Preliminary Experience with the pH‐triggered Pacemaker

Cammilli, L; Alcidi, L; Papeschi, G.; Wiechmann, Volker; Padeletti, Luigi

doi:10.1111/j.1540-8159.1978.tb03506.x

Cited by 33 publications

(5 citation statements)

References 2 publications

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“…PACE, Vol. 10 January-February 1987, Part I (2) 101 ±17 (6) 86 ± 8 (2) 87 ± 17 (4) 80 ±23 (2) 88 ± 7 (4) 92 ± 3 (2) 88 ±10 (4) We did not attempt to see if dynamic-rate VVI pacing would increase exercise tolerance or cardiac output. In a recent study, Humen et al l l demonstrated that an increased exercise tolerance and improved cardiac output occurred while in VVI + "activity" mode pacing compared to fixedrate VVI pacing, in patients with implanted Activitrax pulse generators.…”

Section: Discussionmentioning

confidence: 99%

Chronotropic Response of an Activity Detecting Pacemaker Compared with the Normal Sinus Node

Moura

Gessman

Lai

et al. 1987

Pacing Clinical Electrophis

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We compared the rate responsiveness of an activity-detecting multiprogrammable, single chamber pacemaker (Medtronic Activitrax) to rate responsiveness of the normal sinus node. This pacemaker changes its basic pacing rate in response to physical activity. The rate responsiveness is programmable by selecting one of three activity thresholds, and one of 10 rate response settings. The study included a group of six normal volunteers and 12 patients implanted with Activitrax to examine the similarity of the pacemaker rate to normal sinus rhythm during acceleration and deceleration. The pacemaker was set to Activity mode, at a basic rate of 60 bpm. In volunteers, the device was externally secured on the chest wall and tested at two programmed settings. When programmed at a high threshold of activity and high rate response in volunteers, there was no significant difference in maximum normal sinus rates and pacemaker rates during arm waving, jumping in place, and walking during stress testing. At a medium activity threshold, the only significant difference occurred during submaximal stress testing, when the maximum sinus rate achieved was 141 +/- 19 bpm and the maximum pacing rate was 105 +/- 8 bpm (p less than .02). The pacemaker behaved in a similar manner in patients, successfully simulating the typical fast acceleration and slow deceleration of a normal sinus node in exercise testing. There was no difference in pacer response when implanted in abdominal or infraclavicular locations. The implanted units have functioned normally over a follow-up period of nine to 22 months. Activitrax can be programmed to achieve physiologic pacing rates in response to normal daily activities with appropriate programming.

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Section: Discussionmentioning

confidence: 99%

Chronotropic Response of an Activity Detecting Pacemaker Compared with the Normal Sinus Node

Moura

Gessman

Lai

et al. 1987

Pacing Clinical Electrophis

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“…In the mid-1970s, Cammilli et al [9] provided the first implantable device using central venous pH sensing; the concept was that the decrease of central venous pH associated with exercise would increase pacemaker rate; unfortunately this sensor was not found to be stable in the long-term, and it was abandoned. …”

Section: Rate Responsiveness Traditional Sensorsmentioning

confidence: 99%

Usefulness of Hemodynamic Sensors for Physiologic Cardiac Pacing in Heart Failure Patients

Occhetta

Bortnik

Marino

2011

Cardiology Research and Practice

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The rate adaptive sensors applied to cardiac pacing should respond as promptly as the normal sinus node with an highly specific and sensitive detection of the need of increasing heart rate. Sensors operating alone may not provide optimal heart responsiveness: central venous pH sensing, variations in the oxygen content of mixed venous blood, QT interval, breathing rate and pulmonary minute ventilation monitored by thoracic impedance variations, activity sensors. Using sensors that have different attributes but that work in a complementary manners offers distinct advantages. However, complicated sensors interactions may occur. Hemodynamic sensors detect changes in the hemodynamic performances of the heart, which partially depends on the autonomic nervous system-induced inotropic regulation of myocardial fibers. Specific hemodynamic sensors have been designed to measure different expression of the cardiac contraction strength: Peak Endocardial Acceleration (PEA), Closed Loop Stimulation (CLS) and TransValvular Impedance (TVI), guided by intraventricular impedance variations. Rate-responsive pacing is just one of the potential applications of hemodynamic sensors in implantable pacemakers. Other issues discussed in the paper include: hemodynamic monitoring for the optimal programmation and follow up of patients with cardiac resynchronization therapy; hemodynamic deterioration impact of tachyarrhythmias; hemodynamic upper rate limit control; monitoring and prevention of vasovagal malignant syncopes.

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“…Several ways have been described to control heart rate in patients with sick sinus syndrome based on measuring a property that is a measure for the actual metabolic need. Examples are the QT interval in the cardiac electrogram [296], the pH [297], oxygen saturation [298,299], activity [103,300], right ventricular pressure [80], respiratory frequency [301] and temperature [302]. Oxygen saturation is sensed on the basis of colorimetric principles.…”

Section: Implantable Microsystems For Sick Sinus Syndromementioning

confidence: 99%

Microsystem technologies for implantable applications

Receveur

Lindemans

Rooij

2007

J. Micromech. Microeng.

112

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Microsystem technologies (MST) have become the basis of a large industry. The advantages of MST compared to other technologies provide opportunities for application in implantable biomedical devices. This paper presents a general and broad literature review of MST for implantable applications focused on the technical domain. A classification scheme is introduced to order the examples, basic technological building blocks relevant for implantable applications are described and finally a case study on the role of microsystems for one clinical condition is presented. We observe that the microfabricated parts span a wide range for implantable applications in various clinical areas. There are 94 active and 67 commercial 'end items' out of a total of 142. End item refers to the total concept, of which the microsystem may only be a part. From the 105 active end items 18 (13% of total number of end items) are classified as products. From these 18 products, there are only two for chronic use. The number of active end items in clinical, animal and proto phase for chronic use is 17, 13 and 20, respectively. The average year of first publication of chronic end items that are still in the animal or clinical phase is 1994 (n = 7) and 1993 (n = 11), respectively. The major technology-market combinations are sensors for cardiovascular, drug delivery for drug delivery and electrodes for neurology and ophthalmology. Together these form 51% of all end items. Pressure sensors form the majority of sensors and there is just one product (considered to be an implantable microsystem) in the neurological area. Micro-machined ceramic packages, glass sealed packages and polymer encapsulations are used. Glass to metal seals are used for feedthroughs. Interconnection techniques such as flip chip, wirebonding or conductive epoxy as used in the semiconductor packaging and assembly industry are also used for manufacturing of implantable devices. Coatings are polymers or metal. As an alternative to implantable primary batteries, rechargeable batteries were introduced or concepts in which energy is provided from the outside based on inductive coupling. Long-term developments aiming at autonomous power are, for example, based on electrostatic conversion of mechanical vibrations. Communication with the implantable device is usually done using an inductive link. A large range of materials commonly used in microfabrication are also used for implantable microsystems.

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Preliminary Experience with the pH‐triggered Pacemaker

Cited by 33 publications

References 2 publications

Chronotropic Response of an Activity Detecting Pacemaker Compared with the Normal Sinus Node

Chronotropic Response of an Activity Detecting Pacemaker Compared with the Normal Sinus Node

Usefulness of Hemodynamic Sensors for Physiologic Cardiac Pacing in Heart Failure Patients

Microsystem technologies for implantable applications

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