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Gait initiation (GI) from a quiet bipedal posture has been shown to be influenced by the emotional state of the actor. The literature suggests that the biomechanical organization of forward GI is facilitated when pleasant pictures are shown, as compared to unpleasant pictures. However, there are inconsistencies in the literature, which could be due to the neural dynamics of affective processing. This study aimed to test this hypothesis, using a paradigm whereby participants initiated a step as soon as they saw an affective picture (i.e., onset), or as soon as the picture disappeared from the screen (i.e., offset). Pictures were a priori categorized as pleasant or unpleasant, and could also vary in their arousing properties. We analyzed center-of-pressure and center-of-gravity dynamics as a function of emotional content. We found that gait was initiated faster with pleasant images at onset, and faster with unpleasant images at offset. Also, with offset GI the peak velocity of the COG was reduced, and subjects took smaller steps, with unpleasant images relative to pleasant images. The results are discussed in terms of current knowledge regarding temporal processing of emotions, and its effects on GI., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Aims: We report a single-centre experience of extraction of infected pacing and ICD leads., Methods: Retrospective study of consecutive lead extractions for infection. Lead extraction was by traction, or, if unsuccessful, a laser sheath was used. All procedures were performed in the operating room., Results: Leads were extracted in 82 patients including 66 patients (80%) with infection occurring after replacement of the generator or revision of the leads. Previous treatment, without lead extraction, had failed in 51 patients (62%). Major complications (tamponade or haemothorax) occurred in 6 patients, 2 patients died despite emergency surgery. One patient succumbed to ongoing sepsis. Of the patients alive, a follow-up of at least 6 months (27 +/- 17 months) was available in 76 patients. All patients were cured; none had a recurrence. In 31 patients (41%) pacing was abandoned after lead extraction; all remained asymptomatic., Conclusion: Lead extraction is effective in curing pacemaker or ICD related infection, even after failed conservative therapy, but with a significant complication rate. The routine replacement of the generator should be reconsidered in patients in whom the indication for pacing is no longer valid, as the majority of infections occurred after revision of the system., (Copyright 2004 The European Society of Cardiology)

Today, new pacing algorithms and stimulation methods for the prevention and interruption of atrial tachyarrhythmias can be applied on patients who need bradycardia pacing for conventional reasons. In addition, biventricular pacing as additive treatment for patients with severe congestive heart failure due to ventricular systolic dysfunction and prolonged intraventricular conduction has shown to improve symptoms and reduce hospital admissions. These new pacing technologies and the optimising of the pacing programmes are complex, expensive and time-consuming. Based on many clinical studies the indications for these devices are beginning to emerge. To support the cardiologist's decision-making and to prevent waste of effort and resources, the 'ad hoc committee' has provided preliminary recommendations for implantable devices to treat atrial tachyarrhythmias and to extend the treatment of congestive heart failure respectively.

Aims: Occlusion of the subclavian vein resulting from pacemaker leads prohibits insertion of new leads. We describe the ipsilateral insertion of a new lead without extracting the old lead using a laser sheath in a pacemaker patient with an obstructed vein., Methods and Result: A laser sheath together with an outer sheath were advanced over the malfunctioning lead just beyond the occlusion. The laser sheath was pulled back and a guide wire inserted through the outer sheath kept in position distal of the occlusion. After removal of the outer sheath a peel-away sheath was introduced and a new lead implanted next to the malfunctioning lead that was abandoned and not extracted., Conclusion: By avoiding using the laser along the whole length of the lead we greatly reduced the risk of the procedure but were still able to recanalize the obstructed vein. A risk of bilateral occlusion is avoided and the contralateral site saved as an entry point for future needs.

Aims: The development of new extraction techniques has improved the success rate of intravascular extraction of pacemaker and defibrillator leads, and hence the practice of extraction is expanding. However, the indications for lead extraction of malfunctioning leads in patients with an implantable cardioverter defibrillator (ICD) are still not well established., Methods and Results: We reviewed the literature concerning structural complications of ICD leads. The clinical presentation and detection of malfunction is discussed as well as the consequences for adequate defibrillation therapy. An overview of the current published experience of intravascular extraction of ICD leads is provided including a brief discussion of our own experience., Conclusion: From this overview we conclude that malfunctioning pace-sense or ICD leads can be left in situ if there are no uncovered insulation defects. Inserting a new pace-sense or ICD lead is preferable in this situation given the current known complication rate of lead extraction. Lead extraction should be reserved for damaged leads in which interference with proper detection or defibrillation of newly inserted leads cannot be excluded.

Occlusion of the subclavian or brachiocephalic vein in pacemaker or defibrillator patients prohibits ipsilateral implantation of new leads with standard techniques in the event of lead malfunction. Three patients are presented in whom laser sheath extraction of a non-functional lead was performed in order to recanalise the occluded vein and to secure a route for implantation of new leads. This technique avoids abandoning a useful subpectoral site for pacing or defibrillator therapy. The laser sheath does not affect normally functioning leads at the same site.

The plastic coating of a hydrophilic guide wire tore off during introduction through a beveled single wall arterial entry needle in a 75 year old male. The sheared piece of coating got stuck in his femoropopliteal bypass. It was removed by means of a modified arterial filter set from the contralateral side. The technique of its removal is described.

A patient who underwent prior heterotopic cardiac transplantation had persistent complaints of dyspnea, palpitations, and fatigue in spite of normal pump function of the donor heart. Repeated Holter monitoring excluded paroxysmal arrhythmias. It was thought that synchronization of both heart rates might alleviate his symptoms. The intrinsic heart rate of the donor heart was 90 beats/min, the recipient heart was 60 beats/min with acceleration up to 130 beats/min on exercise. A DDD pacemaker was implanted, the atrial lead was positioned in the right ventricule of the donor heart and the ventricular lead in the atrium of the recipient heart. Search for an optimal AV interval was evaluated by echo-Doppler and intraarterial pressure recordings. By increasing the AV interval from 125 to 300 msec, the maximum aortic flow velocity of the recipient heart increased from 1.0 to 1.2 m/sec. Left ventricular end-diastolic diameter remained unchanged, left ventricular end-systolic diameter decreased from 52 to 48 mm. Wall motion of the recipient left ventricle improved. At an AV interval of 125 msec there was alternate systolic contraction of both hearts, resulting in arterial pressure waves at a rate of 180/min. This did not relieve his symptoms and he complained further of headaches. At an AV interval of 300 msec contraction of the recipient heart just preceded that of the donor heart, resulting in arterial pressure waves at a rate of 90/min, normalization of the wave form, relief of symptoms, and improvement of exercise tolerance.

Holter recording of a patient with an implanted dual chamber rate responsive pacemaker revealed an electrocardiogram, where ventricular depolarization seemed to be initiated by the atrial stimulus. In a second patient with a VVI pacemaker, Holter recording showed delay of the pacemaker impulse that was registered after the onset of ventricular depolarization. Misalignment in one of the recorder heads of the display system was responsible for this phenomenon, which in case of dual chamber pacing could have been easily misinterpreted as pacemaker malfunction.

Episodic failure to sense cardiac activity, with emission of pacemaker stimuli, was unexpectedly found on Holter monitoring of two asymptomatic patients who had had normal function of a VVI pacemaker on direct ECG recording. Pectoral muscle movement was then demonstrated to cause pacemaker noise reversion. After decrease of input sensitivity the phenomenon stopped.

Retrograde atrial activation during ventricular pacing has often been a cause of intermittent or persistent arrhythmias (pacemaker-mediated tachycardia) in AV universal pacemakers. We recently encountered two cases in which VA conduction was responsible for atrial malpacing in patients with an implanted AV universal pacemaker, one programmed in DDD and one in DVI mode. Atrial malpacing was induced by the atrial refractoriness due to retrograde activation. In the first patient, it was observed when the pacemaker was programmed to a rate of 110 ppm (lower rate) and an AV interval of 200 ms in order to check crosstalk. In the second patient, it was observed after ventricular premature contractions.

Three patients with symptomatic sinus bradycardia due to sick sinus syndrome were treated with permanent ventricular pacing for periods ranging from 2.5 to 4 years. All three patients had ventriculo-atrial conduction on routine electrocardiography. Although ventricular pacing was effective, they complained of fatigue, lightheadedness, and near syncope. Hemodynamic studies revealed the presence of regular cannon waves in the right atrium as well as in the pulmonary artery wedge pressure curves. Temporary atrial pacing resulted in disappearance of the cannon waves and a significant rise in cardiac output (32-48%). After normal atrio-ventricular conduction was confirmed by rapid atrial stimulation and His bundle electrocardiography, the pacing mode was changed to permanent atrial pacing on demand. The effort tolerance of the patients markedly improved, and the previously mentioned symptoms disappeared. Control hemodynamic studies 9 to 12 months after implantation of the atrial demand pacemaker showed that the improvement in cardiac performance was maintained.

The influence of pacemaker output on the morphology of the paced QRS complex was studied from standard lead electrocardiograms in 69 patients with bipolar pacemakers. In 40 of the 69 patients (58%), there was a significant (P less than 0.001) change in electrical axis, from -75 degrees at the low output setting (2.7 V, 0.15 msec) to -67 degrees at the high output setting (8.1 V, 2.29 msec). In 30 patients, these changes were also associated with changes in the QRS morphology and in the T-wave. This phenomenon may be explained by additional stimulation from the proximal electrode at high output, thus altering the pattern of depolarization.

We describe a new technique for angioplasty of totally occluded coronary arteries and bypass grafts in the absence of acute myocardial infarction. We used a guiding catheter, a coronary infusion catheter, and a relatively stiff steerable guide wire to perforate the occlusion. Angioplasty of the recanalized vessel was subsequently performed. The procedure was attempted in nine patients; it was successful in eight. There were no complications. The advantages of this technique are discussed.

A 45-year-old man who had been implanted with a VVI pacemaker for sinus arrest complained of syncope, dizziness and throbbing in the neck. His pacemaker function was normal, but during ventricular pacing, retrograde V-A conduction was observed. This pacer was replaced by a DVI unit which caused periodic abdominal muscular contractions. We replaced this unit with an Intermedics Cosmos DDD-M pacemaker. This type of pacemaker in a patient with V-A conduction may cause pacemaker-mediated tachycardia (PMT). However, the Cosmos has a tachycardia-termination algorithm which detects continued pacing at the ventricular tracking rate, allows it to proceed for 15 consecutive pace events, and inhibits the 16th ventricular output pulse, thus breaking the reentry loop. The Cosmos pacer has a number of features to prevent initiation of PMT, and is also able to terminate the tachycardia when it occurs because of the tachycardia-termination algorithm. This feature is valuable in DDD-M pacemakers implanted in patients with V-A conduction. Whether this algorithm will be effective in all cases remains to be determined.

A 67-year-old male, suffering from ventricular tachycardia unresponsive to drug therapy, received a universal AV sequential pacemaker (DDD,M). The pacemaker was programmed in the DVI mode, pacing rate 100 bpm, AV interval 250 ms. After implantation, the patient experiences two episodes of tachycardia that proved to be pacemaker tachycardia with a rate of 150 bpm. The first period was self-terminating, and the second had to be stopped by reprogramming the pulse generator. Pacemaker tachycardia could easily be provoked by instructing the patient to contract the pectoral muscle adjacent to the pulse generator. To our knowledge, this is the first report of pacemaker tachycardia provoked by myopotentials in a pulse generator programmed in the DVI mode.

A patient who had an atrial demand pacemaker (AAI) presented with irregular pacing at a routine examination 5 months after implantation. When a magnet was applied over the pulse generator regular fixed rate pacing was obtained, thus proving oversensing in the system. Reprogramming the input sensitivity level to 2.5 and 5.0 mV did not solve the problem. Programming the pulse generator to the triggered mode (AAT) showed acceleration of the stimulation rate but also inhibition of the system. An S-S interval of 1260 ms was measured at a programmed interval of 857 ms (70 bpm). The pulse generator was disconnected and the intra-atrial electrogram was recorded. This showed different spurious signals varying in morphology and amplitude. Fortunately we were able to remove the lead (Medtronic 6991-U) from the atrial appendage. Subsequently a Helifix 12 mm AT lead was successfully implanted in the right atrial appendage and the same pulse generator was connected to the newly implanted lead. When the removed lead was examined by the manufacturer, a small tear in the insulation of the wire was detected. The dimensions of the tear were 0.1 X 0.7 mm. The tear was caused by stress corrosion cracking in the polyurethane tubing of the lead.

Total inhibition of a bipolar VVI pacemaker was observed in an 84-year-old female after programming the pulse generator to its highest sensitivity (0.6 mV). After a short period of observation it became obvious that P-wave oversensing was responsible for this phenomenon. Frontal and lateral X-rays showed a normal position of the ventricular lead. Although oversensing could easily be avoided by decreasing sensitivity, changing the pacing mode to VVT converted the VVI pacemaker to an atrial synchronous ventricular pacing system.

An implanted ventricular demand pulse generator started firing at a rate of 1200 ppm during routine pacemaker follow-up utilizing the Vitatron VA 1000 pacemaker analyzer. This resulted in complete loss of capture; fortunately the patient had an intrinsic heart rate of 50 bpm and remained asymptomatic. Emergency replacement of the pulse generator resulted in re-establishment of effective ventricular pacing. An artificial origin of the impulses from the measuring equipment was excluded. To the best of our knowledge this is the first report of an externally induced irreversible runaway pacemaker.

Balloon inflation caused by contrast injection through the guiding catheter has been observed during several angioplasty procedures. The phenomenon is observed when employing an 8F USCI guiding catheter in combination with an ACS dilatation catheter. Two cases demonstrating the phenomenon are described in detail, together with an in vitro experiment that illustrates and quantifies the mechanism.

A patient presented with an acute inferior myocardial infarction. Coronary angiography in the acute stage revealed total occlusion of the right coronary artery. Reperfusion was obtained after intracoronary infusion of 250,000 units of streptokinase. Angioplasty was subsequently performed because of a high grade residual stenosis. An 8-French right Judkins guiding catheter with a single side hole (USCI), a 3.0 mm balloon dilatation catheter (ACS), and a 0.018 high torque floppy guide wire (ACS) were used. After successful angioplasty angiography was repeated with the guide wire in the RCA, but the balloon was withdrawn into the guiding catheter. After injection of contrast, it was impossible to withdrawn the balloon catheter out of the guiding catheter. Fluoroscopy revealed extrusion of the balloon through the side hole in the guiding catheter.

In the period between October 1980 and December 1982 we evaluated the outcome of percutaneous transluminal graft and coronary angioplasty when a Judkins type guiding catheter (J gc) was initially used, but the lesion could not be passed and a subsequent attempt was made with the El Gamal guiding catheter (EG gc). Seven of twelve attempts to dilate stenotic coronary artery bypass grafts failed. The EC gc was tried in six, five were successfully dilated; one failed. Our initial attempts to dilate a stenosed right coronary artery failed in 16 of 68 attempts. The EG gc was attempted in 14. We successfully dilated ten, two dissections required emergency coronary artery bypass grafting (CABG); two failed. Our initial attempts to dilate a left anterior descending artery stenosis failed in 14 of 109 attempts. Six lesions were passed when the EG gc was tried. Five were successfully dilated, and one acute dissection required emergency CABG; eight failed. The EG gc is useful for transluminal angioplasty of stenosed aortocoronary bypass grafts. It increased the success rate of right coronary artery dilatation from 76-91%, but was of limited use in dilatation of left anterior descending lesions.