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Dive into the research topics where Gertjan T. Sieswerda is active.

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Featured researches published by Gertjan T. Sieswerda.


Cardiovascular Ultrasound | 2007

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

Arco J. Teske; Bart W.L. De Boeck; Paul G. Melman; Gertjan T. Sieswerda; Pieter A. Doevendans; Maarten Jm Cramer

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.


Heart | 2010

The emerging burden of hospital admissions of adults with congenital heart disease

Carianne L Verheugt; Cuno S.P.M. Uiterwaal; Enno T. van der Velde; Folkert J. Meijboom; Petronella G. Pieper; Gertjan T. Sieswerda; Herbert W.M. Plokker; Diederick E. Grobbee; Barbara J.M. Mulder

Objective To assess the extent and the characteristics of hospital admissions in registered adult patients with congenital heart disease. Design Observational cohort study. Setting The Netherlands. Patients 5798 adult patients with congenital heart disease from the Dutch CONCOR national registry linked to the Dutch National Medical Registration (Prismant). Main outcome measures All hospital admissions from the years 2001 up until 2006. Results During 28 990 patient-years, 2908 patients (50%) were admitted to hospital. Median age at admission was 39 years (range 18–86 years); 46% were male. Admission rate in CONCOR patients was high among all ages (range 11–68%) and exceeded that of the general Dutch population two to three times; this difference was most pronounced in the older age groups. Altogether there were 8916 admissions, 5411 (61%) of which were for cardiovascular indications. Among cardiovascular admissions, referrals for arrhythmias were most common (31%). Of 4926 interventions, 2459 (50%) were cardiovascular, most often reparative interventions or cardioversion (53%). Most non-cardiovascular admissions were obstetric. Among defects, univentricular heart and tricuspid atresia had the highest incidence and duration of admission. Conclusions Healthcare utilisation in registered and medically supervised adult patients with congenital heart disease is high and increases with age. Admission rates are at least two times higher than in the general population, and most marked in the older age groups. With the ageing of this population, a major increase in healthcare utilisation is imminent in the near future. Timely preparation of healthcare resources is crucial to sustain optimal care.


Circulation | 2013

Effect of Valsartan on Systemic Right Ventricular Function A Double-Blind, Randomized, Placebo-Controlled Pilot Trial

Teun van der Bom; Michiel M. Winter; Berto J. Bouma; Maarten Groenink; Hubert W. Vliegen; Petronella G. Pieper; Arie P.J. van Dijk; Gertjan T. Sieswerda; Jolien W. Roos-Hesselink; Aeilko H. Zwinderman; Barbara J.M. Mulder

Background— The role of angiotensin II receptor blockers in patients with a systemic right ventricle has not been elucidated. Methods and Results— We conducted a multicenter, double-blind, parallel, randomized controlled trial of angiotensin II receptor blocker valsartan 160 mg twice daily compared with placebo in patients with a systemic right ventricle caused by congenitally or surgically corrected transposition of the great arteries. The primary end point was change in right ventricular ejection fraction during 3-year follow-up, determined by cardiovascular magnetic resonance imaging or, in patients with contraindication for magnetic resonance imaging, multirow detector computed tomography. Secondary end points were change in right ventricular volumes and mass, ![Graphic][1] peak, and quality of life. Primary analyses were performed on an intention-to-treat basis. A total of 88 patients (valsartan, n=44; placebo, n=44) were enrolled in the trial. No serious adverse effects occurred in either group. There was no significant effect of 3-year valsartan therapy on systemic right ventricular ejection fraction (treatment effect, 1.3%; 95% confidence interval, −1.3% to 3.9%; P =0.34), maximum exercise capacity, or quality of life. There was a larger increase in right ventricular end-diastolic volume (15 mL; 95% confidence interval, 3–28 mL; P <0.01) and mass (8 g; 95% confidence interval, 2–14 g; P =0.01) in the placebo group than in the valsartan group. Conclusions— There was no significant treatment effect of valsartan on right ventricular ejection fraction, exercise capacity, or quality of life. Valsartan was associated with a similar frequency of significant clinical events as placebo. Small but significant differences between valsartan and placebo were present for change in right ventricular volumes and mass. Clinical Trial Registration— URL: . Unique identifier: [ISRCTN52352170][2]. # Clinical Perspective {#article-title-47} [1]: /embed/inline-graphic-1.gif [2]: /external-ref?link_type=ISRCTN&access_num=ISRCTN52352170Background— The role of angiotensin II receptor blockers in patients with a systemic right ventricle has not been elucidated. Methods and Results— We conducted a multicenter, double-blind, parallel, randomized controlled trial of angiotensin II receptor blocker valsartan 160 mg twice daily compared with placebo in patients with a systemic right ventricle caused by congenitally or surgically corrected transposition of the great arteries. The primary end point was change in right ventricular ejection fraction during 3-year follow-up, determined by cardiovascular magnetic resonance imaging or, in patients with contraindication for magnetic resonance imaging, multirow detector computed tomography. Secondary end points were change in right ventricular volumes and mass, peak, and quality of life. Primary analyses were performed on an intention-to-treat basis. A total of 88 patients (valsartan, n=44; placebo, n=44) were enrolled in the trial. No serious adverse effects occurred in either group. There was no significant effect of 3-year valsartan therapy on systemic right ventricular ejection fraction (treatment effect, 1.3%; 95% confidence interval, −1.3% to 3.9%; P=0.34), maximum exercise capacity, or quality of life. There was a larger increase in right ventricular end-diastolic volume (15 mL; 95% confidence interval, 3–28 mL; P<0.01) and mass (8 g; 95% confidence interval, 2–14 g; P=0.01) in the placebo group than in the valsartan group. Conclusions— There was no significant treatment effect of valsartan on right ventricular ejection fraction, exercise capacity, or quality of life. Valsartan was associated with a similar frequency of significant clinical events as placebo. Small but significant differences between valsartan and placebo were present for change in right ventricular volumes and mass. Clinical Trial Registration— URL: http://www.controlled-trials.com. Unique identifier: ISRCTN52352170.


American Journal of Cardiology | 2012

Social Burden and Lifestyle in Adults With Congenital Heart Disease

A. Carla Zomer; Ilonca Vaartjes; Cuno S.P.M. Uiterwaal; Enno T. van der Velde; Gertjan T. Sieswerda; Elly M.C.J. Wajon; Koos Plomp; Paul F.M. van Bergen; Carianne L. Verheugt; Eva Krivka; Cees J. de Vries; Dirk J. Lok; Diederick E. Grobbee; Barbara J.M. Mulder

We aimed to evaluate how the presence and severity of congenital heart disease (CHD) influence social life and lifestyle in adult patients. A random sample (n = 1,496) from the CONgenital CORvitia (n = 11,047), the Dutch national registry of adult patients with CHD, completed a questionnaire on educational attainment, employment and marital statuses, and lifestyle (response 76%). The Utrecht Health Project provided a large reference group (n = 6,810) of unaffected subjects. Logistic regression models were used for subgroup analyses and to adjust for age, gender, and socioeconomic status where appropriate. Of all patients 51.5% were men (median age 39 years, interquartile range 29 to 51) with mild (46%), moderate (44%), and severe (10%) CHD. Young (<40-year-old) patients with CHD were more likely to have achieved a lower education (adjusted odds ratios [ORs] 1.6 for men and 1.9 for women, p <0.05 for the 2 comparisons), significantly more often unemployed (adjusted ORs 5.9 and 2.0 for men and women, respectively), and less likely to be in a relationship compared to the reference group (adjusted ORs 8.5 for men and 4.5 for women). These poorer outcomes were seen in all severity groups. Overall, the CHD population smoked less (adjusted OR 0.5, p <0.05), had more sports participation (adjusted OR 1.2, p <0.05), and had less obesity (adjusted OR 0.7, p <0.05) than the reference group. In conclusion, there was a substantial social disadvantage in adult patients with CHD, which was seen in all severity groups and primarily in young men. In contrast, adults with CHD had healthier lifestyles compared to the reference group.


European Journal of Heart Failure | 2013

Impact of bosentan on exercise capacity in adults after the Fontan procedure : a randomized controlled trial

Mark J. Schuuring; Jeroen C. Vis; Arie P.J. van Dijk; Joost P. van Melle; Hubert W. Vliegen; Petronella G. Pieper; Gertjan T. Sieswerda; Rianne H.A.C.M. de Bruin-Bon; Barbara J.M. Mulder; Berto J. Bouma

An endothelin‐1 receptor blocker, shown to be effective in patients with pulmonary arterial hypertension, might decrease pulmonary vascular resistance to increase cardiac filling and consequently improve exercise capacity in Fontan patients.


Circulation-arrhythmia and Electrophysiology | 2012

Implantable cardioverter defibrillator therapy in adults with congenital heart disease: who is at risk of shocks?

Zeliha Koyak; Joris R. de Groot; Isabelle C. Van Gelder; Berto J. Bouma; Pascal F.H.M. van Dessel; Werner Budts; Lieselot van Erven; Arie P.J. van Dijk; Arthur A.M. Wilde; Petronella G. Pieper; Gertjan T. Sieswerda; Barbara J.M. Mulder

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.


Basic Research in Cardiology | 2008

Genes in congenital heart disease: atrioventricular valve formation

Irene C. Joziasse; Jasper J. van de Smagt; Kelly Smith; Jeroen Bakkers; Gertjan T. Sieswerda; Barbara J.M. Mulder; P. A. Doevendans

Through the use of animal studies, many candidate genes (mainly encoding transcriptional factors and receptors) have been implicated in the development of congenital heart disease. Thus far, only a minority of these genes have been shown to carry mutations associated with congenital disease in humans, e.g., GATA 4, TBX-5, NOTCH1 and NKX2-5. Mutations in these genes can cause a variety of cardiac defects even within the same family. Conversely, similar phenotypes are observed for different gene mutations suggesting a common pathway. Multiple genes and genetic pathways have been related to atrioventricular valve formation, although most of these genes have not yet been demonstrated as causative in human atrioventricular valve defects. Key pathways include the epidermal growth factor receptor pathway and related interacting pathways, most importantly the pathway of UDP-glucose dehydrogenase, resulting ultimately in activation of Ras. Other examples of interacting pathways include that of Nodal/Cited2/Pitx2, Wnt, Notch and ECE. Further studies are needed to investigate the pathways which are crucial for atrioventricular valve formation in humans. Understanding the underlying molecular process of abnormal atrioventricular valve formation in patients with congenital heart disease may provide important insight, in the etiology and possibly into preventive or treatment regimes.


Blood | 2011

Long-term restoration of the human T-cell compartment after thymectomy during infancy: a role for thymic regeneration?

R. van Gent; A.W.L. Schadenberg; Sigrid A. Otto; R.A.J. Nievelstein; Gertjan T. Sieswerda; Felix Haas; Frank Miedema; Kiki Tesselaar; N.J.G. Jansen; José A. M. Borghans

Thymectomy during early childhood is generally thought to have serious consequences for the establishment of the T-cell compartment. In the present study, we investigated the composition of the T-cell pool in the first 3 decades after thymectomy during infancy due to cardiac surgery. In the first 5 years after thymectomy, naive and total CD4(+) and CD8(+) T-cell numbers in the blood and T-cell receptor excision circle (TREC) levels in CD4(+) T cells were significantly lower than in healthy age-matched controls. In the first years after thymectomy, plasma IL-7 levels were significantly elevated and peripheral T-cell proliferation levels were increased by ∼ 2-fold. From 5 years after thymectomy onward, naive CD4(+) and CD8(+) T-cell counts and TRECs were within the normal range. Because TREC levels are expected to decline continuously in the absence of thymic output, we investigated whether normalization of the naive T-cell pool could be due to regeneration of thymic tissue. In the majority of individuals who had been thymectomized during infancy, thymic tissue could indeed be identified on magnetic resonance imaging scans. Whereas thymectomy has severe effects on the establishment of the naive T-cell compartment during early childhood, our data suggest that functional regrowth of thymic tissue can limit its effects in subsequent years.


European Journal of Cardiovascular Nursing | 2012

Patients with a congenital heart defect and Type D personality feel functionally more impaired, report a poorer health status and quality of life, but use less healthcare

Dounya Schoormans; Barbara J.M. Mulder; Joost P. van Melle; Els Pieper; Arie P.J. van Dijk; Gertjan T. Sieswerda; Mariet S. Hulsbergen-Zwarts; Thijs H. W. M. Plokker; Leo G. H. Brunninkhuis; Hubert W. Vliegen; Mirjam A. G. Sprangers

Background: Type D personality, characterized by high levels of negative affectivity and social inhibition, is related to mortality, morbidity, poor health status, quality of life (QoL) and less healthcare utilization in various cardiovascular patient groups. To date, studies in patients with congenital heart disease (CHD) are lacking. Aims: (1) To examine the prevalence of Type D personality in CHD patients; (2) to compare Type D to non-Type D patients with regard to disease severity, functional status, health status and QoL; and (3) to examine the extent to which Type D personality is independently related to healthcare utilization. Methods: A total of 1109 adult CHD patients were included in a questionnaire survey. Due to missing data, 302 patients were excluded. Results: The prevalence of Type D personality was 20.4%. Type D patients reported a poorer functional status, health status and QoL than non-Type D patients (p<0.05). Type D patients reported less healthcare use than non-Type D patients (primary and cardiac outpatient healthcare: adjusted OR=0.56, 95% CI=0.35–0.90; inpatient healthcare: adjusted OR=0.38, 95% CI=0.17–0.83). Results of a post-hoc analysis showed a high prevalence of Type D personality in patients with a poor functional status who did not consult their cardiologist. Conclusion: Type D patients report a poorer functional status, health status and QoL, but less healthcare utilization. In clinical practice, patients should be screened for Type D personality, since social inhibition may prevent them from contacting a healthcare provider in the event of symptom aggravation.


American Heart Journal | 2010

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

Teun van der Bom; Michiel M. Winter; Berto J. Bouma; Maarten Groenink; Hubert W. Vliegen; Petronella G. Pieper; Arie P.J. van Dijk; Gertjan T. Sieswerda; Jolien W. Roos-Hesslink; A. H. Zwinderman; Barbara J.M. Mulder

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.

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Arie P.J. van Dijk

Radboud University Nijmegen

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Hubert W. Vliegen

Leiden University Medical Center

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A.P.J. van Dijk

Radboud University Nijmegen

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B.J. Bouma

Academic Medical Center

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