ABSTRACT
Since 1989, 136 Medtronic 4058 and 4058M bipolar atrial screw-in leads have been implanted at the Mayo Clinic. Early lead related complications included dislodgment in 4 (2.9%). Over a median follow-up time of 14.4 months (1 day to 3.3 years), there were 11 lead related complications (undersensing, failure to capture, diaphragmatic pacing, and gross lead dislodgment). Chronic complications resulted in reoperations in four patients (2.9%). Of 77 patients in whom pacing thresholds were measured between 2 and 4 months after implantation, 9 (11.7%) and 2 (2.6%) had high pacing thresholds and very high thresholds, respectively. The Kaplan-Meier estimate of the probability of 1-year complication-free lead survival was 93.5%. There were no lead material failures. We conclude that the 4058/4058M lead implanted in the atrial position has favorable acute and chronic performance data, with a tendency toward high pacing thresholds at 3 months. The cause of this phenomenon and its course over time should be further evaluated.
Subject(s)
Pacemaker, Artificial/adverse effects , Actuarial Analysis , Adolescent , Adult , Aged , Aged, 80 and over , Child , Equipment Design , Equipment Failure , Female , Humans , Male , Middle Aged , ReoperationABSTRACT
Since 1989, 72 Telectronics 330-201 active fixation, polyurethane insulated ventricular leads (Accufix) have been implanted at the Mayo Clinic. There were four (5.6%) acute lead related complications (perforation, microdislodgment, and macrodislodgment), three of which led to early reoperation. Over a follow-up time of up to 2.7 years (median 9.4 months), there were six (8.3%) chronic lead related complications but no failures of lead material. Most of these complications developed during the first month, and half of them were transient, with documented improvement later. Two patients (2.8%) required reoperation for chronic complications. At follow-up examination of the pacing thresholds, usually performed about 3 months after implantation, 14.3% of the examined patients had high pacing thresholds necessitating high-output programming. The mechanisms and later evolution of this phenomenon should be further evaluated.
Subject(s)
Electrodes, Implanted , Pacemaker, Artificial , Polyurethanes , Adult , Aged , Aged, 80 and over , Cardiac Pacing, Artificial/adverse effects , Cardiac Pacing, Artificial/methods , Electric Impedance , Electrodes, Implanted/adverse effects , Equipment Design , Equipment Failure , Female , Follow-Up Studies , Heart Block/therapy , Heart Ventricles , Humans , Male , Middle Aged , Pacemaker, Artificial/adverse effects , Population Surveillance , Reoperation , Sick Sinus Syndrome/therapy , Survival RateABSTRACT
Since 1989, 168 Telectronics model 330-801 active fixation, polyurethane insulated atrial leads (Accufix) have been implanted at the Mayo Clinic. There were four (2.4%) acute lead related complications, (i.e., perforation, microdislodgment, and pericarditis). Over a median follow-up time of 7.6 months (up to 2.7 years), there were 14 (8.3%) chronic complications, including 1 instance (0.6%) of definite lead failure. Most of these complications were early (within the first month) and transient. Four patients (2.4%) required reoperation for chronic complications. During follow-up, 23% of the examined patients had high pacing thresholds, most at about 3 months after implantation, necessitating high-output programming. The exact mechanism and natural history of this phenomenon should be further investigated.
Subject(s)
Electrodes, Implanted , Pacemaker, Artificial/statistics & numerical data , Polyurethanes , Adolescent , Adult , Aged , Aged, 80 and over , Cardiac Pacing, Artificial , Electric Conductivity , Electric Impedance , Electrodes, Implanted/adverse effects , Electrodes, Implanted/statistics & numerical data , Equipment Design , Equipment Failure , Equipment Safety , Female , Follow-Up Studies , Heart Atria , Humans , Male , Middle Aged , Minnesota/epidemiology , Pacemaker, Artificial/adverse effects , Population Surveillance , Survival Rate , Telemetry , Time FactorsABSTRACT
It is essential that patients with pacemakers capable of rate modulation undergo some form of exercise testing to assure appropriate rate modulation. Informal exercise testing is a reasonable and less expensive alternative to formal treadmill testing. Empiric adjustment of the rate response parameters by assessing the patient's rate response while walking at a self-determined casual and brisk pace has been used. However, no normals exist to determine the appropriate rate response for a "casual" and "brisk" walk. Volunteers were tested with metronome-guided casual and brisk walks in an effort to standardize the informal exercise and determine expected heart rate response for these levels of activity. Results of the metronome-guided rate response in normal volunteers may be useful in determining the appropriate rate response for pacemaker patients when tested in such an informal manner.
