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Peter Geelen

Publications and source records attributed to Peter Geelen.

At least 19 recordsLinked to original sources
PubMed2007

Current strategies in the surgical treatment of atrial fibrillation: review of the literature and Onze Lieve Vrouw Clinic's strategy.

Atrial fibrillation is the most common rhythm disturbance in clinical practice. It is a major source of stroke and morbidity. Although the Cox maze procedure effectively eliminates atrial fibrillation in most patients, the procedure has not found widespread application. As a consequence, new operations that use alternative sources of energy, such as radiofrequency, microwave, cryothermy, laser, and ultrasound have emerged to surgically create lesion sets to treat atrial fibrillation. This article reviews the fundamentals and current strategies in the surgical treatment of atrial fibrillation.

Aortic Valve↗
PubMed2006

Cardiac resynchronization therapy delays heart transplantation in patients with end-stage heart failure and mechanical dyssynchrony.

BACKGROUND: Cardiac dyssynchrony is frequent in advanced heart failure, and cardiac resynchronization therapy (CRT) may offer an alternative to heart transplantation. We aimed to investigate the impact of CRT on freedom from Tx and death in transplant candidates with end-stage heart failure. METHODS: Over a period of 2 years, 46 consecutive patients with refractory congestive heart failure due to dilated cardiomyopathy were referred for heart transplant evaluation. Patients with cardiac dyssynchrony > 107 milliseconds according to tissue Doppler imaging (TDI) or QRS duration > 150 milliseconds were treated with CRT (CRT group, n = 24), whereas patients without dyssynchrony were not treated (non-CRT group, n = 22). RESULTS: At baseline, both groups showed similar hemodynamic and functional parameters, including ejection fraction (19 +/- 10% vs 21 +/- 12%, not statistically significant [NS]) and Vo2max (11.9 +/- 2.0 vs 12.0 +/- 1.8 ml/kg/min, NS). After a follow-up of 488 +/- 346 days, cumulative survival with freedom from transplantation and death was higher in CRT vs non-CRT patients (92% vs 39%; p < 0.001). CRT patients showed a decrease in New York Heart Association (NYHA) class from 3.2 +/- 1.1 to 2.2 +/- 0.9 (p = 0.003) and an increase in Vo2max from 11.9 +/- 2.0 to 13.1 +/- 1.8 ml/kg/min (p = 0.02), and 71% (17 of 24) of these patients were successfully removed from the waiting list. CONCLUSIONS: In heart transplant candidates with significant dyssynchrony, CRT delays heart transplantation and improves NYHA class and exercise capacity. For these patients, CRT should be considered before heart transplantation.

Aged↗
PubMed2006

An unusual form of bundle branch reentrant tachycardia.

INTRODUCTION: We report the case of a 36-year-old patient with a longstanding history of paroxysmal tachycardia. METHODS AND RESULTS: During the electrophysiological study, the H-V interval was prolonged in sinus rhythm, and a second potential (H'') with distal to proximal activation pattern was recorded in the region of the proximal His-Purkinje system. Two wide QRS complex tachycardias were induced, both with V-A dissociation. One application of radiofrequency energy at the site with earliest and largest H'' potential during sinus rhythm cured both tachycardias. The right and left bundle branch block morphology tachycardias were diagnosed as clockwise and counterclockwise bundle branch reentrant tachycardia. The H'' potential represented the retrograde right bundle potential during sinus rhythm and bundle branch block reentrant tachycardia.

Adult↗
PubMed2005

Recurrent cardiac events in patients with idiopathic ventricular fibrillation, excluding patients with the Brugada syndrome.

BACKGROUND: The recurrence of cardiac events in patients with idiopathic ventricular fibrillation (VF) excluding patients with the Brugada syndrome is unclear since this entity remains present in previous studies. METHODS: Since 1992, 18 patients (72% male) with idiopathic VF out of 455 ICD implants were treated with an implantable cardioverter defibrillator (ICD). The mean age at first ICD implantation was 42 +/- 14 years. Brugada syndrome, as well as other primary electrical diseases (e.g. long QT), were systematically excluded in all patients by the absence of the typical electrocardiogram (ST elevation in the right precordial leads) at rest and/or after pharmacological tests (ajmaline, flecainide, or procainamide). Recurrence of cardiac events was prospectively assessed. RESULTS: During a mean follow-up period of 41 +/- 27 months, VF recurrence with appropriate shock occurred in 7 patients (39%) covering a total of 27 shocks. The median time to first appropriate shock was 12 +/- 9 months. There were no deaths. In the electrophysiological study, 39% of patients were inducible, but inducibility failed to predict subsequent arrhythmic events. Forty-four percent of patients suffered 21 inappropriate shocks, which were caused by sinus tachycardia, atrial arrhythmias or lead malfunction. CONCLUSION: Idiopathic ventricular fibrillation patients have a high recurrence rate of potentially fatal ventricular arrhythmias, excluding patients with the Brugada syndrome or other known causes. ICD prevents sudden cardiac death but inappropriate shocks remained a major issue in this young and active population.

Adult↗
PubMed2005

Cibenzoline induced Brugada ECG pattern.

We report a case of a 61-year-old female patient who presented with palpitations. The baseline electrocardiogram showed incomplete right bundle branch block with saddle back pattern of the ST segment in one precordial lead, but without any significant ST elevation. She was treated with oral cibenzoline. The subsequent ECG showed a coved Brugada ECG (type I) pattern, which resolved following the discontinuation of cibenzoline. An ajmaline test reproduced the coved type Brugada ECG pattern. Our case is the first report of oral cibenzoline therapy unmasking the diagnostic coved Brugada ECG pattern in a patient with a baseline normal ECG. Cibenzoline, a class I sodium channel blocker antiarrhythmic drug, should probably be avoided in the treatment of patients with Brugada syndrome.

Anti-Arrhythmia Agents↗
PubMed2005

Tailored echocardiographic interventricular delay programming further optimizes left ventricular performance after cardiac resynchronization therapy.

BACKGROUND: The aim of cardiac resynchronization therapy is correction of left ventricular (LV) dyssynchrony. However, little is known about the optimal timing of LV and right ventricular (RV) stimulation. OBJECTIVES: The purpose of this study was to evaluate the acute hemodynamic effects of biventricular pacing, using a range of interventricular delays in patients with advanced heart failure. METHODS: Twenty patients with dilated ischemic (n = 12) and idiopathic (n = 8) cardiomyopathy (age 66 +/- 6 years, New York Heart Association class III-IV, LV end-diastolic diameter >55 mm, ejection fraction 22% +/- 18%, and QRS 200 +/- 32 ms) were implanted with a biventricular resynchronization device with sequential RV and LV timing (VV) capabilities. Tissue Doppler echocardiographic parameters were measured during sinus rhythm before implantation and following an optimal AV interval with both simultaneous and sequential biventricular pacing. The interventricular interval was modified by advancing the LV stimulus (LV first) or RV stimulus (RV first) up to 60 ms. For each stimulation protocol, standard echocardiographic Doppler and tissue Doppler imaging (TDI) echo were used to measure the LV outflow tract velocity-time integral, LV filling time, intraventricular delay, and interventricular delay. RESULTS: The highest velocity-time integral was found in 12 patients with LV first stimulation, 5 patients with RV first stimulation, and 3 patients with simultaneous biventricular activation. Compared with simultaneous biventricular pacing, the optimized sequential biventricular pacing significantly increased the velocity-time integral (P <.001) and LV filling time (P = .001) and decreased interventricular delay (P = .013) and intraventricular delay (P = .010). The optimal VV interval could not be predicted by any clinical nor echocardiographic parameter. At 6-month follow-up, the incidence of nonresponders was 10%. CONCLUSION: Optimal timing of the interventricular interval results in prolongation of the LV filling time, reduction of interventricular asynchrony, and an increase in stroke volume. In patients with advanced heart failure undergoing cardiac resynchronization therapy, LV hemodynamics may be further improved by optimizing LV-RV delay.

Aged↗
PubMed2004

Improvement of left ventricular function after cardiac resynchronization therapy is predicted by tissue Doppler imaging echocardiography.

BACKGROUND: Cardiac resynchronization therapy was shown to reverse left ventricular (LV) remodeling in patients with congestive heart failure (CHF). However, the prediction of benefit is controversial. We aimed to investigate predictive factors of LV functional recovery and reversed remodeling after biventricular pacing. METHODS AND RESULTS: Forty-nine consecutive patients with CHF and a wide QRS complex (182+/-32 ms) were studied by echocardiography before resynchronization. Intraventricular and interventricular asynchrony and their combination were assessed by pulsed-wave tissue Doppler imaging from measurements of regional electromechanical coupling times in basal segments of the right and left ventricle. At 6-month follow-up, responders were defined by a relative increase in LV ejection fraction > or =25% compared with baseline (n=27). Receiver operating curve analysis revealed the degree of intraventricular asynchrony (area under the curve=0.77), interventricular asynchrony (area under the curve=0.69), and their combination (area under the curve=0.84) as the best predictors of functional recovery after resynchronization. In addition, the degree of intraventricular and interventricular asynchrony correlated significantly with the improvement of LV ejection fraction (r=0.73, P<0.0001), end-diastolic diameter (r=-0.59, P<0.0001), and end-systolic diameter (r=-0.48, P<0.001) at follow-up. QRS duration and conventional echo-Doppler indices were not predictive of reversed LV remodeling. CONCLUSIONS: In patients with CHF, the degree of intraventricular and interventricular asynchrony and their combination are the best predictive factors of LV functional recovery and reversed remodeling after cardiac resynchronization therapy.

Aged↗
PubMed2003

A randomized prospective study of single coil versus dual coil defibrillation in patients with ventricular arrhythmias undergoing implantable cardioverter defibrillator therapy.

ICD implantation is standard therapy for malignant ventricular arrhythmias. The advantage of dual and single coil defibrillator leads in the successful conversion of arrhythmias is unclear. This study compared the effectiveness of dual versus single coil defibrillation leads. The study was a prospective, multicenter, randomized study comparing a dual with a single coil defibrillation system as part of an ICD using an active pectoral electrode. Seventy-six patients (64 men, 12 women; age 61 +/- 11 years) were implanted with a dual (group 1, n = 38) or single coil lead system (group 2,n = 38). The patients represented a typical ICD cohort: 60% presented with ischemic cardiomyopathy as their primary cardiac disease, the mean left ventricular ejection fraction was 0.406 +/- 0.158. The primary tachyarrhythmia was monomorphic ventricular tachyarrhythmia in 52.6% patients and ventricular fibrillation in 38.4%. There was no significant difference in terms of P and R wave amplitudes, pacing thresholds, and lead impedance at implantation and follow-up in the two groups. There was similarly no difference in terms of defibrillation thresholds (DFT) at implantation. Patients in group 1 had an average DFT of 10.2 +/- 5.2 J compared to 10.3 +/- 4.1 J in Group 2, P = NS. This study demonstrates no significant advantage of a dual coil lead system over a single coil system in terms of lead values and defibrillation thresholds. This may have important bearing on the choice of lead systems when implanting ICDs.

Chi-Square Distribution↗
PubMed2003

"Double" potentials define linear lesion conduction block using a novel mapping/linear lesion ablation catheter.

INTRODUCTION: A novel mapping/ablation catheter using a coaxially ablation electrode (E) that is moveable between distal and proximal ring electrodes along its shaft was used to create a linear lesion over the cavotricuspid isthmus (CTI) and bidirectional block in 32 patients (21 men; age 38-79 years) undergoing ablation for counterclockwise atrial flutter. METHODS AND RESULTS: Two bipolar electrograms (E1 and E2) were recorded: between E and the distal ring electrode and between E and the proximal ring electrode. Interpole distance varied for both as the E traversed the slide shaft. Given the catheter's concept, these bipoles are orientated exactly along the line of lesion creation. Prior to ablation, unitary bipolar electrograms were recorded along the catheter slide shaft position. As the CTI lesion was created (E moved along the catheter slide shaft in 2-mm steps with radiofrequency energy delivered to achieve 65 degrees C for 60 sec at each), double potentials (DP) were observed. Interpotential distance became maximal with completion of the linear lesion and bidirectional block. DPs were noted in all these procedures. With pacing from the low septal right atrium at bidirectional block creation, interpotential timing was 140.9 +/- 15 msec and from the low right atrial free wall was 145.13 +/- 18 msec. In sinus rhythm, DP interpotential timing was less (35.13 +/- 9 msec) as activation fronts arrived from both septal and anterior atrial aspects. CONCLUSION: Bipolar recordings from the coaxially moveable electrode catheter provide unique electrogram data. DPs recorded during and after linear lesion creation can define conduction block across that lesion without the need for additional mapping catheters or complex mapping technology.

Adult↗