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Biomedical subjects

Michael Henein

Publications and source records attributed to Michael Henein.

At least 19 recordsLinked to original sources
PubMed2007

Geometry of the left ventricular outflow tract in fixed subaortic stenosis and intact ventricular septum: an echocardiographic study in children and adults.

OBJECTIVE: We compared the echocardiographic geometry of the preoperative and postoperative left ventricular outflow tract in children and adults with isolated fixed subaortic stenosis with age- and weight-matched controls to elucidate whether the geometry can be modified when surgical intervention is performed at a younger age. METHODS: The mitral-aortic valve distance, aortic valve diameter, aorto-left ventricular septal angle, degree of aortic valve dextroposition, aortic valve-subaortic stenosis distance, width of left ventricular outflow tract, left ventricle wall thickness, and septal thickness were determined preoperatively and postoperatively in 21 patients and 21 controls. The measurements were indexed to body surface area. Patients were divided into 3 age groups: group 1 comprised 9 patients aged 1 to 10 years, group 2 comprised 8 patients aged 11 to 20 years, and group 3 comprised 4 patients aged 21 years or more. RESULTS: Compared with controls, patients had a significantly wider mitral-aortic separation (group 1, P = .003; group 2, P = .02), a steeper aortoseptal angle (group 1, P = .02; group 3, P = .03), a smaller left ventricular outflow tract width (group 1, P = .003; group 2, P = .01), a marked aortic valve dextroposition (groups 1 and 3), an increased left ventricle wall thickness (group 1, P = .03), and an increased septal thickness (group 1, P = .01). There was a significant difference between preoperative and postoperative values in aortoseptal angle and left ventricular outflow tract width in patients up to 10 years of age (P = .02 and P = .01, respectively). CONCLUSIONS: Hearts with isolated subaortic stenosis have abnormal left ventricular outflow tract geometry that postoperatively showed changes in left ventricular outflow tract width and aortoseptal angle. Compared with controls, the aortoseptal angle does not "normalize" when surgery is performed in older patients, suggesting that left ventricular outflow tract geometry may be remodeled in younger patients.

Adolescent↗
PubMed2006

Effect of intensive versus standard lipid-lowering treatment with atorvastatin on the progression of calcified coronary atherosclerosis over 12 months: a multicenter, randomized, double-blind trial.

BACKGROUND: Recent clinical trials have suggested that intensive versus standard lipid-lowering therapy provides for additional benefit. Electron-beam computed tomography provides the opportunity to quantify the progression of coronary artery calcification (CAC) in serial measurements. METHODS AND RESULTS: In a multicenter, randomized, double-blind trial, 471 patients (age 61+/-8 years) who had no history of coronary artery disease and no evidence of high-grade coronary stenoses (>50% diameter reduction) were randomized if they had > or =2 cardiovascular risk factors and moderate calcified coronary atherosclerosis as evidenced by a CAC score > or =30. Patients were assigned to receive 80 mg or 10 mg of atorvastatin per day over 12 months. Progression of CAC volume scores could be analyzed in 366 patients. After pretreatment with 10 mg of atorvastatin for 4 weeks, 12 months of study medication reduced LDL cholesterol from 106+/-22 to 87+/-33 mg/dL in the group randomized to receive 80 mg of atorvastatin (P<0.001), whereas levels remained stable in the group randomized to receive 10 mg (108+/-23 at baseline, 109+/-28 mg/dL at the end of the study, P=NS). The mean progression of CAC volume scores, corrected for the baseline CAC volume score, was 27% (95% CI 20.8% to 33.1%) in the 80-mg atorvastatin group and 25% (95% CI 19.1% to 30.8%) in the 10-mg atorvastatin group (P=0.65). CAC progression showed no relationship with on-treatment LDL cholesterol levels. CONCLUSIONS: We did not observe a relationship between on-treatment LDL cholesterol levels and the progression of calcified coronary atherosclerosis. Over a period of 12 months, intensive atorvastatin therapy was unable to attenuate CAC progression compared with standard atorvastatin therapy. The possibility remains that the time window was too short to demonstrate an effect.

Adult↗
PubMed2005

Myocardial tissue Doppler and long axis function in the fetal heart.

UNLABELLED: Current echocardiographic assessment of fetal ventricular function uses relatively crude measures and this has led to inconsistencies in assessment of diastolic function. Long axis parameters may be more insightful. OBJECTIVE: To describe fetal long axis cardiac function and construct reference ranges. DESIGN: 159 normal fetuses were studied cross-sectionally using long axis M-mode to measure displacement of the atrioventricular ring and pulsed wave Doppler ultrasound to record myocardial tissue Doppler velocities at the base of the heart. RESULTS: There was a strong, almost linear gestational relationship for all but late left basal myocardial velocities. Systolic amplitude of the atrioventricular ring increased significantly. Wall thickness increased with gestation and heart rate reduced. Late diastolic mitral and tricuspid flow velocities showed no age-dependence. Right ventricular filling (p<0.0001) and myocardial lengthening (p<0.0001) and shortening velocities (p<0.0001) were higher than left. Aortic velocities were higher than pulmonary (p<0.0001). Right ventricular long axis amplitude was greater than left (p<0.0001). There were no significant differences in right (RV) and left (LV) ventricular and septal thicknesses (RV 2.5 mm [1.2-4.1]; LV (2.4 mm [1.0-4.0] and septum 2.6 mm [1.0-4.3]). Left and right myocardial tissue Doppler velocities showed similar maturation in systole (LV 0.14 vs. RV 0.10 cm/s/week) and early diastole (LV 0.16 vs. RV 0.14 cm/s/week). CONCLUSIONS: This study demonstrates maturational changes occur in both fetal systolic and diastolic ventricular function and moreover the maturational rate of myocardial tissue velocities is similar in both ventricles, despite differential loading conditions.

Blood Flow Velocity↗
PubMed2005

Chronic heart failure with preserved left ventricular ejection fraction: diagnostic and prognostic value of left atrial size.

BACKGROUND: Almost 40% of patients with heart failure (HF) have preserved left ventricular (LV) ejection fraction (EF) and prognosis similar to those with reduced EF. Data on prognostic markers in such patients are limited. We analyzed the prevalence and prognostic value of left atrial (LA) size in this condition. METHODS: 89 normal subjects (Group I), 38 asymptomatic hypertensive patients (Group II) and 183 HF patients with preserved EF (EF >45%) (Group III) were studied. LA diameter (LAD), LV diastolic (LVD) and systolic (LVS) dimensions and mass (LVmass) and EF were measured. E and A wave velocities and E/A were measured. The primary end point was all cause mortality in group III patients. RESULTS: Groups did not differ in age, gender or EF. Group III patients had larger LAD (4.6+-1.0 cm) compared with both Group I (3.7+/-0.6) and Group II (3.7+/-0.5 cm) (p<0.0001). A markedly enlarged (arbitrarily defined as LAD higher or equal 5 cm) had an odds ratio of 34 (95% CI 8-144) in distinguishing HF patients from normals. After a mean follow-up period of 29+/-27 months, 40 patients (21.9%) died. In Cox univariate analysis, NYHA class (HR 2.8 95% C.I. 1.8-4.3; p<0.0001), diastolic blood pressure (DBP) (HR 0.92 95% C.I. 0.88-0.96; p<0.0001), age (HR 1.059 95% C.I. 1.01-1.11; p=0.02) and LAD (HR 1.72 95% C.I. 1.27-2.3; p=0.0005) were predictors of mortality. LAD predicted survival independently of other variables. CONCLUSION: The left atrium is frequently dilated in HF patients compared with controls despite similar EF. LAD showed powerful prognostic value independent of clinical variables.

Aged↗
PubMed2005

Randomized comparison of stentless versus stented valves for aortic stenosis: effects on left ventricular mass.

BACKGROUND: Aortic valve replacement (AVR) is the established treatment for severe aortic stenosis. In response to the long-term results of aortic homografts, stentless porcine valves were introduced as an alternative low-resistance valve. We conducted a randomized trial comparing a stentless with a stented porcine valve in adults with severe aortic stenosis. METHODS AND RESULTS: The primary outcome was change in left ventricular mass index (LVMI) measured by transthoracic echocardiography and, in a subset, by cardiovascular MR. Measurements were taken before valve replacement and at 6 and 12 months. Patients undergoing AVR with an aortic annulus < or =25 mm in diameter were randomly allocated to a stentless (n=93) or a stented supra-annular (n=97) valve. There were no significant differences in mean LVMI between the stentless versus stented groups at baseline (176+/-62 and 182+/-63 g/m2, respectively) or at 6 months (142+/-49 and 131+/-45 g/m2, respectively), although within-group changes from baseline to 6 months were highly significant. Changes in LVMI measured by cardiovascular MR (n=38) were consistent with the echo findings. There was a greater reduction in peak aortic velocity (P<0.001) and a greater increase in indexed effective orifice area (P<0.001) in the stentless group than in the stented group. There were no differences in clinical outcomes between the 2 valve groups. CONCLUSIONS: Despite significant differences in indexed effective orifice area and peak flow velocity in favor of the stentless valve, there were similar reductions in left ventricular mass at 6 months with both stented and stentless valves, which persisted at 12 months.

Aged↗
PubMed2005

Regional and global right ventricular function in healthy individuals aged 20-90 years: a pulsed Doppler tissue imaging study: Umeå General Population Heart Study.

The aim of the present study was to describe regional and global right ventricular (RV) function in a wide age range of healthy subjects of both sexes. We studied 255 (125 females) healthy individuals randomly selected from the Umeå General Population Register, age 58 +/- 19 (range 22-89) years. RV function was studied using myocardial tissue Doppler imaging of the RV free wall. Isovolumic contraction (IVCv), systolic (Sv), early (Ev), and late (Av) diastolic velocities were measured. Furthermore, isovolumic periods and ejection time intervals were also measured. Conventional Doppler was used to study RV global filling properties. While systolic myocardial velocities were conserved over age, there was a decrease in myocardial E/A ratio with increasing age (r =-0.67, P < 0.001, for base) taken from the RV free wall. A similar age relation was found in RV global filling velocities with a reduced tricuspid E/A ratio (r =-0.57, P < 0.001). Furthermore, a significant correlation was found between global and regional E/A ratios at the basal (r = 0.58, P </= 0.001) and mid-segmental levels (r = 0.46, P </= 0.001). Systolic myocardial velocities behaved independent of age whereas regional as well as global E/A ratio were age-related. No relationship was found between regional isovolumic time intervals and age. Knowledge of these age-dependent relationships is fundamental when evaluating RV function in patients.

Adult↗
PubMed2004

Relation of biventricular function quantified by stress echocardiography to cardiopulmonary exercise capacity in adults with Mustard (atrial switch) procedure for transposition of the great arteries.

BACKGROUND: Mustard repair for transposition of the great arteries (TGA) is frequently associated with impaired systemic (right) ventricular function and sometimes exercise intolerance. We hypothesized that a simple quantitative measurement of ventricular function, during rest and pharmacological stress, could identify abnormalities and predict objective exercise capacity. METHODS AND RESULTS: We quantified the performance of systemic and pulmonary (left) ventricles by using echocardiography, at rest and during dobutamine stress, in 27 adults who had undergone Mustard repair for TGA. Systolic and diastolic function of the systemic ventricle were markedly disturbed with respect to pulmonary ventricular function. We also measured exercise capacity by cardiopulmonary exercise testing for peak oxygen uptake. Exercise capacity was significantly predicted by systemic ventricular long-axis excursion both at rest (r=0.66, P<0.001) and at peak dobutamine stress (r=0.53, P=0.006) but not by pulmonary ventricular long-axis excursion at rest (r=0.04) or on stress (r=0.11). Exercise capacity was also predicted by the septal long-axis excursion at rest (r=0.61, P=0.001) but not pulmonary ventricular free wall excursion (P>0.05) or fractional shortening (P>0.05). Peak aortic velocity at maximum dobutamine stress correlated with exercise capacity (r=0.46, P=0.029) but not at rest (r=0.36). Multivariate analysis revealed systemic ventricular long-axis excursion to be the sole significant independent predictor of exercise capacity. CONCLUSIONS: Systemic ventricular function is depressed in most patients with Mustard repair. Quantitative echocardiographic evaluation shows systemic ventricular function to be a key determinant of exercise capacity.

Adrenergic beta-Agonists↗
PubMed2004

Electromechanical left ventricular resynchronisation by coronary artery bypass surgery.

OBJECTIVE: In patients with coronary artery disease (CAD), the normal electromechanical response to dobutamine stress is deranged: QRS duration lengthens rather than shortens, left ventricular asynchrony develops, post-ejection shortening appears, and total isovolumic time (the time in the cardiac cycle when the ventricle is neither ejecting nor filling) increases rather than falls, all of which blunt the normal rise in cardiac output. We aimed to study the effect of revascularisation on these stress-induced electromechanical abnormalities and their effect on peak cardiac output after coronary artery bypass grafting (CABG). METHOD: 20 unselected patients were studied before and after CABG. Long axis asynchrony was determined by (i) delay in the onset of shortening, (ii) amplitude and (iii) duration of post-ejection shortening. Total isovolumic time (in s/min), calculated as [60-(total ejection time+total filling time)] and cardiac output were measured by Doppler echocardiography. RESULTS: Before CABG: QRS duration broadened with stress (by 7+/-8 ms, P<0.01) and post-ejection shortening increased (amplitude by 1.1+/-0.7 mm, P<0.01, duration by 8+/-9 ms, P<0.01). Total isovolumic time increased (by 3+/-3 s/min, P<0.01) and cardiac output rose (by 2.8+/-1.2 l/min, P<0.01). After CABG: QRS duration shortened with stress (by 5+/-4 ms, P<0.01) post-ejection shortening decreased (amplitude and duration fell by 0.4+/-0.5 mm and 22+/-14 ms, respectively), total isovolumic time shortened (by 3+/-3 s/min) and cardiac output increased (by 5.1+/-1.8 l/min, all P<0.01). Changes in total isovolumic time and duration of post-ejection shortening with stress were independent predictors of the increase in peak cardiac output after revascularisation (total R(2)=0.69). Independent predictors of changes in total isovolumic time with stress were those in QRS duration and the duration of post-ejection shortening (total R(2)=0.75). In turn, changes in the duration of post-ejection shortening were closely associated with alterations in the delay in long axis shortening (r(2)=0.50) which correlated with changes in QRS duration (r(2)=0.59, all P<0.001). CONCLUSIONS: Revascularisation resynchronises left ventricular wall motion by restoring the normal activation response to stress, thereby reducing total isovolumic time and normalising peak cardiac output response to stress.

Aged↗
PubMed2004

Influence of valve prosthesis type on the recovery of ventricular dysfunction and subendocardial ischaemia following valve replacement for aortic stenosis.

BACKGROUND: Long-standing aortic stenosis (AS) causes significant progressive left ventricular (LV) dysfunction and may result in subendocardial ischaemia. Following aortic valve surgery, LV function may improve and this may be accompanied by reversal of ischaemia. There is debate about the differential effects of valve substitutes. METHODS: We studied 33 patients with significant AS and impaired LV systolic function. Patients underwent trans-thoracic Doppler echocardiography and 12-lead electrocardiography pre-operatively, prior to discharge from hospital and at 2.5 (range 1.5-3) years follow-up. RESULTS: Twenty patients received a stentless valve and 13 a stented valve. No patient had significant aortic regurgitation, other valvular disease or coronary artery disease. LV fractional shortening (FS) increased from 19+/-6% to 26+/-7% post-operatively and to 33+/-12% at follow-up in the stentless group (p<0.001). In the stented group, no significant change was seen in the post-operative FS, although it improved at follow-up and at this point did not differ from the stentless group. LV mass fell from 338+/-72 to 265+/-64 g post-operatively and to 170+/-77 g at follow-up (p<0.001) in the stentless group, whereas in the stented group a significant fall was seen only at follow-up (329+/-51 g pre-operatively, 304+/-68 g post-operatively, 166+/-28 g at follow-up, p=0.01). LV free wall excursion increased from 0.8+/-0.3 to 1.1+/-0.4 cm (p=0.05) and to 1.4+/-0.3 cm (p=0.02 compared with pre-operative values) in the stentless group. In the stented group, values were 1.0+/-0.4, 1.0+/-0.3 and 1.3+/-0.2 cm (p=0.05 compared with pre-operative) at the three time points, respectively. QRS duration fell from 113+/-36 ms pre-operatively to 99+/-12 ms at follow-up in the stentless group and from 117+/-28 to 99+/-19 ms in the stented group, p=0.01 for both comparisons. QT interval fell from 385+/-54 ms pre-operatively to 366+/-39 ms at follow-up (p=0.04) in the stentless group with no significant change in the stented group (387+/-52 and 375+/-33 ms, p=0.24). There was reversal of LV strain pattern in 11 (55%) of the stentless group and 6 (46%) of the stented group and normalisation of the inverted U wave in two thirds of patients. CONCLUSION: In patients with AS and severe LV dysfunction, there is a more rapid improvement in LV function following aortic valve replacement with a stentless prosthesis. Improvements in those receiving stented valves appear delayed, although there were no differences between the groups in LV function or mass at follow-up. Normalisation of LV free wall systolic behaviour, narrowing of the QRS complex and a reduction in the QT interval suggest that AS is associated with subendocardial ischaemia that reverses following valve replacement.

Aortic Valve↗
PubMed2004

Effects of valve replacement on left ventricular function in patients with aortic regurgitation and severe ventricular disease.

BACKGROUND AND AIM OF THE STUDY: Longstanding aortic regurgitation (AR) can result in left ventricular (LV) dysfunction that may reverse after aortic valve replacement (AVR). Stentless valves may result in a more rapid recovery in function due to a more physiological flow and lower outflow resistance. METHODS: The effect of AVR on LV function was studied in 47 patients who received either a stentless (n = 33) or stented (n = 14) valve for isolated AR. All patients had evidence of pre-existing LV dysfunction (end-systolic dimension (ESD) >50 mm). Patients were studied using transthoracic echocardiography at baseline, postoperatively, and at 2.5-year follow up. RESULTS: Preoperatively, there were no differences in LV dimensions. The end-diastolic dimension fell from 75 +/- 10 mm to 61 +/- 10 mm postoperatively and to 52 +/- 10 mm at follow up in the stentless group (p <0.001), and ESD fell from 54 +/- 10 mm to 36 +/- 8 mm at follow up (p <0.001). There were no significant early changes in patients who received stented valves, though LV dimensions fell at follow up. Fractional shortening (FS) increased from 25 +/- 8% in the postoperative period to 31 +/- 7% in the stentless group (p <0.001), but there was no change in the stented group (20 +/- 7% versus 23 +/- 8%). In the stentless group, LV mass fell from 366 +/- 104 g to 276 +/- 68 g postoperatively and to 219 +/- 79 g at follow up (p <0.001); there was no postoperative change in the stented group, though a late reduction occurred, from 349 +/- 51 g preoperatively to 265 +/- 61 g at follow up (p = 0.06). CONCLUSION: For patients with AR and LV dysfunction, AVR with a stentless prosthesis offers early reductions in LV dimensions, improved LV function, and regression of LV mass. In patients who received a stented valve, these improvements were delayed and less complete. Hence, for some patients with AR and LV dysfunction, a stentless prosthesis may be preferable.

Adult↗
PubMed2002

Nonsurgical reduction of the interventricular septum in patients with hypertrophic cardiomyopathy.

BACKGROUND: In patients with hypertrophic cardiomyopathy and obstruction of the left ventricular outflow tract, nonsurgical reduction of the septum is a treatment option when medical therapy has failed. We investigated the long-term effects of nonsurgical reduction of the septum on functional capacity and electrocardiographic and echocardiographic characteristics. METHODS: Sixty-four consecutive patients with hypertrophic cardiomyopathy and a mean (+/-SD) age of 48.5+/-17.2 years underwent nonsurgical reduction of the septum by injection of ethanol into the septal perforator branch of the left anterior descending coronary artery. These patients were assessed by exercise testing, electrocardiography, and resting and dobutamine (stress-induced) echocardiography after a mean period of 3.0+/-1.3 years. RESULTS: At follow-up, patients had significant improvements in New York Heart Association class, peak oxygen consumption (from 18.4+/-5.8 to 30.0+/-4.4 ml per kilogram of body weight per minute, P<0.001), and left ventricular outflow tract gradients (resting gradient, from 64+/-36 to 16+/-15 mm Hg; P<0.001; stress-induced gradient, from 132+/-34 to 45+/-19 mm Hg; P<0.001). Procedure-related complications included right bundle-branch block in all patients, complete heart block in 31 patients (48 percent), and significant increases in QRS and corrected QT intervals. Seventeen patients (27 percent) required permanent pacing. R-wave amplitude was significantly decreased (from 32+/-8 to 17+/-7 mV, P<0.001). The dimensions of the left ventricular cavity increased, and the interventricular septal thickness was reduced. CONCLUSIONS: Nonsurgical septal reduction leads to sustained improvements in both subjective and objective measures of exercise capacity in association with a persistent reduction in resting and stress-induced left ventricular outflow tract gradients. It is also associated with a high incidence of procedure-related complete heart block, however, often requiring permanent pacing.

Analysis of Variance↗
PubMed2002

Septal q waves as an indicator of risk of mortality in elderly patients with chronic heart failure.

BACKGROUND: The absence of electrocardiographic septal q wave is a recognized marker of left ventricular disease. We aimed to investigate the prognostic significance of absent septal q waves in elderly (age >65 years) patients with chronic heart failure. METHODS: A total of 110 patients (mean age 73 +/- 4 years) with New York Heart Association functional class II to IV and left ventricular ejection fraction of <45% were enrolled in the study. Standard 12-lead electrocardiograms were critically analyzed for the presence or absence of septal q waves in leads I, aVL, V5, and V6. Patient survival was determined from hospital and general practitioner records and National Statistics Registry at a mean follow-up of 4 years. RESULTS: Septal q waves were absent in 71 and present in 39 patients. The overall mortality rate was 47% (43 patients). The incidence of death was 49% (36 patients) in the group with no septal q waves and 18% (7 patients) in those who demonstrated septal q waves. On univariate analysis by Cox proportional hazard method, absence of septal q waves was found to be a strong marker of poor prognosis in CHF (P =.003, hazard ratio 1.40, 95% CI 1.10-1.67). Kaplan-Meier survival curves showed a significant difference in survival independent of age, New York Heart Association functional class, peak VO2, and QRS duration between these 2 groups. CONCLUSIONS: Absence of the normal septal q wave on 12-lead electrocardiography, which may indicate structural heart disease and myocardial fibrosis, is an independent predictor of poor prognosis in elderly patients with CHF.

Aged↗