Rate Responsive Pacemaker Research Articles

Safety and efficacy profile of an indigenous developed CHARAK DDDR 747R dual-chamber rate-responsive pacemaker

Aim: The purpose of this study was to assess the safety and performance of the domestically manufactured Charak DDDR 747R (Pacetronix Ltd, Indore, India) pacemaker device. Materials and Methods: This was a prospective, controlled, single-center study conducted between March 2016 and August 2017. Eligible patients were implanted with a Charak DDDR 747R pacemaker with parameters set as specified on the packaging material unless otherwise advised by the physician. Patients were evaluated before discharge and at the 18-month follow-up. Data such as patient age, gender, and medical history were collected to determine patient eligibility for study participation, monitoring of study progress, and data analysis. Results: A total of 35 patients were analyzed. Males comprised 45.7% and females comprised 54.3% of patients. The average pacing threshold was threshold (atrium) was 1.05 V and the average pacing threshold (ventricle) was 1.07 V. The average impedance (atrium) was 641.09 Ω and the average impedance (ventricle) was 719.31 Ω. No serious adverse events were documented during the follow-up. One death occurred; however, this was not device-related. Conclusions: As per study findings, the Charak DDDR 747R, an indigenous pacemaker, is safe and effective in the Indian population. Durable lead parameters were obtained during the study which remained stable over time referring the same. Future larger studies are needed to confirm the preliminary data obtained from our study.

Heart rate distribution in dogs with third degree atrioventricular block and rate responsive pacemakers

IntroductionIn dogs, single lead ventricular pacing, ventricular sensing, inhibition response, rate adaptive (VVIR) pacemakers are routinely used to treat third degree atrioventricular block. The objectives of this study were to investigate the heart rate distribution in dogs with VVIR pacemakers, and report changes when activity settings were adjusted. AnimalsEighteen client-owned dogs with VVIR pacemakers for third degree atrioventricular block. Materials and methodsThis observational study consisted of a review of medical records of dogs with VVIR pacemakers. For dogs with >50% of paced beats at the lower pacing rate, the activity daily living (ADL) and exertion responses were increased. Re-evaluations were performed after 6–12 months. ResultsHeart rate distribution similar to healthy dogs was absent for all dogs. In nine dogs, the ADL and exertion responses were increased to the highest level. Of these, three dogs showed no improvement in heart rate distribution; for two dogs, one with an epicardial pacemaker, several activity settings were adjusted and pacing at higher heart rates was observed at re-evaluation. Four dogs died or were lost to follow-up. Clinical signs had resolved for all dogs after pacemaker implantation. ConclusionDefault activity settings of VVIR pacemakers do not result in heart rate distribution equivalent to healthy dogs. Increasing the ADL and exertion response settings to the highest levels did not improve the pacemaker rate response. Further investigations into the role of dog size, generator positioning, pacemaker settings, and whether rate responsiveness is required for dogs' quality and quantity of life are warranted.

Application of an accelerometer in adjusting parameters and detecting characteristics in the pacemaker rate response

Objective. To study the application of an accelerometer in adjusting the parameters, setting the sensor indicated rate (SIR) and detecting characteristics in the pacemaker (PM) rate response. Approach. Three-axis (GT9X Link-type) accelerometers were positioned on the waist and chest in 33 participants implanted with rate responsive PMs while wearing an ambulatory ECG recorder (Holter). During the walking test, by collecting vertical axis (Axis-1) activity intensity counts, Axis-1’ metabolic equivalent of energy (METaxis-1) and its expected heart rate (HRmet-axis1) were calculated by the relevant equations, and on the basis of the HRmet-axis1 as the target heart rate, the SIR was set by programming the rate response slope parameter. During the following daily walking activity, the physical activity parameters and Holter ECG was recorded continuously. After the end of the whole test the analysis on these data recorded was performed retrospectively. Main results. After completing the SIR setting, in 24 participants with complete ventricular pacing the comparison between HRmet-axis1 (92.5 ± 7.8 BPM) and the HRvp-Holter (94.0 ± 10.5 BPM) showed no statistical difference (ΔHR: 1.25 ± 6.69 BPM, P: 0.568) during the last one walking test, and there was also no significant difference (ΔHR: 2.8 ± 7.1 BPM, P: 0.398) between the HRmet-axis1 (90.7 ± 7.1 BPM) and HRvp-Holter (93.4 ± 10.3 BPM) during daily walking activity. In addition, in the data of 108 time intervals selected during the daily walking activities in the abovementioned 24 participants, METaxis-1 and HRvp-Holter correlation analysis showed good correlation and the regression equation was HR = 12.4 × MET43.1 (). Significance. An accelerometer can play an important role in adjusting parameters, setting the SIR and detecting characteristics in the PM rate response.

An approach towards individualized lower rate settings for pacemakers.

Author(s): Infeld, Margaret; Avram, Robert; Wahlberg, Kramer; Silverman, Daniel N; Habel, Nicole; Lustgarten, Daniel L; Pletcher, Mark J; Olgin, Jeffrey E; Marcus, Gregory M; Meyer, Markus

Low delay rate adaptive pacemaker using FPGA embedded piezoelectric sensor

This paper presents the hardware implementation of low delay, power-efficient, rate-adaptive dual-chamber pacemaker (RDPM) using a piezoelectric sensor. Rate adaptive pacemaker has the ability to sense the patient’s activity by means of some special sensors and it controls the pacing rate according to the patient’s activity. Ideally, there should be no delay between sensing and the subsequent pacing operation performed by the pacemaker. However, delay in the responses of various components in the circuitry produces an accumulative delay effect in any practical circuit. Physical activity and the physiological needs of the patient can be easily adapted by the rate-responsive pacemakers using a wide range of sensor information. The piezo-electric sensor recognises the pressure on human muscles because of physical activity and converts it to an electrical signal, which is received by the pulse generator of the pacemaker. When the patient is in the rest mode, the heart rate is the only parameter that is to be detected by the pacemaker. Thus, the heart rate and the physical activity both are the inevitable parameters for the design of RDPM. Performance analysis of the proposed RDPM shows a significant reduction in the delay between sensing and pacing. Device utility analysis shows that the proposed design not only requires lesser memory but also reduces the number of components on the chip. Therefore, it becomes very clear that the proposed pacemaker design will consume much lesser power.

Physiological pacing in young patients with complex congenital heart defects.

Young patients with operated complex congenital heart defects (CHD) often develop sinus node dysfunction (SND) requiring permanent pacing with rate-responsive function. Activity-driven sensors cannot account for nonmovement stress and cannot modulate heart rate physiologically. Closed Loop Stimulation (CLS, Biotronik, Berlin, Germany) is a physiological rate-responsive pacemaker based on the indirect measure of ventricular contractility. No data are available on the effects of such pacing strategy in young patients. We report a series of nine patients with CHD and SND who underwent single-chamber CLS-atrial pacing with endocardial or epicardial lead. During the first 30 days, the pacemaker was programmed in AAI pacing mode and then was switched to CLS-atrial pacing mode. An in-hospital control was scheduled 1-2 months later to evaluate the CLS response to neurovegetative stresses (i.e., nonmovement stress [Stroop color test, handgrip] and exercise stress test) and Holter monitor. CLS pacing was compared with rate-responsive accelerometer-driven pacing (AAIR). At telemetric interrogation, CLS pacing showed a more physiological pattern of 24-h heart rate trends than accelerometer sensors. The data obtained during nonmovement/exercise stress demonstrated a physiological increase in the pacing rate with CLS, in synergy with spontaneous events. The accelerometer sensor histogram, during nonmovement stress, showed a "nonresponse" behavior (only lower rate events), and during exercise test showed most events in lower rate range. Holter monitoring showed increase of average and maximum heart rate compared with AAIR. In young CHD patients, endocardial/epicardial CLS-atrial pacing demonstrated a physiological response of heart rate to neurovegetative and physical stresses.

Fail Secure Dual Chamber Cardiac Pacemaker Mechanism with Rate Approachable Control and Cryptographic Safety

The aim of the project is to design a failure safe rate responsive cardiac pacemaker device that could be monitored and configured by a doctor using a secured wireless communication. The contraption firmware relies on upon a hard, consistent RTOS (Real-Time Operating System) piece and hereafter the device helpfulness is guaranteed and is expected to restrict dissatisfactions given programming breakdowns. A made cardiovascular pacemaker is a restorative device that usages electrical inspirations passed on by cathodes getting the heart muscles, to control the throbbing of the heart. The fundamental part of a pacemaker is to keep up a tasteful heart rate, either in light of the fact that the heart's normal pacemaker is not adequately fast, or there is a piece in the heart's electrical conduction structure. Exhibit day pacemakers are remotely programmable and empower the cardiologist to pick the perfect pacing modes for individual patients. Some of them have different anodes strengthening fluctuating positions inside the heart to improve synchronization of the lower chambers (ventricles) of the heart.

A telemonitoring platform for the investigation of blood pressure profiles in pacemaker patients.

Rate responsive pacemakers (PM) use different strategies to adapt the patient paced rate, with the aim of having the best hemodynamic performance in response to internal or external conditions. Closed-loop stimulation (CLS) uses intracardiac impedance as a sensor principle. The evaluation of impact of different pacing modalities and technologies on the blood pressure (BP) profiles is mainly investigated in short-term laboratory settings, mainly due to the need of reliable daily-based BP values. The impact of CLS pacing on systemic blood pressure (BP) has been studied on short term basis, but data on long term effects are scarse. This study present a telemedicine platform designed for evaluating the effect of the rate responsive technology on daily systolic and diastolic BP data. BP and pacemaker data were collected daily from fourteen patients during a 3 month period. The total number of monitoring days was 1277 (91 day/patient), for a total number of 4455 BP measures. On average 3.5 measure/day/patient were received). The analysis of the BP data showed that CLS pacing results in diastolic pressure closer to the normal values than accelerometer-based pacing, which were associated to lower diastolic pressures.

Simulation of Intraoperative Pacemaker Failure

Simulation of Intraoperative Pacemaker Failure

身体活動を感知しpacingrateを制御するペスメーカー(Activitrax)植込み経験

身体活動を感知しpacingrateを制御するペスメーカー(Activitrax)植込み経験

Muscle Noise Effects on Atrial Evoked Response Sensing: Implications on Atrial Auto-Threshold and Auto-Capture Determination

Automatic pacing capture verification algorithms that are based on detection of local evoked response signals are susceptible to interference from myopotential noise. This is especially true in the atrium where the lower signal amplitude and signal-to-noise ratio make pacing capture verification more challenging. The aim of this study is to evaluate the impact of myopotential noise induced by various maneuvers on the atrial evoked response (AER) signal. Data were collected from 18 patients (7 M/11 F, 77.6 ± 8.8 years), implanted with a dual chamber rate response (DDDR) pacemaker and acute and chronic right atrial leads and right ventricular leads, at three regular follow-up visits scheduled at 1, 3, and 6 months after pacemaker implantation or replacement procedures. During each study visit, manual atrial pacing threshold tests during unipolar pacing in the DDD mode were conducted with two evoked response sensing configurations (RA(Ring) → Ind and RA(Ring) → V(Tip) ) while patients performed six different maneuvers. Noise estimates were calculated for each maneuver. The greatest noise estimates in both sensing configurations were measured during the hand-pressing exercise (0.649 ± 0.342 mV in the RA(Ring) → Ind vector, 0.309 ± 0.223 mV in the RA(Ring) → V(Tip) vector). No significant differences in overall noise estimates were observed between the follow-up visits. Of the beats that exhibited noise estimates greater than a sensing floor of 0.3 mV, up to 22% of cardiac beats had a signal-to-noise ratio less than 2 in the RA(Ring) → Ind configuration. Results indicate that myopotential noise generated by performing maneuvers has a demonstrable impact on AER sensing. Therefore, noise mitigation processes are necessary in atrial automatic pacing capture verification algorithms based on evoked response signals to identify and appropriately manage noise.

Carotid sinus syndrome, should we pace? A multicentre, randomised control trial (Safepace 2)

BackgroundCardioinhibitory carotid sinus hypersensitivity (CICSH) is highly prevalent among older people with falls.ObjectiveTo assess the efficacy of dual-chamber pacing in older patients with CICSH and unexplained falls.DesignA multicentre, double blind,...

Device management of arrhythmias after Fontan conversion

We assessed our pacemaker strategy, use of antitachycardia therapies, generator longevity, and need for programming changes in patients having Fontan conversion with arrhythmia surgery. Between 1994 and 2008, of 121 consecutive patients having Fontan conversion and arrhythmia surgeries, 120 patients underwent pacemaker implantation at the time of Fontan conversion (mean age 22.9 +/- 8.1 years). Prior pacemakers were in place in 32/120 (26.7%) patients. Between 1994 and 1998, single-chamber atrial antitachycardia pacemakers were implanted (n = 12); atrial rate-responsive pacemakers (n = 31) were implanted between 1998 and 2002. Dual-chamber rate-responsive pacemakers (n = 16) were used between 2002 and 2003, and subsequently dual-chamber antitachycardia pacemakers (n = 61) have become the pacemaker of choice. Leads have evolved from transatrial endocardial leads to epicardial unipolar and subsequently bipolar leads. Among 87 patients with adequate follow-up, all are currently atrially paced at a minimum lower rate > or =70 beats per minute. Single-chamber atrial pacemakers were implanted in 43 (antitachycardia in 12), and dual-chamber pacemakers in 77 (antitachycardia in 61); multisite ventricular leads were placed in 7 patients. Far-field R-wave sensing in 78.6% of unipolar atrial leads led to use of epicardial bipolar leads. Late atrioventricular block (24%) led to routine implantation of dual-chamber pacemakers. Antitachycardia pacing was utilized in 7%. One patient required acute lead revision and 4 required late upgrade to dual-chamber pacemakers. There was no pacemaker-related infection. Twenty patients required generator change, and the mean device longevity was 7.53 years. Customized pacemaker therapy can optimize management of patients following Fontan conversion. Device longevity is excellent. Based on our experience with 120 Fontan conversions, we recommend placement of a dual-chamber antitachycardia pacemaker with bipolar steroid-eluting epicardial leads in all patients at the time of the conversion.

Usefulness of rate regulation through continuous ventricular pacing in patients with drug-controlled slower atrial fibrillation and normal or depressed left ventricular systolic function

We studied 33 clinically stable patients with permanent atrial fibrillation (AF), implanted with a ventricular demand rate-responsive (VVIR) pacemaker or an automatic defibrillator, in order to evaluate whether continuous right ventricular apex pacing (VP) conferring rate regulation may be advantageous when compared with slower drug-controlled AF. Devices were chronically programmed at ventricular backup pacing. Patients were divided in two groups according to their normal (n = 17) or depressed (n = 16) left ventricular systolic function (LVSF). Ventricular function was studied by using tissue Doppler and color M-mode and echocardiography, as well as B-type natriuretic peptide (BNP) measurements. Baseline data during AF were compared to corresponding measurements following a 1-month pacing period after the devices were programmed at a base rate of 70 beats/min. In both groups, VP worsened some indexes of left and right ventricular function (P < 0.05) without significantly affecting cardiac output, left ventricular filling pressures and BNP (P = not significant). We conclude that VP should not be considered advantageous compared to slower AF.

Six-Minute Walk Test in Patients With Permanent Cardiac Pacemakers

The 6-minute walk test (6MWT) is a simple and reliable method routinely used in the evaluation of many conditions including cardiac diseases. However, it is rarely performed in patients with pacemakers (PMs), and the applicability and safety in this group is not established. The purpose of this study was to verify the applicability and safety of the 6MWT in the evaluation of functional capacity of patients with PMs, considering the ergometry test (ET) as the criterion standard. Twenty-four patients with rate-responsive PMs underwent a treadmill ET, using the Chronotropic Assessment Exercise Protocol, and a 6MWT, performed twice with a rest interval of 20 minutes. Functional capacity, heart rate, and blood pressure in each test were recorded. The distance covered during the 6MWT significantly correlated with the oxygen uptake estimated from the treadmill ET (r = 0.709, P < .001). Peak heart rates and systolic blood pressure levels reached during the 2 tests were also significantly correlated. No adverse events or malignant arrhythmias were observed during the 6MWT. The distance walked during the 6MWT accurately predicted the patient performance on the ET (area under the receiver operating characteristic curve = 0.921). The ability to walk more than 538 m in the 6MWT predicted, with a sensitivity of 90% and a specificity of 79%, an estimated oxygen uptake above 10 metabolic equivalents (METs) on the ET. The 6MWT can be considered safe to assess the submaximal functional capacity and can be used as an alternative test to evaluate the results of interventions in patients with permanent cardiac PMs.

The Bix rule

The patient was a 64-year-old man with a history of myocardial infarction and subsequent episodes of atrial fibrillation and sinus bradycardia. A permanent ventricular inhibited rate responsive pacemaker was inserted 6 months before the outpatient visit, during which the electrocardiogram (ECG) shown in Figure 1 was recorded. He had been taking sotalol 160 mg twice per day for maintenance of sinus rhythm. The patient was asymptomatic apart from somewhat reduced exercise tolerance. His pacemaker was functioning as originally programmed. No changes were made, and he was sent home with instructions for routine follow-up. The cardiogram was originally thought to show sinus rhythm 67 beats/min with marked (0.44 sec) first-degree arteriovenous block and an appropriate paced escape beat at the end of the recording; deep symmetric T-wave inversion in multiple leads re

Perioperative outcome of pacemaker patients undergoing non-cardiac surgery

Perioperative outcome of pacemaker patients undergoing non-cardiac surgery

Rebuttal from Dr. Andreassen

Rebuttal from Dr. Andreassen

Cardiac denervation does/does not play a major role in exercise limitation after heart transplantation

Cardiac denervation does/does not play a major role in exercise limitation after heart transplantation

Rate Responsive Pacemakers: A Rapid Assessment Protocol

Rate responsive (RR) pacemakers are commonly implanted with nominal conservative factory-set responsiveness, which is usually accepted because established exercise protocols are time-consuming. We aimed for efficient assessment of RR pacemaker settings. We tested exercise heart rates in controls and paced patients using a brief exercise test that approximates real-life levels of exertion. The test used a nonmotorized treadmill: 30 seconds walking at patient-determined speed followed by 15 seconds brisk exertion. Subjects totaled 110: 26 with RR pacemakers; 22 with non-RR pacers; 27 "sick" nonpaced control patients; and 35 healthy controls. Heart rate (HR) was measured prior to exercise, after 30 seconds of casual walk, after 15 seconds of brisk walk, and 1 minute into recovery. Testing required <5 minutes from set-up to recovery. The 26 RR pacer patients had a mean HR at rest = 74 +/- 10 beats per minute (bpm), walk = 87 +/- 14, and brisk = 94 +/- 18 (increase 27%). Non-RR pacer patients (n = 22): rest = 73 +/- 12 bpm, walk = 88 +/- 14, and brisk = 94 +/- 17 (increase 24.3%, P = 0.60 vs RR patients). "Sick" controls (n = 27): rest = 78 +/- 14 bpm, walk = 102 +/- 17, and brisk = 117 +/- 18 (increase 51.9%, P< 0.001 vs RR pts). For the healthy controls, HRs were at rest 83+/11 bpm, walk = 104 +/- 12, and brisk = 117 +/- 13 (P< 0.001 compared to both paced groups; P = NS vs sick controls). Nominal RR settings may be suboptimal for many patients. The nonmotorized treadmill test allows quick and inexpensive assessment of RR programming, with the potential for efficient RR optimization.