![]() Theory is obviously useful in making the taxonomy testable. In a related vein, researchers have argued that theory based taxonomies are needed for research to progress. įailure to pace can lead to asystole or a severe decrease in cardiac output in pacemaker-dependent patients. Administration of 160 mM sodium bicarbonate intravenously led to immediate improvement in the abnormalities (37 ). Failure of pacemaker inhibition also occurred. Subsequently, periodic variation of the Wenkenbach type developed in the stimulus-QRS interval with intermittent failure to pace. Interference with ventricular pacing occurred in a patient with a pacemaker who developed severe procainamide toxicity with a serum concentration of 36 ptglml the QRS widened from 0.20 to 0.26 sec and a delay of 0.18 sec appeared between the pacing stimulus and the QRS. Arrows show the presence of a gap in between compiexes. The most commonly encountered problems associated with pacemaker systems include failure to sense, failure to capture, failure to pace and over sensing. Pacemaker malfunctions can often be seen on the 12-lead ECG. Used with permission of Mayo Foundation for Medical Education and Research.).Īs with all manmade devices there is the possibility that the device can be faulty, either due to a fault in the manufacturing process or in the programming of the device. Mount Kisco Futura Publishing, 1993 361 100. A practice of cardiac pacing, third edition. In Furman S, Hayes DL, Holmes DR Jr, editors. An unrelated ohservation (arrowhead on 6 A) is the shallow positioning of the atrial lead, i.e., the J is much wider than 90°. ![]() By convention, the lower of the two leads in the connector block is the ventricular lead, so that this patient must have had intermittent or permanent ventricular failure to output. This difference is more evident on the close-up view. Comparison of the upper and lower pins reveals that the lower of the two unipolar leads is not completely advanced. 18.6 Posteroanterior radiograph (A) and close-up view (B) from a patient with intermittent failure to pace. This can be problematic for patients as it can decrease cardiac ontpnt (Fig. The ECG often shows a gap in between complexes. This is the complete absence of pacing spikes and paced complexes where expected. ![]() ![]() This is seen on the ECG by the presence of pacing spikes without a subsequently paced QRS complex or P wave (Fig. This can again be dangerous for the patient as they can be subject to the condition the pacemaker was inserted to treat if the pacemaker fails to work correctly. The pacemaker fires but fails to pace the myocardium. ![]()
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