Electrocardiographic Diagnosis of Acute Coronary Occlusion Myocardial Infarction in Ventricular Paced Rhythm Using the Modified Sgarbossa Criteria

Evaluation of the ODISEA APP for improving a STEMI regional network

BACKGROUND

The use of technological innovations in ST elevation myocardial infarction (STEMI) care networks has been shown to be effective in improving information flow and coordination, and thus reducing the time to reperfusion. We developed a smartphone application called ODISEA to improve our STEMI care network and evaluated the results of its use.

METHOD

Quasi-experimental study that compared the outcomes of STEMI suspected patients with an alert and indication for transfer to a cath lab during a previous period and a period in which the ODISEA APP was used. The main objective was to examine differences in reperfusion time and the proportion of patients with a final diagnosis other than acute coronary syndrome.

RESULTS

A total of 699 patients were included (415 before and 284 during the ODISEA-APP period). No differences were observed in patient characteristics, infarct type, or acute complications. We observed a reduction in the time from diagnostic ECG to wire crossing with the use of the ODISEA APP (117 vs 102 min, p < 0.001) and a reduction in the percentage of patients with a final diagnosis other than acute coronary syndrome (17.1% vs 9.5%, p = 0.004).

CONCLUSIONS

The use of the ODISEA APP in the management of patients with suspected STEMI may be useful for reducing the time from diagnostic ECG to wire crossing and the percentage of patients with a final diagnosis other than acute coronary syndrome.

Beyond STEMI-NSTEMI Paradigm: Dante Pazzanese's Proposal for Occlusion Myocardial Infarction Diagnosis

Although the existing framework for classifying acute myocardial infarction (AMI) into STEMI and NSTEMI has been beneficial, it is now considered to be falling short in addressing the complexity of acute coronary syndromes. The study aims to scrutinize the current STEMI-NSTEMI paradigm and advocate for a more nuanced framework, termed as occlusion myocardial infarction (OMI) and non-occlusion myocardial infarction (NOMI), for a more accurate diagnosis and management of AMI. A comprehensive analysis of existing medical literature was conducted, with a focus on the limitations of the STEMI-NSTEMI model. The study also outlines a new diagnostic approach for patients presenting with chest pain in emergency settings. The traditional STEMI-NSTEMI model falls short in diagnostic precision and effective treatment, especially in identifying acute coronary artery occlusions. The OMI-NOMI framework offers a more anatomically and physiologically accurate model, backed by a wealth of clinical research and expert opinion. It underscores the need for quick ECG assessments and immediate reperfusion therapies for suspected OMI cases, aiming to improve patient outcomes. The OMI-NOMI framework offers a new avenue for future research and clinical application. It advocates for a more comprehensive understanding of the underlying mechanisms of acute coronary syndromes, leading to individualized treatment plans. This novel approach is expected to ignite further scholarly debate and research, particularly in the Brazilian cardiology sector, with the goal of enhancing diagnostic accuracy and treatment effectiveness in AMI patients.

Takotsubo Syndrome After Pacemaker Implantation: A Case Report and Literature Review

A 78-year-old male patient with complete atrioventricular block underwent an uncomplicated pacemaker implantation. After 24 h, he presented acute chest pain, dyspnea, ST-segment-elevation in the anterior leads, left ventricular apical ballooning, and an ejection fraction of 35%. His coronary angiogram was normal. Within 2 days, his symptoms and electrocardiogram (ECG) abnormalities disappeared, while wall motion abnormalities recovered after 6 weeks. A diagnosis of takotsubo syndrome (TTS) was made. Pacemaker implantation has been described as a potential trigger for TTS. The clinical picture exhibits some peculiarities, including a higher percentage of men and asymptomatic patients and challenging ST-segment interpretation of paced ECGs. It is unclear whether pathophysiologic mechanisms are different compared to other forms of TTS and whether the acute initiation of ventricular pacing plays a role.

International evaluation of an artificial intelligence-powered electrocardiogram model detecting acute coronary occlusion myocardial infarction

Aims

A majority of acute coronary syndromes (ACS) present without typical ST elevation. One-third of non-ST-elevation myocardial infarction (NSTEMI) patients have an acutely occluded culprit coronary artery [occlusion myocardial infarction (OMI)], leading to poor outcomes due to delayed identification and invasive management. In this study, we sought to develop a versatile artificial intelligence (AI) model detecting acute OMI on single-standard 12-lead electrocardiograms (ECGs) and compare its performance with existing state-of-the-art diagnostic criteria.

Methods and results

An AI model was developed using 18 616 ECGs from 10 543 patients with suspected ACS from an international database with clinically validated outcomes. The model was evaluated in an international cohort and compared with STEMI criteria and ECG experts in detecting OMI. The primary outcome of OMI was an acutely occluded or flow-limiting culprit artery requiring emergent revascularization. In the overall test set of 3254 ECGs from 2222 patients (age 62 ± 14 years, 67% males, 21.6% OMI), the AI model achieved an area under the curve of 0.938 [95% confidence interval (CI): 0.924-0.951] in identifying the primary OMI outcome, with superior performance [accuracy 90.9% (95% CI: 89.7-92.0), sensitivity 80.6% (95% CI: 76.8-84.0), and specificity 93.7 (95% CI: 92.6-94.8)] compared with STEMI criteria [accuracy 83.6% (95% CI: 82.1-85.1), sensitivity 32.5% (95% CI: 28.4-36.6), and specificity 97.7% (95% CI: 97.0-98.3)] and with similar performance compared with ECG experts [accuracy 90.8% (95% CI: 89.5-91.9), sensitivity 73.0% (95% CI: 68.7-77.0), and specificity 95.7% (95% CI: 94.7-96.6)].

Conclusion

The present novel ECG AI model demonstrates superior accuracy to detect acute OMI when compared with STEMI criteria. This suggests its potential to improve ACS triage, ensuring appropriate and timely referral for immediate revascularization.

Comparison of diagnostic accuracy of current left bundle branch block and ventricular pacing ECG criteria for detection of occlusion myocardial infarction

BACKGROUND

Electrocardiographic detection of patients with occlusion myocardial infarction (OMI) can be difficult in patients with left bundle branch block (LBBB) or ventricular paced rhythm (VPR) and several ECG criteria for the detection of OMI in LBBB/VPR exist. Most recently, the Barcelona criteria, which includes concordant ST deviation and discordant ST deviation in leads with low R/S amplitudes, showed superior diagnostic accuracy but has not been validated externally. We aimed to describe the diagnostic accuracy of four available ECG criteria for OMI detection in patients with LBBB/VPR at the emergency department.

METHODS

The unweighted Sgarbossa criteria, the modified Sgarbossa criteria (MSC), the Barcelona criteria and the Selvester criteria were applied to chest pain patients with LBBB or VPR in a prospectively acquired database from five emergency departments.

RESULTS

In total, 623 patients were included, among which 441 (71%) had LBBB and 182 (29%) had VPR. Among these, 82 (13%) patients were diagnosed with AMI, and an OMI was identified in 15 (2.4%) cases. Sensitivity/specificity of the original unweighted Sgarbossa criteria were 26.7/86.2%, for MSC 60.0/86.0%, for Barcelona criteria 53.3/82.2%, and for Selvester criteria 46.7/88.3%. In this setting with low prevalence of OMI, positive predictive values were low (Sgarbossa: 4.6%; MSC: 9.4%; Barcelona criteria: 6.9%; Selvester criteria: 9.0%) and negative predictive values were high (all >98.0%).

CONCLUSIONS

Our results suggests that ECG criteria alone are insufficient in predicting presence of OMI in an ED setting with low prevalence of OMI, and the search for better rapid diagnostic instruments in this setting should continue.

AMI in (bi)ventricular pacing - do not discard the ECG

BACKGROUND

There is a growing number of patients with ventricular paced rhythm, who present to the emergency department with chest pain. The diagnosis of ST-segment elevation myocardial infarction (STEMI) and subsequent percutaneous coronary intervention (PCI) is often postponed, as the 12 leads-electrocardiogram (ECG) is discarded as not interpretable. There is a growing body of literature that suggests that Smith-modified Sgarbossa criteria can be applied for the diagnosis of STEMI in patients with paced rhythms. These criteria were originally developed for the interpretation of ECGs in patients with a left bundle branch block (LBBB) and chest pain, but have been expanded to paced ECGs.

METHODOLOGY

We present three case reports with chest pain and right ventricular or biventricular pacing.

FINDINGS

In all three cases, the Smith-modified Sgarbossa was positive and the diagnosis of STEMI could have been made early on.

IMPLICATIONS

It remains important to look for ST-segment deviations and to compare the symptomatic ECG with previous asymptomatic ECGs. As the number of patients with potential acute myocardial infarction (AMI) and paced rhythms is likely to rise in the future, these criteria should be known to emergency physicians and cardiologists.

Acute chest pain in a patient with left bundle branch pacing

We present a patient with left bundle branch (LBB) electronic ventricular pacing with chest pain. ECG showed ventricular pacing and ST elevation in the inferolateral leads. At first it was felt that the Sgarbossa criteria for STEMI in electronic ventricular pacing are not met. However, as symptoms persisted, emergency coronary angiography was performed showing complete occlusion of the left circumflex artery. As LBB pacing results in narrow QRS complexes with incomplete right bundle branch block, ST-segment deviation should not be ignored and the Sgarbossa criteria for patients with LBB block or right ventricular electronic pacing should not be applied.

[The ECG in cardiac rehabilitation]

The concept and the benefits of cardiac rehabilitation are well established and scientifically proven. In the context of shortened in-hospital stays and older patients receiving more complex interventions, complications of those procedures might occur during cardiac rehabilitation. This article discusses guideline-directed diagnosis and treatment of complications after transcatheter aortic valve replacement, especially delayed-onset heart block, post-operative atrial fibrillation, and acute coronary ischemia in the setting of pre-existent bundle branch block.

A case of acute myocardial infarction in paced rhythm. Utility of the Barcelona algorithm

We describe the case of a 70-year-old man with a pacemaker implant who presented to us with atypical chest pain. His admission ECG did not satisfy the criteria for myocardial infarction according to standard Sgarbossa criteria, and Smith modified Sgarbossa criteria. However, we applied the recently developed Barcelona algorithm, which is used to diagnose acute myocardial infarction in the presence of intrinsic left bundle branch block.Electrocardiographic criteria for an acute myocardial infarction were met. Lead V6 displayed a low voltage QRS complex (3 mm) with 1 mm ST depression, satisfying the Barcelona criteria for acute myocardial infarction. He underwent primary angioplasty for critical in-stent restenosis of the left anterior descending coronary artery. This is the first case report, to the best of our knowledge, where Barcelona algorithm has been used to diagnose acute coronary syndrome in right-ventricular paced rhythm.

Identification of Coronary Culprit Lesion in ST Elevation Myocardial Infarction by Using Deep Learning

OBJECTIVE

Early revascularization of the occluded coronary artery in patients with ST elevation myocardial infarction (STEMI) has been demonstrated to decrease mortality and morbidity. Currently, physicians rely on features of electrocardiograms (ECGs) to identify the most likely location of coronary arteries related to an infarct. We sought to predict these culprit arteries more accurately by using deep learning.

METHODS

A deep learning model with a convolutional neural network (CNN) that incorporated ECG signals was trained on 384 patients with STEMI who underwent primary percutaneous coronary intervention (PCI) at a medical center. The performances of various signal preprocessing methods (short-time Fourier transform [STFT] and continuous wavelet transform [CWT]) with different lengths of input ECG signals were compared. The sensitivity and specificity for predicting each infarct-related artery and the overall accuracy were evaluated.

RESULTS

ECG signal preprocessing with STFT achieved fair overall prediction accuracy (79.3%). The sensitivity and specificity for predicting the left anterior descending artery (LAD) as the culprit vessel were 85.7% and 88.4%, respectively. The sensitivity and specificity for predicting the left circumflex artery (LCX) were 37% and 99%, respectively, and the sensitivity and specificity for predicting the right coronary artery (RCA) were 88.4% and 82.4%, respectively. Using CWT (Morlet wavelet) for signal preprocessing resulted in better overall accuracy (83.7%) compared with STFT preprocessing. The sensitivity and specificity were 93.46% and 80.39% for LAD, 56% and 99.7% for LCX, and 85.9% and 92.9% for RCA, respectively.

CONCLUSION

Our study demonstrated that deep learning with a CNN could facilitate the identification of the culprit coronary artery in patients with STEMI. Preprocessing ECG signals with CWT was demonstrated to be superior to doing so with STFT.

Non-specific intraventricular conduction delay or atypical LBBB - How to predict acute coronary occlusion?

We describe two patient cases with acute coronary syndrome (ACS) and broad QRS in the acute phase electrocardiogram (ECG). The patients' ECG findings resembled left bundle branch block (LBBB), but with atypical features. Broad QRS not fulfilling the criteria for LBBB or right bundle branch block (RBBB) is diagnosed as non-specific intraventricular conduction delay (NSIVCD). The case report deals with the challenges of predicting acute coronary occlusion in patients with NSIVCD in their acute phase ECG. In one of the cases, the ECG changed from typical LBBB to NSIVCD or atypical LBBB with the development of systolic dysfunction and clinical heart failure.

Electrocardiographic diagnosis of acute myocardial infarction in a pacemaker patient: a case report

Background

The electrocardiographic diagnosis of acute myocardial infarction (AMI) in the setting of cardiac pacing is often challenging. The original Sgarbossa criteria proposed in 1996 were demonstrated to be valid for diagnosis of AMI in both ventricular paced rhythm and left bundle branch block. To improve accuracy, the modified Sgarbossa criteria (MSC) were proposed.

Case presentation

We presented a case of electrocardiographic diagnosis of AMI in a pacemaker patient. The Electrocardiogram (ECG) was false negative by using the original Sgarbossa criteria, whereas true positive by the MSC at a ratio of − 0.20.

Conclusions

The application of MSC using an appropriate ratio (− 0.20 or − 0.25) may facilitate a timely diagnosis of AMI. Physicians should carefully choose the appropriate cutoff in a case-by-case basis.

Interobserver Variability Among Experienced Electrocardiogram Readers To Diagnose Acute Thrombotic Coronary Occlusion In Patients with Out of Hospital Cardiac Arrest: Impact of Metabolic Milieu and Angiographic Culprit

OBJECTIVES

We sought to evaluate interobserver concordance among experienced electrocardiogram (ECG) readers in predicting acute thrombotic coronary occlusion (ATCO) in the context of abnormal metabolic milieu (AMM) following resuscitated out of hospital cardiac arrest (OHCA).

METHODS

OHCA patients with initial shockable rhythm who underwent invasive coronary angiography (ICA) were included. AMM was defined as one of: pH < 7.1, lactate > 2 mmol/L, serum potassium < 2.8 or > 6.0 mEq/L. The initial ECG following ROSC but prior to ICA was adjudicated by 2 experienced readers using classic ST elevation myocardial infarction [STEMI] and expanded criteria and their combination to predict ATCO on ICA.

RESULTS

152 consecutive patients (mean age 58 years, 76% male) met inclusion criteria. AMM was present in 77%; and 42% had ATCO on ICA. Sensitivity, specificity, PPV, NPV using classic STEMI criteria were 50%, 98%, 94%, 72% (c-statistic 0.74); whereas for combined (STEMI + expanded) criteria they were 69%, 88%, 81%, 79% respectively (c-statistic 0.79). Inter-observer agreement (kappa) was 0.7 for classic STEMI criteria, and 0.66 for combined criteria. Agreement between readers was consistently higher when ATCO was absent and with NMM (kappa 0.78), but lower in AMM (kappa 0.6).

CONCLUSIONS

Despite experienced ECG readers, there was only modest overall concordance in predicting ATCO in the context of resuscitated OHCA. Significant interobserver variations were noted dependent on metabolic milieu and angiographic ATCO. These observations fundamentally question the role of the 12-lead ECG as primary triaging tool for early angiography among patients with OHCA.

Ischemic ST-Segment Depression Maximal in V1-V4 (Versus V5-V6) of Any Amplitude Is Specific for Occlusion Myocardial Infarction (Versus Nonocclusive Ischemia)

Background Occlusion myocardial infarctions (OMIs) of the posterolateral walls are commonly missed by ST-segment-elevation myocardial infarction (STEMI) criteria, with >50% of patients with circumflex occlusion not receiving emergent reperfusion and experiencing increased mortality. ST-segment depression maximal in leads V1-V4 (STDmaxV1-4) has been suggested as an indicator of posterior OMI. Methods and Results We retrospectively reviewed a high-risk population with acute coronary syndrome. OMI was defined from prior studies as a culprit lesion with TIMI (Thrombolysis in Myocardial Infarction) 0 to 2 flow or TIMI 3 flow plus peak troponin T >1.0 ng/mL or troponin I >10 ng/mL. STEMI was defined by the Fourth Universal Definition of Myocardial Infarction. ECGs were interpreted blinded to outcomes. Among 808 patients, there were 265 OMIs, 108 (41%) meeting STEMI criteria. A total of 118 (15%) patients had "suspected ischemic" STDmaxV1-4, of whom 106 (90%) had an acute culprit lesion, 99 (84%) had OMI, and 95 (81%) underwent percutaneous coronary intervention. Suspected ischemic STDmaxV1-4 had 97% specificity and 37% sensitivity for OMI. Of the 99 OMIs detected by STDmaxV1-4, 34% had <1 mm ST-segment depression, and only 47 (47%) had accompanying STEMI criteria, of which 17 (36%) were identified a median 1.00 hour earlier by STDmaxV1-4 than STEMI criteria. Despite similar infarct size, TIMI flow, and coronary interventions, patients with STEMI(-) OMI and STDmaxV1-4 were less likely than STEMI(+) patients to undergo catheterization within 90 minutes (46% versus 68%; P=0.028). Conclusions Among patients with high-risk acute coronary syndrome, the specificity of ischemic STDmaxV1-4 was 97% for OMI and 96% for OMI requiring emergent percutaneous coronary intervention. STEMI criteria missed half of OMIs detected by STDmaxV1-4. Ischemic STDmaxV1-V4 in acute coronary syndrome should be considered OMI until proven otherwise.

Diagnosis of Occlusion Myocardial Infarction in Patients with Left Bundle Branch Block and Paced Rhythms

PURPOSE OF REVIEW

A number of criteria have been developed to aid with the diagnosis of occlusion myocardial infarction (OMI) in patients with left bundle branch block (LBBB) and ventricular paced rhythms (VPR). The current guidelines do not provide clear preference for any specific ECG criteria in LBBB and paced rhythm patients.

RECENT FINDINGS

This review delineates the difficulties of electrocardiographic diagnosis of OMI in both LBBB and VPR patients. We describe the original Sgarbossa and the newer criteria and their diagnostic performances. We highlight the expected changes of newer pacing modalities and how they may interfere with the electrocardiographic diagnosis of OMI. We recommend utilizing the Cai et al. algorithm, which combines clinical assessment with the Smith Modified Sgarbossa ECG criteria, for both LBBB and right ventricular pacing patients with suspected OMI. There is limited data concerning ECG changes of OMI in patients with the newer pacing modalities, such as biventricular, His-bundle, or left bundle branch pacing.

Unmasking an acute coronary occlusive myocardial infarction in patients with right ventricular paced rhythm

Electrocardiographic recognition of an acute myocardial infarction in the setting of a right ventricular paced rhythm (VPR) represents a unique diagnostic challenge. The classical ST-segment patterns of myocardial ischemia can become obscured by the abnormal repolarization changes caused by a right VPR. Consequently, longer door-to-balloon reperfusion times and a higher mortality have been reported among these patients mostly due to a delayed diagnosis. In this population, the use of the modified Sgarbossa Criteria (SC) can aid the clinician in the diagnosis of an acute coronary occlusive myocardial infarction (OMI), as an ST-segment elevation myocardial infarction (STEMI) equivalent. However, there are only a few validating studies and no specific guidelines endorsing their use in patients with VPR. We present three cases with right VPR in which the use of the modified SC was diagnostic of OMI, as well as predictive of the occluded coronary vessel. Our review of the current evidence favors that identification of at least one modified SC in patients with right VPR represents an OMI finding with a similar accuracy as when these are used in patients with LBBB.