Accidental Atrial and Ventricular Stimulation by Pacemaker Event Marker (original) (raw)
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Pacemaker Stimulation Criticism at ECG
New Concepts in ECG Interpretation, 2018
Cardiac implantable electronic devices' (CIEDs) numbers have grown up worldwide over the last years [1]. At the same time, functions and algorithms' complexity implementation also expanded. It will be therefore more and more frequent for the clinician to deal with pacemaker (PM) ECGs and unusual device behaviors, particularly when they mimic pseudo-malfunctions. In this chapter, we present some examples of challenging electrocardiograms, aiming to show how the clinician, just by analyzing the ECG, could reach or at least suspect the correct diagnosis. 16.1 Case 1 An 82-year-old man with a history of systemic hypertension and previous dual-chamber PM implantation for second-degree atrioventricular (AV) block was referred to our clinic with a suspected PM malfunction. The patient was asymptomatic. ECG is shown in Fig. 16.1a, b.
Pacemaker Stimulus Alternans: What Is the Mechanism?
Pacing and Clinical Electrophysiology, 2008
A 77-year-old man was admitted due to decompensated heart failure. Eight years prior to this admission, a single-chamber VVI pacemaker (Pikos LP01, Biotronik, Berlin, Germany) and a bipolar lead (TIR 60-BP, Biotronik) had been implanted due to sick sinus syndrome. This device was programmed for unipolar pacing at 70 bpm. The patient had not undergone a pacemaker check-up for several years. An electrocardiogram (ECG) recorded at admission showed no inhibition of pacemaker output by intrinsic QRS complexes, and an apparent pacing rate of 32 bpm, with occasional lack of capture. However, further inspection of the tracing revealed that the pacemaker spikes actually occurred at a rate of 63 bpm, but every second spike was very small and did not cause ventricular capture. Several subsequent longer ECG tracings confirmed this observation. What was the mechanism underlying this ECG pattern?
Abstract Background: The aim of this study was to evaluate the reliability of pacemaker diagnostic function in diagnosing ventricular arrhythmias. Methods: We compared the occurrence of ventricular ectopic beats in 51 simultaneous 24-hour electrocardiogram (ECG) recordings and pacemaker event counters printouts. The diagnostic function of a pacemaker allowed also for a qualitative assessment in 38 patients. In these cases, the occurrence of complex forms of ventricular arrhythmias was cross-checked for accelerated ventricular rhythms together with ventricular tachycardia, and triplets and couplets. The detection of at least one type of complex ventricular form of arrhythmia, diagnosed by both methods, was considered as an agreement between the methods. Results: The results of ventricular ectopic beat counts differed significantly between the methods. In three (6%) patients, the results were consistent; in 20 (39%) the pacemaker underestimated results; in 28 (55%) they were overestimated. When more liberal criteria of agreement were applied, clinically significant differences were observed in 24 (47%) patients; in seven (29%) patients the count made by the pacemaker was lowered; and in 17 (71%) it was overestimated. Ventricular tachycardias were recorded in 24-hour ECG in eight patients. In three, they were identified by the pacemaker diagnostic function. In five, the pacemaker did not recognize tachycardia (because of its frequency being below 120/min). In nine, tachycardia was recognized falsely. The sensitivity in ventricular tachycardia diagnosis by pacemaker diagnostic function was 38%, specificity — 70%, the value of a positive result — 25%, negative — 81%. Conclusions: The evaluation of ventricular arrhythmias by pacemaker cannot serve as the only reliable diagnostic method of arrhythmias. The presence of a large number of sequences that may correspond to ventricular arrhythmia or failure to sense, should result in verification via 24-hour ECG monitoring. (Cardiol J 2010; 17, 5: 495–502)
Course of Symptoms and Spontaneous ECG in Pacemaker Patients: A 5-Year Follow-up Study
Pacing and Clinical Electrophysiology, 1988
LANGENFELD, H,, ET AL.: Course of symptoms and spontaneous ECG in pacemaker patients: A 5-year follow-up study. We investigated the course of symptoms and the spontaneous ECG retrospectiveiy in 308 patients who had received a pacemaker because of a trio ventricuJar (AV) block fn = 115), sick sinus syndrome fSSS, n = 107), bradyarrhythmic atriai jibriJiation fbradyarrhythmia, n = 51). carotid sinus syndrome (CSS, n = 16), complete bi/ascicuiar block associated with 1st degree AV block (n = 13) and with other indications fn = 6). The mean impiantation time was 63 months. The c\ir\ica\ state of 93% of all patients improved after pacemaker implantation; their symptoms decreased markedly. Persisting syncopy in some patients with SSS, however, supports a restricted implantation policy. We rarely saw improved AV conduction in patients with AV block fn%). Furthermore, in patients with SSS, afriaJ /ibriliotion occmed significantly more often (35 %) than in those with AV block (17 %; P < 0.01). Only 3% of patients with SSS developed 2nd and 3rd degree AV block within the observation period. In all patients with Initial bi/ascicular block and additional 1st degree AV block, pacing prevented further syncopaJ attacks; four of them showed 3rd degree AV block at control, indicating that pacemaker impiantation is mandatory in symptomatic patients with bifascicular disease and 1st degree AV block. (PACE, Vol. 11, December 1988) folow-up, pacemaker patients, symptoms, spontaneous ECC Address for reprints: Heiner Langenfeld. MD
Pacemaker induced torsades de pointes tachycardia
Heart, 1998
Objective-To assess the stability and reproducibility of computerised QT dispersion (QTd) measurement in healthy subjects, as this is presently being incorporated into commercial electrocardiographic systems. Methods-70 healthy volunteers (mean (SD) age 38 (10) years, 35 men, 35 women) with a normal 12 lead electrocardiogram (ECG) were studied. From each subject, 70 ECG recordings were taken using the MAC VU ECG recorder (Marquette). In study A, 50 ECGs were recorded in each subject: 10 supine, 10 sitting, 10 standing, 10 holding breath in maximum inspiration, and 10 holding breath in maximum expiration. After a mean interval of 8 (3) days (range 7 to 23), 10 recordings in supine and 10 in the standing position were repeated in each subject (study B). On measurements made using a research version of the commercial software without manual modification, the reproducibility of QTd was assessed by coeYcient of variance (CV) and relative error, and comparisons made with other ECG indices. Results-(1) QTd measurements were stable and not influenced by changes in posture and respiratory cycle; (2) there was no diVerence in QTd measurements between men and women, or between age groups dichotomised at 35 years; (3) no correlation was found between QTd and heart rate or QT interval; (4) short term reproducibility of all QTd measurements (CV 15.6% to 43.8%) was worse than that of conventional ECG indices (CV 1.4% to 5.3%); (5) long term reproducibility of QTd measurements (relative error 27.4% to 31.0%) was also worse than that of conventional ECG indices (relative error 1.8% to 7.9%) (p < 0.0001); (6) the reproducibility of QTd measurements tended to increase when several serial recordings were averaged. Conclusions-Computerised measurements of global QTd and global QT-SD from 12 lead ECG by the MAC VU/QT Guard system are not significantly altered by changes in posture and respiration. The reproducibility of all QTd measurements is inferior to that of conventional ECG indices in healthy subjects.
Enhanced software based detection of implanted cardiac pacemaker stimuli
2009 36th Annual Computers in Cardiology Conference, 2009
With increasing use and sophistication of implantable cardiac pacemaker devices, new techniques are required to ensure accurate detection of pacemaker stimuli. This study aimed to (i) compare the accuracy of enhanced pacemaker spike detection logic using 32,000 samples/sec (sps) data against existing software based on current AAMI/IEC standards; (ii) assess the ability of the new logic to aid in the detection of biventricular (BiV) pacing; (iii) develop and test a method for the detection of BiV pacing based on QRS morphology. 72 patients were recruited. 63 were used to assess spike detection accuracy and 62 to assess the accuracy of reporting BiV pacing. 33/62 had BiV pacemakers. 9 patients were excluded for various reasons. The new logic improved accuracy of spike detection from 46/63 to 62/63. For BiV pacing, the new logic had a sensitivity of 97% and a specificity of 100% while the QRS morphology logic had a sensitivity of 70% and a specificity of 93%.