Inovise 12L Interpretive Algorithm Physicians Guide Rev G

Use this guide with software version 02.30.01.00 or later

The issue date for the Inovise 12L Interpretive Algorithm Physician’s Guide (REF 9650-001357-01 Rev. G) is September, 2019. ZOLL is a registered trademark of ZOLL Medical Corporation. All other registered trademarks and trademarks are property of their respective owners. Copyright © 2019 ZOLL Medical Corporation. All rights reserved.

ZOLL Medical Corporation 269 Mill Road Chelmsford, MA USA 01824-4105 ZOLL International Holding B.V. Newtonweg 18 6662 PV ELST The Netherlands

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Preface Intended Use ...i Warnings ...i How to Use This Manual ...ii Physician’s Guide Updates ...ii Conventions ...ii

Chapter 1

Introduction

Algorithm Overview... 1-2 Inovise 12L Interpretive Analysis Information ... 1-2

Chapter 2

Interpreting Myocardial Infarction

STEMI and Acute Myocardial Infarction: Clinical Focus ... 2-2 Definitions ... 2-2 STEMI ... 2-3 STEMI Example #1 ... 2-3 STEMI Example #2 ... 2-4 nSTEMI ... 2-4 nSTEMI Example ... 2-5 STEMI Equivalent ... 2-5 STEMI Equivalent Example ... 2-6 AHA/ACCF/HRS STEMI Guidelines ... 2-7 Guideline Limitations ... 2-7 Gender and Age Considerations ... 2-8 Confounding Condition Considerations ... 2-8 QRS Changes Associated with Evolving and Acute MI ... 2-8 Acute MI: Categories of Findings... 2-9 Category 1: “Acute ST Elevation {location} Infarct” ... 2-9 Category 2: “Probable Acute ST Elevation {location} Infarct” ... 2-10 Category 3: “Acute Anterior Infarct” ... 2-10 Category 4: “{location} infarct, probably acute” ... 2-10 Category 5: “{location} infarct, possibly acute” ... 2-11 Category 6: “Probable subendocardial injury” ... 2-12 Reasons Associated with Acute MI Findings ... 2-12

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Confounding Conditions ... 2-13 LBBB Reference Example: AMI Negative ... 2-14 LBBB STEMI Example #1: Anterolateral AMI ... 2-15 LBBB STEMI Example #2: Inferior AMI ... 2-16 LBBB STEMI Example #3: Posterior-Inferior AMI ... 2-17 RBBB Reference Example: AMI Negative ... 2-18 RBBB STEMI Example #1: Anterior AMI ... 2-19 RBBB STEMI Example #2: Inferior AMI ... 2-20 RBBB STEMI Example #3: Posterior-Inferior AMI ... 2-21 IVCD Reference Example: AMI Negative ... 2-22 IVCD STEMI Example: Inferior AMI ... 2-23 LAFB Reference Example: AMI Negative ... 2-24 LAFB STEMI Example: Anterior AMI ... 2-25 LVH Reference Example: AMI Negative ... 2-26 LVH STEMI Example: Anterolateral AMI ... 2-27 RAE Reference Example: AMI Negative ... 2-28 RAE STEMI Example: Inferior AMI ... 2-29 Chronic Myocardial Infarction ... 2-30 Categories of Findings, Age-Undetermined MI (AUMI) ... 2-30 Category 1 – Infarcts of Unspecified Size ... 2-31 Category 2 – Infarcts of Large Size ... 2-31 Reasons Associated with Age-Undetermined MI ... 2-32 Statements of Rationale for Age-Undetermined MI ... 2-32 Excluding and Error Conditions for MI Analysis ... 2-33 Excluding Conditions for MI Analysis ... 2-33 Error Conditions for MI Analysis ... 2-33

Chapter 3

Non-Myocardial Infarction Analysis Statements

Arm Lead Reversal and Dextrocardia... 3-2 Criteria ... 3-2 Rationale ... 3-2 Wolff-Parkinson-White ... 3-3 Criteria ... 3-3 Atrial Enlargement ... 3-4 Criteria ... 3-4 Rationale ... 3-4 Axis Deviation ... 3-5 Criteria ... 3-5 Rationale ... 3-5 Low Voltage ... 3-6 Criteria ... 3-6 S1-S2-S3 Pattern... 3-7 Criteria ... 3-7 Pulmonary Disease... 3-8 Criteria ... 3-8 Rationale ... 3-8

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Right Bundle Conduction ... 3-9 Criteria ... 3-9 Rationale ... 3-10 Left Bundle Conduction ... 3-11 Criteria ... 3-11 Rationale ... 3-12 Non-Specific Conduction Abnormality ... 3-13 Criteria ... 3-13 Rationale ... 3-13 Right Ventricular Hypertrophy ... 3-14 Criteria ... 3-14 Left Ventricular Hypertrophy ... 3-16 Findings for LVH ... 3-16 Reasons behind Findings for Evidence of LVH ... 3-17 Statements of Rationale for Men ... 3-17 Statements of Rationale for Women ... 3-17 Excluding Conditions for LVH ... 3-18 Early Repolarization... 3-19 Criteria ... 3-19 Pericarditis ... 3-20 Criteria ... 3-20 ST Depression ... 3-21 Criteria ... 3-21 ST Segment Elevation ... 3-22 Criteria ... 3-22 T Wave Abnormality, Ischemia... 3-23 Criteria ... 3-23 T Wave Abnormality, Nonspecific... 3-25 Criteria ... 3-25 Rhythm Statements ... 3-26 Rhythm Statements and Modifiers ... 3-26

Chapter 4

Glossary

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Preface

Preface Intended Use This manual is intended for use by medical practitioners who perform electrocardiography (ECG) and similar tests, and for physicians who interpret ECG data. The Inovise 12L Interpretive Algorithm provides automated detection and advanced identification of myocardial infarction (MI) and left ventricular hypertrophy (LVH) and standard interpretation of other types of rhythms and morphologies. While the 12L Interpretive Algorithm’s enhanced MI/LVH sensitivity should generally improve the clinical decision process, no diagnostic test has perfect sensitivity and specificity. The 12L Interpretive Algorithm’s interpretive statements are designed to enhance the diagnostic process. They are no substitute for the qualified judgment of a properly trained, supervised clinician. As with any diagnostic test, always give consideration to patient symptoms, history and other relevant factors. 12L Interpretive Algorithm testing is indicated for patients who present with cardiac symptoms, including shortness of breath, and for patients who are at risk for heart disease. 12L Interpretive Algorithm testing is indicated only for patients 18 years of age or older. 12L Interpretive Algorithm analyses are not valid for patients under 18 years of age. If a patient has one or more particular underlying heart conditions, the 12L Interpretive Algorithm might not analyze ECG abnormalities excluded by the particular underlying conditions. If any of these conditions occur, the unit displays a detailed message in its Analysis Results.

Warnings Inovise 12L Interpretive Algorithm analyses are not valid for patients under 18 years of age. Ensure qualified clinicians carefully review Inovise 12L charts from patients with implanted pacemakers. Implanted pacemakers can affect the Inovise 12L Interpretive Algorithm ECG analysis. The 12L Interpretive Algorithm incorporates pacemaker detection technology, but it might not detect all pacemakers. Before performing defibrillation or applying any high frequency surgical equipment to a patient, remove ECG electrodes from the chest area in order to prevent patient burns. Enter the correct age and gender for each patient before performing ECG analysis using the Inovise 12L Interpretive Algorithm. This enables the 12L Interpretive Algorithm to analyze patient data correctly. By default, the 12L Interpretive Algorithm is configured to test an 18+ year-old male.

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PREFACE

How to Use This Manual The Inovise 12L Interpretive Algorithm Physician’s Guide provides information operators need for the safe and effective use and care of the unit. It is important that all persons using this device read and understand all the information contained within. Please read thoroughly the safety considerations and warnings section in this guide.

Physician’s Guide Updates An issue or revision date for this Physician’s Guide is shown on the inside cover. If more than three years have elapsed since this date, contact ZOLL Medical Corporation to determine if additional product information updates are available. All users should carefully review each manual update to understand its significance and then file it in its appropriate section within this manual for subsequent reference. Product documentation is available through the ZOLL website at www.zoll.com. From the Products menu, choose Product Manuals.

Conventions This guide uses the following conventions: Within text, the names and labels for the unit’s physical buttons and softkeys appear in boldface type (for example, “Press the SHOCK button or the Code Marker softkey”). This guide uses uppercase italics for the unit’s audible prompts and for text messages displayed on the screen (for example, Acute Anterior Infarct).

WARNING!

Warning statements alert you to conditions or actions that can result in personal injury or death.

Caution

Caution statements alert you to conditions or actions that can result in damage to the unit.

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Chapter 1 Introduction This chapter provides an overview of the Inovise 12L Interpretive Algorithm (Inovise algorithm) and the interpretive statements provided from its analysis of a 12-lead ECG.

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CHAPTER 1 INTRODUCTION

Algorithm Overview The Inovise algorithm surpasses the traditional 12-lead ECG by providing an advanced analysis of 12-lead, resting ECG data. The Inovise algorithm uses advanced algorithms to extract data from the ECG criteria in order to create a detailed analysis of heart conditions. The unit provides a screen display of the Inovise algorithm findings on Analysis Pages 1 and 2. The unit can also print the Inovise algorithm findings on a strip chart with the ECG traces. This makes it easier for practitioners to understand the results and to educate patients about heart conditions.

Inovise 12L Interpretive Analysis Information The Inovise algorithm’s strip chart and screen display (Analysis Page 1 and 2) consolidates conventional ECG traces with advanced analysis statements to provide a concise report on the condition of the patient’s heart. The Inovise algorithm displays and prints the following information: • Patient demographics and rescue department/unit information. • Analysis results, summarized by Inovise algorithm’s Analysis Statements, which we

describe in detail in Chapters 2 and 3.

• Basic measurements. This includes the patient’s ventricular heart rate, PR interval, QRS

duration, QT interval, and so on.

• ECG traces

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Inovise 12L Interpretive Analysis Information

Information provided by Inovise algorithm includes the following fields: 12L Analysis Information Field

Indicates

Name:

Patient name.

ID:

Alphanumeric code used to identify patient.

12 Lead:

Date and time during which 12 Lead data was acquired.

Age:

Patient’s age.

Sex:

Patient’s gender.

Filtered Diagnostic

Indicates that the diagnostic filter was applied to the ECG sample.

NF=OFF

Indicates that the ECG notch filter is OFF.

Dept:

Alphanumeric label to identify rescue department.

Unit:

Alphanumeric label to identify unit in rescue department.

S/N

Serial Number of the unit used in rescue.

SW:

Software revision installed in the unit.

Analysis Results

Heading identifying the Analysis Statements and ECG measurements produced by the Inovise algorithm.

HR:

Patient’s heart rate in Beats Per Minute (bpm).

PR Interval:

Average duration of the 12 Lead sample’s PR interval in milliseconds (ms).

QRS Duration:

Average duration of the12 Lead sample’s QRS complex in milliseconds (ms).

QT Interval:

Average width of the 12 Lead sample’s QT Interval in milliseconds (ms).

QTc:

Average width of the 12 Lead sample’s QTc (QT Interval Corrected) in milliseconds (ms). The formula that the Inovise algorithm uses to derive QTc is as follows:

QT ------------RR where QT is the QT interval, and RR is the RR interval in seconds. The formula that the Inovise algorithm uses to derive RR is as follows:

60 --------HR where HR is the heart rate in Beats Per Minute (BPM). P Axis:

Axis of P wave in degrees.

QRS Axis

Axis of R wave in degrees.

T Axis:

Axis of T wave in degrees.

STJ (mm)

Lead-by-Lead deviation of the ST segment in mm, measured at the J-point

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CHAPTER 1 INTRODUCTION

The following strip chart sections provide an example of what the unit prints after the Inovise algorithm has determined the occurrence of an ST-Elevation Myocardial Infarction (*** STEMI***):

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Chapter 2 Interpreting Myocardial Infarction This chapter describes the analysis statements that the Inovise 12L Interpretive Analysis Algorithm (Inovise algorithm) provides for the interpretation of myocardial infarction. For each analysis statement, this chapter provides the criteria and the rationale from which the Inovise algorithm derives the analysis statement.

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Chapter 2 Interpreting Myocardial Infarction

STEMI and Acute Myocardial Infarction: Clinical Focus Electrocardiographic (ECG) evaluation for acute ischemic heart disease plays a central role in defining hospital-based STEMI protocols and it is crucial for reducing door-to-balloon time for STEMI cases. The Inovise algorithm is aligned with these clinical goals and validated retrospectively using very large databases of 12-lead ECGs in which the clinical status of the subjects was established through the following inputs: • Patient history • Patient physical examination, • Cardiac biomarker findings • Hospital discharge diagnosis.

Validation of the Inovise algorithm MI interpretation also included comparison with cardiac angiography imaging findings and reperfusion therapy results.

Definitions Term

Definition

Acute Myocardial Infarction (AMI)

AMI is broadly defined to be myocardial ischemia severe enough that if unresolved will result in myocardial tissue necrosis.

ST Elevation Acute Myocardial Infarction (STEMI)

STEMI is considered a subcategory of AMI caused by a 100% blockage of one coronary artery.

Non-ST Elevation Acute MI (nSTEMI)

nSTEMI may be defined as an AMI caused by a severely narrowed, but not completely blocked, coronary artery.

STEMI Equivalent

STEMI Equivalent is may be defined by: • STEMI ECG evidence in the presence of Left Bundle Branch Block (LBBB), • Isolated STEMI ECG evidence for the posterior wall • Left main occlusion. Note: An alternate definition for STEMI Equivalent is to associate it with high-grade left main coronary artery (LMCA) disease.

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STEMI and Acute Myocardial Infarction: Clinical Focus

STEMI STEMI (ST Elevation Acute Myocardial Infarction) is a subcategory of AMI usually caused by a 100% blockage of one of the coronary arteries. An ECG interpretation of STEMI is based upon evaluating cardio-electric signals captured at the skin surface from specific locations on the patient’s torso and limbs. A clinical workup for STEMI would typically include interpretation of the ECG and evaluation of patient presentation and history, cardiac biomarker and imaging study results, and inputs derived from other methods. As a result, ECG interpretation of STEMI is distinct from a clinical diagnosis of STEMI, though ECG results are an important input to the clinical diagnosis. The definitional differences between a clinical workup versus ECG interpretation for STEMI can create confusion when deciding the role of ECG findings for activation of STEMI protocols. This confusion can be partially, but not wholly, eliminated by applying published guidelines for interpreting ECG evidence for STEMI. Guidelines for the interpretation of STEMI can be found in the document, “AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram: Part VI: Acute Ischemia/Infarction: A Scientific Statement From the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: Endorsed by the International Society for Computerized Electrocardiology”. The examples that follow show representative samples of information delivered when the Inovise algorithm interprets the occurrence of STEMI, nSTEMI, and STEMI Equivalent.

STEMI Example #1 Below is the hospital admitting ECG with Inovise algorithm interpretation for a 67 year old female suffering from chest pain. The ECG exhibits prominent ST elevation in leads V2-V5 consistent with anterior wall STEMI. Cardiac biomarker results for the patient were positive for AMI. Angiography imaging results confirmed a proximal high-grade lesion of the LAD.

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Chapter 2 Interpreting Myocardial Infarction

STEMI Example #2 Below is the hospital admitting ECG with Inovise algorithm interpretation for a 50 year old male suffering from chest pain. The ECG exhibits ST elevation in the inferior leads that meets established STEMI criteria. The clinical workup for this patient included a 12-Lead ECG, cardiac enzymes and angiographic imaging. The admitting CK-MB was negative at 1 ng/ml. The angiogram revealed a 95% occlusion of the mid RCA which was subsequently resolved via PCI. The post-PCI CK-MB was highly positive for myocardial injury at 23.1 ng/ml.

nSTEMI nSTEMI may be defined as an AMI caused by a severely narrowed, but not completely blocked, coronary artery. Similar to the STEMI circumstance, an ECG interpretation of nSTEMI is distinct from a clinical diagnosis of nSTEMI. However, there are additional considerations for an nSTEMI diagnosis for these reasons: • An absence of a universally agreed upon definition for ECG evidence for nSTEMI. • An absence of clinical guidelines for treating nSTEMI that include a quantitative ECG

definition for nSTEMI.

One accepted definition for nSTEMI is myocardial infarction without ECG evidence of ST elevation. With this definition, the nSTEMI ECG is described as exhibiting widespread ST depression. However, a crucial deficiency with this definition is that it does not identify or categorize a significant group of AMI positive subjects where ST elevation is present, but insufficient to meet STEMI criteria.

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STEMI and Acute Myocardial Infarction: Clinical Focus

Note:

See the STEMI Equivalent section in this chapter for a description of how the Inovise algorithm interprets marked ST depression.

Clinical workup for these subjects often reveals high-grade coronary artery disease (CAD) or total occlusions of a coronary artery, suggesting the importance of considering interventional strategies for these cases that is comparable to that pursued when STEMI criteria are met. In order to address this potentially under-served population, the Inovise algorithm uses an alternate definition for nSTEMI that entails identifying AMI when there is a pattern of ST elevation present in the ECG that localizes to the coronary anatomy but is insufficient to meet established STEMI criteria. The Inovise algorithm accompanies this type of AMI finding with the annotation ***ACUTE MI***.

nSTEMI Example Below is the hospital admitting ECG with Inovise algorithm interpretation for a 38 year old male suffering from chest pain. While the ECG exhibits ST elevation in the inferior leads, the magnitude is insufficient to meet established STEMI criteria, which requires 100uV in two anatomically contiguous leads. The clinical workup for this patient included a 12-Lead ECG, cardiac enzymes and angiographic imaging. The admitting CK-MB was negative at 1.9 ng/ml. The angiogram revealed a 95% occlusion of the distal RCA which was subsequently resolved via PCI. The post-PCI CK-MB was highly positive for myocardial injury at 91.5 ng/ml.

STEMI Equivalent STEMI Equivalent also represents an important risk category for interventional consideration. There are two definitional conventions for STEMI Equivalent that may be considered. The first convention for STEM Equivalent includes: 1. STEMI ECG evidence in the presence of Left Bundle Branch Block (LBBB). 2. Isolated STEMI ECG evidence for the posterior wall. 3. Left main occlusion. 9650-001357-01 Rev. G

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Chapter 2 Interpreting Myocardial Infarction

The Inovise algorithm employs an alternate definition for the first two of these three clinical scenarios. • For the case of STEMI evidence in the presence of LBBB and other primary STT

confounding conditions, such as Right Bundle Branch Block (RBBB) or Left Ventricular Hypertrophy (LVH), the Inovise algorithm annotates these as ***STEMI***. The AMI interpretive statement includes an equivocation of the form “Probable Acute ST Elevation Infarct” due to the uncertainties introduced by the presence of a confounding condition.

• For the case of STEMI evidence for posterior wall AMI, the Inovise algorithm considers

these as “***STEMI***”, consistent with published guidelines for the identification of posterior wall STEMI.

The second definitional convention for STEMI Equivalent is to associate it with high-grade left main coronary artery (LMCA) disease, a very high-risk pathology. Acute LMCA disease manifests in the ECG as widespread, apically directed ST depression. A challenge with applying this ECG interpretation lies with differentiating LMCA from acutely severe three-vessel disease, which can produce a similar ECG. To address this challenge, the Inovise algorithm provides a finding of “subendocardial injury” as the ECG interpretation that covers both of these underlying pathologies.

STEMI Equivalent Example Below is the hospital admitting ECG with Inovise algorithm interpretation for a 76 year old male suffering from chest pain and dyspnea. The ECG does not exhibit a localizing pattern of ST elevation and does not meet any STEMI criteria but does show marked, widespread ST depression directed toward the apex. The ECG also shows strong evidence for LVH. STJ normalized for the effects of LVH is sufficient to support a finding of subendocardial injury. The clinical workup for this patient included a 12-Lead ECG, cardiac enzymes and angiographic imaging. The admitting CK-MB was negative with a reading of 2.9 ng/ml. The angiogram revealed severe left main disease. Peak CK-MB was positive at 53.5 ng/ml.

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AHA/ACCF/HRS STEMI Guidelines

AHA/ACCF/HRS STEMI Guidelines Published guidelines from an AHA/ACCF/HRS working group standardize ECG interpretation for STEMI. The guideline STEMI definition relies upon ST elevation measurements taken in pairs of anatomically contiguous ECG leads with ST elevation thresholds uniform at 100uV for limb lead measurements and for precordial leads V4-V6. The thresholds for precordial leads V1-V3 are nominally set at 200uV. The Inovise algorithm AMI finding includes the annotation ***STEMI*** whenever the ECG ST measurements meet the criteria as described in the guidelines document, “AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram: Part VI: Acute Ischemia/Infarction: A Scientific Statement From the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: Endorsed by the International Society for Computerized Electrocardiology”. This document is available from the websites of the following organizations: Organization

URL

American Heart Association

http://my.americanheart.org

American College of Cardiology Foundation

http://www.acc.org

Heart Rhythm Society

http://www.hrsonline.org

Guideline Limitations Limitations to the guidelines for a STEMI diagnosis emerge with the consideration of gender and age and with STT confounding conditions. Currently, the AHA/ACCF/HRS guidelines offer only limited criteria adjustments for the following patient groups: • Female • Young Male (under 40 years) • LBBB patients

The Inovise algorithm incorporates the existing AHA/ACCF/HRS guideline criteria adjustments and specifies additional adjustments, based on very large databases of ECGs clinically correlated to be AMI positive or AMI negative for females and on a broader category of STT confounding conditions other than LBBB. As a result, the Inovise algorithm will annotate some ECGs as ***STEMI*** that are not identified as such by the guideline criteria for STEMI. These criteria adjustments and extensions enable the Inovise algorithm to have an improved sensitivity for STEMI while maintaining very high specificity.

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Chapter 2 Interpreting Myocardial Infarction

Gender and Age Considerations The STEMI guideline threshold adjustments that account for gender and age differences are limited to the lead pair V2-V3. • For females, the guidelines decrease the threshold from 200uV to 150uV. • For males under 40 years, the guidelines increase the threshold from 200uV to 250uV.

As a result of the study of extensive databases of clinically correlated ECGs, the Inovise algorithm uses a proprietary method to make further gender and age adjustments for STEMI and nSTEMI/AMI determination. These adjustments result in improved overall accuracy for STEMI, and for nSTEMI/AMI.

Confounding Condition Considerations The AHA/ACCF/HRS guidelines recognize LBBB as a primary confounder for interpreting ST elevation for STEMI. The Inovise algorithm supports the guideline by employing specific STEMI criteria in the presence of LBBB. It also surpasses the guideline through additional criteria for other ECG conditions known to perturb the STT and confound the interpretation of ST deviation for AMI. The Inovise algorithm does this by employing a proprietary method for quantifying the effect on STT measurements due to these confounding conditions. With this method, the algorithm mathematically removes the quantified effect of these confounders, effectively normalizing the STJ in such a manner that STEMI thresholds, consistent with guideline definitions, can be applied. See the section below entitled “Confounding Conditions” for a list and further discussion of confounders and Inovise algorithm findings in the presences of these confounders.

QRS Changes Associated with Evolving and Acute MI The early stages of AMI (STEMI, nSTEMI, and STEMI Equivalent) are accompanied by STT changes. As an AMI evolves from its early stages, QRS changes emerge, that indicate depolarization and repolarization abnormalities which result from hibernating or necrotic myocardial cells. With this understanding of AMI evolution, a relationship emerges between the time of AMI onset, the timing of reperfusion intervention, and the degree of myocardial salvage that can be accomplished with such interventions. Understanding this relationship is crucial to the STEMI protocol objective to minimize door-to-balloon time to less than one hour for many hospitals. The Inovise algorithm is optimized to have the highest possible accuracy for detection of early-stage AMI. The algorithm then differentiates early AMI from evolving AMI and chronic MI through evaluation of QRS changes. The algorithm relies the Selvester QRS Score as a means to quantify the degree of myocardial scar present within the left ventricle. This information is incorporated into the AMI assessment as follows: 1. If AMI STT abnormalities are prominent, and QRS changes are minor or modest, the Inovise algorithm produces an AMI finding of the form “MI, probably acute”, indicating the AMI is actively evolving but is no longer in the earliest stage.

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Acute MI: Categories of Findings 2. If AMI STT abnormalities are modest and QRS changes are modest, the Inovise algorithm

produces an AMI finding of the form “MI, possibly acute”, indicating the AMI has likely undergone significant evolution, but may still be considered actively acute. 3. If AMI STT abnormalities are modest or have resolved and QRS changes are prominent, the Inovise algorithm produces a finding of “MI, age undetermined”, indicating the MI has likely completely evolved and therefore may be considered chronic. This aspect of the Inovise algorithm is intended to aid the clinician’s decision to pursue interventional therapies considerate of both patient risk and the potential opportunity to salvage myocardium.

Acute MI: Categories of Findings Findings for the acute portion of the Inovise algorithm are divided into six categories that are discussed in this section.

Category 1: “Acute ST Elevation {location} Infarct” This finding is reported when no STT confounding conditions are present, and when ST levels measured meet the published guideline definition for STEMI. This statement is accompanied by a ***STEMI*** annotation.

Statement Location Variants Acute ST Elevation Anterior Infarct Acute ST Elevation Posterior Infarct Acute ST Elevation Inferior Infarct Acute ST Elevation Apical Infarct Acute ST Elevation Anterolateral Infarct Acute ST Elevation Anterior-Inferior Infarct Acute ST Elevation Inferior Infarct w/ Posterior Extension Acute ST Elevation Posterior Infarct w/ Inferior Extension Acute ST Elevation Posterior-Anterolateral Infarct Acute ST Elevation Inferoapical Infarct

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