Contrast echocardiography for detection of myocardial perfusion abnormalities : A clinical perspective.

Myocardial contrast echocardiography (MCE) is a well-established imaging technique in the assessment of patients with known or suspected coronary artery disease. The use of ultrasound contrast agents has optimized the evaluation of left ventricular function and, moreover, permits simultaneous assessment of the myocardial perfusion. This technique utilizes microbubbles that remain in the intravascular space and the contrast intensity reflects the concentration of the microbubbles in the myocardium. A homogeneous opacification of the myocardium after destruction of the microbubbles during high-power imaging is regarded as normal perfusion and absence of CAD. If the replenishment rate is reduced, this is suggestive of significant CAD. In comparison with other techniques, MCE shows comparable sensitivity, specificity, and diagnostic accuracy while it is an easy-to-perform bedside technique that can be a valuable tool for the clinician.

A meta-analysis for echocardiographic assessment of right ventricular structure and function in ARVC.

INTRODUCTION: Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is an inherited pathology that can increase the risk of sudden death. Current Task Force Criteria for echocardiographic diagnosis do not include new, regional assessment tools which may be relevant in a phenotypically diverse disease. We adopted a systematic review and meta-analysis approach to highlight echocardiographic indices that differentiated ARVC patients and healthy controls. METHODS: Data was extracted and analysed from prospective trials that employed a case-control design meeting strict inclusion and exclusion as well as a-priori quality criteria. Structural indices included proximal RV outflow tract(RVOT1) and RV diastolic area(RVDarea). Functional indices included RV fractional area change (RVFAC), Tricuspid Annular Systolic Excursion(TAPSE), peak systolic and early diastolic myocardial velocities (S' and E' respectively) and myocardial strain. RESULTS: Patients with ARVC had larger RVOT1 (mean  SD; 34 vs. 28 mm P<0.001) and RVDarea (23 vs. 18 cm2 P<0.001) compared to healthy controls. ARVC patients also had lower RVFAC (38 vs. 46 % P<0.001), TAPSE(17 vs. 23 mm P<0.001), S' (9 vs. 12 cm.s-1 P<0.001), E' (9 vs. 13 cm.s-1 P<0.001) and myocardial strain (-17 vs. -30% P<0.001). CONCLUSION: The data from this meta-analysis support current Task Force criteria for the diagnosis of ARVC. In addition, other RV measures that reflect the complex geometry and function in ARVC clearly differentiated between ARVC and healthy controls and may provide additional diagnostic and management value. We recommend that future working groups consider this data when proposing new / revised criteria for the echocardiographic diagnosis of ARVC.

Do traditional risk stratification models for cerebrovascular events apply in irradiated head and neck cancer patients?

BACKGROUND: Primary radical radiotherapy (RT) for head and neck cancer (HNC) often results in significant radiation dose to the carotid arteries. AIM: We assessed whether HNC patients are at increased risk of a cerebrovascular event primarily due to RT or other risk factors for atherosclerosis by (i) risk-stratifying patients according to validated QRISK-2 and QSTROKE scores and (ii) comparing the prevalence of carotid artery stenosis (CAS) in irradiated and unirradiated carotid arteries. DESIGN: HNC patients treated with an RT dose >50 Gy to one side of the neck ≥2 years previously were included. METHODS: QRISK-2 (2014) and Q-STROKE (2014) scores were calculated. We compared the prevalence of CAS in segments of the common carotid artery on the irradiated and unirradiated sides of the neck. RESULTS: Fifty patients (median age of 58 years (interquartile range (IQR) 50-62)) were included. The median QRISK-2 score was 10% (IQR 4.4-15%) and the median QSTROKE score was 3.4% (IQR 1.4-5.3%). For both scores, no patient was classified as high risk. Thirty-eight patients (76%) had CAS in one or both arteries. There was a significant difference in the number of irradiated arteries with stenosis (N = 37) compared with unirradiated arteries (N = 16) (P < 0.0001). There were more plaques on the irradiated artery compared with the unirradiated side - 64/87 (73.6%) versus 23/87 (26.4%), respectively (P < 0.001). CONCLUSIONS: Traditional vascular risk factors do not play a role in radiation-induced carotid atherosclerosis. Clinicians should be aware that traditional risk prediction models may under-estimate stroke risk in these patients.

Clinical features of radiation-induced carotid atherosclerosis.

Carotid arteries frequently receive significant incidental doses of radiation during the treatment of malignant diseases, including head and neck cancer, breast cancer and lymphoma. Vascular injury after treatment may result in carotid artery stenosis and increased risk of neurological sequelae, such as stroke and transient ischaemic attack. The long latent interval from treatment to the development of clinical complications makes investigation of this process difficult, particularly in regard to the design of interventional clinical studies. Nevertheless, there is compelling clinical evidence that radiation contributes to carotid atherosclerosis. This overview examines the effect of radiotherapy on the carotid arteries, the underlying pathological processes and their clinical manifestations. The use of serum biomarkers in risk-prediction models and the potential value of new imaging techniques as tools for defining earlier surrogate end points will also be discussed.

The increased prevalence of left ventricular hypertrophy and concentric remodeling in U.K. Indian Asians compared with European whites.

Individuals of Indian Asian ethnicity living in the U.K. have at least a 50% excess of cardiovascular disease (CVD) mortality compared with European whites, yet there are no validated tools capable of identifying this excess risk. Left ventricular hypertrophy (LVH) is a powerful prognosticator for future CVD events but its prevalence in Indian Asians is unknown. We examined the prevalence of LVH and the degree of concentric remodeling amongst healthy U.K. Indian Asians compared with European whites recruited to the LOLIPOP (London Life Sciences Prospective Population) study. Transthoracic echocardiography was performed in 2127 subjects aged 35-75 years without history of clinical CVD events. The prevalence of LVH was defined and relative wall thickness was calculated to provide a measure of concentric remodeling. The prevalence of LVH was significantly higher amongst Indian Asian men as compared with European white men, with an unadjusted odds ratio (OR) of 1.8 (95% CI: 1.4-2.6). Following adjustment for clinical and hemodynamic variables, the magnitude of this effect increased (OR 2.8, 95% CI: 1.9-4.2). The degree of concentric remodeling was higher amongst Indian Asians as compared with European whites (adjusted relative wall thickness for men: 0.41 vs. 0.39, P<0.001; women: 0.40 vs. 0.38, P<0.01). An almost threefold higher prevalence of LVH amongst Indian Asian men and a greater degree of concentric remodeling amongst Indian Asian men and women was evident. Investigation of the mechanisms underlying the pathogenesis of LV remodeling and blood pressure etiology may help redress the excess CVD mortality observed in Indian Asians.

Power modulation contrast enhanced ultrasound for postoperative perfusion monitoring following free tissue transfer in head and neck surgery.

This feasibility study evaluated whether contrast enhanced ultrasound (CEU) was able to assess free flap perfusion following free tissue transfer in the head and neck region. Thirty-six patients underwent standard clinical monitoring (SCM) and CEU postoperatively. The time taken for each technique to detect flap failure was recorded. Qualitative CEU analysis by visual assessment predicted survival in 30/30 (100%) and failure in 5/6 (83%) flaps with sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of 100, 86, 97 and 100%, respectively. Quantitative CEU measurement of blood volume (α) values within healthy perfused flaps was over 60 times higher than in failing flaps (8.25±2.82dB vs. 0.12±0.17dB, respectively, P<0.0001). If a cut-off α value of <1.5dB was used to predict future flap failure, the accuracy of the test was 100% (sensitivity, specificity, PPV, NPV). If a cut-off α value of >1.9dB indicated flap success, the PPV and NPV are 100%. Following surgery, SCM took 76 (±15) h to detect flap failure compared with 18 (±38) h with CEU (P<0.05). CEU is highly accurate in its ability to distinguish between perfused and failing flaps. The technique is quick (<10min) and capable of imaging all flap types.

The utility of volunteer home-visiting support to prevent maternal depression in the first year of life.

BACKGROUND: Maternal depression can be detrimental to infant development. Structured home visiting initiated either in pregnancy or soon after the birth by a professional has led to better outcomes for mothers and their children but some vulnerable families may respond more favourably to a local volunteer. The value of volunteer support provided in the UK by Home-Start for maternal well-being is noted in qualitative studies, but there is no evidence of its impact from trials. The support is not structured and both the frequency and content of visits may vary. METHODS: A cluster randomized study allocated Home-Start local schemes to intervention or control conditions. Mothers in all areas were screened at routine health checks in late pregnancy. In intervention areas names of those scoring 9+ on the Social Disadvantage Screening Index were passed to Home-Start to be offered a volunteer. Not all those offered the support accepted the offer. In control areas no support was offered. Research assessments were conducted at 2 and 12 months. The outcomes were major or minor depression occurring between 2 and 12 months (Structured Clinical Interview for Diagnostic and Statistical Manual - Third Edition - Revised) and depression symptoms at 12 months (Edinburgh Postnatal Depression Scale). Three groups were compared: supported, case-matched controls and those offered but not receiving support. RESULTS: Almost one-third experienced depression during the time period. Volunteer support had no identifiable impact on the emergence of maternal depression from 2 to 12 months or on depression symptoms when infants were 12 months. The major predictor of both was depression identified at 2 months. CONCLUSIONS: It was not found that informal support initiated following screening for disadvantage in pregnancy reduced the likelihood of depression for mothers with infants.

An update on contrast echocardiography.

Ultrasound contrast agents, used with contrast-specific imaging techniques, have an established role for diagnostic cardiovascular imaging in the echocardiography laboratory. The advent of tissue harmonic imaging, albeit a significant advancement in ultrasound technology, still fail to produce diagnostically useful images in a significant proportion of patients. This therefore, often leads to inaccurate assessment of left ventricular function, neccesitating the use of other more laborious and expensive imaging techniques purely for diagnostic purposes. Historically, contrast agents have not been an integral component of the echocardiography imaging laboratory. However the need for a more robust method for the assessment of left ventricular function facilitated the developement of a unique class of contrast agents composed of microbubbles, which together with ultrasound, produce opacification of the left ventricular cavity, thus enabling accurate quantification of its function. The use of these contrast agents have now gone beyond the assessment of wall motion and function to the assessment of myocardial perfusion. Myocardial contrast echocardiography has enabled the assessment of cardiac anatomy, function and perfusion, all in one sitting, by the bedside. Contrast ultrasound imaging has now been applied to even newer techniques such as real-time three-dimensional echocardiography and is also showing promise in the assessment of carotid ultrasound for intima-media thickness. Contrast agents therefore have a significant role in cardiovascular diagnostics and its use can only improve patient care.

Independent value of left atrial volume index for the prediction of mortality in patients with suspected heart failure referred from the community.

BACKGROUND: The left atrial volume index (LAVI) reflects left ventricular (LV) filling pressure and has been shown to predict outcome in various cardiovascular diseases. However, its value for the prediction of mortality in patients referred for suspected heart failure (HF) is unknown. OBJECTIVE: To assess the value of LAVI for the prediction of mortality independently of clinical, electrocardiographic (ECG) and echocardiographic prognostic parameters in patients with suspected HF referred from the community. METHODS: 356 (mean (SD) age 72 (13) years) patients with suspected HF referred from the community were followed up for mortality after undergoing clinical assessment, ECG and echocardiography, including Doppler, to assess LV filling. RESULTS: Data were obtained for 335/356 (94%) patients (162 male, 173 female) over a mean (SD) follow-up period of 30 (10) months, during which 38 (11.3%) died. The univariate predictors for all-cause mortality were age, symptom of leg swelling, clinical signs of HF, abnormal ECG, LV ejection fraction, LAVI, LV end-systolic (LVESD) and diastolic dimension, septal wall thickness and the presence of other significant cardiac abnormalities. The only independent predictors of mortality were age (hazard ratio (HR) = 2.15, 95% CI 1.42 to 3.25, p<0.001), symptom of leg swelling (HR = 2.83, 95% CI 1.43 to 5.59, p = 0.005), LAVI (HR = 1.25, 95% CI 1.01 to 1.54, p = 0.04) and LVESD (HR = 1.32, 95% CI 1.02 to 1.70, p = 0.04). CONCLUSION: LAVI provided independent information over clinical and other echocardiographic variables for predicting mortality in patients with suspected HF referred from the community.

Effects of left bundle-branch block on cardiac structure, function, perfusion, and perfusion reserve: implications for myocardial contrast echocardiography versus radionuclide perfusion imaging for the detection of coronary artery disease.

BACKGROUND: We aimed to investigate the cardiac effects of left bundle-branch block (LBBB) using myocardial contrast echocardiography (MCE) to ascertain the value of MCE for detecting coronary artery disease (CAD) and to uncover the mechanism that affects the accuracy of single-photon emission computed tomography (SPECT) in these patients. METHODS AND RESULTS: Sixty-three symptomatic LBBB patients (group A), 10 left ventricular ejection fraction-matched control subjects without LBBB and no CAD (group B), and 10 normal control subjects (group C) underwent resting echocardiography. Rest and vasodilator MCE and SPECT were undertaken in LBBB patients. Septal (SW) and posterior wall (PW) thickness, thickening, quantitative myocardial blood flow (MBF), and MBF reserve were measured. SW/PW thickness and percentage thickening ratios were lower (P<0.01 and P<0.05, respectively) in group A compared with both groups B and C, but resting SW/PW MBF and MBF reserve ratios were similar in all 3 groups. MBF reserve but not MBF was reduced in groups A and B (2.2+/-0.7 versus 2.2+/-0.2; P=0.98) compared with group C (3.1+/-0.5; P<0.01). SW thickness was an independent predictor (P=0.006) of SPECT perfusion defects in LBBB patients without CAD. MCE (92%) had a sensitivity similar to SPECT (92%); however, the specificity of MCE (95%) was superior (P<0.0001) to SPECT (47%) for the detection of CAD. CONCLUSIONS: Despite asymmetrical reduction in SW thickness and function, MBF is preserved and MBF reserve is homogeneously reduced in LBBB patients with left ventricular systolic dysfunction. Because of partial volume effects, the accuracy of SPECT for detecting CAD was significantly compromised compared with MCE in this patient cohort.

Treat the patient not the blood test: the implications of an increase in cardiac troponin after prolonged endurance exercise.

Collapse after prolonged endurance exercise is common and usually benign. This case study reports a triathlete who suffered a vaso-vagal associated collapsed after exercise. Misdiagnosis of myocardial injury in the presence of elevated cardiac troponins and ECG anomalies led to inappropriate management and highlights the difficulty in treating the collapsed athlete following arduous exercise.

Observation of a comb of optical squeezing over many gigahertz of bandwidth.

We experimentally demonstrate the generation of optical squeezing at multiple longitudinal modes and transverse Hermite-Gauss modes of an optical parametric amplifier. We present measurements of approximately 3 dB squeezing at baseband, 1.7 GHz, 3.4 GHz and 5.1 GHz which correspond to the first, second and third resonances of the amplifier. We show that both the magnitude and the bandwidth of the squeezing at the higher longitudinal modes is greater than can be observed at baseband. The squeezing observed is the highest frequency squeezing reported to date.

Diagnostic and prognostic role of cardiac troponin I (cTnI) measured on the DPC Immulite.

OBJECTIVE: To evaluate the diagnostic and prognostic role of the Immulite cTnI assay for the detection of acute coronary syndromes (ACS). POPULATION: 150 males and 63 females with a median age of 63 years, range 28 to 88, and an interquartile range of 18 years were admitted within 24 h of chest pain and non-ST segment elevation ACS were studied. The median onset of symptoms was 3 h (range 0-23). METHODS: Venous samples were taken on admission (t = 0) and at 24 h (t = 24). The serum samples were assayed for CK, CK-MB and cTnT on an Elecsys 1010 (Roche Diagnostics, Lewes, UK). The cTnT assay CV was 5.5% at 0.32 microg/l and 5.4% at 6.0 microg/l, and the detection limit was 0.01 microg/l with an upper limit of 25 microg/l. For cTnI using the Immulite (DPC, Gwynedd, Wales), the detection limit was 0.1 microg/l, and the upper limit was 180 microg/l. Final diagnostic categorization was performed by both WHO and European Society of Cardiology criteria using cTnT as the diagnostic cardiac biomarker. Patients were followed for the major adverse cardiac events (MACE), endpoints cardiac death, AMI or need for urgent revascularization. ROC curves were constructed using final diagnosis. Outcome prediction was assessed by ROC curves and Kaplan-Meier survival curves. RESULTS: Both methods had equivalent diagnostic efficiency using WHO criteria for AMI. When ESC criteria were used the AUC for admission and 24 h cTnT and cTnI values were 0.945 vs. 0.910, P = 0.20 and 0.998 vs. 0.937, P = 0.005, respectively. Both methods predicted outcome as either death or MI or MACE and were not significantly different. CONCLUSION: The Immulite cTnI assay can be used for diagnosis and risk stratification in patients admitted with non-ST segment elevation acute coronary syndromes.

Myocardial viability assessed by dobutamine stress echocardiography predicts reduced mortality early after acute myocardial infarction: determining the risk of events after myocardial infarction (DREAM) study.

OBJECTIVE: To establish further the role of dobutamine stress echocardiography (DSE) in prognostication of outcome early after acute myocardial infarction (AMI) METHODS: Consecutive patients presenting with AMI were screened for inclusion into the study. 212 stable consenting patients underwent DSE a mean (SD) of 4.8 (1.5) days after AMI. Patients were then followed up for 803 (297) days. RESULTS: The mean (SD) resting systolic wall thickening index (SWTI) was 1.6 (0.4), 44% patients had evidence of viability at low dose, and 38% had evidence of ischaemia. During the follow up period 27 (13%) patients died and 16 (8%) had a non-fatal AMI. Independent predictors of both mortality and combined mortality and non-fatal AMI were age (hazard ratio (HR) 1.04/year, p = 0.01, and HR 1.03/year, p = 0.04, respectively) and SWTI at low dose (HR 3.6, p < 0.01, and HR 2.5, p = 0.02, respectively). Low dose DSE provided incremental information over clinical and resting left ventricular function data for predicting death and non-fatal AMI. For patients who were not revascularised SWTI at peak dose dobutamine was the only independent predictor of mortality. CONCLUSION: DSE is a powerful predictor of outcome in stable survivors of AMI. The presence of myocardial viability has a positive impact on survival.

Early experiences and their relationship to maternal eating disorder symptoms, both lifetime and during pregnancy.

BACKGROUND: There is some evidence that early sexual abuse is an aetiological factor for eating disorder. However, there is sparse information from large-scale, non-clinical studies. AIMS: This study was designed to explore which early experiences, recalled during pregnancy, were associated with both lifetime and antenatal eating disorder symptoms in a community sample. METHOD: Univariate and multivariate analyses were conducted of data from questionnaires administered during pregnancy to a community sample of pregnant women. RESULTS: Recall of parental mental health problems and of early unwanted sexual experiences were independently associated with both lifetime eating problems, laxative use and vomiting during pregnancy, and marked concern during pregnancy over shape and weight. CONCLUSIONS: There are public health implications for these results. Eating disorders in mothers represent a risk for child development. It may be important to enquire during pregnancy about a history of eating problems and to provide the opportunity for early experiences to be discussed.

Ethnic differences in the prevalence and aetiology of left ventricular systolic dysfunction in the community: the Harrow heart failure watch.

OBJECTIVE: To assess ethnic differences in the prevalence and aetiology of left ventricular systolic dysfunction (LVSD) in the community. DESIGN: Community cohort study. All patients underwent echocardiography and those found to have LVSD underwent myocardial perfusion imaging with or without coronary angiography to diagnose underlying coronary artery disease (CAD). SETTING: Seven representative general practices in Harrow, UK, a community hospital, and a local district general hospital. PATIENTS: 1392 patients >or= 45 years old randomly selected from the computer records of seven general practices. MAIN OUTCOME MEASURES: The prevalence and aetiology of LVSD in the community, assessing differences between white and non-white populations, and the proportion of patients with LVSD with undiagnosed CAD. RESULTS: 734 patients (53%) attended, 518 (71%) white and 216 (29%) non-white, the majority South Asian. Thirty nine patients (5.5%) had probable LVSD and 25 (3.5%) definite LVSD. No significant differences in prevalence were seen with ethnicity. CAD underlay most cases of LVSD. Non-white patients had a higher prevalence of CAD as the underlying aetiology of significant LVSD than white patients (100% v 56%, p = 0.04) and a trend towards less alcoholic cardiomyopathy. 8% of patients with LVSD had undiagnosed CAD. CONCLUSIONS: LVSD is common. White and non-white patients have a similar overall prevalence of LVSD. Non-white patients, the majority South Asians in this study, have a higher prevalence of CAD as the underlying cause for LVSD than white patients. CAD underlies most cases of LVSD in the community, although it may be undiagnosed unless formally assessed.