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Biomedical subjects

S C Hammill

Publications and source records attributed to S C Hammill.

At least 19 recordsLinked to original sources
PubMed1999

Utility of a single-stage isoproterenol tilt table test in adults: a randomized comparison with passive head-up tilt.

OBJECTIVES: This study was conducted to develop a time-efficient tilt table test. BACKGROUND: Current protocols of tilt table testing are quite time-consuming. This study was designed to assess the diagnostic value, tolerance and procedural time of a single-stage isoproterenol tilt table protocol. METHODS: A single-stage isoproterenol tilt table test was compared with the passive tilt table test. The study was prospectively designed in a randomized and crossover fashion. RESULTS: The study population consisted of 111 patients with a history of syncope (mean age 55 +/- 20 years). Of the total, 62 patients (56%; 95% confidence interval, 46% to 65%) had a positive vasovagal response during isoproterenol tilt table testing and 35 (32%; 23% to 41%) during passive tilt table testing (p = 0.002). The mean procedural times of the study population were 11.7 +/- 3.6 min and 36.9 +/- 13.3 min for isoproterenol and passive tilt table testing, respectively (p < 0.001). All patients tolerated single-stage isoproterenol testing. In the 23 control subjects (mean age 34 +/- 11 years), the apparent specificities were 91% (72% to 99%) and 83% (61% to 99%) for passive and single-stage tilt table testing, respectively. CONCLUSIONS: The single-stage isoproterenol tilt table test was more effective in inducing a positive vasovagal response in an adult population than the standard passive tilt table test, and it significantly reduced the procedural time. The increase in positive yield was associated with a moderate decrease in apparent specificity. These observations support the conclusion that single-stage tilt table testing could be a reasonable diagnostic option in patients undergoing syncope evaluation.

Adult↗
PubMed1999

A stepwise testing protocol for modern implantable cardioverter-defibrillator systems to prevent pacemaker-implantable cardioverter-defibrillator interactions.

Current use of newer implantable cardioverter-defibrillators (ICDs) has changed the spectrum of pacemaker-ICD interactions and provided new tools for testing and understanding those interactions. Testing for pacemaker-ICD interactions was performed in 31 procedures involving 22 patients. The protocol included: (1) evaluation of pacemaker stimulus artifact amplitude and its ratio to that of the evoked ventricular electrogram, (2) testing for inhibition of ventricular fibrillation (VF) detection by the ICD during asynchronous pacing at maximum output, (3) evaluation by pacemaker event marker recordings of pacemaker sensing behavior while programmed to nonasynchronous mode during ventricular tachycardia (VT) or VF, and (4) evaluation of postshock interactions. Inhibition of detection of VT/VF was found in 6 of 22 patients (27.2%). Large stimulus artifact amplitude (>2 mV) or stimulus artifact:evoked QRS ratio > 1/3 had a positive predictive accuracy of 18% and 14.4%, respectively, and a negative predictive accuracy of 100% and 92.3%, respectively, for clinically significant interaction. Asynchronous pacing occurred in 16 of 31 procedures (51.6%), and was due to underdetection by the pacemaker in 4 of 16 (25%) and noise reversion in 12 of 16 (75%). Postshock phenomena occurred in 6 cases, 3 of which were clinically significant. Overall, 11 of 22 patients (50%) had clinically significant interactions discovered by this protocol, which led to system revisions in 6 and to pacemaker output reprogramming in 5. Thus, pacemaker-ICD interactions are frequently detected using a thorough and systematic protocol. Most cases can be managed by system revision or pacemaker reprogramming.

Artifacts↗
PubMed1999

Relation between mode of pacing and long-term survival in the very elderly.

OBJECTIVES: This study analyzes the relationship between pacing mode and long-term survival in a large group of very elderly patients (> or = 80 years old). BACKGROUND: The relationship between pacing mode and long-term survival is not clear. Because the number of very elderly who are candidates for pacing is increasing, issues related to pacemaker (PM) use in the elderly have important clinical and economic implications. METHODS: We retrospectively reviewed 432 patients (mean age, 84.5+/-3.9 years) who received their initial PM (ventricular in 310 and dual chamber in 122) between 1980 and 1992. Follow-up was complete (3.5+/-2.6 years). Observed survival was estimated by the Kaplan-Meier method. Age- and gender-matched cohorts from the Minnesota population were used for expected survival. Log-rank test and Cox regression hazard model were used for univariate and multivariate analyses. RESULTS: Patients with ventricular PMs appeared to have poor overall survival compared with those with dual-chamber PMs. Observed survival after PM implantation in high grade atrioventricular block (AVB) patients was significantly worse than expected survival of the age- and gender-matched population (p < 0.0001), whereas observed survival of patients with sinus node dysfunction was not significantly different from expected survival of the matched population (p = 0.413). By univariate analysis, ventricular pacing in patients with AVB appeared to be associated with poor survival compared with dual-chamber pacing (hazard ratio [HR] 2.08; 95% confidence interval [CI] 1.33 to 3.33). After multivariate analysis, this difference was no longer significant (HR 1.41; 95% CI 0.88 to 2.27). Independent predictors of all-cause mortality were number of comorbid illnesses, New York Heart Association functional class, left ventricular depression and older age at implant. Pacing mode was not an independent predictor of overall survival. Older age at implantation, diabetes mellitus, dementia, history of paroxysmal atrial fibrillation and earlier year of implantation were independent predictors of ventricular pacemaker selection. CONCLUSIONS: After PM implantation, long-term survival among very elderly patients was not affected by pacing mode after correction of baseline differences. Selection bias was present in pacing mode in the very elderly, with ventricular pacing selected for sicker and older patients, perhaps partly explaining the apparent "beneficial impact on survival" observed with dual-chamber pacing.

Aged↗
PubMed1999

Sensitivity to orthostatic stress and beta-receptor activation in patients with isoproterenol-induced vasovagal syncope: a case controlled study.

Cardiomotor and vasomotor responses were assessed during isoproterenol tilt-induced vasovagal reaction in patients with a history of syncope. In a case controlled study, all patients and controls were subjected to a standard protocol: baseline supine (10 min), baseline tilt (70 degrees, 45 min), isoproterenol supine (0.05 microgram/kg per min, 10 min), and isoproterenol tilt (70 degrees, 10 min). The participants were 11 consecutive patients referred for syncope evaluation (5 men, 6 women; mean age, 34.1 +/- 10.4 years; range, 18-56 years) and 11 age and sex matched controls (5 men, 6 women; mean age, 35.5 +/- 12.2 years; range, 19-63 years). On-line, beat-to-beat measurements of cardiomotor functions (heart rate, stroke volume, and cardiac output) and vasomotor functions (systolic, mean, and diastolic blood pressures and total peripheral resistance [TPR]) were detected noninvasively by volume clamp photoplethysmography and impedance cardiography. Patients and controls had similar cardiomotor and vasomotor responses during passive tilt and during isoproterenol infusion in the supine position. Immediately after tilt during isoproterenol infusion and before the onset of symptoms, decreases in vasomotor functions were significant in study patients when compared with those in controls; whereas responses in cardiomotor functions were similar between the two groups. When compared with baseline supine findings, TPR decreased by 56.5% +/- 10.9% and 29.5% +/- 23.3% in the patient population and controls, respectively (P = 0.005). When compared with isoproterenol supine findings, TPR decreased by 27.5% +/- 22.8% in the study patients and increased by 22.6% +/- 48.1% in the controls (P = 0.005). The inability to overcome isoproterenol-induced vasodilation during orthostatic stress played an important role in the initiation of a vasovagal response. These observations hold the key to early detection of hemodynamic changes and potential therapeutic interventions before patients become symptomatic.

Adolescent↗
PubMed1998

High failure rate for an epicardial implantable cardioverter-defibrillator lead: implications for long-term follow-up of patients with an implantable cardioverter-defibrillator.

OBJECTIVES: The purpose of this study was to determine the risk of epicardial lead failure during long-term follow-up and its mode of presentation. BACKGROUND: Despite the high prevalence of epicardial lead-based implantable cardioverter-defibrillators, their long-term performance is unknown, and appropriate follow-up has not been established. METHODS: The study group comprised all patients in whom an epicardial lead system was implanted at the Mayo Clinic between October 31, 1984 and November 3, 1994. The number of lead fractures and leads with fluid within the insulation and the mode of presentation were determined retrospectively by review of patient visits, radiographs of lead systems and data derived from formal lead testing. RESULTS: At 4 years, the survival rate free of lead malfunction, using formal lead testing, for 160 Medtronic epicardial patches (models 6897 and 6921) was 72% compared with 92.5% for the 179 Cardiac Pacemaker, Inc. (CPI) patches (models 0040 and 0041) (p = 0.01). In addition, five Medtronic patches in three patients had fluid within the lead insulation but no obvious fracture. No CPI patches had fluid identified within the leads. Of 330 Medtronic epicardial pace/sense leads (model 6917), the 4-year survival rate free of lead malfunction as assessed by lead testing was 96%. In all, 19 presentations of lead malfunction were found in 17 patients (2 patients had more than one lead fracture at different times). In 11 (58%) of these presentations, the patients were asymptomatic despite the presence of obvious lead fracture. CONCLUSIONS: Epicardial lead malfunction is common on long-term follow-up, and some leads have a failure rate of 28% at 4 years. Many patients with fractured leads remain asymptomatic, despite involvement of multiple leads in some cases. Therefore, consideration should be given to regular periodic lead testing in addition to routine X-ray examination, as asymptomatic lead malfunction can present with normal chest X-ray findings.

Aged↗
PubMed1998

Agreement and coding reliability of the Minnesota and Mayo electrocardiographic coding systems.

PROBLEM: To determine whether diagnoses of myocardial infarction assigned by a system that uses Marquette 12SL electrocardiographic (ECG) codes with manual over-reading agree with diagnoses assigned by Minnesota ECG codes. STUDIES UNDERTAKEN: Agreement and recode reliability of Minnesota and Mayo coding systems based on 768 ECGs plus chest pain history and serum enzyme values were analyzed for a stratified random sample of 141 patients with an event in 1990 or 1991 coded as HICDA 410.x, 411, 413 or 796.9. The population was reconstructed from the stratified random sample so that population-based inferences could be made from the analysis. RESULTS: For the stratified random sample, exact agreement on 4 categories (evolving diagnostic, diagnostic, equivocal, or other ECG) between Mayo and Minnesota ECG coding was 53.9% (kappa = 0.37 +/- 0.05). Code-recode agreement was higher for Minnesota coding (83.0%; kappa = 0.74 +/- 0.05) compared with Mayo coding (73.8%; kappa = 0.64 +/- 0.05). The same pattern was present for the reconstructed population. For coding myocardial infarction based on the ECG, serum enzyme levels, and the presence or absence of ischemic chest pain, agreement between Mayo and Minnesota coding was 84.4% (kappa = 0.72 +/- 0.05) based on the stratified random sample and 81.7% (kappa = 0.67 +/- 0.06) based on the reconstructed population. For the stratified random sample, reliability of diagnosis of myocardial infarction was 93.6% (kappa = 0.88 +/- 0.04) for the Minnesota system and 94.3% (kappa = 0.90 +/- 0.03) for the Mayo system. CONCLUSION: ECG interpretation by the Mayo and Minnesota coding systems differs significantly, and Mayo ECG coding is less reliable than Minnesota ECG coding. Coding of myocardial infarction on the basis of ECGs, serum enzymes, and ischemic chest pain, however, is equally reliable for both systems.

Chest Pain↗
PubMed1998

Importance of pacemaker noise reversion as a potential mechanism of pacemaker-ICD interactions.

Numerous types of interactions between pacemakers and implantable cardioverter defibrillators (ICDs) have been described. Pacemaker outputs preventing appropriate detection of ventricular tachycardia or ventricular fibrillation by the ICD is one of the more serious. Asynchronous pacemaker activity during ventricular arrhythmias may be caused by either nonsensing of the arrhythmia or by noise reversion, which is an algorithm that causes the pacemaker to switch to asynchronous pacing when repetitive sensing at a high rate occurs. We analyzed the mechanisms underlying asynchronous pacemaker activity in ventricular arrhythmias using pacemaker telemetry during the arrhythmia. Thirty-nine induced arrhythmias from 26 different procedures in 19 patients with both pacemakers and ICDs were analyzed. Of the 39 arrhythmias, asynchronous pacemaker activity occurred in 16. The underlying mechanism was nonsensing in 4 episodes and noise reversion in 12 episodes. Clinically significant interference with detection arose on three occasions. Conditions favoring the occurrence of noise reversion include specific pacemaker models, arrhythmia cycle lengths in the range causing noise reversion of the individual pacemaker model, long noise sampling periods, and VVI pacing mode. Noise reversion can be diagnosed by telemetering the pacemaker marker channel during ventricular arrhythmias as a part of routine pacemaker-ICD interaction evaluation. It can be prevented or minimized by programming short ventricular refractory periods or using pacemakers with short retriggerable refractory periods.

Bradycardia↗
PubMed1998

Randomized prospective pilot study of long-term dual-site atrial pacing for prevention of atrial fibrillation.

OBJECTIVE: To determine whether dual-site atrial pacing is feasible, safe, and effective. DESIGN: We undertook a randomized prospective single-blind crossover study. MATERIAL AND METHODS: Nine patients with at least two episodes per month of symptomatic paroxysmal atrial fibrillation participated in a randomized crossover study involving three separate 3-month blocks of single-site atrial pacing, dual-site atrial pacing, and control (support-only) pacing. RESULTS: Dual-site atrial pacing resulted in shorter P wave duration (81 +/- 14 ms) than did single-site pacing (111 +/- 12 ms) or control sinus rhythm (123 +/- 9 ms) (P<0.0001) and in fewer premature atrial complexes on Holter monitoring (P = 0.06). The arrhythmia-free interval was longer with dual-site pacing (67 +/- 17 days) than with single-site (62 +/- 30 days) or support-only (49 +/- 34 days) pacing (P = 0.10). This pilot study was not statistically powered to detect a difference between pacing modes. CONCLUSION: (1) Dual-site atrial pacing is feasible and safe; (2) it shortens the P wave duration and tends to decrease premature atrial complexes on Holter monitoring; (3) any atrial pacing tends to prolong the arrhythmia-free interval; and (4) this pilot study enrolled too few patients to determine whether a significant difference in pacing modes exists and supports the need for a larger study.

Adult↗
PubMed1997

Indications, effectiveness, and long-term dependency in permanent pacing after cardiac surgery.

The purposes of this study were to define predictors of long-term pacemaker dependency in patients having permanent pacemakers implanted shortly after cardiac surgery, and to evaluate short- and long-term results and survival in this population. Data from 120 adult patients with implantation since 1980 were retrospectively analyzed. Acute and chronic complication rates (4.2% and 16.6%, respectively) were not higher than those expected in the general paced population. In addition, continuous rhythm was evaluated by use of pacemaker inhibition in a subgroup of 20 patients to verify the validity of clinical criteria for pacemaker dependency. Of the patients evaluated for dependency, 41% eventually became nondependent. Prolonged monitoring with an inhibited pacemaker confirmed the accuracy of our method of clinical evaluation of pacemaker dependency. Significant predictors of long-term pacemaker dependency were complete atrioventricular block as the indication and bypass time of > 120 minutes (by multivariate and univariate analyses, respectively). Postoperative complete atrioventricular block is the most important predictor of pacemaker dependency, enabling an earlier decision on permanent pacemaker implantation (no later than the sixth and the ninth postoperative days for wide-complex and narrow-complex escape, respectively). Further prospective studies are needed to define optimal implantation times for indications other than complete atrioventricular block.

Adult↗
PubMed1997

Hemodynamic analysis during isoproterenol-induced vasovagal syncope.

An isoproterenol-mediated increase in cardiomotor tone and a decrease in afterload contribute to the induction of vasovagal syncope. Contrary to conventional belief, a significant decrease in preload is not observed immediately before isoproterenol-induced syncope.

Adolescent↗
PubMed1997

New criteria for the diagnosis of healed inferior wall myocardial infarction in patients with left bundle branch block.

The diagnosis of healed inferior myocardial infarction (MI) in patients with left bundle branch block (LBBB) is difficult because there are no established criteria. To develop criteria, we retrospectively examined the electrocardiograms of 166 patients with complete LBBB who had either normal images (normals) or an isolated, unequivocal inferior MI on delayed stress thallium imaging. Diagnostic Q waves were defined as a significant Q or QS of at least 30-ms duration. Diagnostic T-wave inversion was defined as complete T inversion or biphasic waves with initial, predominantly negative deflection. The most useful diagnostic findings were in lead aVF, where a Q wave was present in 10 of 35 patients in the MI group compared with only 4 of 131 patients in the normal group (p <0.00001). Diagnostic T-wave inversion was noted in 23 of 35 patients in the MI group compared with 8 of 131 patients in the normal group (p <0.00001). The presence in lead aVF of either a diagnostic Q-wave or T-wave inversion was seen in 30 of 35 patients with inferior MI (sensitivity of 86%) compared with only 12 of 131 patients with uncomplicated LBBB (specificity 91%). Thus, these criteria are potentially useful for the diagnosis of inferior MI in patients with LBBB.

Aged↗
PubMed1997

Value and limitations of noninvasive assessment of syncope.

The noninvasive assessment of patients who present with syncope is based on a thorough, complete history and physical examination. The history requires close attention to precipitating events and the description of the spell. Often, patients are poor historians with regard to symptoms leading up to and following the episode of syncope. Therefore, it is important to interview individuals who observed the spell to improve the accuracy of the history and sort out whether or not the spell was due to cardiogenic syncope, vasodepressor syncope, or a neurologic disorder. Carotid sinus massage is a useful procedure that can be performed during the routine physical examination, identifying patients who are at increased risk for carotid sinus syncope because of hypersensitivity of the carotid sinus. The clinician must be careful to attribute the clinical syncope to carotid sinus hypersensitivity only when the spell induced at the time of carotid massage reproduces the clinical spell. Routine laboratory tests are commonly performed, although the blood tests rarely yield information to confirm the cause of syncope. The routine ECG is often helpful identifying abnormalities of rhythm, conduction, or morphology that give a clue as to the cause for the patient's syncope. The most helpful aspect of ECG recording is to obtain a recording during an episode of syncope when exact correlation can be made between the ECG findings and the patient's symptoms. Recording the ECG during the spell can be achieved using 24-hour ambulatory monitoring, an event recorder, or a memory loop recorder. Twenty-four-hour ambulatory monitoring is useful in patients who have frequent spells that would be expected to be recorded during 1 or 2 days of monitoring. These individuals need to have a non-life-threatening spell and therefore be safe to evaluate as an outpatient. The event recorder and loop memory recorder have proved extremely helpful in evaluating spells that occur too infrequently to be recorded by 24-hour or 48-hour ambulatory monitoring. The nature of these recording devices does require that the patient or a companion be able to activate the monitor at the time of symptoms. If a patient experiences syncope but is unable to activate the device, the important information as to what the rhythm was doing at the time of symptoms is lost. The implantable loop recorder should prove to be uniquely advantageous by allowing extended ECG recording with the device activated by the patient or companion recording 20 minutes before and 4 minutes after device activation. Signal-averaged electrocardiography is most helpful in assessing patients with ischemic heart disease with a substrate capable of supporting a reentrant ventricular arrhythmia. This test should be used in combination with other historical or laboratory predictors of arrhythmic events such as history of myocardial infarction or abnormal ventricular function assessed by echocardiography. In this setting, the signal-averaged ECG helps to identify patients at increased risk for ventricular tachycardia as the cause of syncope who thus may benefit from electrophysiologic testing.

Carotid Sinus↗
PubMed1997

Pacing mode and long-term survival in elderly patients with congestive heart failure: 1980-1985.

Dual-chamber pacing may improve short-term hemodynamics and functional class in some patients with congestive heart failure, even in the absence of conventional indications for pacemaker implantation. However, the impact of different pacing modes on survival of patients with congestive heart failure is controversial. In this retrospective study we analyzed survival data from 546 elderly patients, aged 70 years and older, who underwent implantation of a permanent dual-chamber (DDD, n = 62, DVI, n = 102) or single-chamber (VVI) pacemaker (n = 382) between 1980 and 1985. Survival was further analyzed according to the presence of absence of congestive heart failure, and pacemaker mode (DDD vs. DVI vs. VVI). Overall, dual-chamber pacing (DDD and DVI) was associated with a more favorable long-term outcome when compared with single-chamber ventricular pacing, although differences were only significant for DDD pacing (P = 0.002). When patients with and without preexisting congestive heart failure were analyzed separately, survival following dual-chamber pacing (DDD and DVI) was significantly better than survival following single-chamber pacing in patients without congestive heart failure (P = 0.03), but not in patients with preexisting heart failure (P = 0.139). When patients were analyzed according to the electrophysiological indication for pacemaker implantation, overall survival of patients with AV block (P = 0.0025) but not sinus node dysfunction (P = 0.346) was improved with dual-chamber pacing. This survival advantage in patients with AV block following dual-chamber pacing was lost in the presence of heart failure (P = 0.11). These findings suggest that dual-chamber pacing, in particular DDD pacing, improves the survival in elderly patients without preexisting congestive heart failure. In contrast to the short-term hemodynamic improvement observed in selected patients with congestive heart failure, dual-chamber pacing in elderly patients with congestive heart failure, paced for conventional indications, is not associated with improved survival when compared with single-chamber ventricular pacing.

Aged↗
PubMed1997

Effects of slow pathway ablation on fast pathway function in patients with atrioventricular nodal reentrant tachycardia.

INTRODUCTION: This study investigated whether fast pathway conduction properties are altered by slow pathway ablation in patients with AV nodal reentrant tachycardia. METHODS AND RESULTS: Forty consecutive patients who underwent successful ablation of the slow pathway were prospective subjects for the study. Isoproterenol was used to enhance conduction and to differentiate interactive mechanisms. Potential electrotonic interactions were assessed by comparing patients with and those without residual dual AV node physiology after slow pathway ablation. Paired and unpaired t-tests were used when appropriate P < 0.05 was considered statistically significant. In the entire study population, heart rates were not significantly different before and after slow pathway ablation (RR = 770 +/- 114 msec before and 745 +/- 99 msec after, P = 0.07). Anterograde fast pathway conduction properties were unchanged after slow pathway ablation (effective refractory period, 348 +/- 84 msec before and 336 +/- 86 msec after, P = 0.13; shortest 1:1 conduction, 410 +/- 93 msec before and 400 +/- 82 msec after, P = 0.39). Retrograde fast pathway characteristics also were similar before and after ablation. Neither anterograde nor retrograde fast pathway conduction properties during isoproterenol infusion were changed by slow pathway ablation. When the study population was further divided into patients with (n = 13) or without (n = 27) residual dual AV node physiology, no significant change was detected in fast pathway function in either group after slow pathway ablation. CONCLUSIONS: Fast pathway conduction characteristics were not affected by slow pathway ablation. In patients with AV nodal reentrant tachycardia, observations suggest that fast and slow pathways are functionally distinct.

Adolescent↗
PubMed1997

Effect of infarct-related artery patency and late potentials on late mortality after acute myocardial infarction.

OBJECTIVE: To assess the effect of patency of the infarct-related artery and the presence of late potentials on late cardiac mortality after myocardial infarction. MATERIAL AND METHODS: We studied the influence of the infarct-related artery patency and the presence of late potentials during signal-averaged electrocardiography on late mortality in 124 survivors of acute myocardial infarction. In addition, we assessed predictive factors of cardiac mortality by univariate and multivariate statistical analysis. RESULTS: A study group of 98 men and 26 women (mean age, 59 years) who were survivors of acute myocardial infarction underwent follow-up for a mean of 3.6 +/- 1.0 years. Immediate reperfusion therapy (thrombolysis or direct angioplasty) was accomplished in 71 patients (57%). During follow-up, 13 cardiac-associated deaths occurred. Infarct-related artery patency was strongly associated with improved survival, but the presence of late potentials did not correlate with increased mortality, even among patients with impaired left ventricular function. Univariate and multivariate analyses identified occluded infarct-related arteries, prior myocardial infarction, reduced left ventricular ejection fraction, and advanced age, but not late potentials, as predictors of increased late cardiac mortality. CONCLUSION: These data suggest that coronary angiography may, but signal-averaged electrocardiography may not, identify patients with increased late risk of cardiac-related death after myocardial infarction. The low mortality among patients who have undergone successful reperfusion therapy may reduce the ability of noninvasive tests to distinguish between high- and low-risk patients.

Analysis of Variance↗
PubMed1996

Survival and functional independence after implantation of a permanent pacemaker in octogenarians and nonagenarians. A population-based study.

BACKGROUND: The number of very elderly persons who are candidates for implantation of a permanent pacemaker is increasing, but the effect of cardiac pacing on long-term survival and functional variables has not been determined. OBJECTIVE: To determine long-term survival after implantation of a permanent pacemaker in octogenarians and nonagenarians and to assess functional independence after such implantation. DESIGN: Retrospective, population-based cohort study. SETTING: Epidemiologic setting from an unselected population. PATIENTS: 157 octogenarians and nonagenarians who initially received a pacemaker between 1962 and 1988 and were followed through 1992. MAIN OUTCOME MEASURES: Overall mortality rate, functional capabilities, and placement in a nursing home. RESULTS: Observed survival in patients with heart disease was significantly worse than that in age-and sex-matched controls (P < 0.001). Observed survival in community residents without heart disease was similar to that in controls (P > 0.2). Multivariable analysis identified congestive heart failure, chronic obstructive pulmonary disease, old age, syncope, cancer, and atrioventricular block as independent predictors of increased mortality. Symptoms decreased in 118 patients (75%) after pacemaker implantation. After implantation, 70 patients (45%) were permanently placed in nursing homes; this number is similar to the estimated probability of lifetime use of nursing homes from the National Mortality Followback Survey. Dementia developed or worsened in 51 patients (32%), and orthopedic disability occurred in 41 patients (26%). CONCLUSIONS: Normal relative survival in octogenarians and nonagenarians without heart disease is reassuring; the poor prognosis in patients with heart disease warrants careful evaluation of the methods and indications for cardiac pacing. Permanent pacing alleviates bradycardia-related symptoms. Placement in a nursing home and development or worsening of cardiac, neurologic, or orthopedic disabilities frequently occur after implantation of a permanent pacemaker in the very elderly.

Activities of Daily Living↗