Single Versus Double Chamber Rate Responsive Cardiac Pacing: Comparison by Cardiopulmonary Noninvasive Exercise Testing (original) (raw)
Related papers
Circulation, 1987
In this study, sequential cardiopulmonary exercise testing was used to assess the physiologic benefits of a single-chamber ventricular pacing system that utilizes a piezoceramic sensor to adjust heart rate by detecting "physical activity." An initial exercise test was conducted with the pacemaker programmed (based on a randomization table) to either the fixed rate (VVI, 70 beats/min) or rate-variable (VVI-Act) mode, and the results were compared with those obtained during a second exercise test in which the pacemaker was programmed to the alternate pacing mode. A 1.5 to 2 hr rest period was permitted between exercise tests, each of which consisted of a symptom-limited constant speed (3.0 mph) Balke protocol with 2 min stages commencing at 0.0% grade with increments of 2.5% at end of each stage. Compared with findings during fixed-rate VVI pacing, VVI-Act pacing was associated with (1) greater exercise-induced positive chronotropic response (mean maximum heart rate VVI-Act 128 ± 15.3 beats/min vs VVI 90 ± 28.4 beats/min; p < .01), (2) prolongation of exercise duration (VVI-Act 10.2 + 3.8 min vs VVI 7.7 2.5 min; p < .01), (3) increased peak oxygen consumption (VVI-Act 1617 656 ml 02/min vs VVI 1325 ± 451 ml 02/min; p < .01), and (4) onset of anaerobic threshold at a higher oxygen consumption (VVI-Act 1208 ± 343 ml 02/min vs VVI 1064 + 377 ml 02/min: p < .01). Additionally, of 44 comparable exercise stages tested in the two pacing modes, perceived exertion (assessed by a numerical grading system) was lower in 38 of 44 instances during VVI-Act compared with VVI pacing. Thus provision of chronotropic response during exercise by single chamber rate-variable ventricular pacing substantially improved exercise tolerance and therefore may be of benefit for patients with bradycardia-related symptoms in whom associated sinoatrial disease or difficulty establishing or maintaining atrial sensing preclude optimum function of conventional atrial-tracking pacing systems.
Pacing and Clinical Electrophysiology, 1990
MCMEEKIN, |,D., KT AL.: Importance of Heart Rate Response During Exercise in Patients Using Atrioventricuiar Synchronous and Ventricular Pacemakers. Atrioventricuiar synchronous pacing o^ers advanfages over fixed-rate ventricular fWI) pacing both at rest and during exercise. This study compared the hemodynamic effects at rest and exercise of ventricuiar pacing at a rate of 70 beats/min, ventricuiar pacing where the rate was increased during exercise and duaJ chamber pacing. Ten patients, age 63 ± 8 years, with muifiprogrammable DDD pacemakers were studied using supine bicycle radionuclide ventriculography. Radionuclide data during dual chamber pacing was acquired at rest and during a subniaximai ivorkioad of 200-400 kpm/min. The pacemakers were then programmed to WI pacing at a rate of 70 beats/min, and 1 week later, studies were repeated in the WJ mode at rest, during exercise at a rate of 70 beats/min, and during exercise with the WI pacemaker programmed to a rate adapted to the DDD pocing exercise rate. At rest, the cardiac output was lower in the WI compared with the AV sequential mode (4.1 ± 1.1 vs 5.7 ± 1.1 l/min. P < 0.01}. During exercise, the cardiac output increased/rom resting values in the DDD and WI pacing modes, however cardiac output in the rate-adapted WI mode was higher than in the WI mode with the rate maintained at 70 beats/min (8.1 ± 1.5 vs 6.3 ± 1.1 l/min, P = 0.02}. Three patients completed lower workloads with WI pacing at 70 beats/min compared with AV synchronous pacing. At rest, AV sequential pacing was superior to WI pacing, suggesting the importance of the atrial contribution to ventricular jiJling. With WI pacing during exercise, cardiac output was improved with an increased pacemaker rate, suggesting (hat the heart rate response during exercise was the major determinant of the higher cardiac output. (PACE, Vol. 13. January 1990) dual chamber pacing, rate-adapted ventricular pacing, ventricular pacing, radionuclide ventriculography, exercise hemodynamics
Effect of ventricular function on the exercise hemodynamics of variable rate pacing
Journal of the American College of Cardiology, 1988
When implantable pacemakers were introduced in 1959, their primary function was to prolong life. As pacemakers became more sophisticated, improving the quality of life became an imp&ant goal as well. Studies (I-7) have cornlimted that the use of dual chamber pacing. which provides rate variability and alrioventricular (AV) synchrony. in. creases exercise time and work capacity and provides important benefits for selected patients. However, in patients who have sinus node disease with an inadequate increase in atrial rate during exercise or other times of metabolic need, dual chamber pacing provides AV synchrony ht not rate variability. In patients with chronic atrial fibrillation dual &amber pacing is less effective and may deliver an inapprcpriatc rate. In addition, the added costs and problems associated with dual chamber pacemakers have limited their use (8). t'wthermore. a variety of studies (9-l I) have shown that during exercise. an increase in heart rate is ttmre intxxtant than AV synchrony. ihex factors have led to the development of single chamber pacemakers with sensors that detect the need for heart rate changes by tracking variables other than atrial function (12-191. Clinical investigators (12-21) using these new devices have reported beneficial effects in selected patients. However, the exact characteristics of patients likely to benefit from these pacemakers have not been precisely defmcd. Patients who have chronotropic incompetcnce or at&l flbritlation with high degree AV block tindications foor a variable mtc pacemaker1 may be more likely to have underlying heart disease with coexisting left ventricular
Heart, 1995
Objective-To compare symptoms and exercise tolerance during dual chamber universal (DDD) and ventricular rate response (VVIR) pacing in elderly (> 75) patients. Design-Randomised, double blind, crossover study. Setting-Regional cardiac department. Patients-Twenty elderly patients (mean age 80 5 (1) years) with high grade atrioventricular block and sinus rhythm. Patients with pre-existing risk factors for the pacemaker syndrome and chronotropic incompetence were excluded. Intervention-After four weeks of WI pacing foliowing pacemaker implantation, patients underwent consecutive two week periods of VVIR and DDD pacing. Main outcome measures-Patient preference, symptom scores, "daily activity exercises," and perceived level of exercise (Borg score). Results-Eleven patients preferred DDD mode to either VVI or VVIR mode. Mean (SE) total symptom scores during VVI, VVIR, and DDD pacing were 5*9 (1.1), 6-1 (1.0), and 3 5 (0.9) respectively (P < 0.01). The corresponding mean (SE) pacemaker syndrome symptom scores were 4-8 (0.7), 5-2 (0 8), and 2-9 (0.8) (P < 0.05). Symptom scores during WI and VVIR pacing were not significantly different. Exercise performance and
Pacing and Clinical Electrophysiology, 1999
maker. The dromotropic pacemaker concept needs a rate responsive algorithm in which the pacing rate is controlled by the atrioventricular conduction time (AVCT). To develop basic concepts for such a rate responsive algorithm, the influence of the pacing rate on the AVCT was investigated. Seven patients (62 ± 7.8 years) with sick sinus syndrome and intact atrioventricular conduction underwent two cardiopulmonary exercise tests (CPX) on a treadmill. According to the determination of the anaerobic threshold (A T) and the patients maximum capacity in the first incremental CPX the work rate for two exercise levels below and above the AT were chosen for the second constant workload CPX. The calculation of the optimal pacing rate (HR^pt) was based on the oxygen uptake (VO2) during exercise after reaching steady-state conditions. According to the increase of the \lO2fr0m 14.8 ± 2.3 mL/min per kilogram during aerobic work (38.3 ± 16.0 W) to 19.4 ± 4.7 mL/min per kilogram during anaerobic work (80.6 ± 32.3 W), the HH^pt was calculated to be 98.6 ± 6.9 beats/min and 116.4 ±4.7 beats/min. Starting from HR^,,t, the pacing rate was increased (overpacing) and decreased (underpacing) by about 5 beats/min every minute. At optimal pacing rate the AVCT decreased significantly from 233.0 ± 30.5 ms during aerobic work and to 226.4 ± 27.3 ms during anaerobic work (P < 0.05). Whereas overpacing induced a significant prolongation of the AVCT during aerobic work (4.17 ± 1.78 ins per 10 beats/min) and anaerobic work (3.84 ± 1.60 ms per 10 beats/min), underpacing yielded a significant shortening of the AVCT by about 4.49 ± 2.64 ms per 10 beats/min during aerobic work and 4.75 ± 1.87 ms per 10 beats/min during anaerobic work (P < 0.01). The slopes of the regression lines of the relationship between A VCT and pacing rate were not significantly different. Based on the reciprocal relationship of heart rate (HR) and AVCT. basic concepts may be established for a dromotropic rate responsive algorithm. (PACE 1999; 22:1782-1791 atrioventricular conduction, rate responsive pacemaker, sick sinus syndrome
Pacing and Clinical Electrophysiology, 2000
IJIRI, H., fciT AL.: Improvement of Exercise Tolerance by Single Lead VDD Pacemaker; Evaluation Using Cardiopulmonary Exercise Test. We used a cardiopulmonary test to assess the physiological benefit of single lead VDD pacing in ten patients (six men, four women; aged 32-84 years, mean 69 years) with atrioventricular block. Maximal symptom-limited treadmill exercise test using a ramp protocol was performed under VDD and VVIH or VVI pacing (WI) in random sequence. The pacemaker was then programmed to the VDD mode, and Holter ECG was recorded in nine patients. Compared with findings during the VVI, the VDD mode had a greater chronotropic response (mean maximal heart rate. VDD 106 ± 17 beats/min vs VVI 79 ± 19 beats/min, P = 0.03), and was associated with prolongation of exercise duration (VDD 11.2 ± 2.9 minute vs VVI 10.5 ± 3.1 minute; P = O.Ol), and the onset of anaerobic threshold at a higher oxygen uptake (VDD 12.4 ± 3.4 mL/min per kilogram vs VVI 10.0 ±2.1 mUmin per kilogram; P < 0.01), Atrial sensing was recognized in almost all normal sinus P waves for all cases examined using Holter ECC. Thus, chronotropic response during exercise by VDD pacemaker improved exercise tolerance, indicating that a VDD pacemaker might be useful for patients requiring physical activity.
Clinical Experience with Dual-Chamber Rate Responsive Pacemakers
Journal of Electrophysiology, 1989
The development of dual-chamber rate responsive pacing is the logical consequence of technical and clinical developments and research in pacemaker technology. The first rate responsive dual-chamber pacemaker was implanted in June 1986 and the successful performance of this device encouraged manufacturers to further develop this technology. The rhythmic corrections that could be achieved were a strong argument to make use of this new technology in patients suffering from combined sinus node and AV nodal disease. DDD rate responsive pacemakers, therefore, have been implanted in 16 patients with a mean follow-up of 10.4 months. No technical complications were encountered, 2 patients died from causes not related to an arrhythmic problem. Of the 14 remaining patients, 12 are still in a dual-chamber rate responsive mode, 2 are in DDD or DDI-mode because of chronotropic competence of the sinus node. Therefore, we, conclude that dual-chamber rate responsive pacing is a reliable mode for long-term physiological pacing. Different features that can be included in a DDDR pacemaker may widen its use so that 85% of pacemaker indications might be covered
Physiological Sensitivity of Respiratory-Dependent Cardiac Pacing: Four-Year Follow-Up
Pacing and Clinical Electrophysiology, 1988
Clinical and physiological data on long-term follow-up of 143 patients with respiratory-dependent pacemakers (RDP3} are reported; 121. patients received ventricular (WI-RD) and 22 patients atrial {AAI-HD} respiratory-dependent stimulation. Functional evaluation was based on the exercise testing (130 pts) with oxygen uptake VO2, ventilation, ECG and arterial pressure monitoring and the dynamic Hoiter electrocardiogram (95 pts}. In each patient, the stimulation rate curve selected was that which produced the best work tolerance and moved the anaerobic threshold to (he right. Respiratory levels were assessed by telemetry verifying proper sensing 0/tidal volume variations and absence 0/interference and artefacts. In patients with WIR or AAIfi stimulation, exercise tolerance, oxygen uptake and anaerobic threshold increased signijicantly in comparison with WI or AAl pacing respectively. The physiological sensitivity of the stimulation system (i.e., a linear relationship of the pacing rate with metabolic requirements] was excellent (up to exhaustion] in 70%, very good (up to anaerobic threshold] in 20% and erratic (no relationship between pacing rate and VE/VO2] in 10% of patients. In dynamic electrocardiographic monitoring, the automatic pacing rate was always predominant during the night and during rest periods; the pacing rate increased properly with daily activity; myopotentiai inhibition (none longer than 3,500 ms} was observed in 38 patients, but without subjective complaints. The incidence of the HDP3 malfunction was less than 8%; it may have stemmed from the pacing system itself, or from other clinical conditions. Oversensing of impedance system pulses has not been recorded in the last 3 years. Partial respiration undersensing results from incorrect accessory lead position, pulmonary emphysema, marked obesity or other causes. Respiratory sensing becomes erratic at the anaerobic threshold point in such patients, but functions well at submaximum exercise levels. In patients with left ventricular failure, exercise tolerance was improved by setting a lower ratio between the pacing rate and respiration, which prevented the occurrence of excessive pacing rates.
Congestive Heart Failure, 2008
I n responders to cardiac resynchronization therapy (CRT), cardiorespiratory function improves after implantation of a biventricular (BiV) pacemaker. A 7% to 18% improvement in peak oxygen consumption following BiV pacemaker implantation has been reported by previous studies. This effect is composed of an acute improvement in left ventricular (LV) and right ventricular (RV) synchronicity and a delayed improvement through a positive remodeling process (ie, a decrease in LV end-systolic and end-diastolic diameters and volumes). On the other hand, pacing of the RV apex by conventional pacemakers has been shown to result in LV asynchrony, heart failure, increased incidence of hospitalizations, and death. 5-11 Smaller studies show that upgrading patients with a conventional (dual-chamber rate-responsive [DDDR]) pacemaker to a BiV device yields an improvement in functional New York Heart Association (NYHA) class, symptoms, echocardiographic parameters, and walking distance in the 6-minute walking test. Currently, prospective randomized studies assessing the benefit of BiV pacing in patients who require RV pacing due to high-degree atrioventricular (AV) block are being carried out. 16,17 It is not known, however, to what degree short-term RV pacing impairs cardiorespiratory function in patients with a BiV pacemaker. The goal of this study was to assess the acute effect of short-term RV pacing on exercise capacity determined by symptom-limited spiroergometry.
Intrinsic Heart Rate Response as a Predictor of Rate-Adaptive Pacing Benefit
CHEST Journal, 1995
Objective: More than half of the pacemaker systems now being implanted can be rate adaptively paced. Our objective was to determine which patients benefit from rate-adaptive pacing in terms of improvement in maximum performance and aerobic capacity. Methods: Thirty patients with implanted accelerometer-driven, rate-adaptive pacemakers underwent a standardized, ergospirometrically and maximally symptoms=limited cardiopulmonary exercise (CPX) stress test with both rate-adaptive and fixed-rate stimulation in a randomized order. The patients were divided into three groups depending on the intrinsic heart rate achieved during maximum workload: group 1 achieved 'Z90 beats per minute (bpm), group 2 achieved 90 to-'110 bpm, and group 3 achieved >110 bpm. Results: Group 1 demonstrated a significant increase (p'.0.01) in maximum oxygen uptake from 16.4±5.6 mL/kg/min with fixed-rate pacing to 23.2±11.1 mL/ kg/min (+41.5%) with rate-adaptive pacing. At the anaerobic threshold, oxygen uptake significantly increased (p'0.01) from 11.8 ± 2.7 mL/kg/min to 15.7 ± 5 mL/kg/min (+33.1%). Group 2 patients showed an increase in maximum oxygen uptake from 23.3 ± 5.4 mL/ kg/min to 25.3±4.9 mL/kg/min (+8.5%., p.0.05) as well as an increase in oxygen uptake at the anaerobic A human's maximum performance and aerobic capacity are strongly dependent on the cardiovascular system, respiration, and muscular fitness. With physical exercise, an increase in the individual's oxygen uptake effects an increase in stroke volume and heart rate (HR) and thus an increase in cardiac output. Analysis of respiratory gas exchange facilitates determination of maximum performance and aerobic capacity in both healthy patients and in those with cardiac disease.' Oxygen uptake (Vo2) demonstrates a mostly linear relationship to performance and heart rate.2'3 The individual correlation is influenced by the patient's physical fitness; the relationship between HR and Vo2 varies from 2 to 6 beats per minute (bpm) per milliliter per kilogram per minute.3 This correlation is vital in pacemaker therapy, since chronotropic incompetence is common to many patients with pacemakers and limits their physical