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Abnormal repolarization in the acute myocardial infarction patients: a frequency-based characterization.

Giuliani C, Agostinelli A, Fioretti S, Nardo FD, Burattini LB - Open Biomed Eng J (2014)

Bottom Line: Repolarization dispersion caused f99 distributions to be significantly lead dependent.Instead, lead-system analysis, performed to overcome dispersion issues, provided the best results when averaging over the 6 precordial leads (Se= 81% and Sp=74%).In conclusion, our new f99 index appears as a promising tool for non-invasively and reliably discriminate AMI patients from healthy subjects.

View Article: PubMed Central - PubMed

Affiliation: Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy.

ABSTRACT
Despite ST elevation having poor sensitivity for acute myocardial infarction (AMI), it remains the main electrocardiographic (ECG) repolarization index for AMI diagnosis. Aim of the present study was to propose a new f99 index, defined as the frequency at which the repolarization normalized cumulative energy reaches 99%, for ECG AMI discrimination from health with good sensitivity and good specificity. Evaluation of such f99 index was performed on 12-standard-lead (I, II, III, aV1, aVr, aVf, V1 to V6) ECG recordings of 47 healthy controls and 108 acute myocardial infarction (AMI) patients. Repolarization dispersion caused f99 distributions to be significantly lead dependent. In most leads (leads I, II, aVl, aVr, V2-V6), f99 median value was lower in the healthy controls (10-17 Hz) than in the AMI patients (12-38 Hz) indicating higher frequency components (i.e. a more fragmented repolarization) in the latter population. AMI patients from healthy controls discrimination by f99, evaluated in terms of sensitivity (Se) and specificity (Sp), was also lead dependent. Single-lead analysis indicated leads I (Se=80%, Sp=77%) and aVl (Se=84%, Sp=74%) as optimal. Instead, lead-system analysis, performed to overcome dispersion issues, provided the best results when averaging over the 6 precordial leads (Se= 81% and Sp=74%). In conclusion, our new f99 index appears as a promising tool for non-invasively and reliably discriminate AMI patients from healthy subjects.

No MeSH data available.


Related in: MedlinePlus

Typical normalized spectra of a healthy control (panel a) and an AMI patient (panel b). Plots refer to lead V2. The inset represents a zoomed portion (from 10 to 100 Hz) of the larger graph finalized to highlight high-frequency components that otherwise would remain hidden because of the presence of much higher-amplitude low-frequency (below 10 Hz) components.
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Figure 2: Typical normalized spectra of a healthy control (panel a) and an AMI patient (panel b). Plots refer to lead V2. The inset represents a zoomed portion (from 10 to 100 Hz) of the larger graph finalized to highlight high-frequency components that otherwise would remain hidden because of the presence of much higher-amplitude low-frequency (below 10 Hz) components.

Mentions: Single-lead analysis. In most leads, the AMI patients’ spectra were characterized by larger high-frequency components than the healthy controls’ spectra (Fig. 2). Consequently, compared to the AMI patients, the healthy controls were usually characterized by ERPS% curves saturating at lower frequencies (Fig. 3) and by significantly lower f99 values (Table 2). Lead III was the only one showing an opposite trend, whereas aVf and V1 f99 distributions did not differ significantly between the two populations (Table 2). Analogous findings were obtained when comparing ANAMI and INAMI subgroups against the healthy controls (Table 2). Ability of f99 in discriminating pathological from healthy conditions, evaluated in terms of Se and Sp, was lead dependent (Table 3). Optimal leads could also vary with AMI subgroup. Leads I and aVl discriminated both the ANAMI and INAMI patients from the healthy controls. Instead, lead V2 discriminated the ANAMI group better than the INAMI group, while lead V5 vice versa (Table 3).


Abnormal repolarization in the acute myocardial infarction patients: a frequency-based characterization.

Giuliani C, Agostinelli A, Fioretti S, Nardo FD, Burattini LB - Open Biomed Eng J (2014)

Typical normalized spectra of a healthy control (panel a) and an AMI patient (panel b). Plots refer to lead V2. The inset represents a zoomed portion (from 10 to 100 Hz) of the larger graph finalized to highlight high-frequency components that otherwise would remain hidden because of the presence of much higher-amplitude low-frequency (below 10 Hz) components.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126187&req=5

Figure 2: Typical normalized spectra of a healthy control (panel a) and an AMI patient (panel b). Plots refer to lead V2. The inset represents a zoomed portion (from 10 to 100 Hz) of the larger graph finalized to highlight high-frequency components that otherwise would remain hidden because of the presence of much higher-amplitude low-frequency (below 10 Hz) components.
Mentions: Single-lead analysis. In most leads, the AMI patients’ spectra were characterized by larger high-frequency components than the healthy controls’ spectra (Fig. 2). Consequently, compared to the AMI patients, the healthy controls were usually characterized by ERPS% curves saturating at lower frequencies (Fig. 3) and by significantly lower f99 values (Table 2). Lead III was the only one showing an opposite trend, whereas aVf and V1 f99 distributions did not differ significantly between the two populations (Table 2). Analogous findings were obtained when comparing ANAMI and INAMI subgroups against the healthy controls (Table 2). Ability of f99 in discriminating pathological from healthy conditions, evaluated in terms of Se and Sp, was lead dependent (Table 3). Optimal leads could also vary with AMI subgroup. Leads I and aVl discriminated both the ANAMI and INAMI patients from the healthy controls. Instead, lead V2 discriminated the ANAMI group better than the INAMI group, while lead V5 vice versa (Table 3).

Bottom Line: Repolarization dispersion caused f99 distributions to be significantly lead dependent.Instead, lead-system analysis, performed to overcome dispersion issues, provided the best results when averaging over the 6 precordial leads (Se= 81% and Sp=74%).In conclusion, our new f99 index appears as a promising tool for non-invasively and reliably discriminate AMI patients from healthy subjects.

View Article: PubMed Central - PubMed

Affiliation: Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy.

ABSTRACT
Despite ST elevation having poor sensitivity for acute myocardial infarction (AMI), it remains the main electrocardiographic (ECG) repolarization index for AMI diagnosis. Aim of the present study was to propose a new f99 index, defined as the frequency at which the repolarization normalized cumulative energy reaches 99%, for ECG AMI discrimination from health with good sensitivity and good specificity. Evaluation of such f99 index was performed on 12-standard-lead (I, II, III, aV1, aVr, aVf, V1 to V6) ECG recordings of 47 healthy controls and 108 acute myocardial infarction (AMI) patients. Repolarization dispersion caused f99 distributions to be significantly lead dependent. In most leads (leads I, II, aVl, aVr, V2-V6), f99 median value was lower in the healthy controls (10-17 Hz) than in the AMI patients (12-38 Hz) indicating higher frequency components (i.e. a more fragmented repolarization) in the latter population. AMI patients from healthy controls discrimination by f99, evaluated in terms of sensitivity (Se) and specificity (Sp), was also lead dependent. Single-lead analysis indicated leads I (Se=80%, Sp=77%) and aVl (Se=84%, Sp=74%) as optimal. Instead, lead-system analysis, performed to overcome dispersion issues, provided the best results when averaging over the 6 precordial leads (Se= 81% and Sp=74%). In conclusion, our new f99 index appears as a promising tool for non-invasively and reliably discriminate AMI patients from healthy subjects.

No MeSH data available.


Related in: MedlinePlus