Permanent Pacemaker Therapy Research Articles

Permanent cardiac pacing in patients with end-stage renal disease undergoing dialysis.

Studies investigating the risk of cardiac dysrhythmia warranting permanent pacemaker therapy for end-stage renal disease (ESRD) patients are limited. This study investigated the incidence rate of permanent cardiac pacing in dialysis patients. Using the Taiwan National Health Insurance Database, we identified 28 471 newly diagnosed ESRD patients in 2000-2010 [9700 on peritoneal dialysis (PD) and 18 771 on hemodialysis (HD)] and 113 769 randomly selected controls without kidney disease, frequency-matched by sex, age and diagnosis date. We also established propensity score-matched HD and PD cohorts with 9700 patients each. Incidence rates and hazard ratios (HRs) of implantation were evaluated by the end of 2011. Complications were also evaluated among patients with implantation. The incidence rates of permanent pacemaker implantation were 5.93- and 3.50-fold greater in HD and PD patients than in controls (1.44 and 0.85 versus 0.24 per 1000 person-years, respectively). The adjusted HRs (aHRs) of implantation were 3.26 [95% confidence interval (CI) = 2.41-4.42] and 2.36 (95% CI = 1.56-3.58) for HD and PD patients, respectively, compared with controls. The pacemaker implantation rate was 0.33 per 1000 person-years greater in the propensity score-matched HD cohort than in the PD cohort, with an aHR of 1.30 (95% CI = 0.82-2.05) for the HD cohort compared with the PD cohort. Dialysis patients are at an increased risk of dysrhythmia requiring pacemaker implantation compared with the general population. The risks are not significantly different between HD and PD patients.

QRS and QT ventricular conduction times and permanent pacemaker therapy after transcatheter aortic valve implantation

Abstract Transcatheter aortic valve implantation is a therapy for patients with reduced left ventricular ejection fraction and symptomatic aortic stenosis. The aim of the study was to compare the pre-and post- transcatheter aortic valve implantation procedures to determine the QRS and QT ventricular conduction times as a potential predictor of permanent pacemaker therapy requirement after transcatheter aortic valve implantation. QRS and QT ventricular conduction times were prolonged after transcatheter aortic valve implantation in heart failure patients with permanent dual chamber pacemaker therapy after transcatheter aortic valve implantation. QRS and QT ventricular conduction times may be useful parameters to evaluate the risk of post-procedural ventricular conduction block and permanent pacemaker therapy in transcatheter aortic valve implantation.

The role of permanent pacemaker therapy in vasovagal syncope: a systematic review

The role of permanent pacemaker therapy in vasovagal syncope: a systematic review

Syncope in paced patients with sick sinus syndrome from the DANPACE trial: incidence, predictors and prognostic implication

ObjectivesSyncope is a cause of significant morbidity in sick sinus syndrome (SSS) which may not be resolved with permanent pacemaker therapy. We aimed to determine the incidence, predictors and prognostic...

Acquired Gerbode defect and third‐degree atrioventricular block secondary to vehicular trauma in a dog

To describe a case of traumatically acquired left ventricular to right atrial communication (Gerbode defect), atrial septal defect (ASD), and third-degree atrioventricular block (AVB) necessitating permanent pacemaker placement in a dog. A 1.5-year-old neutered male Newfoundland dog was struck by a car and was referred for further evaluation and treatment of hemoabdomen. Persistent third-degree AVB, a right-sided cardiac murmur and right-sided congestive heart failure (CHF) were identified, and echocardiographic examination revealed a type-A Gerbode defect and ASD. Pimobendan, furosemide, and enalapril therapies were initiated for treatment of CHF. Persistent AVB eventually necessitated permanent pacemaker implantation. Initial attempts at minimally invasive occlusion of the Gerbode defect were unsuccessful; however the dog continues to do well clinically on chronic cardiac medications. To our knowledge, an acquired Gerbode defect secondary to trauma with associated ASD, CHF, and third-degree AVB necessitating permanent pacemaker therapy have not yet been reported in the veterinary literature. The extended survival and follow-up available on this patient postpacemaker implantation also documents that longer term survival is possible with this defect.

Association of Heart Block with Uncommon Disease States

A variety of diseases, other than the common Lev-Lenègre disease, are associated with cardiac conduction system abnormalities. These include acute processes, such as acute rheumatic fever, and other disorders, such as sarcoidosis, connective tissue disorders, neoplasms, and bacterial endocarditis with cardiac abscess formation. The purpose of the study is to raise awareness of these rare conditions. We present 10 adult patients (4 males and 6 females) with a mean age of 47 years (range: 19-69), with various rare diseases associated with heart block, who needed temporary or permanent pacemaker therapy in the past two decades. These conditions included acute rheumatic carditis, Wegener granulomatosis, cardiac involvement of metastatic breast cancer, bacterial endocarditis, sarcoidosis, S/P chest radiotherapy, and quadriplegia with syringomyelia postspinal cord injury, and adult congenital heart block. We conclude that patients with these disorders should be followed periodically, to allow for early detection and treatment of cardiac conduction disturbances, with pacemaker therapy.

Permanent Pacemaker Therapy for Neurally Mediated Syncope

Neurally mediated syncope (also known as fainting and vasovagal syncope) is by far the most common cause of transient loss of consciousness. Fainting is almost always benign, and most people who faint have nontraumatic syncope episodes occasionally throughout their lives with minimal adverse consequences. Most episodes of fainting occur in the erect posture and have typical warning symptoms such as light-headedness or nausea that allow the individual to avoid serious injury if he or she loses consciousness. In a small number of people, however, fainting is a serious medical problem; typically, these are patients with episodes that occur with little or no warning or occur very frequently. Recurrent neurally mediated syncope can mean the inability to drive or to work, and syncope episodes can cause serious injury, albeit rarely. In such patients, neurally mediated syncope is a significant medical problem for which there are no easy solutions. Article see p 2566 Reflex vasodilation and bradycardia are the 2 main pathophysiological mechanisms underlying neurally mediated syncope, often acting together. Most pharmacological therapies are directed at limiting the vasodilation component; however, there is little evidence that medical therapies (fluid loading, β-blockers, fludrocortisone, or midodrine) are effective; a recent meta-analysis concluded that there are no proven effective pharmacological therapies for the prevention of neurally mediated syncope.1 There is modest evidence that countermaneuvers such as leg crossing can help some patients.2 Because transient bradycardia or asystole is often observed during neurally mediated syncope, cardiac pacing has been evaluated to treat severely symptomatic patients with frequent events. The challenge of pacemaker therapy for this condition, however, is that vasodilatation may still cause fainting, even after bradycardia is prevented by …

Pacemaker therapy: the newborn and the nonagenarian

This editorial refers to ‘Long-term outcome of cardiac pacing in octogenarians and nonagenarians’ by E. O. Udo et al ., on page 502 and ‘Permanent epicardial pacing in children: long-term results and factors modifying outcome’ by P. Kubus et al ., on page 509 The average age of patients with an indication for pacing is ∼75 years at the time of implantation. However, permanent pacemaker therapy can be necessary at all ages, from newborn to the nonagenarian. Particularly in these age groups, age matters: in small children, there are technical and anatomical considerations that render pacemaker implantation difficult; in very old patients, their relatives, in particular, but also physicians may have concerns about pacemaker implantation that is perceived as too invasive for such an old patient with significant comorbidity. Two publications in this issue of the journal address pacemaker therapy in these two age groups.1,2 Pacemaker therapy in children faces several challenges. Transvenous implantation may not be feasible due to lack of venous access to cardiac cavities, or may be difficult due to the small venous diameter that either prevents lead introduction or—if the lead can be introduced—obliterates soon after implantation. Lead dysfunction (lead fracture, exit block, and sensing failure) during growth can occur despite formation of loops of the lead at the time of implant. Therefore, epicardial pacing remains the preferred mode of implantation in small children. As an advantage, the epicardial approach allows dual-chamber pacing earlier than transvenous implantation and left ventricular pacing to prevent adverse haemodynamic long-term consequences of right ventricular pacing. Even though pacing is increasingly applied in paediatric patients, only few long-term data are available …

Invited Commentary

Recent reports have suggested that tricuspid valve repair performed at the time of mitral valve operation results in a lower incidence of advanced heart failure, defined as New York Heart Association (NHYA) functional class III or IV, and improves survival [1]. The operation is not without risk. One of those risks, as demonstrated by Jokinen and colleagues [2], is that almost one-quarter of patients undergoing a tricuspid valve operation (whether isolated or as part of a multiple valve operation) require permanent pacemaker therapy.

Asystolic pauses in atrial fibrillation. Incidence, dependence on the underlying disease and significance for pacemaker therapy

The frequency and duration of asystolic pauses in atrial fibrillation was investigated in 100 consecutive patients using 24-hour ECG's obtained by Holter monitoring. Patients were subdivided, according to the length of the maximal RR-interval, into group A (no asystolic pauses over 2 seconds duration), group B (pauses between 2 and 4 seconds) and group C (asystoles over 4 seconds duration). Pauses longer than 2 seconds occurred in 57% of patients, but longer than 4 seconds only in 6 cases. A statistically higher frequency was seen in patients with permanent (78.3%) than in those with paroxysmal (24.5%) atrial fibrillation, and in patients with rheumatic valve disease (82.4%) in comparison with the rest (54.3%). In contrast, pauses over 2 seconds occurred in only 22.2% of general medical ward patients. Up to 50% of all asystoles in groups A and B were registered during the night, whereas a day-night variation for group C was not apparent. No correlation could be demonstrated between dizziness and bradycardic conduction in group A and B, but all patients in group C made such complaints during the monitoring period. Asystoles of up to 4 seconds duration in atrial fibrillation can be regarded as "normal"; longer asystoles must be anticipated particularly in patients with rheumatic valvular disease. It is only here that permanent pacemaker therapy appears to be indicated.

Incidence of ventricular tachyarrhythmias during permanent pacemaker therapy in low-risk patients results from the German multicentre EVENTS study

Current studies found an incidence of 12-31% ventricular tachyarrhythmias and sudden cardiac death during cardiac pacing months or even years after pacemaker insertion. MADIT(12) and MUSTT(13) demonstrated that patients with poor LV function after Myocardial infarction (MI) showing non-sustained ventricular tachycardia (nsVT) and inducibility during electrophysiologic testing benefit from an ICD. The present study was dedicated to assess the global incidence of non-sustained ventricular arrhythmias in a general population of pacemaker patients. Special regard was on patients with a potential ICD indication, e.g. those matching the MADIT/MUSTT criteria. Two hundred and thirty-one patients (72 +/- 11 years; 134 men) with an indication for dual chamber pacing entered the study. In all patients pacemaker systems capable of automatic storing of intracardiac electrocardiograms were implanted (Pulsar, Discovery, Guidant). Follow-up time was 15 months after inclusion. In 54 (25.7%) of 210 patients with at least one follow-up, episodes of nsVT were documented by stored electrocardiograms (up to >30 beats, >200 b.p.m.). Multiple-up to nine-episodes of ventricular tachycardia were retrieved in 31 of these patients. Three out of 14 patients with an LVEF <40% after MI presented nsVT during the follow-up. One of these patients received an ICD. A significant number of pacemaker patients present with ventricular tachycardia. Intracardiac electrocardiograms and alert functions from pacemakers may enhance physicians' awareness of the patient's intrinsic arrhythmic profile and help uncover underlying mechanisms of arrhythmias by storing the initiation of the arrhythmia.

Upper Body Venous Access for Transvenous Lead Placement—Review of Existent Techniques

Recent developments in permanent pacemaker and implantable cardioverter-defibrillator therapy have focused on the endocardial placement sites of leads ("selective site pacing"), detection and pacing algorithms, and indications for device therapy. In comparison, the surgical and venous access aspects of device therapy have received relatively little attention. Obtaining central venous access is a prerequisite for delivering device therapy through transvenously placed leads. This article reviews the different techniques available for obtaining upper body venous access for transvenous lead placement, even though the information will also be relevant to other specialties that require central venous access for other purposes.

The Expectation Effect and Cardiac Pacing for Refractory Vasovagal Syncope

Background Clinical trials of pacing for vasovagal syncope have shown conflicting results. We performed a meta-analysis to determine whether permanent pacemaker therapy prevents refractory vasovagal syncope. Methods Randomized trials comparing pacemaker therapy with medical therapy, usual care, placebo, or different pacing algorithms in the prevention of recurrent vasovagal syncope were considered. The primary endpoint was first recurrence of syncope. Results Nine randomized trials (2 double blind, 7 open label or single blind) were included. There was significant heterogeneity when all 9 trials were pooled ( P =.0009 and I 2 = 69.6%), reflecting methodological diversity in blinding and the nature of the control therapy. When pooled by trial methodology, heterogeneity was no longer apparent. Permanent pacing reduced the risk of recurrent syncope in unblinded studies (odds ratio [OR] 0.09, 95% confidence interval [CI], 0.04 to 0.22) and in studies comparing pacemaker algorithms (OR 0.04, 95% CI, 0.0 to 0.23). No effect was seen in double-blinded trials (OR 0.83, 95% CI, 0.41 to 1.70). Awareness that a permanent pacemaker was implanted and functional was associated with a significant ‘expectation’ effect, which itself reduced the risk of recurrent syncope (OR 0.16, 95% CI, 0.06 to 0.40, P =.0001). Results were similar when restricted to patients with a marked cardioinhibitory response on baseline tilt table testing. Conclusion The results of small, preliminary trials have overestimated the treatment effect of pacemakers due to a lack of blinding of physicians and patients. Blinded trials suggest that the apparent response is due to a strong expectation response to pacing.

Review Article

Review Article

Clinical characteristics of hypervagotonic sinus node dysfunction.

BackgroundSinus node dysfunction (SND) is caused not only by intrinsic sinus node disease, but also by the extrinsic factors. Among the extrinsic factors, autonomic imbalance is most common. Symptomatic SND usually requires permanent pacemaker therapy. However, the clinical characteristics and patient response to medical therapy for hypervagotonic SND have not been properly clarified.Materials and MethodsThirty two patients (14 men, 18 women, 51 ± 14 years) with hypervagotonic SND were included in this study, but those patients who had taken calcium antagonists, beta-blockers or other antiarrhythmic drugs were excluded. Hypervagotonic SND was diagnosed if the abnormal electrophysiologic properties of the sinus node were normalized after the administration of atropine (0.04 mg/kg).ResultsThe presenting arrhythmias were 16 cases of sinus bradycardia (50.0%), 12 of sinus pause (37.5%), 3 of sinoatrial block (9.4%) and 1 of tachy-bradycardia (3.1%). Nine (28.1%) patients had hypertension, 7 (21.9%) smoked, 2 (6.3%) had diabetes mellitus, and 1 (3.1%) had hypercholesterolemia. Among the patients, 3 had no remarkable symptoms, 13 had dizziness, 7 had syncope, 3 had weakness and 6 had shortness of breath. Twenty five (78.1%) patients were treated with theophylline, 1 patient with tachy-bradycardia syndrome was treated with digoxin and propafenone, and 6 (18.8%) were treated with no medication. During the 43±28 month follow-up, 25 patients remained asymptomatic, but 6 who took no medication developed mild dizziness. One patient needed permanent pacemaker implantation owing to recurrent syncope despite of theophylline treatment.ConclusionThese results show that hypervagotonic SND has a benign course and most of the patients can be managed safely without implanting a pacemaker. (Ed note: I like the abstract. It is short and direct, as it should be.)

Role of pacemakers in treating neurocardiogenic syncope.

Patients with frequent vasovagal syncope have a poor quality of life and often resist treatment with standard pharmacologic approaches. Clinical vasovagal syncope may be associated with some degree of bradycardia. Studies of temporary pacing during tilt table tests showed that pacing prevented syncope in a little more than half of patients who developed a vasovagal response. Six open-label studies of permanent pacing show that permanent pacemaker therapy is associated with substantial improvement over medical therapy. The roles of specific pacemaker modes have not been determined, although there is some evidence that rate-drop responsiveness helps. The second Vasovagal Pacemaker Study will quantify the true benefits of pacing for vasovagal syncope and assess the role of rate-drop response algorithms.

Permanent cardiac pacing to prevent vasovagal syncope.

Patients with frequent vasovagal syncope have a poor quality of life and often resist treatment with standard pharmacologic approaches. Although the evidence is weak, clinical vasovagal syncope is probably associated with some degree of bradycardia. Studies of temporary pacing during tilt table tests showed that pacing prevented syncope in a little over half of patients who developed a vasovagal response. Six open-label studies of permanent pacing show that permanent pacemaker therapy is associated with substantial improvement over medical therapy. The roles of specific pacemaker modes have not been determined, although there is some evidence that rate-drop responsiveness helps. The second Vasovagal Pacemaker Study will quantify the true benefits of pacing for vasovagal syncope and assess the role of rate-drop response algorithms.

Syncope in the elderly: new trends in diagnostic approach and nonpharmacologic management.

Syncope in the elderly is an important health care issue because of the large patient population, challenging diagnostic and therapeutic approaches, and potentially devastating consequences. Significant comorbidity and atypical clinical presentations render a precise determination of the cause of syncope difficult. Recent studies suggest that noninvasive tests, such as carotid sinus massage or tilt-table testing, can be helpful in the diagnostic workup. It has been shown that permanent pacemaker therapy benefits elderly patients with carotid sinus hypersensitivity, and younger patients with recurrent vasovagal syncope. The implantable wireless loop recorder can be effective in documenting transient arrhythmias as causes of syncope in selected patients. Elderly patients with syncope and a low ejection fraction are at increased risk of sudden death due to malignant ventricular arrhythmia. Electrophysiologic study and electrophysiology-guided therapy should be considered in this segment of the population.

Permanent pacemaker therapy before and after the reunification of Germany: 16 years of experience at an East German regional pacing center.

The reunification of Germany had a significant influence on the management of patients with bradyarrhythmias. The current study was performed in a regional pacing center located in the former German Democratic Republic. It compares the situation of patients with critical bradyarrhythmias before and after the reunification of Germany in 1990 focusing on (1) indication for pacemaker implantation, (2) pacemaker modalities and function, (3) type of leads, (4) frequency of reintervention, and (5) early and late complications. The study covers 9 years before and 7 years after the reunification. A total of 1,125 patients were included, and the database was formed by the patients' files and the protocols of implantation. The situation before reunification was characterized by a nonavailability of modern physiological pacing devices and insufficient diagnostic equipment. Between 1981 and 1990, 384 patients underwent pacemaker implantation solely receiving single chamber devices with no or only minimal feasibility of programming. Between 1990 and 1996, 741 patients were treated, and they all received modern pacemakers having the capability of multiprogramming and telemetry. Regarding complications of pacemaker therapy, lead related problems significantly decreased after the reunification (dislocation, 5.3% vs 1.7%, P < 0.05; exit block, 6.7% vs 1.4%, P < 0.05) opposite to pacemaker infections, which significantly increasing after dual chamber pacemakers were implanted (2.2% vs 6.0%, P < 0.05). The reunification of Germany dramatically improved the situation of patients with critical bradyarrhythmias leading to free access to high-tech pacing equipment within a few months. However, the abrupt change from antiquated to modern pacemaker therapy created some new problems, especially regarding application and handling of modern physiological pacing devices.

Cardiac Pacing During Neurocardiogenic (Vasovagal) Syncope

Head-up tilt testing is increasingly being used as a diagnostic modality in patients with unexplained syncope who are thought to have neurocardiogenic (vasovagal) mechanisms of syncope. Although large-scale placebo-controlled trials are still awaited, pharmacologic therapy is usually effective in preventing syncope or presyncope in this patient population. However, the role of permanent pacemaker therapy remains controversial. Because hypotension is usually associated with paradoxical bradycardia and occasionally asystole, it has been argued that permanent pacemaker therapy may be useful in preventing syncope and, thus, injury, in the so-called "malignant vasovagal cardioinhibitory response" in which the onset of syncope is thought to be abrupt. The onset of hypotension, however, usually precedes bradycardia during neurocardiogenic syncope, and pacing may thus not prevent syncope or presyncope in these patients. The role of cardiac pacing in patients with neurocardiogenic syncope is reviewed.