ST-segment elevation in non-atherosclerotic coronaries: a brief overview

Case Report: Intravascular ultrasound-guided management of acute myocardial infarction in a rare coronary artery case with multiple ostia and varied lesions

Anomalous origin of the coronary artery (AOCA) in coronary arteries represent a rare congenital variation, especially when three or more openings coexist, accompanied by conditions such as myocardial infarction, acute heart failure, and severe stenosis in three vessels, making it even rarer. This study reports a rare case of a patient admitted for the first time with acute myocardial infarction. Coronary angiography revealed four openings, along with the aforementioned rare conditions. Guided by intravascular ultrasound (IVUS), treatments were administered for different lesions in various vessels. IVUS confirmed a rare case with a 1 mm extremely short left main coronary artery and three openings. The two-year follow-up results for this patient are deemed satisfactory, indicating a favorable prognosis.

Using Multi-Task Learning-Based Framework to Detect ST-Segment and J-Point Deviation From Holter

Artificial intelligence is increasingly being used on the clinical electrocardiogram workflows. Few electrocardiograms based on artificial intelligence algorithms have focused on detecting myocardial ischemia using long-term electrocardiogram data. A main reason for this is that interference signals generated from daily activities while wearing the Holter monitor lowered the ability of artificial intelligence to detect myocardial ischemia. In this study, an automatic system combining denoising and segmentation modules was developed to detect the deviation of the ST-segment and J point. We proposed a ECG Bidirectional Transformer network that applied in both denoising and segmentation tasks. The denoising model achieved RMSEde, SNRimp, and PRD values of 0.074, 10.006, and 16.327, respectively. The segmentation model achieved precision, sensitivity (recall), and F1-score of 96.00, 93.06, and 94.51%, respectively. The system’s ability to distinguish the depression and elevation of the ST-segment and J point was also verified by cardiologists as well. From our ECG dataset, 103 patients with ST-segment depression and 10 patients with ST-segment elevation were detected with positive predictive values of 80.6 and 60% respectively. Using Holter ECG and transformer-based deep neural networks, we can detect subtle ST-segment changes in noisy ECG signals. This system has the potential to improve the efficacy of daily medicine and to provide a broader population-level screening for asymptomatic myocardial ischemia.

Neurocardiology

Neurocardiology refers to the interplay between the nervous system and the cardiovascular system. Stress-related cardiomyopathy exemplifies the brain-heart connection and occurs in several conditions with acute brain injury that share oversympathetic activation. The brain's influences on the heart can include elevated cardiac markers, arrhythmias, repolarization abnormalities on electrocardiogram, myocardial necrosis, and autonomic dysfunction. The neurogenic stunned myocardium in aneurysmal subarachnoid hemorrhage represents one end of the spectrum, and is associated with an explosive rise in intracranial pressure that results in excess catecholamine state and possibly CBN. A brain-heart link is more known to cardiologists than neurologists. This chapter provides some insight into the pathophysiology of these pathologic neurocardiac states and their most appropriate management relevant to neurologists.

ST-segment elevation after direct current shock mimicking acute myocardial infarction: a case report and review of the literature

External direct current (DC) shocks are and have long been commonly used for electrical cardioversion/defibrillation of atrial or ventricular arrhythmias. ST-segment elevation after cardio version with DC is an easily ignored phenomenon, occurring acutely and resolving during the first few minutes postshock. Here, we describe electrocardiographic findings of widespread ST-segment elevation lasting at least 1 hour after DC cardioversion for ventricular defibrillation due to Brugada syndrome and mimicking acute myocardial infarction (AMI). This case of ST-segment elevation without a dynamic and evolving AMI underscores the need to consider other causes of ST-segment elevation.

ST elevation without myocardial infarction

Acute myocarditis may mimic myocardial infarction because the affected patients report 'classical' chest pain; the ECG changes and echocardiography are identical to those observed in acute coronary syndromes, and serum markers are increased. We describe a case with ST segment elevation on admission ECG, and coronary angiography was normal. Cardiac magnetic resonance with myocardial delayed enhancement sequences is a non-invasive alternative for diagnosing myocarditis.

Differential diagnosis of acute pericarditis from normal variant early repolarization and left ventricular hypertrophy with early repolarization: an electrocardiographic study

BACKGROUND

Differentiation of ST-segment elevation on electrocardiogram (ECG) from acute pericarditis (AP), normal variant early repolarization (ER) and early repolarization of left ventricular hypertrophy (ERLVH) can be problematic. Hence, the authors evaluated the accuracy of the ST/T ratio in ECG to more optimally differentiate between AP, ST-segment elevation, ER and ERLVH.

METHODS

Between September 2006 and July 2010, 80 patients were enrolled in this study consisting of 25 individuals with AP, 27 with ER and 28 with ERLVH. Each ECG was analyzed in a systematic manner including the measurement of PR interval, QRS duration, QT-segment duration, PR-segment deviation, ST-segment deviation and the height of T wave. The ratio of the height of ST segment to the height of T wave was measured in leads I, II, III, aVF and V2 through V6.

RESULTS

The mean ages of the patients with AP, ER and ERLVH were 32 ± 16.5, 36 ± 15.4 and 53 ± 16 years, respectively. The ratio of the amplitude of ST segment to the amplitude of the T wave in leads I, V4, V5 and V6 proved to be a significant discriminator at a value of ≥0.25 (P < 0.05 for all).

CONCLUSIONS

Leads I, V4, V5 and V6 can all be used to differentiate AP from ER and ERLVH. When ST elevation is present in lead I, the ST/T ratio has the best predictive value (0.82) to more accurately discriminate between AP, ER and ERLVH.

Blunted temporal activity of microvascular perfusion heterogeneity in metabolic syndrome: a new attractor for peripheral vascular disease?

A key clinical outcome for peripheral vascular disease (PVD) in patients is a progressive decay in skeletal muscle performance and its ability to resist fatigue with elevated metabolic demand. We have demonstrated that PVD in obese Zucker rats (OZR) is partially due to increased perfusion distribution heterogeneity at successive microvascular bifurcations within skeletal muscle. As this increased heterogeneity (γ) is longitudinally present in the network, its cumulative impact is a more heterogeneous distribution of perfusion between terminal arterioles than normal, causing greater regional tissue ischemia. To minimize this negative outcome, a likely compensatory mechanism against an increased γ should be an increased temporal switching at arteriolar bifurcations to minimize downstream perfusion deficits. Using in situ cremaster muscle, we determined that temporal activity (the cumulative sum of absolute differences between successive values of γ, taken every 20 s) was lower in OZR than in control animals, and this difference was present in both proximal (1A-2A) and distal (3A-4A) arteriolar bifurcations. Although adrenoreceptor blockade (phentolamine) improved temporal activity in 1A-2A arteriolar bifurcations in OZR, this was without impact in the distal microcirculation, where only interventions against oxidant stress (Tempol) and thromboxane A(2) activity (SQ-29548) were effective. Analysis of the attractor for γ indicated that it was not only elevated in OZR but also exhibited severe reductions in range, suggesting that the ability of the microcirculation to respond to any challenge is highly restricted and may represent the major contributor to the manifestation of poor muscle performance at this age in OZR.