Pacemaker Follow-Up: Its Role in the Detection and Correction of Pacemaker System Malfunction

The goal of pacemaker follow-up is not only to detect battery depletion but also to detect all malfunctions of the pacing system and, when possible, to correct such problems using programming. During one year, we discovered 61 such malfunctions in a clinic of 1065 patients (5.7%). These were more frequent in the first year (7.7%) than in the third to fifth years of follow-up (range 3.1-4.8%). The incidence rose again in the sixth and subsequent years (7-7.7%). Despite a significant occurrence of malfunctions (5.2%) among multiprogrammable pacemakers, the necessity for operative intervention for their correction was low (1.2%). Sensing problems were the most common (57%) and the most likely to be corrected by reprogramming (85%); problems involving loss of capture were less likely to be corrected by programming (38.5%). Battery depletion accounted for only 18% of malfunctions, occurring earliest in the forty-third month of follow-up. Pulse generator longevity of those devices reaching end of battery life during the study period was 68.6 +/- 16.7 months (mean + SD). We conclude that specialized pacemaker follow-up continues to be necessary despite improved pulse generator reliability and longevity. Indeed, with reprogramming, it presently plays an even more important role than in the past. Follow-up should be oriented not only to the detection of battery depletion but also toward a comprehensive surveillance of pacemaker system function.     

Particularities of Dual Chamber Pacemaker Therapy in Patients after Orthotopic Heart Transplantation

Since August 1981, 33 orthotopic heart transplantations were performed in our hospital. Three of these patients (9%) had sinus bradycardias with rates as low as 30 beats/min; they were treated by implantation of a dual chamber pacemaker. These patients had two atria as a result of orthotopic heart transplantation, but only the donor atrium was suitable for positioning the atrial lead. In the postoperative period, some nonsurgical complications were observed in one patient who developed atrial fibrillation which we treated with drugs. A cyclosporin-evoked tremor produced several asystoles due to false inhibition by myopotential interference in the VVI mode. During an episode of acute rejection combined with renal insufficiency, loss of atrial and ventricular sensing occurred. The other patients showed no pacemaker-related complications. Our findings in this unique population of pacemaker patients are discussed.     

Use of Single Lead VDD Pacing in Children

The development of transvenous ventricular pacing leads with proximal electrodes capable of atrial sensing and the recent availability of smaller generators has created the opportunity to treat children with complete AV block and normal sinus node function with a transvenous single lead VDD pacing system. Studies in adults have demonstrated this system to be efficacious with low complication rates. Transvenous single lead VDD pacemakers were implanted in ten children, aged 5–15 years, between December 1993 and April 1996, in our institution. The indications were complete AV block with severe bradycardia in 5 patients, second-degree or complete A V block following congenital heart surgery in 3, complete A V block with long QT syndrome in 1, and second-degree AV block and syncope in 1. There were no complications related to the procedure in any case. P and R wave amplitudes were measured and thresholds were determined intraoperatively on all patients. Amplitudes and thresholds were remeasured on seven patients with a mean follow-up of 17 months; Holter monitors were performed on seven patients with a mean follow-up of 16 months. P and H wave amplitudes were generally diminished at follow-up compared to initial values but remained within an acceptable range for all patients. Four patients required reprogramming after pacemaker insertion, 1 received an atrial lead for dual chamber pacing, 1 required repositioning for lead dislodgment. and 1 patient required a new lead for an inadequate ventricular pacing threshold. No patient had evidence of failure to sense or capture as evaluated by Halter monitoring at last follow-up. Single lead VDD pacing systems can be successfully used in properly selected children with high degree or complete AV block with normal sinus node function.     

Complete Heart Block in the Setting of Mitochondrial Cytopathy: Implantation of a Permanent Pacemaker in a 6-Year-Old Boy

The case of a 6-year-old boy with cytochrome oxidase (complex IV) deficiency and complete heart block, treated with permanent pacemaker implantation, is reported.     

Complications with the MICRA TPS Pacemaker System: Persistent Complete Heart Block and Late Capture Failure

A Medtronic MICRA transcatheter pacing system (Medtronic, Minneapolis, MN, USA) was implanted in an 86‐year‐old patient with sick sinus syndrome and left bundle branch block after transfemoral aortic valve implantation. During implantation she developed a persistent complete heart block due to manipulation with the large‐bore delivery catheter. Two weeks later, acute pacemaker dysfunction occurred due to massive increase of pacing threshold and impedance without obvious pacemaker dislocation or myocardial perforation. Recurrent capture failure was seen with pacing output set at 5 V/1.0 ms. Hence, microdislocation or fixation of the tines in the right ventricular trabeculae has to be assumed.     

Failure Rates of Leads, Pulse Generators, and Programmers Have Not Diminished Over the Last 20 Years: Formal Monitoring of Performance is Still Needed

Formal Monitoring of Performance is Still Needed. In order to detect trends in the number of device or component failures that have occurred among permanent pacemaker systems since the 1970s, we reviewed the data of the five largest pacemaker manufacturers from the Bilitch Registry of permanent pacemaker pulse generators, the Stimarec failure registry, the general accounting office summaries of the United States Veterans Administration (VA) Registry of Pacemaker Leads, and the Implantable Lead Registry, from the Cleveland Clinic Lead registry, and the recalls and safety alerts issued by the United States Food and Drug Administration (FDA) over the last 20 years. The definition of failure followed the criterion, or criteria, developed within each registry and differed significantly between the registries. The 20-year period between 1976 and 1995 was divided into 5-year quartiles (QT): QT 1 = 1976–1980; QT2 = 1981–1985; QT 3 = 1986–1990; and QT4 = 1991–1995. For pulse generators, the number of models with failures in each quartile in the Bilitch Registry were: QT 1 = 9; QT 2 = 11; QT 3 = 17; QT 4 = 13. In Stimarec, the number of units reported as having reached a dangerous condition were: QTl = 710; QT2 = 212; QT3 = 114; QT4 = 310. From the FDA reports, the number of units included in recalls or safety alerts were: QT 3 = 6,085; QT4 = 135, 766. For permanent pacemaker leads, the numbers of failed or dangerous leads recorded in Stimarec were: QT 3 = 16; QT 4 = 32. In the VA Registry, the number of models having a below average survival was 2/92 (2.7%). In the Implantable Lead Registry, the number of models having a below average survival was 3/21 (14%). In the Cleveland Clinic series, 6/13 (46%) of lead models were recognized to have some failure involving the conductor, insulation, or connector. In the FDA reports, the number of leads involved in either recall or safety alert were: QT3 = 20,354; QT 4 = 332,105. For programmers, the number of units involved either in a recall or safety alert were: QT 3 = 11,124; QT 4 = 3,528. In all of these series, each of the five largest manufacturers had some models or units involved in each time period. This review of programs has revealed: 1. The incidence of failures, recalls, or safety alerts did not decline over time; and 2. Despite changes in technology, formal monitoring of pacemaker systems is still warranted.     

Ventricular Pacing in Children

Ventricular pacing in children. Ventricular pacing was performed in forty-one children ranging from one day to twenty years of age (median age = 10). Weight of the recipient at implant ranged from 2 kg. to 86 kg. Indications included presyncope, syncope, dyspnea on exertion, congestive heart failure, postoperative infra-Hisian heart block, and inadequate cardiac rate during pharmacotherapy. Four patients died during follow-up, but no deaths were attributable to pacemaker management. In contrast, 66% of the patients required more than one pacemaker related-operative procedure, and 43% of leads implanted failed by 48 hours. Indications for permanent cardiac pacing in this population at this time are symptomatic congenital AV block, symptomatic sinus node disease, and AV block in the postoperative period. Technological developments which might reduce complications seen in this population and electrophysiologic techniques which may better define indications for pacing in children are also reviewed.     

Ventricular Endocardial Right Bifocal Stimulation in the Treatment of Severe Dilated Cardiomyopathy Heart Failure with Wide QRS

PACHÓN, J.C., et al. : Ventricular Endocardial Right Bifocal Stimulation in the Treatment of the Severe Dilated Cardiomyopathy Heart Failure with Wide QRS. The QRS widening by ventricular conventional pacing impairs the systolic and diastolic functions and increases mitral regurgitation. The aim of this study was to compare conventional pacing to an alternative stimulation mode with a narrower QRS using two leads in the RV. Thirty‐nine (25 men, 14 women; mean age 60.1 ± 15.1 years ) dilated cardiomyopathy patients (Chagas' disease [n = 17], coronariopathy [n = 9], AV ablation for tachycardiomyopathy [n = 3], and other [n = 10] ) with cardiac failure (NYHA 3.1 ± 0.8 ), pacemaker indication, and chronic AV block (22 AF) had endocardial pacemaker implantations (27 Biotronik, 12 Guidant). Two RV leads (one septal, one conventional [RV apex] were connected, respectively, to the atrial and ventricular pacemaker plugs. After clinical stabilization they were studied under three stimulation modes in the same session: AAI (septal), VVI (conventional), and ventricular endocardial right bifocal stimulation (VERBS) (DDT/DVI/DDD = AV interval = 15/10 ms). In comparison to conventional pacing, VERBS increased ejection fraction (0.124), cardiac output (19.5%), and peak filling rate (31.0%), and decreased QRS duration (24.7%), left atrium area (11.9%), mitral regurgitation area (32.3%), the diastolic transmitral flow (E/A relation) (19.3%), and the propagation flow time (18.0%) from the mitral valve to the left ventricular apex (tE_col), (P < 0.05). The quality‐of‐life showed an impressive score reduction of 50.4%. The septal stimulation alone showed a less expressive benefit. In severe dilated cardiomyopathy with classic pacemaker indication, VERBS showed significantly better performance than the septal or the conventional stimulation alone. There was a good systolic and a remarkable diastolic improvement causing an important reduction in the quality‐of‐life score.     

The Underlying Heart Rhythm in Patients with an Artificial Cardiac Pacemaker

One-hundred forty-two patients with atrioventricular block (AVB) and 61 patients with sick sinus syndrome (SSS) were followed for an average of 50 months after permanent pacemaker insertion. Their underlying heart rhythms (UHR) were evaluated repeatedly by chest wall stimulation (CWS). A deficient UHR was defined as ventricular asystole lasting 4 seconds or longer. The underlying conduction disturbance increased in 14% of AVB patients, decreased in 14%, and remained constant in 68%. The occurrence of Adams-Stokes attacks before pacemaker implantation was associated with a higher incidence of deficient UHR both in AVB and SSS; a deficient UHR was seen more frequently in AVB than in SSS. Among AVB patients (1) atrial fibrillation, flutter or tachycardia and (2) sinus rhythm with incomplete AVB, especially Mobitz 1, when present before pacemaker implantation, were associated with a significantly lower incidence of deficient UHR during subsequent pacing in comparison with other AVB patients. CWS is a non-invasive method which allows the evaluation of UHR and which can contribute to the early recognition of pacemaker-dependent patients.     

Transatrial Lead Implantation Using the 4‐Fr Lumenless Pacing Lead and Delivery System in Young Adults with Congenital Heart Disease

We report the technique of transatrial delivery of the Medtronic 3830 SelectSecure lead (Medtronic Inc., Minneapolis, MN, USA) for right ventricular endocardial pacing in two young adults with congenital heart disease who had multiple pacing lead failures and superior vena cava occlusion. The deflectable catheter delivery system used to position the SelectSecure lead provided the opportunity to map the right ventricular endocardial surface and determine the best available pacing site. At midterm follow‐up, both systems are functioning well.     

Acute Hemodynamic Improvement by Pacing in Patients with Severe Congestive Heart Failure

Since the first report on dual chamber pacing for congestive heart failure (CHF) in 1991, a number of investigators have explored the topic with conflicting results. These conflicts may arise from an incomplete understanding of the mechanisms by which pacing improves cardiac function. Potential mechanisms include: (1) increase in filling time: (2) decrease in mitral regurgitation: (3) optimization of left heart mechanical atrioventricular delay (left heart MAVD); and (4) normalization of ventricular activation. One or more of these mechanisms may be operative in an individual patient, implying that patients may require individuol optimization. Acute pacing studies were conducted on nine CHF patients, NYHA Class II-III to Class IV. Measurements of conduction times in sinus rhythm revealed: (1) normal interatrial conduction times (59 ± 5 ms) in all patients, with wide variations in interventricular conduction times (range, ?15–105 ms); and (2) a wide range of left heart MAVD (range, 97–388 ms). While pacing the right, left, or both ventricles, measurement of high fidelity aortic pressure and mitral and aortic velocities revealed the following: (1) 6 of 9 patients increased mean pulse pressure over sinus value during RV orLV pacing at an optimal A V delay: (2) the maximum aortic pulse pressure was achieved when the atrium was not paced: an 8% increase over sinus pulse pressure with paced RV versus a 5% decrease for paced atrium and RV at optimum AV delay (paired Student's t-test, P = 0.01), and a 0% increase over sinus with paced LV versus 7% decrease for paced atrium and LV at optimum AV delay, P < 0.05: (3) significant dependence on pacing site was noted, with 4 patients doing best with RV pacing. 3 patients achieving a maximum with LV pacing, and 2 patients showing no preference; and (4) 2 of 4 patients with restrictive filling patterns were converted to nonrestrictive patterns with optimum pacing. Patient hemodynamics appear to benefit acutely from individually optimized pacing. Increases in filling time, optimization of left heart MAVD, and normalization of intraventricular activation are the most significant mechanisms. Atrial pacing is inferior to atrial sensed modes if the patient has a functional sinus node.     

Remote Occurrence of High Degree Heart Block Following Failure of Transcatheter AV Junctional Ablation: Incidence and Clinical Significance

We report on two patients out of a series of 22 who underwent transcatheter ablation of the atrioventricular (AV) junction. The procedure failed to induce permanent complete heart block in 15 patients, 12 of whom were in sinus rhythm with 1:1 AV conduction before hospital discharge. Of the 12 patients, two (16.6%) were found to be in high degree heart block, one month later. We discuss the mechanism of late occurrence of high degree heart block and we emphasize the need for systematic implantation of permanent ventricular or dual chamber pacemakers, despite failure of transcatheter ablation of the AV junction     

Spontaneous Heart Activity in Pacemaker Treated Patients with High-grade Atrioventricular Block A Holter Monitor Study

A Holter monitor study. A Holter monitor study was performed to assess the occurrence of spontaneous heart activity in 70 pacemaker treated patients (mean age 72.1 years) with high-grade atrioventricular (AV) block, who had been treated with permanent pacemakers for a mean of 60 months (range 5-161). Nineteen patients had asynchronous (VOO), and 51 QRS-inhibited (VVI) pacemakers. The patients were monitored for a mean of 23 hours (range 15.5-26). Twenty-five patients were re-studied for day-by-day variations in spontaneous heart activity. At clinical observation, thirty-eight patients had pacemaker rhythm only. During monitoring, all patients studied had some kind of spontaneous cardiac activity, mostly ventricular ectopic beats. Three patients had short episodes of sinus rhythm of more than 70 beats/min. Patients in functional class III-IV (NYHA) or with an enlarged heart had the most spontaneous heart activity; those with asynchronous pacemakers had the least spontaneous cardiac activity. No tachyarrhythmias precipitated by interference between intrinsic heart beats and asynchronous pacemakers were seen. Twenty patients studied twice had a relatively stable occurrence of spontaneous heart activity, while five (20%) varied considerably. On the basis of these long-term observations it is difficult to predict when interference rhythm will occur, and asynchronous pacemakers therefore cannot be recommended for the first implantation. (PACE, Vol. 4, November-December, 1981)     

Pacemaker implantation as a risk factor for heart failure in young adults with congenital heart disease

AIM: Complete postoperative heart block following open-heart surgery and sinus node dysfunction are indications for permanent cardiac pacing in children with congenital heart defects. The purpose of our study was to evaluate if cardiac pacing is a risk factor of heart failure during longtime follow-up of grown ups with congenital heart disease (GUCH). METHODS: For an objective assessment of heart failure, NT-Pro brain natriuretic peptide (BNP) and maximal oxygen uptake index (VO2max) during the cardiopulmonary exercise testing were measured in 346 consecutive GUCH patients during a longtime follow-up examination. RESULTS: Thirty-nine of these patients who had pacemaker implantation had significantly increased BNP levels (448.2 +/- 76.8 vs 123.8 +/- 9.7 pg/mL, P < 0.0001) and significantly decreased VO(2max) (22.5 +/- 0.9 vs 27.4 +/- 0.4, P < 0.0001). Heart failure in pacemaker patients was associated with significantly prolonged QRS complex durations (171.1 +/- 8.3 ms vs 108.7 +/- 1.8 ms, P < 0.0001), increased right ventricular end diastolic diameters (38.7 +/- 2.1 mm vs 27.8 +/- 0.5mm, P < 0.0001), lower heart rates at rest (69.5 +/- 1.9/min vs 82 +/- 1/min, P < 0.0001), and at exercise (140.3 +/- 5.8/min vs 163.5 +/- 1.2/min, P < 0.0001). Mean fractional shortening of the left ventricle was normal in both patient groups. CONCLUSION: Pacemaker implantation may be associated with heart failure during longtime follow-up of GUCH indicated by significantly elevated BNP levels and decreased VO2max. Possible explanations are prolongation of QRS complex duration, decreased maximal heart rates during exercise, and dilatation of the right ventricle.     

DDD versus VVIR Pacing in Patients,Ages 70 and Over,with Complete Heart Block

Background : Dual‐chamber pacing is believed to have an advantage over single‐chamber ventricular pacing. The aim of the study was to determine whether elderly patients with implanted pacemaker for complete atrioventricular block gain significant benefit from dual‐chamber (DDD) compared with single‐chamber ventricular demand (VVIR). Methods : The study was designed as a double‐blind randomized two‐period crossover study—each pacing mode was maintained for 3 months. Thirty patients (eight men, mean age 76.5 ± 4.3 years) with implanted PM were submitted to a standard protocol, which included an interview, functional class assessment, quality of life (QoL) questionnaires, 6‐minute walk test, and transthoracic echocardiographic examinations. QoL was measured by the SF‐36. All these parameters were obtained on DDD mode pacing and VVIR mode pacing. Paired data were compared. Results : QoL was significantly different between the two groups and showed the best values in DDD. Overall, no patient preferred VVIR mode, 18 preferred DDD mode, and 12 expressed no preference. No differences in mean walking distances were observed between patients with single‐chamber and dual‐chamber pacing. VVI pacing elicited marked decrease in left ventricle ejection fraction and significant enlargement of the left atrium. DDD pacing resulted in significant increase of the peak systolic velocities in lateral mitral annulus and septal mitral annulus. Early diastolic velocities on both sides of mitral annulus did not change. Conclusion : In active elderly patients with complete heart block, DDD pacing is associated with improved quality of life and systolic ventricular function compared with VVI pacing. (PACE 2010; 583–589)