Search PubMed⌕ Search

Biomedical subjects

I C van Gelder

Publications and source records attributed to I C van Gelder.

At least 19 recordsLinked to original sources
PubMed2006

[Rhythm control as treatment for patients with medication-resistant atrial fibrillation: maze surgery and percutaneous pulmonary vein isolation by catheter ablation].

In patients with atrial fibrillation, a decision must be made whether to accept the arrhythmia (rate control) or to pursue maintenance of sinus rhythm (rhythm control). Randomized trials have shown no difference between these strategies with respect to morbidity, mortality, and quality of life. In these studies, morbidity and mortality appeared to be related predominantly to the underlying heart disease rather than to the arrhythmia itself. However, other analyses suggest that long-term sinus rhythm may improve prognosis. At any rate, complaints caused by the arrhythmia may definitely be a reason to strive for rhythm control. If pharmacological rhythm control fails, maze surgery, both in patients with lone atrial fibrillation and as concomitant surgery, is highly successful. This, however, necessitates cardiac surgery. New techniques have now emerged, including pulmonary vein isolation by means of percutaneous catheter ablation. This is less invasive and therefore nowadays the treatment of first choice if pharmacological rhythm control has failed.

Anti-Arrhythmia Agents↗
PubMed2006

[Non-pharmacological treatment of heart failure: implantable cardioverter defibrillator (ICD) and cardiac resynchronisation therapy].

The non-pharmacological therapy of heart failure, in particular an implantable cardioverter defibrillator (ICD) and cardiac resynchronisation therapy or biventricular stimulation, improves symptoms and survival in patients with heart failure. An ICD is indicated in many patients with heart failure following cardiac arrest unless reversible causes are demonstrable. Selected patients with a left ventricular ejection fraction < or = 35% due to either ischaemic (>40 days after a myocardial infarction) or nonischaemic cardiomyopathy are candidates for ICD implantation as the primary prevention of sudden cardiac death. Patients who continue to have severe symptoms despite maximal pharmacotherapy, with a left ventricular ejection fraction < or = 35% and a wide QRS complex, are candidates for cardiac resynchronisation therapy to improve both symptoms and survival.

Defibrillators, Implantable↗
PubMed2006

[Life-threatening ventricular tachycardia during flecainide treatment for symptomatic atrial fibrillation in a patient with a structural cardiac disorder].

A 37-year-old man with symptomatic acute atrial fibrillation and a low-voltage electrocardiogram was treated with flecainide intravenously. Instead of conversion to sinus rhythm, he developed a wide-complex tachycardia suggestive of ventricular tachycardia. The patient recovered following electric cardioversion. First-choice therapy for symptomatic atrial fibrillation of recent onset (duration < 48 hours) is chemical conversion with a class IC antiarrhythmic drug (e.g. flecainide, propafenone). However, in patients with structural heart disorders, these drugs may induce ventricular tachycardia. A low-voltage electrocardiogram is suggestive of left ventricular damage. For these patients, electric cardioversion is a better alternative.

Adult↗
PubMed2006

[Cardiological (pharmaco)therapy and dental practice].

In recent years much progress has been made in the treatment of acute coronary syndromes, heart failure and cardiac rhythm disturbances. Polypharmacy including two antiplatelet drugs (aspirin and clopidogrel) is common in many patients after a percutaneous coronary intervention using a 'stent'. Discontinuation of these drugs for invasive dental treatment may result in coronary rethrombosis. However, in many patients with coronary artery disease, a temporal pause in the use of aspirin appears safe and may decrease the risk of bleeding after a dental procedure. An increasing number of patients with heart failure and/or life threatening rhythm disturbances receive an implantable cardioverter defibrillator (ICD). Such a device, equipped with a left ventricular lead, also stimulates the left ventricle in case of delayed electrical conduction (e.g. a left bundle branch block). This so called cardiac resynchronization therapy decreases morbidity and mortality in selected patients. ICDs are safe in the dental office even in case of discharge. In patients with prosthetic heart valves, endocarditis prophylaxis according to the current guidelines is recommended before invasive dental treatment. Dentists are advised to contact the Dutch Thrombosis Service to discuss the dose of oral ancicoagulants and the required INR value. In case of urgent and/or extended dental procedures, admittence to a hospital must be considered to secure optimal therapy.

Aspirin↗
PubMed2005

Paroxysmal atrial fibrillation, quality of life and neuroticism.

BACKGROUND: Paroxysmal atrial fibrillation (AF) is associated with significant impairment of quality of life (QoL), which is to a large extent independent of objective measures of disease severity. We sought to investigate the potential role of neuroticism in the impairment of QoL in patients with paroxysmal AF. METHODS: The study group (AF group) comprised 73 patients with paroxysmal AF (mean age 55.5 +/- 113.3 years, 50 males). On average, patients had a three-year history of one symptomatic paroxysm a week lasting two hours. QoL was assessed using the Medical Outcomes Study Short Form (SF-36) and neuroticism was assessed using the short-scale Eysenck Personality Questionnaire (EPQ). RESULTS: The degree of neuroticism in the AF patient group did not differ from the degree of neuroticism in a group of age- and sex-matched controls (mean EPQ score on neuroticism 4.1 +/- 3.0 and 3.9 +/- 3.1, respectively; p = NS). Within the AF group, multivariate regression analyses showed that QoL in the physical domain (SF-36 physical functioning, physical role function, vitality and pain subscales) was not related the degree of neuroticism. In contrast, significant inverse relations were observed between scores on the mental health and social functioning subscales and the degree of neuroticism (beta coefficients p < .05), independent of age, sex and symptoms. CONCLUSION: Based on the present study, patients with paroxysmal AF appear to have on average a degree of neuroticism similar to age- and sex-matched controls. However, the impairment of QoL in these patients, in particular regarding social functioning and mental health, seems to be related to a relatively high degree of neuroticism, independent of age and sex.

Anxiety↗
PubMed2004

[Arrhythmogenic right-ventricular cardiomyopathy: different manifestations as precursors of sudden death which might be prevented].

Two men aged 47 and 56 and one woman aged 21 presented at our cardiology department with presyncope, heart failure and exercise induced palpitations, respectively. Using the criteria of McKenna et al., a diagnosis of arrhythmogenic right-ventricular cardiomyopathy (ARVC) was made. Following implantation of a defibrillator, one of the men experienced seven appropriate interventions within six months and also developed psychological problems. The other man was problem-free and the woman recovered reasonably well, having only one appropriate intervention from the defibrillator one year after implantation. Indications of ARVC were also found in her mother but not in any other family members. Because ARVC manifests itself in various different ways it is difficult to diagnose. It is important to consider ARVC in patients with exercise-induced palpitations, presyncope, and unexplained cardiomyopathies or arrhythmias, especially if there is a family history of unexpected deaths. ARVC is a potentially life-threatening disease, that may require implantation of a cardioverter defibrillator. Furthermore, since genetics play an important role and ARVC can be asymptomatic, evaluation of close relatives for preclinical symptoms is important.

Adult↗
PubMed2004

[Cardiac rehabilitation in patients with a congenital heart disease, an implantable cardioverter defibrillator or chronic heart failure].

Cardiac rehabilitation is no longer just used to treat patients after the manifestation of a coronary artery disease such as a myocardial infarct, after a PTCA or after a coronary bypass operation. Patients with a congenital heart disease, patients who have received an implantable cardioverter defibrillator (ICD) and patients with stable chronic heart failure are also suitable candidates for a multidisciplinary cardiac rehabilitation programme. The new Dutch guidelines for cardiac rehabilitation, published in 2004, can be helpful in identifying potential candidates for a programme. Physical training is often a component of the treatment, but psycho-social counselling and education targeted at reducing anxiety and uncertainty, accepting the heart disease and learning to cope with it, can be just as important as those aspects targeted at improving the physical condition. Cardiac rehabilitation that includes physical training is safe for patients with congenital heart disease, for patients who have undergone an ICD implantation and for patients with stable chronic heart failure, as long as the pretraining exercise test is given a guiding role in selecting the appropriate physical work load. Patients with stable chronic heart failure should continue their physical training in order to maintain its beneficial physical and psychological effects.

Defibrillators, Implantable↗
PubMed2001

Quality of life in patients with paroxysmal atrial fibrillation and its predictors: importance of the autonomic nervous system.

AIMS: To determine the impact of paroxysmal atrial fibrillation on quality of life and to determine the predictors of quality of life, particularly the role of symptomatology and autonomic function. METHODS AND RESULTS: The study group comprised 73 patients with paroxysmal atrial fibrillation (mean age 54.1 years, 51 males). On average, patients had a 3-year history of one paroxysm per week lasting 2 h. Quality of life was assessed using the SF-36 (Medical Outcomes Study Short-Form Health Survey) and compared with age-matched controls. Autonomic function was assessed using Holter monitoring with analysis of heart rate variability and autonomic function tests. Symptoms during paroxysms of atrial fibrillation were also scored. Multivariate analysis was performed to identify independent predictors of quality of life. Quality of life scores were markedly lower in patients than in controls in four of the eight subscales (P<0.001): physical role function, emotional role function, vitality and general health. Structural heart disease did not predict quality of life, whereas frequency of paroxysms was predictive only of physical role function. In contrast, autonomic variables (baroreflex-sensitivity, total power (heart rate variability), response to deep breathing, 30-15 ratio (standing up)) were predictive in all four respective subscales (P<0.05), depressed vagal function being predictive of low scores. Symptoms, particularly severe perspiration, were also predictive of low scores (P<0.05). CONCLUSIONS: This study shows that paroxysmal atrial fibrillation causes significant impairment of quality of life. Further, symptomatology and autonomic function are important predictors of quality of life in this patient group.

Aged↗
PubMed2000

Electrophysiological changes of angiotensin-converting enzyme inhibition after myocardial infarction.

To investigate whether prevention of remodeling would translate into a more stable electrophysiological profile, the investigators randomized 56 patients to treatment with angiotensin-converting enzyme (ACE) inhibition or placebo for 3 months after myocardial infarction. Programmed electrical stimulation revealed no significant differences in inducibility of monomorphic sustained ventricular tachycardia (VT), whereas ventricular fibrillation (VF) tended to be lower in the ACE-inhibitor group. Effective refractory periods were consistently longer, and dispersion of refractoriness was significantly shorter in the ACE-inhibitor group. The investigators conclude that in this small patient group ACE inhibition may mildly add to a more stable electrophysiological profile.

Action Potentials↗
PubMed2000

Prognostic value of the presence and development of atrial fibrillation in patients with advanced chronic heart failure.

AIMS: To examine whether the presence, or development, of atrial fibrillation in patients with advanced chronic heart failure, is associated with a poorer prognosis, compared to patients with sinus rhythm and chronic heart failure. METHODS AND RESULTS: We examined 409 patients with moderate to severe chronic heart failure, and compared patients with sinus rhythm (n=325) to those with atrial fibrillation (n=84). At baseline, the two groups were similar regarding most indices of severity of chronic heart failure, such as left ventricular ejection fraction (0.23) and New York Heart Association (NYHA) functional class, while they were different for age (70 years for atrial fibrillation vs 67 years for sinus rhythm patients), aetiology of chronic heart failure, blood pressure, concomitant treatment, and plasma neurohormones (all P<0.05). During a mean follow-up of 3.4 years (range 2.0-5.4), 203 patients (50%) died. The majority of deaths was due to progressive chronic heart failure (55%) or was sudden (28%), but there was no difference in mode of death between sinus rhythm and atrial fibrillation patients. Overall mortality was higher in atrial fibrillation patients (60%), than in those with sinus rhythm (47%; risk ratio 1.40, 95% CI 1.01-1.92, P=0. 04). After adjusting for important prognostic variables, such as age, left ventricular ejection fraction, NYHA class, renal function, and blood pressure, the presence of atrial fibrillation was no longer related to increased mortality (risk ratio 0.86, range 0.59-1.24, P=ns). Of the 325 patients who had sinus rhythm at baseline, 30 (9%) developed atrial fibrillation during the study. These patients were older (70 vs 66 years, P<0.007), and had slightly lower blood pressure and plasma norepinephrine concentrations (P<0.05), but were otherwise similar. During follow-up, mortality was similar in these two groups (47% in those with new onset atrial fibrillation, vs 47% in those who had sinus rhythm throughout the study). CONCLUSIONS: The present data do not support the concept that the presence, or the development of atrial fibrillation in patients with advanced chronic heart failure is independently related to an adverse outcome during long-term follow-up. The generally observed higher mortality in patients with atrial fibrillation thus seems to be related to other factors, associated with atrial fibrillation.

Aged↗
PubMed1999

Gene expression of proteins influencing the calcium homeostasis in patients with persistent and paroxysmal atrial fibrillation.

OBJECTIVE: Persistent atrial fibrillation (AF) results in an impairment of atrial function. In order to elucidate the mechanism behind this phenomenon, we investigated the gene expression of proteins influencing calcium handling. METHODS: Right atrial appendages were obtained from eight patients with paroxysmal AF, ten with persistent AF (> 8 months) and 18 matched controls in sinus rhythm. All controls underwent coronary artery bypass grafting, whereas most AF patients underwent Cox's MAZE surgery (n = 12). All patients had a normal left ventricular function. Total RNA was isolated and reversely transcribed into cDNA. In a semi-quantitative polymerase chain reaction the cDNA of interest and of glyceraldehyde-3-phosphate dehydrogenase were coamplified and separated by ethidium bromide-stained gel electrophoresis. Slot blot analysis was performed to study protein expression. RESULTS: L-type calcium channel alpha 1 and sarcoplasmic reticulum Ca(2+)-ATPase mRNA (-57%, p = 0.01 and -28%, p = 0.04, respectively) and protein contents (-43%, p = 0.02 and -28%, p = 0.04, respectively) were reduced in patients with persistent AF compared to the controls. mRNA contents of phospholamban, ryanodine receptor type 2 and sodium/calcium exchanger were comparable. No changes were observed in patients with paroxysmal AF. CONCLUSIONS: Alterations in gene expression of proteins involved in the calcium homeostasis occur only in patients with long-term persistent AF. In the absence of underlying heart disease, the changes are rather secondary than primary to AF.

Aged↗
PubMed1999

Human SCN5A gene mutations alter cardiac sodium channel kinetics and are associated with the Brugada syndrome.

BACKGROUND: Primary dysrhythmias other than those associated with the long QT syndrome, are increasingly recognized. One of these are represented by patients with a history of resuscitation from cardiac arrest but without any structural heart disease. These patients exhibit a distinct electrocardiographic (ECG) pattern consisting of a persistent ST-segment elevation in the right precordial leads often but not always accompanied by a right bundle branch block (Brugada syndrome). This syndrome is associated with a high mortality rate and has been shown to display familial occurrence. METHODS AND RESULTS: Pharmacological sodium channel blockade elicits or worsens the electrocardiographic features associated with this syndrome. Hence, a candidate gene approach directed towards SCN5A, the gene encoding the alpha-subunit of the cardiac sodium channel, was followed in six affected individuals. In two patients missense mutations were identified in the coding region of the gene: R1512W in the DIII-DIV cytoplasmic linker and A1924T in the C-terminal cytoplasmic domain. In two other patients mutations were detected near intron/exon junctions. To assess the functional consequences of the R1512W and A1924T mutations, wild-type and mutant sodium channel proteins were expressed in Xenopus oocytes. Both missense mutations affected channel function, most notably a 4-5 mV negative voltage shift of the steady-state activation and inactivation curves in R1512W and a 9 mV negative voltage shift of the steady-state activation curve in A1924T, measured at 22 degrees C. Recovery from inactivation was slightly prolonged for R1512W channels. The time dependent kinetics of activation and inactivation at -20 mV were not significantly affected by either mutation. CONCLUSIONS: Two SCN5A mutations associated with the Brugada syndrome, significantly affect cardiac sodium channel characteristics. The alterations seem to be associated with an increase in inward sodium current during the action potential upstroke.

Action Potentials↗
PubMed1997

Efficacy, safety, and determinants of conversion of atrial fibrillation and flutter with oral amiodarone.

Amiodarone is effective for long-term maintenance of sinus rhythm after electrical cardioversion of refractory atrial fibrillation or flutter. To examine its efficacy and safety for pharmacologic conversion of these arrhythmias, we studied 129 patients with refractory atrial fibrillation or flutter who had failed previous intensive conventional antiarrhythmic treatment. In anticipation of electrical cardioversion, patients were loaded with amiodarone, 600 mg/day during a 4-week period. The main outcome measure was pharmacologic conversion during this period. During the loading period, 23 patients (18%) converted to sinus rhythm. When analyzed in a multivariate model, conversion was related to desethylamiodarone plasma level (p = 0.0006), arrhythmia duration (p = 0.04), left atrial area (p = 0.02), and concomitant treatment with verapamil (p = 0.01). During ongoing atrial fibrillation after loading, the ventricular rate decreased from 100 +/- 25 to 87 +/- 27 beats/ min (p <0.001). Amiodarone appeared to be safe and did not have to be discontinued because of intolerable side effects. Thus, amiodarone loading is safe and is still able to convert refractory atrial fibrillation or flutter. Conversion is related to increased desethylamiodarone plasma levels and concomitant treatment with verapamil. Because prolonged loading may increase desethylamiodarone plasma concentrations, this may enhance efficacy and obviate the need for electrical cardioversion.

Aged↗