Enhancing Diagnosis of Anterior and Inferior Myocardial Infarctions Using UWB Radar and AI-Driven Feature Fusion Approach

Despite significant improvement in prognosis, myocardial infarction (MI) remains a major cause of morbidity and mortality around the globe. MI is a life-threatening cardiovascular condition that requires prompt diagnosis and appropriate treatment. The primary objective of this research is to identify instances of anterior and inferior myocardial infarction by utilizing data obtained from Ultra-wideband radar technology in a hospital for patients of anterior and inferior MI. The collected data is preprocessed to extract spectral features. A novel feature engineering approach is designed to fuse temporal features and class prediction probability features derived from the spectral feature dataset. Several well-known machine learning models are implemented and fine-tuned to obtain optimal performance in the detection of anterior and inferior MI. The results demonstrate that integration of the fused feature set with machine learning models results in a notable improvement in both the accuracy and precision of MI detection. Notably, random forest (RF) and k-nearest neighbor showed superb performance with an accuracy of 98.8%. For demonstrating the capacity of models to generalize, K-fold cross-validation is carried out, wherein RF exhibits a mean accuracy of 99.1%. Furthermore, the examination of computational complexity indicates a low computational complexity, thereby indicating computational efficiency.

Early right ventricular dysfunction after primary percutaneous coronary intervention in anterior versus isolated inferior myocardial infarction assessed by tissue Doppler imaging and speckle tracking echocardiography

This study hypothesized that imaging provides information indicating the right ventricular (RV) involvement after anterior or inferior ST-elevation myocardial infarction (STEMI), beyond standard electrocardiogram (ECG) due to the increasing interest in RV function and assessment techniques. This study aimed to compare RV function between anterior and inferior MI without RV involvement using different echocardiographic modalities. This study included 100 patients with anterior (50 patients) and inferior (50 patients) STEMI, who underwent primary percutaneous coronary intervention (PPCI) and two-dimensional echocardiographic imaging within 24 h after PPCI with RV function analysis by left ventricular (LV) infarct size, LV filling pressure, and RV strain rate. Our primary endpoint was the subclinical RV dysfunction in anterior or inferior MI using tissue Doppler and speckle tracking (STE). The study population included 80 (80%) males and 20 (20%) females. Patients with the anterior STEMI had higher mean creatine kinase-MB (CKMB) and troponin than those with inferior STEMI. This study revealed worse RV dysfunction in patients with anterior than those with inferior STEMI, as reflected by significantly lower RV systolic function, tricuspid annular plane systolic excursion (p ≤ 0.0001), tissue Doppler-derived velocity (p ≤ 0.0001), and STE-derived strain magnitude and rate (p ≤ 0.0001). RV dysfunction occurs in patients without ECG evidence of RV STEMI. RV dysfunction is worse in anterior than inferior MI. Moreover, RV systolic functions were affected by declined LV ejection fraction irrespective of the infarction site, which clinically implies prognostic, treatment, survival rate, and outcome improvement between both conditions. (Trial registration ZU-IRB#:4142/26-12-2017 Registered 26 December 2017, email: IRB_123@medicine.zu.edu.eg).

Characteristics and mechanism of reciprocal ST-segment depression in acute ST segment elevation myocardial infarction: Reciprocal ST-segment depression and ST segment elevation myocardial infarction

At present, the mechanism of reciprocal ST-segment depression (RSTD) is unclear. ST-segment changes may be caused by the potential difference between the positive and negative electrodes, although this requires further investigation. The characteristics of RSTD and their relationship with ST-segment elevation in acute ST segment elevation myocardial infarction (STEMI) patients were analyzed. We replaced the negative electrode of the precordial leads of an inferior wall myocardial infarction patient and observed the changes in the ST-segment of the precordial leads. A total of 85 patients were included, of which 75 were patients with RSTD. All 45 patients with inferior myocardial infarction had limb lead RSTD, and 37 had anterior lead ST-segment depression. All ST-segment changes in STEMI can be explained by the proposed mechanism, and the value of ST segment depression in limb leads can be calculated by the value of ST segment elevation. In summary, the mechanism of RSTD in acute myocardial infarction may be that the action potential (AP) of the negative electrode of the lead weakens or disappears and the AP of the positive electrode may not be completely offset, resulting in ST-segment depression. Animal experimental studies are needed for further confirmation. When the negative electrode of the precordial lead is changed in acute inferior wall myocardial infarction patient, the ST-segment of the precordial lead changes accordingly. All the changes are consistent with our analysis.

[Detection of inferior myocardial infarction based on morphological characteristics]

Early accurate detection of inferior myocardial infarction is an important way to reduce the mortality from inferior myocardial infarction. Regrading the existing problems in the detection of inferior myocardial infarction, complex model structures and redundant features, this paper proposed a novel inferior myocardial infarction detection algorithm. Firstly, based on the clinic pathological information, the peak and area features of QRS and ST-T wavebands as well as the slope feature of ST waveband were extracted from electrocardiogram (ECG) signals leads Ⅱ, Ⅲ and aVF. In addition, according to individual features and the dispersion between them, we applied genetic algorithm to make judgement and then input the feature with larger degree into support vector machine (SVM) to realize the accurate detection of inferior myocardial infarction. The proposed method in this paper was verified by Physikalisch-Technische Bundesanstalt (PTB) diagnostic electrocardio signal database and the accuracy rate was up to 98.33%. Conforming to the clinical diagnosis and the characteristics of specific changes in inferior myocardial infarction ECG signal, the proposed method can effectively make precise detection of inferior myocardial infarction by morphological features, and therefore is suitable to be applied in portable devices development for clinical promotion.

Acute Posterior-inferior Myocardial Infarction Caused by Total Occlusion Distal to the Apex of the Hyperdominant Left Anterior Descending Artery

A 77-year-old woman was admitted to our hospital with severe ongoing chest pain. Electrocardiography showed ST-segment elevation in the inferior leads and tall R waves in leads V1-2. Posterior-inferior myocardial infarction was diagnosed. Emergent coronary angiography (CAG) revealed the wrap-around left anterior descending artery (LAD) with total occlusion distal to the cardiac apex. She underwent percutaneous coronary intervention (PCI). Despite difficulty navigating the long and tortuous LAD, we successfully performed reperfusion of the wrap-around LAD. CAG post-PCI showed the posterior descending artery arising from the LAD, described as hyperdominant LAD.

A new electrocardiographic pattern indicating inferior myocardial infarction

BACKGROUND

We identified a specific pattern that does not display contiguous ST-segment elevation (STE), indicating acute inferior myocardial infarction (MI) with concomitant critical stenoses on the other coronary arteries. We sought to define the frequency, underlying anatomic substrate, diagnostic power and prognostic implications of this pattern.

METHODS

One thousand patients with a diagnosis of non-STEMI were enrolled as the study group. Within the same date range, all patients with inferior STEMI and 1000 patients, who had been excluded for MI (no-MI), were also enrolled. The coronary angiograms were reviewed by two interventional cardiologists, who were blinded to the ECGs. Echocardiographic wall motion bullseye displays and coronary angiography maps were constructed for each group. The dead or alive status was checked from the electronic national database.

RESULTS

The final study population consisted 2362 patients. The prespecified ECG pattern was observed in 6.3% (61/966) of the non-STEMI cohort and 0.5% (5/1000) of no-MI patients. These patients had a larger infarct size as evidenced by 24-hour troponin levels, higher frequency of angiographic culprit lesion, and higher frequency of composite acute coronary occlusion endpoint compared to their non-STEMI counterparts. On the other hand, they had a similar in-hospital (5% vs. 4%, respectively; P = 0.675) and one-year mortality compared to the patients with inferior STEMI (11% vs. 8%, respectively; P = 0.311).

CONCLUSION

We here define a new ECG pattern indicating inferior MI in patients with concomitant critical lesion(s) in coronary arteries other than the infarct-related artery. Patients with this pattern have multivessel disease and higher mortality.

Infarction or Pseudo-infarction?

An applicant with a history of paroxysmal atrial fibrillation is found to have QS waves in leads III and AVF suggestive of a prior inferior wall myocardial infarction. Using the relationship between Q wave and T wave vectors in the inferior leads, an alternative explanation is explored.

Electrocardiographic inverse problem: spatial characterization of the left ventricle potential

In this work, we present a method for spatial characterization of the electrical activity of the left ventricle (LV). The presented method, electrocardiographic LV imaging, aims at characterization of main morphological features of the LV electrical activity via simple inverse reconstruction of the electrocardiogram on a standard LV segment model. The method is demonstrated with a case study dealing with the spatial characterization of an old myocardial infarction (MI). The results are encouraging: the centroid of the MI region is localized correctly, and the shape of the reconstructed infarcted region is similar to that in the golden standard solution, even though a patient-specific thorax model was not used.

Vectorcardiographic Residua of Inferior Infarction

Seventy-eight patients with well-documented inferior infarction were studied by the Frank vectorcardiographic technic.

The commonest residual was superior and leftward orientation of the early forces that moved clockwise in the frontal projection.

Quantitative data on the duration, magnitude, and leftward sweep of these forces are presented.

In 52 cases, the entire frontal loop was clockwise. When sagittal loop reversal, partial or total, ocurred in this group, a high correlation with associated anterior infarction or left ventricular enlargement was noted.

In 24 patients, the returning frontal limb was deformed due to upward bowing. When anterior forces were well preserved in the presence of this deformity, a characteristic "pollywog" shape in the sagittal loop resulted.

Conduction defects were twice as common in the cases with mid-loop frontal deformity as in the cases without such defects.

Anterior forces of prominent voltage and prolonged duration were noted in 19 cases. Quantitative data on these cases, presumably reflecting associated posterior infarction, are presented.

The vectorcardiographic residua of inferior infarction may be classified according to rotational characteristics of the frontal and sagital loops. Classification may be of value in providing clues to associated anterior disease, left ventricular enlargement, and conduction defect.

THE Q WAVE IN L III AND AVF OF THE ELECTROCARDIOGRAM. A VECTORCARDIOGRAPHIC ANALYSIS WITH THE USE OF THE FRANK SYSTEM

Seventy-three consecutive patients with a Q wave in Lead III and aVF in the electrocardiogram were studied. Vectorcardiograms were recorded with the use of the Frank system. In 32 cases the ECG's were compatible with the diagnosis of an inferior myocardial infarction based on a Q wave in Lead III and/or aVF greater than 0.04 second duration and greater than 25 per cent of the amplitude of the R wave. In this group, there were 16 patients with coronary disease and the VCG confirmed the electrocardiographic diagnosis of an infarction in 14 cases. In 13 of the other 16 cases without history of coronary disease the VCG did not suggest the presence of an infarction. In all 17 cases with questionable electrocardiographic diagnosis of an inferior infarction, and without history of coronary disease, the VCG denied the presence of an infarction. In 18 cases with small Q III or Q aVF the VCG's were within normal limits. In two cases with normal Q III and Q aVF the VCG's did not detect the presence of an infarction in both cases. The vectorcardiographic diagnosis of an inferior myocardial infarction was based on the superior orientation (at or above 360 degrees) of the 10, 20, 25 and 30-msec vectors in the frontal plane, superior displacement of the maximum QRS vector and clockwise rotation. In the left sagittal plane the 10, 20, 25 and 30-msec vectors were oriented at or above 180 degrees with the loop rotating counterclockwise. The data presented suggest that vectorcardiography is a useful adjunct to electrocardiography in the diagnosis of an inferior myocardial infarction.

The frontal plane QRS loop in the normal heart and in diaphragmatic myocardial infarction

The efferent limb of the frontal plane QRS loop of the vectorcardiogram was studied quantitatively in 100 normal subjects and in 50 patients with electrocardiographic QRS evidence of diaphragmatic infarction. Efferent limb analysis consisted of determination of the position of the .02-second and maximal vectors in the triaxial reference frame and of the ratio born by the magnitude of the .02-second vector to that of the maximal vector. This ratio was not found to be greater than 0.16 in the normal heart with clockwise loop inscription and a superiorly directed .02-second vector. When 20 patients with only ST-T changes of diaphragmatic infarction in the electrocardiogram were similarly studied, 13 showed significant QRS loop evidence of this infarction.