Hans-Jørgen Smith

New Noninvasive Method for Assessment of Left Ventricular Rotation: Speckle Tracking Echocardiography

Background— Left ventricular (LV) torsion is due to oppositely directed apical and basal rotation and has been proposed as a sensitive marker of LV function. In the present study, we introduce and validate speckle tracking echocardiography (STE) as a method for assessment of LV rotation and torsion. Methods and Results— Apical and basal rotation by STE was measured from short-axis images by automatic frame-to-frame tracking of gray-scale speckle patterns. Rotation was calculated as the average angular displacement of 9 regions relative to the center of a best-fit circle through the same regions. As reference methods we used sonomicrometry in anesthetized dogs during baseline, dobutamine infusion, and apical ischemia, and magnetic resonance imaging (MRI) tagging in healthy humans. In dogs, the mean peak apical rotation was −3.7±1.2° (±SD) and −4.1±1.2°, and basal rotation was 1.9±1.5° and 2.0±1.2° by sonomicrometry and STE, respectively. Rotations by both methods increased (P<0.001) during dobutamine infusion. Apical rotation by both methods decreased during left anterior descending coronary artery occlusion (P<0.007), whereas basal rotation was unchanged. In healthy humans, apical rotation was −11.6±3.8° and −10.9±3.3°, and basal rotation was 4.8±1.7° and 4.6±1.3° by MRI tagging and STE, respectively. Torsion measurement by STE showed good correlation and agreement with sonomicrometry (r=0.94, P<0.001) and MRI (r=0.85, P<0.001). Conclusions— The present study demonstrates that regional LV rotation and torsion can be measured accurately by STE, suggesting a new echocardiographic approach for quantification of LV systolic function.

Global longitudinal strain measured by two-dimensional speckle tracking echocardiography is closely related to myocardial infarct size in chronic ischaemic heart disease

2D-STE (two-dimensional speckle tracking echocardiography) is a novel echocardiographic modality that enables angle-independent assessment of myocardial deformation indices. In the present study, we tested whether peak systolic epsilon(parallel) (longitudinal strain) values measured by 2D-STE could identify areas of MI (myocardial infarction) as determined by CE MRI (contrast-enhanced magnetic resonance imaging). Conventional echocardiographic apical long-axis recordings were performed in 38 patients, 9 months after a first MI. Peak systolic epsilon(parallel) measured by 2D-STE in 16 left ventricle segments was compared with segmental infarct mass and transmurality assessed by CE MRI. Segmental values were averaged to global and territorial values for assessment of global function and myocardial function in the coronary distribution areas. CE MRI identified transmural infarction in 27 patients, and a mean infarct size of 36+/-25 g. Peak systolic epsilon( parallel) correlated with the infarct mass at the global level (r=0.84, P<0.001). A strain value of -15% identified infarction with 83% sensitivity and 93% specificity at the global level and 76% and 95% at the territorial level, and a strain value of -13% identified transmural infarction with 80% sensitivity and 83% specificity at the segmental level. Global infarct mass correlates with the wall motion score index (r=0.70, P<0.001), and left ventricular ejection fraction measured by MRI or echocardiography (r=-0.71 and -0.58, both P<0.001). In chronic infarction, peak systolic epsilon(parallel) measured by 2D-STE correlates with the infarct mass assessed by CE MRI at a global level, and separates infarcted from non-infarcted tissue. Global strain is an excellent predictor of myocardial infarct size in chronic ischaemic heart disease.

Prevalence and characteristics of asymptomatic tears of the rotator cuff: AN ULTRASONOGRAPHIC AND CLINICAL STUDY

We undertook clinical and ultrasonographic examination of the shoulders of 420 asymptomatic volunteers aged between 50 and 79 years. MRI was performed in selected cases. Full-thickness tears of the rotator cuff were detected in 32 subjects (7.6%). The prevalence increased with age as follows: 50 to 59 years, 2.1%; 60 to 69 years, 5.7%; and 70 to 79 years, 15%. The mean size of the tear was less than 3 cm and tear localisation was limited to the supraspinatus tendon in most cases (78%). The strength of flexion was reduced significantly in the group with tears (p = 0.01). Asymptomatic tears of the rotator cuff should be regarded as part of the normal ageing process in the elderly but may be less common than hitherto believed.

Noninvasive Separation of Large, Medium, and Small Myocardial Infarcts in Survivors of Reperfused ST-Elevation Myocardial Infarction A Comprehensive Tissue Doppler and Speckle-Tracking Echocardiography Study

Background—The objective of the study was to evaluate the ability of established and new parameters of global systolic left ventricle function to estimate myocardial infarct size. Increasing infarct extent is associated with impaired prognosis in chronic ischemic heart disease. Systolic myocardial deformation is a complex 3D process that is mainly influenced by the amount and transmural distribution of viable myocardium. Speckle-tracking echocardiography (2D-STE) enables deformation assessment along the 3 main cardiac axes independent of insonation angle. Methods and Results—Global longitudinal, circumferential, and radial strain and left ventricle twist by 2D-STE, global longitudinal strain rate and strain by tissue Doppler imaging, and left ventricle ejection fraction and wall motion score index were assessed in 40 patients 8.5±5.4 months after a first myocardial infarct and compared with global myocardial infarct mass assessed by contrast-enhanced MRI. Longitudinal and circumferential strain by 2D-STE and longitudinal strain and strain rate by tissue Doppler imaging significantly separated medium-sized infarcts from small or large infarcts at the global level (P<0.05). All deformation indices correlated significantly with global infarct mass (P<0.01). Circumferential and longitudinal strains by 2D-STE demonstrated the best ability to identify medium-sized global myocardial infarcts. Conclusions—Circumferential and longitudinal strains by 2D-STE correlate with myocardial infarct mass and significantly differentiate among large, medium, and small myocardial infarcts.

The natural history of asymptomatic rotator cuff tears: a three-year follow-up of fifty cases.

BACKGROUND Little is known about the clinical and anatomic progression of asymptomatic rotator cuff tears. The purpose of our study was to assess if deterioration in rotator cuff tear anatomy would be correlated to the development of symptoms. METHODS Fifty patients with initially asymptomatic full-thickness rotator cuff tears were followed clinically, sonographically, and by magnetic resonance imaging over three years. Changes of tear size, muscle atrophy, fatty degeneration, and condition of the long head of the biceps tendon were compared between tears that developed symptoms and those that did not. RESULTS Eighteen of fifty tears developed symptoms during follow-up. There was a significantly larger increase (p = 0.02) in the mean tear size in the newly symptomatic group (10.6 mm) when compared with the still-asymptomatic group (3.3 mm). The rate of progressing to advanced muscle atrophy was higher (p = 0.08) in the newly symptomatic group (35% [six of seventeen subjects]) when compared with the still-asymptomatic group (12% [three of twenty-five subjects]). The rate of fatty degeneration was significantly higher (p = 0.02) in the newly symptomatic group (35% [six of seventeen subjects]) when compared with the still-asymptomatic group (4% [one of twenty-five subjects]). The rate of pathology of the long head of the biceps tendon was significantly higher (p = 0.02) in the newly symptomatic group (33% [six of eighteen subjects]) when compared with the still-asymptomatic group (6% [two of thirty-two subjects]). CONCLUSIONS During a relatively short-term follow-up, a substantial percentage of asymptomatic rotator cuff tears became symptomatic and underwent anatomic deterioration. Increase in tear size and decrease of muscle quality were correlated to the development of symptoms. Subjects diagnosed with an asymptomatic rotator cuff tear should be informed about the natural history of the condition and follow-up with repeated imaging may be indicated to monitor tear progression.

Recurrent primary sclerosing cholangitis after liver transplantation: A magnetic resonance cholangiography study with analyses of predictive factors

Primary sclerosing cholangitis (PSC) is a well‐established indication for orthotopic liver transplantation (OLT), but post‐OLT bile duct strictures complicate the outcome for these patients. These strictures might represent recurrent PSC (rPSC). To estimate the risk factors for post‐OLT non‐anastomotic bile duct strictures in PSC patients and to find their possible etiology, we performed magnetic resonance cholangiography (MRC) and angiography (MRA) in all PSC patients who had undergone OLT and were alive (median follow‐up 6.4 years, range 1.4‐15.2 years). This group of PSC patients was compared to a group of 45 non‐PSC patients who had also undergone OLT. A logistic regression analysis was performed to find predictors of rPSC. Bile duct strictures were found in 19/49 PSC patients and in 4/45 non‐PSC patients (P = 0.001). In the PSC group nine patients without other possible explanations for bile duct strictures than rPSC were identified, i.e., the estimated risk of rPSC was 9/49 (18%); surprisingly similar changes were also seen in one patient without a pre‐transplant PSC diagnosis. Severe liver disease due to rPSC was seen in 4/9 patients (one patient died and three are being evaluated for re‐OLT). Steroid‐resistant rejection was the only significant predictor for rPSC. In conclusion, our study shows that by the use of MRC we found more bile duct strictures in PSC patients post‐OLT compared to controls and that steroid‐resistant rejections was a predictor of such changes. (Liver Transpl 2005.)

Vigorous physical activity impairs myocardial function in patients with arrhythmogenic right ventricular cardiomyopathy and in mutation positive family members

Exercise increases risk of ventricular arrhythmia in subjects with arrhythmogenic right ventricular cardiomyopathy (ARVC). We aimed to investigate the impact of exercise on myocardial function in ARVC subjects.

A novel infraclavicular brachial plexus block: the lateral and sagittal technique, developed by magnetic resonance imaging studies.

A new infraclavicular brachial plexus block method has the patient supine with an adducted arm. The target is any of the three cords behind the pectoralis minor muscle. The point of needle insertion is the intersection between the clavicle and the coracoid process. The needle is advanced 0°–30° posterior, always strictly in the sagittal plane next to the coracoid process while abutting the antero-inferior edge of the clavicle. We tested the new method using magnetic resonance imaging (MRI) in 20 adult volunteers, without inserting a needle. Combining 2 simulated needle directions by 15° posterior and 0° in the images of the volunteers, at least one cord in 19 of 20 volunteers was contacted. This occurred within a needle depth of 6.5 cm. In the sagittal plane of the method the shortest depth to the pleura among all volunteers was 7.5 cm. The MRI study indicates that the new infraclavicular technique may be efficient in reaching a cord of the brachial plexus, often not demanding more than two needle directions. The risk of pneumothorax should be minimal because the needle is inserted no deeper than 6.5 cm. However, this needs to be confirmed by a clinical study.

Use of magnetic resonance imaging to define the anatomical location closest to all three cords of the infraclavicular brachial plexus.

Infraclavicular techniques are often used to perform brachial plexus blocks. In our volunteer study we used magnetic resonance imaging to identify the brachial plexus and axillary vessels in a sagittal plane corresponding to the lateral sagittal infraclavicular block. In 20 volunteers, all cords were positioned within 2 cm from the artery approximately within 2/3 of a circle. We derived an injection site that was closest to all cords, cranio-posterior and adjacent to the axillary artery. We conclude that this knowledge may be useful for the performance of infraclavicular blocks aided by ultrasound. However, our proposals should be tested by clinical studies.

Comparison between surgery and physiotherapy in the treatment of small and medium-sized tears of the rotator cuff: A RANDOMISED CONTROLLED STUDY OF 103 PATIENTS WITH ONE-YEAR FOLLOW-UP

In order to compare the outcome from surgical repair and physiotherapy, 103 patients with symptomatic small and medium-sized tears of the rotator cuff were randomly allocated to one of the two approaches. The primary outcome measure was the Constant score, and secondary outcome measures included the self-report section of the American Shoulder and Elbow Surgeons score, the Short Form 36 Health Survey and subscores for shoulder movement, pain, strength and patient satisfaction. Scores were taken at baseline and after six and 12 months by a blinded assessor. Nine patients (18%) with insufficient benefit from physiotherapy after at least 15 treatment sessions underwent secondary surgical treatment. Analysis of between-group differences showed better results for the surgery group on the Constant scale (difference 13.0 points, p - 0.002), on the American Shoulder and Elbow surgeons scale (difference 16.1 points, p < 0.0005), for pain-free abduction (difference 28.8 degrees , p = 0.003) and for reduction in pain (difference on a visual analogue scale -1.7 cm, p < 0.0005).