Biomedical subjects

L M van Gelder

Publications and source records attributed to L M van Gelder.

13 recordsLinked to original sources

PubMed1992

Shearing of the plastic coating of a hydrophilic guide wire in a right femoropopliteal bypass graft: removal from the contralateral side.

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.

Cardiac Catheterization↗

PubMed1992

Optimized hemodynamics by implantation of a dual chamber pacemaker after heterotopic cardiac transplantation.

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.

Adult↗

PubMed1991

Fusion or confusion on Holter recording.

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.

Adult↗

PubMed1989

Changes in morphology of the paced QRS complex related to pacemaker output.

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.

Aged↗

PubMed1988

P-wave sensing in VVI pacemakers: useful or a problem?

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.

Aged↗

PubMed1986

Inadvertant balloon extrusion through a side hole in a guiding catheter.

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.

Cardiac Catheterization↗

PubMed1985

Improved success rate of percutaneous transluminal graft and coronary angioplasty with the El Gamal 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.

Angioplasty, Balloon↗

PubMed1985

Ventriculoatrial conduction: a cause of atrial malpacing in AV universal pacemakers. A report of two cases.

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.

Aged↗

PubMed1984

Balloon inflation caused by contrast injection through the guiding catheter: an unusual observation during coronary angioplasty.

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.

Aged↗

PubMed1984

Tachycardia-termination algorithm: a valuable feature for interruption of pacemaker-mediated tachycardia.

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.

Abdominal Muscles↗

PubMed1984

Myopotential interference inducing pacemaker tachycardia in a DVI programmed pacemaker.

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.

Aged↗

PubMed1983

False inhibition of an atrial demand pacemaker caused by an insulation defect in a polyurethane lead.

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.

Bradycardia↗

PubMedDate not supplied

A new technique for angioplasty of occluded coronary arteries and bypass grafts, not associated with acute myocardial infarction.

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.

Adult↗