This paper presents the results of a study in which the method of ECG decomposition in the time domain (DMTD) was applied, followed by a spectral analysis. A digital signal with trigeminy of the ...first lead of a standard electrocardiograph was processed. Using digital filtering in time domain, the electrocardiogram (ECG) was cleared of noise, what results the reduction of spurious components by 10-20%. To represent and classify the frequency characteristics throughout the entire processed cardiac signal, the QRS complexes were removed, P and T waves were left unchanged. Due to considerable influence on the spectral analysis sharp peaks of the ECG signal with small characteristic times of the leading and trailing edges, the obtained result differs considerably from the sum of the harmonic components of the smooth part of the signal. The spectral processing reveals peaks at multiple frequencies, 1.6 Hz, 3.2 Hz, 4.7 Hz, corresponding to a smooth function of P and T waves before the appearance of extra systoles. Based on the obtained data, the frequencies corresponding to the peaks of the cardiogram with a stable sinus rhythm were identified. The acquired data represent regular harmonics, which allow adequate quantitative ECG analysis.
Correction
Journal of the American College of Cardiology,
03/2018, Letnik:
71, Številka:
9
Journal Article
Recenzirano
McNamara RL, Kennedy KF, Cohen DJ, Diercks DB, Moscucci M, Ramee S, Wang TY, Connolly T, Spertus JA Predicting In-Hospital Mortality in Patients With Acute Myocardial Infarction J Am Coll Cardiol ...2016;68:626-35. The first item in the Heart Rate column, read <40, but should have read: <=40.
Background: A type 1 Brugada pattern (T1-BrS) is a recognised marker of arrhythmic risk. Twelve-lead 24-hour Holter monitoring with V1 and V2 in standard and high precordial electrocardiogram (ECG) ...lead (HPL) positions, can identify transient spontaneous T1-BrS pattern in BrS patients with a concealed T1-BrS at presentation. Aim: To investigate the yield and prognostic value of 12-lead 24-hour Holter monitoring with additional high precordial ECG leads (HPL-Holter) in a large single-centre cohort of BrS patients. Methods: A total of 278 subjects with BrS (56% male, mean age at presentation 43 ± 15 years) were included in this study, for whom complete clinical and follow-up data and HPL-Holter(s) after initial evaluation were available. Of these, 59 had a spontaneous T1-BrS pattern at presentation (Group 1) and 219 did not (Group 2), usually requiring ajmaline provocation testing to confirm the diagnosis. Results: From 2008 to 2022, 552 HPL-Holters were recorded in the study cohort (median 2, range 1–6). In total, 43 (73%) subjects in Group 1 and 32 (15%) in Group 2 showed a T1-BrS pattern during HPL-Holter monitoring at least once; this was evident on the 1st follow-up recording in 95% of cases in Group 1 and 66% in Group 2 (median 10 months, IQR 45, range 0.5–64), with at least 2 recordings needed in 28% of subjects in this latter group. Patients with a newly identified T1-BrS in Group 2 tended to be older (mean age 48 ± 14 vs 42 ± 16 years; p=0.05) and to carry the proband status (56% vs 52%; p<0.05) than those without, whereas there were no significant differences in gender, family history of sudden cardiac death and the presence of previous symptoms. Over a median follow-up of 68 months (IQR 64), significant arrhythmic events (appropriate ICD shocks on VT/VF) occurred in 2 subjects in Group 1 (1/43 showing T1-BrS during HPL-Holter monitoring and 1/16 not showing it; p=NS) and in 4 subjects in Group 2 (2/32 with newly identified spontaneous T1-BrS and 2/187 without; p<0.05). Conclusions: Twelve-lead 24-hour ambulatory ECG monitoring including additional HPLs can identify a transient spontaneous T1-BrS in up to 15% of the subjects without the diagnostic pattern at presentation, most during the first year after the diagnosis. In this group, the presence of a T1-BrS pattern is associated with arrhythmic events. We recommend re-evaluation with high precordial 12-lead Holter monitoring of subjects without spontaneous T1-BrS at presentation once a year for at least the first 2 years post-diagnosis. ❑ Image Omitted
Background We attempted to validate the performance of a fast myocardial perfusion imaging (MPI) protocol in diagnostically challenging patients. Methods 78 patients with BetaMuΙ > 24.9, LVH or three ...vessels disease underwent two sequential gated-MPI studies. The first at 15 (Early Imaging, EI) and the second at 45 (Late Imaging, LI) minutes post 99mTc-injection, at both stress and rest. Counts over heart (H), liver (Liv) and subdiaphragmatic space (Sub) and image quality, and myocardial perfusion and function parameters were compared between the two protocols. Coronary angiography was performed within 2 months from MPI, and ROC analysis was used to compare the diagnostic accuracy for the detection of greater than or equal to50% diameter luminal stenosis. Results Quality was optimal-good in 93% of EI and 98% of LI studies (P = .12), H/Liv and stress H/Sub ratios were similar, but rest H/Sub ratio was lower in EI (P = .009). SSS 10 (0 to 46) vs 9 (0 to 36), P = .006 and SDS 3 (0 to 35) vs 2 (0 to 34), P = .02 were higher in EI protocol. LVEF, motion and thickening scores did not differ between the two protocols. A highly significant (P < .001) linear relationship with clinically negligible mean differences in Bland-Altman analysis was observed for all perfusion and function-related data. Sensitivity (EI 81%, LI 80%) and specificity (65% for both) did not differ (P = .23) between the two protocols. Conclusion The fast protocol is technically feasible and diagnostically accurate compared to the established protocol in diagnostically challenging patients.
Der Aktivitat des autonomen Nervensystems wird im Bereich der Schmerzwahrnehmung ein bedeutsames Gewicht beigemessen, welche auch Placeboeffekte beeinflussen konnte. Bisher ist jedoch wenig daruber ...bekannt, ob sich die Schmerzsensitivitat und Placeboanalgesie bei Kindern und Jugendlichen anhand ihrer Herzratenvariabilitat (HRV) vorhersagen lasst.
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