Comparison of Four-Dimensional Flow MRI, Two-Dimensional Phase-Contrast MRI and Echocardiography in Transposition of the Great Arteries

Pulmonary artery (PA) stenosis is a common complication after the arterial switch operation (ASO) for transposition of the great arteries (TGA). Four-dimensional flow (4D flow) CMR provides the ability to quantify flow within an entire volume instead of a single plane. The aim of this study was to compare PA maximum velocities and stroke volumes between 4D flow CMR, two-dimensional phase-contrast (2D PCMR) and echocardiography. A prospective study including TGA patients after ASO was performed between December 2018 and October 2020. All patients underwent echocardiography and CMR, including 2D PCMR and 4D flow CMR. Maximum velocities and stroke volumes were measured in the main, right, and left PA (MPA, LPA, and RPA, respectively). A total of 39 patients aged 20 ± 8 years were included. Maximum velocities in the MPA, LPA, and RPA measured by 4D flow CMR were significantly higher compared to 2D PCMR (p < 0.001 for all). PA assessment by echocardiography was not possible in the majority of patients. 4D flow CMR maximum velocity measurements were consistently higher than those by 2D PCMR with a mean difference of 65 cm/s for the MPA, and 77 cm/s for both the RPA and LPA. Stroke volumes showed good agreement between 4D flow CMR and 2D PCMR. Maximum velocities in the PAs after ASO for TGA are consistently lower by 2D PCMR, while echocardiography only allows for PA assessment in a minority of cases. Stroke volumes showed good agreement between 4D flow CMR and 2D PCMR.

Common Genetic Variants Contribute to Risk of Transposition of the Great Arteries

RATIONALE

Dextro-transposition of the great arteries (D-TGA) is a severe congenital heart defect which affects approximately 1 in 4,000 live births. While there are several reports of D-TGA patients with rare variants in individual genes, the majority of D-TGA cases remain genetically elusive. Familial recurrence patterns and the observation that most cases with D-TGA are sporadic suggest a polygenic inheritance for the disorder, yet this remains unexplored.

OBJECTIVE

We sought to study the role of common single nucleotide polymorphisms (SNPs) in risk for D-TGA.

METHODS AND RESULTS

We conducted a genome-wide association study in an international set of 1,237 patients with D-TGA and identified a genome-wide significant susceptibility locus on chromosome 3p14.3, which was subsequently replicated in an independent case-control set (rs56219800, meta-analysis P=8.6x10-10, OR=0.69 per C allele). SNP-based heritability analysis showed that 25% of variance in susceptibility to D-TGA may be explained by common variants. A genome-wide polygenic risk score derived from the discovery set was significantly associated to D-TGA in the replication set (P=4x10-5). The genome-wide significant locus (3p14.3) co-localizes with a putative regulatory element that interacts with the promoter of WNT5A, which encodes the Wnt Family Member 5A protein known for its role in cardiac development in mice. We show that this element drives reporter gene activity in the developing heart of mice and zebrafish and is bound by the developmental transcription factor TBX20. We further demonstrate that TBX20 attenuates Wnt5a expression levels in the developing mouse heart.

CONCLUSIONS

This work provides support for a polygenic architecture in D-TGA and identifies a susceptibility locus on chromosome 3p14.3 near WNT5A. Genomic and functional data support a causal role of WNT5A at the locus.

Two decades of aortic coarctation treatment in children; evaluating techniques

Objective

This study focuses on the evolution of treatment techniques for aortic coarctation in children and assesses long-term morbidity.

Methods

This retrospective cohort study evaluates patients treated for native aortic coarctation, with at least 7 years of follow-up. To assess time-related changes, three time periods were distinguished according to year of primary intervention (era 1, 2 and 3). Operative and long-term follow-up data were collected by patient record reviews.

Results

The study population consisted of 206 patients (177 surgical and 29 catheter-based interventions), with a median follow-up of 151 months. Anterior approach with simultaneous repair of aortic arch and associated cardiac lesions was more common in the most recent era. Median age at intervention did not change over time. Reintervention was necessary in one third of the cohort with an event-free survival of 74% at 5‑year and 68% at 10-year follow-up. Reintervention rates were significantly higher after catheter-based interventions compared with surgical interventions (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.04–3.00, p = 0.04) and in patients treated before 3 months of age (HR 2.1, 95% CI 1.27–3.55, p = 0.003). Hypertension was present in one out of five patients.

Conclusion

Nowadays, complex patients with associated cardiac defects and arch hypoplasia are being treated surgically on bypass, whereas catheter-based intervention is introduced for non-complex patients. Reintervention is common and more frequent after catheter-based intervention and in surgery under 3 months of age. One fifth of the 206 patients remained hypertensive.

Medication in adults after atrial switch for transposition of the great arteries: clinical practice and recommendations

Aims

Heart failure is the main threat to long-term health in adults with transposition of the great arteries (TGA) corrected by an atrial switch operation (AtrSO). Current guidelines refrain from recommending heart failure medication in TGA-AtrSO, as there is insufficient data to support the hypothesis that it is beneficial. Medication is therefore prescribed based on personal judgements. We aimed to evaluate medication use in TGA-AtrSO patients and examine the association of use of renin–angiotensin–aldosterone system (RAAS) inhibitors and β-blockers with long-term survival.

Methods and results

We identified 150 TGA-AtrSO patients [median age 30 years (interquartile range 25–35), 63% male] included in the CONCOR registry from five tertiary medical centres with subsequent linkage to the Dutch Dispensed Drug Register for the years 2006–2014. Use of RAAS inhibitors, β-blockers, and diuretics increased with age, from, respectively, 21% [95% confidence interval (CI) 14–40], 12% (95% CI 7–21), and 3% (95% CI 2–7) at age 25, to 49% (95% CI 38–60), 51% (95% CI 38–63), and 41% (95% CI 29–54) at age 45. Time-varying Cox marginal structural models that adjusted for confounding medication showed a lower mortality risk with use of RAAS inhibitors and β-blockers in symptomatic patients [hazard ratio (HR) = 0.13 (95% CI 0.03–0.73); P = 0.020 and HR = 0.12 (95% CI 0.02–0.17); P = 0.019, respectively]. However, in the overall cohort, no benefit of RAAS inhibitors and β-blockers was seen [HR = 0.93 (95% CI 0.24–3.63); P = 0.92 and HR = 0.98 (0.23–4.17); P = 0.98, respectively].

Conclusion

The use of heart failure medication is high in TGA-AtrSO patients, although evidence of its benefit is limited. This study showed lower risk of mortality with use of RAAS inhibitors and β-blockers in symptomatic patients only. These findings can direct future guidelines, supporting use of RAAS inhibitors and β-blockers in symptomatic, but not asymptomatic patients.

New developments in adult congenital heart disease

Congenital heart disease (CHD) affects 0.8% of live births and over the past decades technical improvements and large-scale repair has led to increased survival into adulthood of over 95% of the new-born. A new group of patients, those who survived their congenital heart defect, has emerged but late complications including heart failure, pulmonary hypertension (PH), arrhythmias, aneurysms and endocarditis appeared numerous, with a huge impact on mortality and morbidity. However, innovations over the past years have changed the landscape of adult CHD dramatically. In the diagnostic process important improvements have been made in the use of MRI, biomarkers, e‑health concepts and 3D visualisation of anatomy. Care is now concentrated in specialised centres, with a continuous emphasis on education and the introduction of weekly multidisciplinary consultations on diagnosis and intervention. Surgery and percutaneous intervention have been refined and new concepts applied, further reducing the burden of the congenital malformations. Research has matured from case series to global networks. Currently, adults with CHD are still facing high risks of early mortality and morbidity. By global collaboration and continuous education and development and innovation of our diagnostic and therapeutic arsenal, we will improve the perspectives of these young patients.

Echocardiography and MRI parameters associated with exercise capacity in patients after the arterial switch operation

BACKGROUND

The arterial switch operation (ASO) for transposition of the great arteries has excellent survival, but a substantial number of patients suffer from a reduced exercise capacity. The goal of this study was to identify imaging parameters associated with a reduced exercise capacity in patients after ASO.

METHODS

A retrospective analysis was performed of ASO patients who underwent cardiopulmonary exercise testing (CPET) between 2007 and 2017. Reduced exercise performance was defined as a reduced workload peak (W_peak) with Z-score <-2 or a peak oxygen uptake indexed for weight (VO_2peak/kg) with Z-score <-2. Data on echocardiography and cardiac magnetic resonance performed within 1 year of the CPET were collected for comparison.

RESULTS

A total of 81 ASO patients (age 17±7 years) were included. Reduced exercise performance was found in 22 patients (27%) as expressed by either a reduced W_peak and/or a reduced VO_2peak/kg. Main pulmonary artery gradient and tricuspid regurgitation gradient by echocardiography were found to be associated with reduced W_peak (p=0.031; p=0.020, respectively). The main pulmonary artery gradient and tricuspid regurgitation gradient by echocardiography were found to be associated with reduced VO_2peak/kg (p=0.009; p=0.019, respectively). No left ventricular parameters were found to be associated with abnormal exercise performance.

CONCLUSION

This study demonstrates that ASO patients frequently experience reduced exercise capacity. Echocardiographic evidence of main pulmonary artery stenosis and increased right ventricular pressure were associated with reduced exercise capacity, and are therefore key to monitor during serial follow-up of ASO patients.

Safety and efficacy of stenting for aortic arch hypoplasia in patients with coarctation of the aorta

Background

Despite a successful repair procedure for coarctation of the aorta (CoA), up to two-thirds of patients remain hypertensive. CoA is often seen in combination with abnormal aortic arch anatomy and morphology. This might be a substrate for persistent hypertension. Therefore, we performed endovascular aortic arch stent placement in patients with CoA and concomitant aortic arch hypoplasia or gothic arch morphology. The goal of this retrospective analysis was to investigate the safety and efficacy of aortic arch stenting.

Methods

A retrospective analysis was performed in patients who underwent stenting of the aortic arch at the University Medical Center Utrecht. Measurements collected included office blood pressure, use of antihypertensive medication, invasive peak-to-peak systolic pressure over the arch, and aortic diameters on three-dimensional angiography. Data on follow-up were obtained at the date of most recent outpatient visit.

Results

Twelve patients underwent stenting of the aortic arch. Mean follow-up duration was 14 ± 11 months. Mean peak-to-peak gradient across the arch decreased from 39 ± 13 mm Hg to 7 ± 8 mm Hg directly after stenting (p < 0.001). There were no major procedural complications. Mean systolic blood pressure decreased from 145 ± 16 mm Hg at baseline to 128 ± 9 mm Hg at latest follow-up (p = 0.014).

Conclusion

This retrospective study shows that stenting of the aortic arch is successful when carried out in a state-of-the-art manner. A direct optimal angiographic and haemodynamic result was shown. No major complications occurred during or after the procedure. At short- to medium-term follow-up a decrease in mean systolic blood pressure was observed.

Medium-term systemic blood pressure after stenting of aortic coarctation: a systematic review and meta-analysis

OBJECTIVE

Long-term prognosis of patients with coarctation of the aorta (CoA) is impaired due to the high prevalence of hypertension and consequent cardiovascular complications. Although stent implantation results in acute anatomical and haemodynamic benefit, limited evidence exists regarding the late clinical outcome. In this meta-analysis, we aimed to evaluate the medium-term effect of stent placement for CoA on systemic blood pressure (BP).

METHODS

PubMed, EMBASE and Cochrane databases were searched for non-randomised cohort studies addressing systemic BP ≥12 months following CoA stenting. Meta-analysis was performed on the change in BP from baseline to last follow-up using a random-effects model. Subgroup analyses and meta-regression were conducted to identify sources of heterogeneity between studies.

RESULTS

Twenty-six studies with a total of 1157 patients and a median follow-up of 26 months were included for final analysis. Meta-analysis showed a 20.3 mm Hg (95% CI 16.4 to 24.1 mm Hg; p<0.00001) reduction in systolic BP and an 8.2 mm Hg (12 studies; 95% CI 5.2 to 11.3 mm Hg; p<0.00001) reduction in diastolic BP. A concomitant decrease in the use of antihypertensive medication was observed. High systolic BP and peak systolic gradient at baseline and stenting of native CoA were associated with a greater reduction in systolic BP at follow-up.

CONCLUSIONS

Stent implantation for CoA is associated with a significant decline in systolic and diastolic BP during medium-term follow-up. The degree of BP reduction appears to be dependent on baseline systolic BP, baseline peak systolic gradient, and whether stenting is performed for native or recurrent CoA.

Cardiovascular biochemical risk factors among women with spontaneous preterm delivery

OBJECTIVE

To determine whether women delivering preterm have unfavorable cardiovascular profiles as compared with women who deliver at term.

METHODS

A prospective observational cohort study enrolled 165 women with spontaneous preterm delivery (sPTD) at 24⁺⁰ and 36⁺⁶ gestational weeks in three perinatal care centers in The Netherlands between August 2012 and August 2014. Total cholesterol, triglycerides, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, apolipoprotein, glucose, and homocysteine were measured within 24 hours after delivery. Lipids and cardiovascular biochemical risk factors were compared between women with sPTD and an external comparison group of 30 women with term delivery via analysis of covariance.

RESULTS

Mean gestational age at delivery was 30.7 ± 3.6 weeks in the sPTD group and 40.3 ± 1.3 weeks in the reference group. Data were adjusted for body mass index, age, and center. As compared with the reference group, total cholesterol and LDL-cholesterol levels were lower and glucose levels were higher among women with sPTD.

CONCLUSION

An association between sPTD and unfavorable lipids and cardiovascular biochemical risk factors was not established. The higher levels of glucose in the sPTD group might be due to increased insulin resistance, which is associated with a higher risk of sPTD.

Echocardiographic findings associated with mortality ortransplant in patients with pulmonary arterial hypertension:A systematic review and meta-analysis

Background

Identification of patients at risk of deterioration is essential to guide clinical management in pulmonary arterial hypertension (PAH). This study aims to provide a comprehensive overview of well-investigated echocardiographic findings that are associated with clinical deterioration in PAH.

Methods

MEDLINE and EMBASE databases were systematically searched for longitudinal studies published by April 2015 that reported associations between echocardiographic findings and mortality, transplant or clinical worsening. Meta-analysis using random effect models was performed for echocardiographic findings investigated by four or more studies. In case of statistical heterogeneity a sensitivity analysis was conducted.

Results

Thirty-seven papers investigating 51 echocardiographic findings were included. Meta-analysis of univariable hazard ratios (HRs) and sensitivity analysis showed that presence of pericardial effusion (pooled HR 1.70; 95 % CI 1.44–1.99), right atrial area (pooled HR 1.71; 95 % CI 1.38–2.13) and tricuspid annular plane systolic excursion (TAPSE; pooled HR 1.72; 95 % CI 1.34–2.20) were the most well-investigated and robust predictors of mortality or transplant.

Conclusions

This meta-analysis substantiates the clinical yield of specific echocardiographic findings in the prognostication of PAH patients in day-to-day practice. In particular, pericardial effusion, right atrial area and TAPSE are of prognostic value.

Electronic supplementary material

The online version of this article (doi: 10.1007/s12471-016-0845-3) contains supplementary material, which is available to authorized users.

Aortic valve prosthesis-patient mismatch and exercise capacity in adult patients with congenital heart disease

OBJECTIVES

To report the prevalence of aortic valve prosthesis-patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease (ACHD) with a history of aortic valve replacement may outgrow their prosthesis later in life. However, the prevalence and clinical consequences of aortic PPM in ACHD are presently unknown.

METHODS

From the national Dutch Congenital Corvitia (CONCOR) registry, we identified 207 ACHD with an aortic valve prosthesis for this cross-sectional cohort study. Severe PPM was defined as an indexed effective orifice area ≤0.65 cm2/m2 and moderate PPM as an indexed orifice area ≤0.85 cm2/m2 measured using echocardiography. Exercise capacity was reported as percentage of predicted exercise capacity (PPEC).

RESULTS

Of the 207 patients, 68% was male, 71% had a mechanical prosthesis and mean age at inclusion was 43.9 years ±11.4. The prevalence of PPM was 42%, comprising 23% severe PPM and 19% moderate PPM. Prevalence of PPM was higher in patients with mechanical prostheses (p<0.001). PPM was associated with poorer exercise capacity (mean PPEC 84% vs. 92%; p=0.048, mean difference =-8.3%, p=0.047). Mean follow-up was 2.6±1.1 years during which New York Heart Association (NYHA) class remained stable in most patients. PPM showed no significant effect on death or hospitalisation during follow-up (p=0.218).

CONCLUSIONS

In this study we report a high prevalence (42%) of PPM in ACHD with an aortic valve prosthesis and an independent association of PPM with diminished exercise capacity.

Haemodynamics in a patient with Fontan physiology undergoing laparoscopic cholecystectomy

Laparoscopic surgery in patients with Fontan circulation is a haemodynamic challenge; venous return may be compromised by insufflation of carbon dioxide into the abdomen (increasing intra-abdominal pressure), the use of reverse Trendelenburg position and positive pressure ventilation. Combined with an increase in pulmonary vascular resistance due to hypercarbia, cardiac output may be reduced. However, for non-haemodynamic reasons, laparoscopic surgery has advantages over open surgery: less postoperative pain, shorter hospital stay, a reduction in postoperative wound infections and a reduction of respiratory complications. In this case report, we present a patient with Fontan circulation who underwent uneventful laparoscopic cholecystectomy.

Implantable Cardioverter Defibrillator Therapy in Adults With Congenital Heart Disease

Background—

The value of implantable cardioverter defibrillators (ICDs) in adults with congenital heart disease (CHD) is unknown. We investigated the long-term outcome after ICD implantation and developed a simple risk stratification score for ICD therapy.

Methods and Results—

A total of 136 adults with CHD and ICD (mean age±SD, 41±13 years; 67% male) were identified from 10 tertiary referral centers in the Netherlands and Belgium. The indication for ICD implantation was primary prevention in 50% of patients. Diagnoses included tetralogy of Fallot (51%), septal defects (20%), (congenitally corrected) transposition of the great arteries (13%), and other (16%). Thirty-nine patients (29%) received appropriate ICD shocks during a median follow-up of 4.6 years. Secondary prevention indication (hazard ratio [HR], 3.6; 95% CI, 1.3–9.5; P= 0.009), coronary artery disease (HR, 2.7; 95% CI, 1.0–7.2; P= 0.042), and symptomatic nonsustained ventricular tachycardia (NSVT; HR, 9.1; 95% CI, 2.8–29.2; P= 0.001) were associated with appropriate ICD shocks. A risk score was developed to evaluate the likelihood of appropriate ICD shocks. The 8-year survival curve to first appropriate shocks was 94%, 57%, and 26% for low-, intermediate-, and high-risk patients, respectively. In primary prevention, symptomatic NSVTs (HR, 8.0; 95% CI, 2.3–27.1; P= 0.001) and subpulmonary ventricular dysfunction (HR, 3.0; 95% CI, 1.2–12.6; P =0.02) were associated with appropriate shocks in univariable analysis. Inappropriate shocks occurred in 41 patients (30%). In addition, 40 patients (29%) experienced 45 implantation-related complications.

Conclusions—

Adults with CHD and ICDs receive high rates of appropriate and effective shocks. Patients with secondary prevention indication, coronary artery disease, and symptomatic NSVT are at highest risk of receiving appropriate ICD shocks. ICD implantation is accompanied by considerable morbidity, including inappropriate shocks and procedure- related complications.

Effects of high-dose insulin infusion on left ventricular function in normal subjects

Background. Only a few studies have reported on the effect of high-dose insulin (HDI) infusion on cardiac function in healthy volunteers. Methods. We studied ten healthy volunteers with low-dose dobutamine (LDD, 10 mug/kg/min) echo-cardio-graphy and HDI echocardiography (insulin administration for one hour) by volume and Doppler analysis. Results. During LDD, cardiac output increased from 5.7+/-1.3 l/min to 9.0+/-2.1 l/min (p<0.001) and during HDI from 5.5+/-1.2 l/min to 6.2+/-1.1 l/min (p=0.048). Increase was not only due to increase in frequency, which was only present in the LDD study, but also due to increase in stroke volume (from 82+/-15 ml to 110+/-23 ml, p<0.001 during LDD and from 82+/-16 ml to 93+/-24 ml, p=0.014 during HDI). The increase in stroke volume was the result of a decrease in end-systolic volume with an unchanged end-diastolic volume. Conclusion. High-dose insulin infusion results in increased cardiac output by improving systolic myocardial function. (Neth Heart J 2010;18:183-9.).

Rationale and design of a trial on the effect of angiotensin II receptor blockers on the function of the systemic right ventricle

BACKGROUND

Angiotensin II receptor blockers have been proven to be beneficial in left ventricular failure. In patients with a morphologic right ventricle supporting the systemic circulation, its efficacy has not yet been established.

METHODS

We designed a multicenter, prospective, randomized, double-blind, placebo-controlled trial studying the effect of valsartan in patients with a systemic right ventricle due to a congenitally or surgically corrected transposition of the great arteries. The primary end point is the change in right ventricular ejection fraction as measured by cardiovascular magnetic resonance or multidetector row cardiac computed tomography in case of pacemaker patients.

CONCLUSION

This large prospective, double-blind, randomized, placebo-controlled trial will establish the role of angiotensin II receptor blockers (valsartan) in the treatment of patients with a systemic right ventricle.

Ultrasound enhanced prehospital thrombolysis using microbubbles infusion in patients with acute ST elevation myocardial infarction: rationale and design of the Sonolysis study

BACKGROUND

Experimental studies have shown that ultrasound contrast agents enhance the effectiveness of thrombolytic agents in the presence of ultrasound in vitro and in vivo. Recently, we have launched a clinical pilot study, called "Sonolysis", to study this effect in patients with ST-elevation myocardial infarction based on proximal lesions of the infarct-related artery.

METHODS/DESIGN

In our multicenter, randomized, placebo controlled clinical trial we will include patients between 18 and 80 years of age with their first ST-elevation myocardial infarction based on a proximal lesion of the infarct-related artery. After receiving a single bolus alteplase 50 mg IV (Actilyse(R) Boehringer Ingelheim GmbH), a loading dose of aspirin 500 mg, and heparin 5000 IU in the ambulance according to the prehospital thrombolysis protocol, patients, following oral informed consent, are randomized to undergo 15 minutes of pulsatile ultrasound with intravenous administration of ultrasound contrast agent or placebo without ultrasound. Afterwards coronary angiography and, if indicated, percutaneous coronary intervention will take place. A total of 60 patients will be enrolled in approximately 1 year.The primary endpoints are based on the coronary angiogram and consist of TIMI flow, corrected TIMI frame count, and myocardial blush grade. Follow-up includes 12-lead ECG, 2D-echocardiography, cardiac MRI, and enzyme markers to obtain our secondary endpoints, including the infarct size, wall motion abnormalities, and the global left ventricular function.

DISCUSSION

The Sonolysis study is the first multicenter, randomized, placebo controlled clinical trial investigating the therapeutic application of ultrasound and microbubbles in acute ST-elevation myocardial infarction patients. A positive finding may stimulate further research and technical innovations to implement the treatment in the ambulance and maybe obtain even more patency at an earlier stage.

TRIAL REGISTRATION

Trialregister NTR161.

Relation of physical activity, cardiac function, exercise capacity, and quality of life in patients with a systemic right ventricle

Exercise is recommended in patients with left ventricular failure. Although right ventricular failure is common in patients with a systemic right ventricle (RV), no data are available on the effect of physical activity in these patients. The aim of this study was to evaluate the relation of physical activity and cardiac function, exercise capacity, and quality of life in patients with a systemic RV. Forty-seven patients (64% men, mean age 35 years, range 21 to 69) with a systemic RV (31 with an atrially switched transposition of the great arteries and 16 with a congenitally corrected transposition of the great arteries) were included. Cardiac function was assessed by cardiovascular magnetic resonance or computed tomography, exercise tests, and serum N-terminal prohormone brain natriuretic peptide (NT-pro-BNP) levels. Habitual physical activity was assessed using the Short Questionnaire to Assess Health-Enhancing Physical Activity (SQUASH) and quality of life using the Medical Outcomes Study Short Form 36-Item Health Survey. Mean systemic right ventricular ejection fraction was impaired (36.8 +/- 7.8%), as was maximal exercise capacity (78.5 +/- 23.9% of predicted). NT-pro-BNP level was increased (median 269 ng/L, range 34 to 4,476). Mean SQUASH score was 6,808 +/- 3,241, indicating a decreased level of habitual physical activity. Although patients' scores on mental quality-of-life domains were comparable to the general population, scores on most physical quality-of-life domains were significantly lower. SQUASH scores were found to be a significant predictor for exercise capacity (p <0.01) and physical quality of life (p <0.001). However, we found no relation between SQUASH scores and right ventricular ejection fraction or NT-pro-BNP. In conclusion, physical activity in patients with a systemic RV is positively associated with exercise capacity and quality of life, irrespective of cardiac performance.

Echocardiographic quantification of myocardial function using tissue deformation imaging, a guide to image acquisition and analysis using tissue Doppler and speckle tracking

Recent developments in the field of echocardiography have allowed the cardiologist to objectively quantify regional and global myocardial function. Regional deformation (strain) and deformation rate (strain-rate) can be calculated non-invasively in both the left and right ventricle, providing information on regional (dys-)function in a variety of clinical settings. Although this promising novel technique is increasingly applied in clinical and preclinical research, knowledge about the principles, limitations and technical issues of this technique is mandatory for reliable results and for implementation both in the clinical as well as the scientific field.

In this article, we aim to explain the fundamental concepts and potential clinical applicability of strain and strain-rate for both tissue Doppler imaging (TDI) derived and speckle tracking (2D-strain) derived deformation imaging. In addition, a step-by-step approach to image acquisition and post processing is proposed. Finally, clinical examples of deformation imaging in hypertrophic cardiomyopathy (HCM), cardiac resynchronization therapy (CRT) and arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) are presented.

Glucose-insulin-potassium echocardiography detects improved segmental myocardial function and viable tissue shortly after acute myocardial infarction

Previous studies showed that glucose-insulin-potassium (GIK) increases cardiac output in patients after cardiac surgery and improves segmental myocardial wall motion. We hypothesized that GIK improves regional wall motion, detects contractile reserve, and predicts functional recovery at follow-up to a similar extent as low-dose dobutamine (LDD) in patients with recent myocardial infarction. Forty-one patients underwent LDD and GIK echocardiography. Data were analyzed according to a 13-segment model. Segments were scored from 0 (normokinesia) to 2 (a-/dyskinesia). Wall motion score index was calculated for baseline and intervention. During GIK, wall motion score index improved from 0.60 +/- 0.25 to 0.39 +/- 0.20 (P < .0001) and from 0.58 +/- 0.25 to 0.39 +/- 0.21 (P < .0001) during LDD. Overall agreement between GIK and LDD echocardiography to detect contractile reserve (improvement of segmental function by >or= 1 point) was 93% with a kappa value of 0.88. Sensitivity, specificity, and positive and negative predictive values of GIK echocardiography to predict functional recovery at follow-up (mean time to follow-up, 13 months) were 74%, 84%, 85%, and 72% respectively, and values were similar to LDD echocardiography. Thus, GIK infusion improves regional left ventricular function and allows the detection of myocardial viability to a similar extent as LDD in patients shortly after infarction.

Real-time perfusion imaging: a new echocardiographic technique for simultaneous evaluation of myocardial perfusion and contraction

Myocardial contrast echocardiography (MCE) with high acoustic energy and triggered harmonic imaging is the best established ultrasound technique to date for the assessment of myocardial perfusion. With this technique, however, the ultimate goal of MCE (noninvasive real-time simultaneous assessment of myocardial perfusion and function after an intravenous injection of microbubbles) is not met. Recently, technologic advances have enabled myocardial opacification to be visualized during low-energy real-time imaging. During real-time perfusion imaging, wall motion and myocardial perfusion may be assessed simultaneously, obviating the need of the presently time-consuming combination of different imaging modalities. When high-energy ultrasound bursts are periodically transmitted to produce bubble destruction during low-power imaging, the consecutive frames after destruction delineate the restoration of contrast intensity. Microbubble replenishment rate and peak intensity may be determined subsequently, and provide reliable quantitative parameters of regional microcirculatory flow. This review will introduce the modalities used for real-time perfusion imaging with focus on power pulse inversion imaging and quantitative analysis. Furthermore, we will describe the clinical role the technique may have in the identification of coronary artery disease, quantification of coronary stenosis severity, assessment of myocardial viability, determination of infarction size, and evaluation of reflow and no- or low-reflow after acute myocardial infarction.

Comparison of effects on systolic and diastolic left ventricular function of nebivolol versus atenolol in patients with uncomplicated essential hypertension

This was a double-blind, randomized, prospective study comparing the effects of nebivolol and atenolol on systolic diastolic left ventricular function in patients with essential hypertension. A significant difference was seen in stroke volume between these 2 drugs. The blood pressure lowering effect of atenolol was strongly related to cardiac output and heart rate reduction. The blood pressure lowering effect of nebivolol was related to a reduction in peripheral resistance and an increase in stroke volume with preservation of cardiac output. This preservation of cardiac output, together with a reduced peripheral resistance, may be potentially important in treating heart failure.

Predictive value of markers of myocardial reperfusion in acute myocardial infarction for follow-up left ventricular function

This study evaluated recently suggested invasive and noninvasive parameters of myocardial reperfusion after acute myocardial infarction (AMI), assessing their predictive value for left ventricular function 4 weeks after AMI and reperfusion defined by myocardial contrast echocardiography (MCE). In 38 patients, angiographic myocardial blush grade, corrected Thrombolysis In Myocardial Infarction frame count, ST-segment elevation index, and coronary flow reserve (n = 25) were determined immediately after primary percutaneous transluminal coronary angioplasty (PTCA) for first AMI, and intravenous MCE was determined before, and at 1 and 24 hours after PTCA to evaluate myocardial reperfusion. Results were related to global wall motion index (GWMI) at 4 weeks. MCE 1 hour after PTCA showed good correlation with GWMI at 4 weeks (r = 0.684, p <0.001) and was in an analysis of variance the best parameter to predict GWMI 4 weeks after AMI. The ST-segment elevation index was close in its predictive value. Considering only invasive parameters of reperfusion myocardial blush grade was the best predictor of GWMI at 4 weeks (R(2) = 0.3107, p <0.001). A MCE perfusion defect size at 24 hours of > or =50% of the MCE perfusion defect size before PTCA was used to define myocardial nonreperfusion. In a multivariate analysis, low myocardial blush grade class was the best predictor of nonreperfusion defined by MCE. Thus, intravenous MCE allows better prediction of left ventricular function 4 weeks after AMI than other evaluated parameters of myocardial reperfusion. Myocardial blush grade is the best predictor of nonreperfusion defined by MCE and is the invasive parameter with the greatest predictive value for left ventricular function after AMI. Coronary flow parameters are less predictive.

Intermittent harmonic imaging and videodensitometry significantly enhance ability of intravenous air-filled ultrasonographic contrast agent to produce ventricular and myocardial opacification

We used visual and videodensitometric evaluation to investigate the influence of intermittent harmonic imaging (IHI) compared with intermittent fundamental imaging on cavity and myocardial signal intensity after administration of the air-filled transpulmonary contrast agent BY963. Twelve patients were studied with intermittent fundamental imaging and IHI after administration of 5 mL and 10 mL of contrast agent. Contrast effect was graded in the parasternal short-axis view. Visually, IHI improved opacification of both the right and left ventricular cavities, especially the left. Densitometrically, right ventricular opacification did not differ significantly between imaging modalities, whereas left ventricular cavity opacification was significantly higher when using IHI. Myocardial opacification was observed in a small minority of segments when assessed by visual estimation, whereas videodensitometry revealed opacification in 42 of 48 anterior, 39 of 48 posterior, and 42 of 48 septal segments. Differences were not significant between doses. We conclude that with IHI and densitometry, air-filled contrast agents like BY963 show significantly improved performance in producing cavity and myocardial contrast effects.

Myocardial contrast echocardiography: clinical benefit and practical issues

Real-time bedside evaluation of myocardial perfusion after intravenous application of microbubbles is the ultimate goal for contrast echocardiography. Over the past decade rapid evolution has occurred in the development of contrast agents, ultrasound equipment tailored to their detection, and image interpretation. This article offers a review of the basic concepts of the technique's background, contrast agent design, and imaging technology. The major clinical indications of myocardial contrast echocardiography are evaluation of acute ischemic syndromes, diagnosis of viable myocardium following AMI, and the detection of CAD using stress contrast perfusion imaging. Furthermore, the article addresses the most significant practical problems and suggested solutions to master those problems. As major new achievements are realistic expectations for the first decade of the twenty-first century, we conclude that the coupling of a new generation of contrast agents with innovative echocardiographic instrumentation will ultimately enable the full potential of myocardial contrast echocardiography to be realized which may revolutionize modern echocardiography.

Assessment of myocardial reperfusion by intravenous myocardial contrast echocardiography and coronary flow reserve after primary percutaneous transluminal coronary angioplasty [correction of angiography] in patients with acute myocardial infarction

BACKGROUND

This study investigated whether the extent of perfusion defect determined by intravenous myocardial contrast echocardiography (MCE) in patients with acute myocardial infarction (AMI) treated by primary percutaneous transluminal coronary angioplasty (PTCA) relates to coronary flow reserve (CRF) for assessment of myocardial reperfusion and is predictive for left ventricular recovery.

METHODS AND RESULTS

Twenty-five patients with first AMI underwent intravenous MCE with NC100100 with intermittent harmonic imaging before PTCA and after 24 hours. MCE before PTCA defined the risk region and MCE at 24 hours the "no-reflow" region. The no-reflow region divided by the risk region determined the ratio to the risk region. CFR was assessed immediately after PTCA and 24 hours later. Left ventricular wall motion score indexes were calculated before PTCA and after 4 weeks. CFR at 24 hours defined a recovery (CFR >/=1.6; n=17) and a nonrecovery group (CFR <1.6; n=8). Baseline CFR did not differ between groups. MCE ratio to the risk region was smaller in the recovery group compared with the nonrecovery group (34+/-49% vs 81+/-46%, P=0.009). A ratio to the risk region of </=50% defined an MCE reperfusion group. It was associated with improvement of CFR from 1.67+/-0.47 at baseline to 2. 15+/-0.53 at 24 hours (P<0.001) and of regional wall motion score index from 2.6+/-0.5 to 1.9+/-0.5 at 4 weeks (P<0.001).

CONCLUSIONS

Intravenous MCE can be used to define perfusion defects after AMI. Assessment of microcirculation by MCE corresponds to evaluation by CFR. Serial intravenous MCE has the potential to identify patients likely to have improved left ventricular function after AMI.

Affinity chromatography with the immobilized agonist N-0434 yields an active and highly purified preparation of the dopamine D-2 receptor from bovine striatum

Partial purification of the dopamine D-2 receptor from bovine striatum, solubilized in the presence of 1% digitonin, was obtained by chromatography on wheat germ lectin agarose. The preparation was purified approximately 10-fold. The stability of the receptor preparation was considerably improved and non-specific protein absorption on the affinity gel used later was decreased. Further purification was achieved on a column containing a D-2-selective agonist, N-0434. Approximately 90% of the receptor activity was bound to the gel and 20-40% of the activity could be eluted by pH shock. The total purification factor after one affinity chromatography step was estimated to be at least 1500. An active preparation of at least 20% purity was obtained after a second cycle of affinity chromatography. This corresponds to an enrichment of more than 5000 times compared to the solubilized receptor preparation.