Analyzing Electrocardiography Abnormalities in COVID-19 Patients Admitting to Emergency Department

Stress Cardiomyopathy: The Midventricular Variant

Acute ST-segment elevation myocardial infarction (STEMI) is a serious disease in clinical practice. The rapid and accurate diagnosis of this critical illness can lead to prompt reperfusion, and it enables the reduction of cardiac ischemic damage and results in improved subsequent outcomes. The shorter the time to reperfusion, the greater the benefits. 1) The American College of Cardiology/American Heart Association STEMI guidelines recommend primary percutaneous coronary intervention for the treatment of STEMI with a doorto-balloon time of less than 90 minutes. 2) Therefore, the prompt and accurate diagnosis of STEMI is an important issue. In the diagnosis of STEMI, the 12-lead electrocardiogram (ECG) is an indispensable diagnostic tool directing the emergent management of patients with acute STEMI. However, a variety of other conditions aside from STEMI can cause ST-segment elevation on the ECG. 3)4) Several recent studies have found a frequency of false-positive catheterization laboratory activation. ] In another study, the prevalence of false-positive STEMI diagnosis was 10.4% and the characteristics and prognosis in patients with a false-positive STEMI diagnosis in an emergency department was investigated. 9) In this study, false-positive STEMI diagnosis patients had a lower incidence of typical chest pain or chest tightness. Inferior ST-segment

A Multidisciplinary Approach to Reducing Door-to-Balloon Time in a Community Hospital

Clinical case: A 58-year-old woman called 9-1-1 with acute onset of chest pain that had persisted for 30 minutes. She had a history of hypertension, hyperlipidemia, and type 2 diabetes mellitus but no previous history of myocardial infarction or heart failure. Her medications included aspirin, atorvastatin, lisinopril, and metoprolol. Paramedics were dispatched, and a prehospital ECG demonstrated 3- to 4-mm ST-segment elevation in leads I, aVL, and V2 through V6 (Figure 1). Her examination revealed a regular pulse of 90 bpm, a blood pressure of 100/60 mm Hg, clear lungs, and normal heart sounds with no murmurs. Paramedics interpreted the prehospital ECG and activated the catheterization laboratory en route to the hospital. On hospital arrival, the patient was transported directly to the catheterization laboratory. Coronary angiography demonstrated an occluded proximal left anterior descending artery, which was successfully treated with balloon angioplasty and a stent. The pertinent time intervals were as follows: paramedic dispatch to balloon time, 56 minutes; paramedic arrival at the scene to balloon time, 46 minutes; hospital door to balloon time, 23 minutes. Her biomarkers revealed a peak troponin T of 2.42 ng/mL and a peak creatine kinase muscle-brain isoenzyme of 26.8 ng/mL. An echocardiogram demonstrated normal left ventricular ejection fraction of 55%, with mild anterior hypokinesis, and the patient was discharged on hospital day 3. Figure 1. Prehospital ECG. American Heart Association national guidelines,1–3 as well as other consensus and scientific statements,4–11 recommend that emergency medical services (EMS) acquire and use prehospital ECGs to evaluate patients with suspected acute coronary syndrome. Despite these recommendations, prehospital ECGs are used in fewer than 10% of patients with ST-segment–elevation myocardial infarction (STEMI),12,13 and this rate has not substantially changed since the mid-1990s. Furthermore, even when a prehospital ECG is acquired, the information is often not …

The Need for Uniform Definitions in the Regionalized Care of ST‐segment Elevation Myocardial Infarction

Electrocardiographic features of patients with COVID-19: One year of unexpected manifestations

Background. Many prehospital protocols require acquisition of a single 12-lead electrocardiogram (ECG) when assessing a patient for ST-segment elevation myocardial infarction (STEMI). However, it is known that ECG evidence of STEMI can evolve over time. Objectives. To determine how often the first and, if necessary, second or third prehospital ECGs identified STEMI, and the time intervals associated with acquiring these ECGs and arrival at the emergency department (ED). Methods. We retrospectively analyzed 325 consecutive prehospital STEMIs identified between June 2008 and May 2009 in a large third-service emergency medical services (EMS) system. If the first ECG did not identify STEMI, protocol required a second ECG just before transport and, if necessary, a third ECG before entering the receiving ED. Paramedics who identified STEMI at any time bypassed participating local EDs, taking patients directly to the percutaneous coronary intervention (PCI) center. Paramedics used computerized ECG interpretation with STEMI diagnosis defined as an “acute MI” report by GE/Marquette 12-SL software in ZOLL E-series defibrillator/cardiac monitors (ZOLL Medical, Chelmsford, MA). We recorded the time of each ECG, and the ordinal number of the diagnostic ECG. We then determined the number of cases and frequency of STEMI diagnosis on the first, second, or third ECG. We also measured the interval between ECGs and the interval from the initial positive ECG to arrival at the ED. Results. STEMI was identified on the first prehospital ECG in 275 cases, on the second ECG in 30 cases, and on the third ECG in 20 cases (cumulative percentages of 84.6%, 93.8%, and 100%, respectively). For STEMIs identified on the second or third ECG, 90% were identified within 25 minutes after the first ECG. The median times from identification of STEMI to arrival at the ED were 17.5 minutes, 11.0 minutes, and 0.7 minutes for STEMIs identified on the first, second, and third ECGs, respectively. Conclusions. A single prehospital ECG would have identified only 84.6% of STEMI patients. This suggests caution using a single prehospital ECG to rule out STEMI. Three serial ECGs acquired over 25 minutes is feasible and may be valuable in maximizing prehospital diagnostic yield, particularly where emergent access to PCI exists. Key words: prehospital emergency care; myocardial infarction; ECG; STEMI

The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines was formed to make recommendations regarding the diagnosis and treatment of patients with known or suspected cardiovascular disease. Coronary artery disease (CAD) is the leading cause of death in the United States. Unstable angina (UA) and the closely related condition non–ST-segment elevation myocardial infarction (NSTEMI) are very common manifestations of this disease. These life-threatening disorders are a major cause of emergency medical care and hospitalizations in the United States. In 1996, the National Center for Health Statistics reported 1 433 000 hospitalizations for UA or NSTEMI. In recognition of the importance of the management of this common entity and of the rapid advances in the management of this condition, the need to revise guidelines published by the Agency for Health Care Policy and Research (AHCPR) and the National Heart, Lung and Blood Institute in 1994 was evident. This Task Force therefore formed the current committee to develop guidelines for the management of UA and NSTEMI. The present guidelines supersede the 1994 guidelines. The customary ACC/AHA classifications I, II, and III summarize both the evidence and expert opinion and provide final recommendations for both patient evaluation and therapy: Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective . Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment. Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy. Class IIb: Usefulness/efficacy is less well established by evidence/opinion. Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective and in some cases may be harmful. The weight of the evidence was ranked highest (A) if the data …

The long-term cardiovascular outcomes of a population-based cohort presenting to the emergency department (ED) with chest pain and classified with a clinical risk stratification algorithm are not well documented. The Olmsted County Chest Pain Study is a community-based study that included all consecutive patients presenting with chest pain consistent with unstable angina presenting to all EDs in Olmsted County, Minnesota. Patients were classified according to the Agency for Health Care Policy and Research (AHCPR) criteria. Patients with ST elevation myocardial infarction and chest pain of noncardiac origin were excluded. Main outcome measures were major adverse cardiovascular and cerebrovascular events (MACCE) at 30 days and at a median follow-up of 7.3 years, and mortality through a median of 16.6 years.The 2271 patients were classified as follows: 436 (19.2%) as high risk, 1557 (68.6%) as intermediate risk, and 278 (12.2%) as low risk. Thirty-day MACCE occurred in 11.5% in the high-risk group, 6.2% in the intermediate-risk group, and 2.5% in the low-risk group (p < 0.001). At 7.3 years, significantly more MACCE were recorded in the intermediate-risk (hazard ratio [HR], 1.91; 95% confidence intervals [CI], 1.33-2.75) and high-risk groups (HR, 2.45; 95% CI, 1.67-3.58). Intermediate- and high-risk patients demonstrated a 1.38-fold (95% CI, 0.95-2.01; p = 0.09) and a 1.68-fold (95% CI, 1.13-2.50; p = 0.011) higher mortality, respectively, compared to low-risk patients at 16.6 years. At 7.3 and at 16.6 years of follow-up, biomarkers were not incrementally predictive of cardiovascular risk.In conclusion, a widely applicable rapid clinical algorithm using AHCPR criteria can reliably predict long-term mortality and cardiovascular outcomes. This algorithm, when applied in the ED, affords an excellent opportunity to identify patients who might benefit from a more aggressive cardiovascular risk factor management strategy.

Analysis of depolarization abnormality and autonomic nerve function after stereotactic body radiation therapy for ventricular tachycardia in a patient with old myocardial infarction

Usefulness of Ventricular Premature Complexes to Predict Coronary Heart Disease Events and Mortality (from the Atherosclerosis Risk In Communities Cohort)

Scenario: This is a resting 12-lead electrocardiogram (ECG) from a 68-year-old man during his first annual physical examination with a new provider. He has no significant medical history, has a normal body weight, and takes a daily aspirin. Of note, he shares that he has not seen a provider since he was 60 years old because he has anxiety about seeing health care providers.Normal sinus rhythm at 60 beats per minute with inferolateral ventricular strain pattern and premature ventricular contractions (PVCs) in a trigeminal pattern.Despite the PVCs, it is important to note that the overall rhythm is sinus. This means that the dominant pacemaker is the sinoatrial (SA) node. Looking at the 10-second rhythm strip in lead II, at the bottom of the 12-lead ECG, it can be appreciated that the first 2 beats are sinus, each preceded by a P wave and then followed by a PVC. This pattern of 2:1 (sinus to PVC) continues and is called ventricular trigeminy. During PVCs, the ventricles are stimulated by pacemaker cells called the Purkinje fibers. Because the PVCs are premature, there is a pause before the next regular beat. This is labeled as a complete compensatory pause, which occurs because the SA node continues to pace uninterrupted. These PVCs would be labeled as unifocal, because they all have the same morphology, which means that they are being generated in the same ventricular location. Clinically, another important ECG pattern that is present is a ventricular strain pattern seen in the inferolateral leads (inferior, II, III and aVF and lateral, V3 to V6), especially with the presence of the discordant direction (opposite) of the QRS complex to the T wave. This pattern is associated with left ventricular hypertrophy (LVH), which is due to increased ventricular mass. With an increase in the mass of the left ventricle, there can also be a lengthening of the QT interval, as seen here. Last, LVH is a common cause of PVCs and may be the source of the trigeminal rhythm seen in this patient.In this case, the PVCs may be a sign that the patient has undetected LVH. The presence of the strain pattern, an ECG marker for the presence of LVH, merits a referral to cardiology to obtain an echocardiogram, the gold standard test for chamber enlargement. In addition, the patient should be screened for hypertension which is a contributing risk factor for LVH and is often asymptomatic. Valvular heart disease (ie, aortic, pulmonic) may also lead to LVH; hence, an echocardiogram could also rule in or out this possible source. LVH is prevalent in nearly 15% of men and 9% of women in the total population, and the prevalence increases with age. Notably, LVH increases the risk of a myocardial infarction, cerebral stroke, and/or death. Recently, some evidence suggests that LVH may actually be a modifiable cardiovascular risk factor; thus, with optimal care, patients could have better outcomes.

ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction--executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients With Acute Myocardial Infarction).

Change in out-of-hospital 12-lead ECG diagnostic classification following resuscitation from cardiac arrest

Introduction: The change in cardiac position caused by the thoracic deformity in patients with pectus excavatum (PEX) produces characteristic electrocardiogram (ECG) findings. However, the significance of ECG changes during exercise is unknown. Hypothesis: The ECG changes with exercise in PEX are related to worsening severity of PEX and location of PEX in relation to the heart. Methods: This was a retrospective review of patients ≤19 years old that underwent an institution-based protocol for preoperative PEX evaluation with ECG, echocardiogram (TTE), chest computerized tomography (CT) and cardiopulmonary exercise test (CPET) between January 2015 and December 2021. ECG changes with exercise were compared to the severity of PEX as defined by the Haller index (HI; mild = 2-3.2, moderate = 3.2-3.5, severe &gt; 3.5) and location of the PEX as determined by right ventricular compression on CT. ECG changes were also compared to tricuspid valve annulus size (TVAS) on TTE and resting heart rate (HR) and HR reserve on CPET. Pearson's χ2 was used to compare categorical variables. Two-sample T-test was used to compare categorical with continuous variables. Results: There were 124 patients (85% male; median age 15 years [10-19 years]) with median HI 3.7 (2.4-20). Abnormal ECG changes with exercise were seen in 33 % of patients. Premature ventricular complexes (PVC) were the most frequently encountered (n=30; 73%). There was no significant difference in severity of PEX in patients with PVCs [χ2 =0.93, p 0.33; median HI of 3.9 (IQR 1.6) vs 3.7 (IQR 1.4)]. The majority of patients (96%) with PVCs had evident right ventricular compression on CT (χ2 = 5.20, p 0.02). Similarly, those with abnormal ECG changes with exercise were more likely to have a lower TVAS in comparison to those without [χ2 = 4.17, p 0.04; median TVAS z score -2.06 (IQR 1.22) vs -2.32 (IQR 0.75)]. The CPET indices were not significantly different between the two groups. Conclusions: The most frequent ECG abnormality seen with exercise in PEX in this cohort is PVCs. Lower TVAS and right ventricular compression on CT were significantly correlated with the development of PVCs with exercise. Follow-up evaluation of ECG during CPET after PEX repair may help affirm resolution of ectopy.