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Dominic A M J Theuns

Publications and source records attributed to Dominic A M J Theuns.

17 recordsLinked to original sources
PubMed2007

Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy.

AIMS: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) > or =60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Sixty patients (72% males, mean age 59 +/- 10 years) who were referred for CRT according to the ACC/ESC guidelines were enrolled in the study. All patients underwent spectral PW-TDI before and 1 year after CRT. Two left ventricular (LV) dyssynchrony time intervals, T(O) and T(P) (time to onset and peak of LV myocardial velocity, respectively), LSD were recorded. Left ventricular dyssynchrony was defined as LSD > or =60 ms. Clinical response was defined as an improvement in >1 NYHA class plus improvement in 6-min walk distance (6MWD) > or =25%, echocardiographic response was defined as a > or =15% reduction in LV end-systolic volume (LV-ESV). One year after CRT, 50 patients (83%) were clinical responders and 47 patients (78%) were echocardiographic responders. Both T(O) and T(P) LV dyssynchrony indices failed to predict echocardiographic CRT outcome. In addition, there were no significant differences between 'synchronous' and 'dyssynchronous' patient populations at baseline or follow-up in either clinical (NYHA class and 6MWD) or echocardiographic (LV ejection fraction, LV end-diastolic, and end-systolic) variables. CONCLUSION: The great majority of patients referred for CRT benefit clinically from it. However, spectral PW-TDI failed to predict CRT outcome. When PW-TDI dyssynchrony was applied for selection of proper CRT patients, up to 80-86% of the patients with synchronous LSD that had proven clinical and echocardiographic benefit from CRT would have been denied CRT.

Cardiac Pacing, Artificial↗
PubMed2006

Effects of cardiac resynchronization therapy on overall mortality and mode of death: a meta-analysis of randomized controlled trials.

AIMS: Cardiac resynchronization therapy (CRT) has been shown to improve symptoms and exercise tolerance in patients with advanced heart failure (HF). However, studies were underpowered to address its effect on overall mortality. To evaluate whether CRT alone (without a combined defibrillator function) reduces overall mortality as compared with optimal pharmacological therapy, and how it affects the mode of death in patients with advanced HF. METHODS AND RESULTS: Public domain databases were systematically searched. Randomized controlled studies that evaluated the effects of CRT alone in patients with advanced HF and a depressed left ventricular systolic performance were selected for this analysis. Trials, which did not independently report data on CRT alone or had a follow-up period of less than 3 months, were excluded. Five studies were identified and analyzed. They included a total of 2371 patients, 1028 controls and 1343 CRT-treated patients. Pooled analysis demonstrated that CRT alone, as compared with optimal medical therapy, significantly reduced all-cause mortality by 29% [16.9 vs. 20.7%; odds ratio (OR), 0.71; 95% confidence interval (CI), 0.57-0.88] and mortality due to progressive HF by 38% (6.7 vs. 9.7%; OR, 0.62; 95% CI, 0.45-0.84). No effect on sudden cardiac death (SCD) was observed with CRT (6.4 vs. 5.9%; OR, 1.04; 95% CI, 0.73-1.22). CONCLUSIONS: CRT alone as compared with optimal medical therapy reduces all-cause mortality in patients with advanced HF. It predominantly reduces worsening HF mortality, not affecting SCD.

Aged↗
PubMed2006

Evaluation of morphology discrimination for ventricular tachycardia diagnosis in implantable cardioverter-defibrillators.

BACKGROUND: To reduce inappropriate therapy from implantable cardioverter-defibrillators (ICDs), electrogram morphology discrimination has been developed to improve arrhythmia discrimination without compromising device safety. OBJECTIVES: The purpose of this study was to determine the accuracy of the morphology discrimination algorithm for detecting ventricular tachycardia (VT). METHODS: Stored electrograms of 795 tachyarrhythmias from 106 patients with a St. Jude Medical ICD (51 single-chamber and 55 dual-chamber) were analyzed by the investigators. The data were analyzed for morphology discrimination alone, sudden onset and stability, and morphology discrimination in combination with sudden onset and stability. Data were corrected for multiple episodes within a patient with the generalized estimating equation method. RESULTS: Using the nominal template match of 60%, morphology discrimination alone provided sensitivity and specificity of 78% and 95% for single-chamber ICDs and 63% and 92% for dual-chamber ICDs, respectively. Based on the receiver operator characteristic curve, the optimal-match percent threshold was 80% to 85% but at the expense of specificity. Morphology discrimination combined with sudden onset and stability increased sensitivity to 98% with specificity of 86% in single-chamber devices. In dual-chamber devices, the loss in sensitivity is compensated by rate branch analysis, yielding a sensitivity of 98%. CONCLUSION: Arrhythmia discrimination based on electrogram morphology has the potential to reject atrial tachyarrhythmias. However, there is a risk for underdetection of ventricular tachyarrhythmias if arrhythmia discrimination is primarily based on morphology. To guarantee patient safety in single-chamber devices, the morphology discrimination algorithm must be programmed in combination with established detection algorithms. In dual-chamber devices, loss of sensitivity is compensated by the V > A rate branch.

Algorithms↗
PubMed2006

One-year follow-up in a prospective, randomized study comparing radiofrequency and cryoablation of arrhythmias in Koch's triangle: clinical symptoms and event recording.

AIMS: To rely solely on clinical symptoms of recurrent palpitations to evaluate the success of interventional procedures can be misleading. This study was designed to assess the efficacy of event recording in evaluating long-term success in patients treated for atrioventricular nodal reentrant tachycardia (AVNRT) or right posteroseptally located accessory pathways (RPS) either by radiofrequency (RF) or by cryoablation (CA). METHODS AND RESULTS: Sixty-three patients with AVNRT and eight with RPS were randomized. Patients were encouraged to activate an event recorder in the case of recurrent palpitations for the first 3 months. One year after the procedure, patients were asked specific arrhythmia related questions. Thirty-six patients underwent RF and 35 CA. Acute success was finally achieved in 34 (94%) patients in the RF and 33 (94%) in the CA groups. Assessment of long-term success demonstrated a similar proportion of palpitations in the RF and CA groups: 11 (31%) vs. 17 (49%). Only 12 patients activated the event recorder, four patients in RF, including one patient with chest pain, and eight in the CA group. Analysis of recordings revealed recurrent AVNRT or circus movement tachycardia in four patients (one RF and three CA), atrial fibrillation in one RF patient, and sinus tachycardia in six (one RF and five with CA). In addition, a complete 12 lead ECG of a recurrent arrhythmia was made in three RF and two CA patients (in-hospital or after the event recording). A total of seven patients underwent a second procedure (four RF and three CA). Without the event recorder, seven patients would have been misclassified as having recurrent arrhythmia. CONCLUSION: Event recording enhances the sensitivity of detecting arrhythmia recurrences in evaluating therapy efficacy and should be considered in every interventional follow-up study. Analysis of recordings showed that CA is as effective as RF in the treatment of AVNRT and RPS at long-term follow-up.

Arrhythmias, Cardiac↗
PubMed2006

Left ventricular lead placement within a coronary sinus side branch using remote magnetic navigation of a guidewire: a feasibility study.

BACKGROUND: A novel magnetic navigation system (MNS) allowing remote guidance of catheters and guidewires might assist in implantation of left ventricular (LV) pacing leads. OBJECTIVE: To assess the feasibility of deploying a LV pacing lead into a coronary sinus (CS) side branch using a magnetically guided wire and of performing the procedure without a CS guiding sheath. METHODS: Twenty-one patients were included in this study. Nine underwent CRT device implantation using a MNS to steer the guidewire (MNS group) while 12 patients were conventionally implanted (control group). In 6 patients in the MNS group, the procedure was performed using a CS guiding sheath. In 3 others, the decision was to perform the procedure without a CS sheath. In these patients the wire was advanced manually, while the external magnets oriented it toward the CS os. In the CS, "vector based" navigation was used to guide the wire to the desired side branch. RESULTS: In all 9 patients in the MNS group, the target vessel could be successfully engaged by the magnetically guided wire. In 7, the LV lead was lodged in the target vessel. In 2 patients, the LV lead was repositioned in an anterolateral side branch due to instability or inability to engage the vessel with it. Mean total procedure time was 164 +/- 58 minutes (without sheath 229 +/- 52 vs with sheath 132 +/- 26 minutes; P = 0.007). Mean fluoroscopy time was 28 +/- 9 minutes. For control patients, the procedure and fluoroscopy time were similar (144 +/- 41 minutes and 26 +/- 12 minutes, respectively). No major complications occurred. CONCLUSION: LV lead implantation can be performed using a remote magnetically steered guidewire. Though the lead could be implanted without a CS guiding sheath, longer procedure times were required.

Cardiac Pacing, Artificial↗
PubMed2005

Outcome in patients with an ICD incorporating cardiac resynchronisation therapy: differences between primary and secondary prophylaxis.

BACKGROUND: The incidence of ventricular tachyarrhythmias in ICD patients with cardiac resynchronisation therapy (CRT-D) is not well studied. AIM: To analyse event free survival in CRT-D patients with a primary or a secondary prophylactic ICD indication. METHODS: Prospective, single centre. Eighty-six patients, 44% with a primary prophylactic indication. Actuarial event-free rates for mortality and arrhythmias were calculated. RESULTS: Baseline clinical characteristics were not significantly different between primary and secondary prophylaxis. Primary prophylaxis patients were more likely to be in NYHA class III. Over 21 months, 724 ventricular events with therapy occurred in 36 patients (42%). The actuarial event-free rates, at 1 and 3 years, from appropriate ICD therapy were higher (P<0.001) for primary (79.0% and 67.8%) than for secondary prophylaxis (45.6% and 27.0%). Appropriate ICD therapy occurred more in NYHA class II compared to class III (P=0.016). Underlying disease (ischemic versus non-ischemic) and functional class did not play a role in multivariate analysis. CONCLUSION: Important arrhythmic events in patients with heart failure, and CRT-D occur at a very high rate when the indication is secondary prophylaxis. Patients with primary prophylaxis have an annual event rate of 10%, even though they tend to have a worse heart failure class.

Aged↗
PubMed2005

Defibrillation efficacy testing: long-term follow-up and mortality.

AIMS: Extensive defibrillation threshold testing is no longer necessary to perform as devices have become more effective. We assessed the lowest effective defibrillation (LED) level at implantation and before hospital discharge and related this to outcome. METHODS AND RESULTS: One hundred and twenty-seven consecutive patients with biphasic shock and active can devices were studied at intraoperative and predischarge testing. A subgroup of 67 patients had > or = 3 VF inductions at implant. Improvement was defined when LED decreased by > or = 3 J. The LED was significantly higher at implantation compared with predischarge (P < 0.001). Improvement was seen in 73/127 patients (58%). In the group with > or = 3 VF inductions, an implantation LED > 9 J was related to a lower LVEF (P < 0.01); 34/67 patients (51%) had improvement in LED. During follow-up, 18/127 patients died, four received heart transplantation. No different outcome was observed in patients with and without improvement. However, for those with > or = 3 VF inductions, an independent predictor of mortality was implantation LED > 9 J without improvement on the second test. Safety margin < 10 J was not related to mortality. CONCLUSION: Repeated defibrillation efficacy testing before hospital discharge may confirm that a relatively high defibrillation energy is required. This is related to a higher mortality in long-term follow-up.

Adult↗
PubMed2005

Concerns about the implantable cardioverter defibrillator: a determinant of anxiety and depressive symptoms independent of experienced shocks.

BACKGROUND: Patients with an implantable cardioverter defibrillator (ICD) are at increased risk of anxiety disorders. In turn, anxiety has been identified as a precipitant of ventricular arrhythmias. Anxiety may in part be attributed to concerns about the ICD firing, but the relationship between ICD concerns, psychological morbidity, and shocks has not been systematically investigated. We examined the relative importance of experienced shocks versus subjective concerns about the ICD as determinants of anxiety and depressive symptoms in ICD patients. METHODS: Consecutive surviving patients ( n = 182, response rate = 82%) having had an ICD implanted between October 1998 and January 2003 at the Erasmus Medical Centre Rotterdam were asked to fill in the ICD Patient Concerns Questionnaire and the Hospital Anxiety and Depression Scale. Clinical variables were obtained from the patients' medical records. RESULTS: A total of 55 (30%) patients had received a shock from the ICD. Although patients who had experienced a shock scored higher on ICD concerns, ICD concerns was the only independent determinant of anxiety (odds ratio 6.35, 95% CI 2.84-14.20) and depressive symptoms (odds ratio 2.29, 95% CI 1.06-4.96) adjusting for shocks and all other factors. CONCLUSIONS: Patient concerns about the ICD may be an important indicator of psychosocial adjustment. Screening for ICD patient concerns using the ICD Patient Concerns Questionnaire may identify patients at risk for psychological morbidity after ICD implantation.

Adult↗
PubMed2005

The presence of contractile reserve has no predictive value for the evolution of left ventricular function following atrio-ventricular node ablation in patients with permanent atrial fibrillation.

AIMS: Transcatheter ablation of the atrio-ventricular (AV) node followed by ventricular pacing has been shown to improve symptoms and quality of life (QOL) of patients with permanent atrial fibrillation (AF). In a considerable number of patients, cardiac function deteriorates after AV node ablation. We aimed to determine whether the absence of contractile reserve assessed by low dose dobutamine stress echocardiography (LDDSE) could identify those patients whose left ventricular (LV) function deteriorates after AV node ablation. METHODS: All 25 patients studied had permanent AF for at least 12 months. LVEF was determined 6 days and 3 months after AV node ablation by radionuclide ventriculography (RNV), at a paced rate of 80 beats/min. Deterioration in cardiac function was defined as a decrease in LVEF>5%. LDSE was performed in all patients before and after ablation. The presence of contractile reserve was defined as an improvement in regional function of >or=1 grade at low dose dobutamine in at least 4 segments. QOL measurements were taken using Minnesota, NHBP and MPWB questionnaires. RESULTS: LVEF showed no improvement in the overall group (52.8+/-11.1% vs. 51.8+/-9.8%, p=NS). QOL showed significant improvement in all questionnaires (Minnesota: 4.1+/-2.1 vs. 2.5+/-2, p=0.001; NHBP: 54.8+/-43.3 vs. 34.2+/-34.3, p=0.002; MPWB: 22.2+/-4.6 vs. 19.4+/-6.2, p=0.03). There was no significant difference in change of LVEF between patients with and without contractile reserve (-0.4+/-8.7 vs. 1.6+/-11.3, p=NS). However, patients with a preserved LVEF at baseline showed more frequently a reduced LVEF after AV node ablation (62.2+/-10.4% vs. 47.5+/-7.6%, p=0.001). CONCLUSIONS: (1) The absence of contractile reserve does not predict deterioration of cardiac function after AV node ablation. (2) AV node ablation results in a significant improvement in QOL, which is not necessarily associated with improvement of LVEF. (3) Higher baseline LVEF predicts deterioration of cardiac function. These data suggest that although AV node ablation is an excellent way of controlling symptoms, it should be avoided in patients with normal LV function.

Adult↗
PubMed2004

Prevention of inappropriate therapy in implantable cardioverter-defibrillators: results of a prospective, randomized study of tachyarrhythmia detection algorithms.

OBJECTIVES: The purpose of this randomized study was to investigate the performance of single- and dual-chamber tachyarrhythmia detection algorithms. BACKGROUND: A proposed benefit of dual-chamber implantable cardioverter-defibrillators (ICDs) is improved specificity of tachyarrhythmia detection. METHODS: All ICD candidates received a dual-chamber ICD and were randomized to programmed single- or dual-chamber detection. Of 60 patients (47 male, age 58 +/- 14 years, left ventricular ejection fraction 30%), 29 had single-chamber and 31 had dual-chamber settings. The detection results were corrected for multiple episodes within a patient with the generalized estimating equations method. RESULTS: A total of 653 spontaneous arrhythmia episodes (39 patients) were classified by the investigators; 391 episodes were ventricular tachyarrhythmia (32 patients). All episodes of ventricular tachyarrhythmias were appropriately detected in both settings. In 25 patients, 262 episodes of atrial tachyarrhythmias were recorded. Detection was inappropriate for 109 atrial tachyarrhythmia episodes (42%, 18 patients). Rejection of atrial tachyarrhythmias was not significantly different between both groups (p = 0.55). Episodes of atrial flutter/tachycardia were significantly more misclassified (p = 0.001). Overall, no significant difference in tachyarrhythmia detection (atrial and ventricular) between both settings was demonstrated (p = 0.77). CONCLUSIONS: The applied detection criteria in dual-chamber devices do not offer benefits in the rejection of atrial tachyarrhythmias. Discrimination of atrial tachyarrhythmias with a stable atrioventricular relationship remains a challenge.

Adult↗
PubMed2004

Guiding and optimization of resynchronization therapy with dynamic three-dimensional echocardiography and segmental volume--time curves: a feasibility study.

OBJECTIVE: To assess a new approach for guiding and hemodynamic optimization of resynchronization therapy, using three-dimensional (3D) transthoracic echocardiography. BACKGROUND: Resynchronization therapy for heart failure provides the greatest hemodynamic benefit when applied to the most delayed left ventricular (LV) site. Currently, the ideal LV pacing site is selected according to acute invasive hemodynamic assessment and/or tissue Doppler imaging. METHODS: A total of 16 patients with advanced heart failure and an implanted biventricular pacemaker were included in this study. Transthoracic apical LV images at equidistant intervals were obtained using a prototype, fast-rotating second harmonic transducer to reconstruct 3D LV datasets during sinus rhythm (SR), right ventricular (RV) apical and biventricular pacing mode. A semi-automated contour analysis system (4D LV analysis, TomTec, Germany) was used for segmental wall motion analysis and identification of the most delayed contracting segment and calculation of global LV function. RESULTS: Data acquisition duration was 10 s and analyzable 3D images were obtained in 12 patients. Of these patients, data during SR were available in 9 and during biventricular pacing in 11. The greatest contraction delay during SR was found in the anterior and antero-septal segments in five of nine patients. Biventricular pacing resulted in reduction of the contraction delay in seven of eight patients. The global LV function did not change significantly. CONCLUSION: 3D echocardiography with appropriate analytic software allows detection of the most delayed LV contracting segment and can be used to select the optimal pacing site during resynchronization therapy.

Aged↗
PubMed2004

Ice mapping during cryothermal ablation of accessory pathways in WPW: the role of the temperature time constant.

AIM: Cryothermal energy has the ability reversibly to demonstrate loss of function with cooling, ice mapping, at less deep temperatures. The purpose of this study was to investigate the time course of the temperature during ice mapping of accessory pathways. METHODS AND RESULTS: Thirteen patients with the Wolff-Parkinson-White (WPW) syndrome underwent cryoablation. After identification of a prospective ablation site, ice mapping was performed by cooling the tip to a minimum of -30 degrees C. Successful ice mapping was defined by loss of accessory pathway (AP) conduction. A total of 104 ice maps were analyzed. Successful ice mapping was demonstrated in 17 attempts. There was no significant difference in mapping temperature between successful and unsuccessful ice mapping (-29.4+/-3.2 degrees Celsius vs -30.4+/-1.7 degrees Celsius). The temperature time constant tau during successful ice mapping was significantly shorter compared with unsuccessful ice mapping (7.0+/-1.1 s vs 10.1+/-1.3 s; P<0.0001). The response time (RT) to mapping temperature of -30 degrees C was significantly prolonged in unsuccessful ice mapping attempts (35.8+/-4.5 s vs 53.5+/-11.0 s; P<0.0001). Significant correlations were found between successful ice mapping and the temperature time constant, and between RT and the temperature time constant (P<0.001). CONCLUSION: The ability to identify prospective ablation sites by ice mapping was demonstrated. Successful ice mapping attempts were characterized by a short temperature time constant and a short response time to mapping temperature with a sudden disappearance of pathway conduction.

Adult↗
PubMed2002

Interatrial septum pacing guided by three-dimensional intracardiac echocardiography.

OBJECTIVES: Currently, the interatrial septum (IAS) pacing site is indirectly selected by fluoroscopy and P-wave analysis. The aim of the present study was to develop a novel approach for IAS pacing using intracardiac echocardiography (ICE). BACKGROUND: Interatrial septum pacing may be beneficial for the prevention of paroxysmal atrial fibrillation. METHODS: Cross-sectional images are acquired during a pull-back of the ICE transducer from the superior vena cava into the inferior vena cava by an electrocardiogram- and respiration-gated technique. Both atria are then reconstructed using three-dimensional (3D) imaging. Using an "en face" view of the IAS, the desired pacing site is selected. Following lead placement and electrical testing, another 3D reconstruction is performed to verify the final lead position. RESULTS: Twelve patients were included in this study. The IAS pacing was achieved in all patients including six suprafossal (SF) and six infrafossal (IF) lead locations all confirmed by 3D imaging. The mean duration times of atrial lead implantation and fluoroscopy were 70 +/- 48.9 min and 23.7 +/- 20.6 min, respectively. The IAS pacing resulted in a significant reduction of the P-wave duration as compared to sinus rhythm (98.9 +/- 19.3 ms vs. 141.3 +/- 8.6 ms; p < 0.002). The SF pacing showed a greater reduction of the P-wave duration than IF pacing (59.4 +/- 6.6 ms vs. 30.2 +/- 13.6 ms; p < 0.004). CONCLUSIONS: Three-dimensional ICE is a feasible tool for guiding IAS pacing.

Adult↗
PubMed2002

A cool ablation.

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Atrioventricular Node↗
PubMedDate not supplied

Type D personality is associated with increased anxiety and depressive symptoms in patients with an implantable cardioverter defibrillator and their partners.

OBJECTIVE: We investigated the prevalence of anxiety and depressive symptoms in patients with an implantable cardioverter defibrillator (ICD) and their partners, and the role of personality factors and social support as determinants of distress. METHODS: Of all surviving patients (n = 221) having had an ICD implanted between October 1998 and January 2003, 182 patients and 144 partners completed the Hospital Anxiety and Depression Scale, the Type D Personality Scale, and the Perceived Social Support Scale. Type D personality defines those who tend to experience increased negative distress and who do not express these negative emotions in social interactions. Clinical variables for the patients were obtained from medical records. RESULTS: Thirty-one percent of patients versus 42% of partners suffered from symptoms of anxiety (p =.048); symptoms of anxiety were particularly prevalent in male partners. Twenty-eight vs. 29% suffered from depressive symptoms (p =.901). In patients, Type D personality was independently related to anxiety (OR: 7.03; 95% CI: 2.32-21.32) and depressive symptoms (OR: 7.40; 95% CI: 2.49-21.94) adjusting for all other variables. Underlying cardiac disease pathology did not explain differences in patient distress. In partners, Type D personality was independently associated with increased symptoms of anxiety (OR: 8.77; 95% CI: 3.19-24.14) and depression (OR: 4.40; 95% CI: 1.76-11.01). CONCLUSION: Partners experienced similar levels of depression but higher levels of anxiety compared with ICD patients. Personality was an important explanatory factor of distress in both ICD patients and their partners. Research is now warranted to investigate the implications of this finding for the clinical course of ICD patients, as Type D personality has been associated with adverse prognosis in patients with coronary artery disease.

Anxiety Disorders↗