was designed with emphasis on content validity, clarity, brevity, and ease of use.
DESIGN—At baseline, patients completed the LVD-36 and a range of measures reflecting general health and disease severity. The LVD-36 was repeated after one week. After six months, it was repeated again, along with a transition question to measure global changes in health.
SETTING—Patients were recruited from the cardiology and general medical clinics at a south west London hospital.
PATIENTS—60 patients with chronic left ventricular dysfunction.
INTERVENTIONS—None.
MAIN OUTCOME MEASURES—Short form 36 questionnaire (SF-36), Minnesota living with heart failure questionnaire (LIhFE), New York Heart Association criteria, and exercise performance and echocardiographic tests.
RESULTS—The LVD-36 showed good internal consistency (κ = 0.95) and repeatability (r_i = 0.95). Its scores were significantly associated with SF-36 mental and physical component scores (r = −0.48 and −0.75; p < 0.0001), with exercise capacity (r = −0.52; p < 0.0001), and with systolic shortening fraction (r = −0.27; p < 0.05). Change in the LVD-36 over six months was associated with change in overall health (F = 5.7; p < 0.001). In tests of validity and responsiveness, the LVD-36 performed similarly to or marginally better than the LIhFE.
CONCLUSIONS—The LVD-36 showed a high level of reliability and validity, and appears to measure changes in health. It provides a short, simple, valid, and reliable measure of health status in patients with left ventricular dysfunction.


Keywords: health status; quality of life; heart failure; left ventricular dysfunction     

A follow up study of myocardial involvement in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS)

Objective—To investigate cardiac function in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) and clarify the clinical features of cardiomyopathy in MELAS.
Patients—11 consecutive patients with MELAS (mean age at initial examination 11.3 years, range 4 to 16 years) were enrolled in the study. Six were followed for more than five years.
Results—On echocardiographic examination, three patients showed increased left ventricular end diastolic posterior wall thickness (LVPWTd), exceeding 140% of the normal value. Four patients, including these three, had an ejection fraction of less than 50%, and two also had increased left ventricular end diastolic volume (LVEDV) exceeding 140% of the normal value (%N). The LVPWTd%N was correlated positively with the LVEDV%N (R = 0.669, p < 0.05) and negatively with the ejection fraction (R = −0.6701, p < 0.05). One patient died of heart failure aged 22 years.
Conclusions—The cardiomyopathy in MELAS is characterised by an abnormally thick left ventricular wall with progressive dilatation and poor left ventricular contraction developing over several years, indicating hypertrophic cardiomyopathy advancing to dilated cardiomyopathy.

Keywords: MELAS;  cardiomyopathy