Pacemaker assessing function

To demonstrate the ability of these hES cell-derived cardiomyocytes to survive, function and integrate in an in vivo heart. Professor Gepstein and colleagues assessed the ability to function as a biological pacemaker in an animal model of a slow heart rate and successfully paced its heart to normal rates. The animal model of... 

Clarke M, Allen A, Use of telemetered electrograms in the assessment of normal pacemaker function, J Electrophysiol 1987 1 388-395. 

Famularo MA, Kennedy HL, Ambulatory electrocardiography in the assessment of pacemaker function. Am Heart J 1982 104 1086-1094. 

As with pacemaker analysis an electrocardiogram (EGG) cable can be attached to the patient to provide EGG rhythm strips. They can aid in assessing the pacing and sensing functions of the IGD. "Marker chaimel" annotations are also available. They vary from those for pacemakers in that additional annotations are used to delineate ventricular events that occur within the various IGD tachycardia treatment zones (i.e. "VT" for VT zone or "VE" for VF zone for the below example). These tachycardia annotations differ between IGD manufacturers, but tend to convey similar information. 

The third example is of a 48-year-old woman in whom bilateral pacers were inserted at the age of 16 because of primary alveolar hypoventilation. She remained very stable and was employed on a full-time basis. Her VC was 106% predicted, FEVi/FVC was 88%, MIP 87% predicted, and MEP 66% predicted. Regular follow-up showed excellent gas exchange, although on assessing her pacemakers, the right side had failed to function for some years. 

Immersions of polymer microtensile specimens in solutions of metal ions or lipid emulsions at elevated temperatures for 16 weeks have been reported [32]. Temperatures of 37, 70, and 90°C are recommended with sampling monthly to establish trends. For pacemaker leads, the solutions should include all the metals found within the device, a base, and an acid. For example, aqueous solutions of 1 M AgNOs or 0.1 M C0CI2 (acetylacetanoate) can assess oxidation. Immersion in 1 N acetic acid. Ringer s solution, and 1.0 N HCl can assess hydrolytic resistance. Immersion in 20% intralipid (soybean) emulsion can assess the propensity to absorb lipids. However, in our experience, none of the above in vitro tests appear to be reliably predictive of performance in pacemaker lead insulation. Why The in vivo environment cannot be duplicated in vitro. For example, the oxidation state of an ion varies as a function of what it is dissolved in. Distilled water containing a metal ion does not represent the environment within a lead. This accelerated test predicts that Ag+ will oxidize and degrade polyether polyurethanes while Co will not. Multiple in vivo studies clearly demonstrate exactly the opposite [14, 33]. Traces of cobalt will degrade the polymer in vivo whereas silver will not. 

Use a systematic approach to assess pacemaker function for problems ... 

When you apply a magnet to a pacemaker, the device reverts to a predefined (asynchronous) response mode that allows you to assess various aspects of pacemaker function. Specifically, you can accomplish the following ... 

---