Continuing Education Activity

Acute coronary syndromes are a significant cause of morbidity and mortality. Early diagnosis has a central role in allowing a timely reperfusion strategy. The de Winter electrocardiogram pattern is a finding that, in a proper setting, is highly suggestive of acute occlusion of the left anterior descending artery. This electrocardiogram finding consists of an ST-segment upsloping depression at the J point of 1 to 3 mm in leads V1 to V6, associated with tall, peaked positive T waves. The pattern is considered to be equivalent to an ST elevation as a clinical indication of myocardial infarction. Therefore, clinical recognition of this finding and the additional evaluation it should precipitate is critical to improving patient outcomes. Emergent consultation with a cardiologist should be undertaken when the de Winter electrocardiogram pattern is observed to allow for timely cardiac catheterization and primary percutaneous coronary intervention, if appropriate, to ensure appropriate reperfusion as per ST-elevation myocardial infarction (STEMI) guidelines. This activity reviews the evaluation and treatment of patients who present with the de Winter electrocardiogram pattern and highlights the role of the interprofessional team in evaluating and treating patients with this condition.

Objectives:

• Apply the pathophysiology of the de Winter electrocardiogram pattern.

• Identify the typical presentation and the adequate evaluation of patients with the de Winter electrocardiogram pattern.

• Compare the differential diagnosis associated with the de Winter electrocardiogram pattern.

• Collaborate amongst the interprofessional team to enhance care delivery for patients with the de Winter electrocardiogram pattern in an appropriate clinical context.

Introduction

Ischemic heart disease (IHD) is a major cause of morbidity and mortality.[1] Although there have been significant improvements in the overall management of patients suffering from acute coronary syndromes (ACS), this entity is still associated with a relevant clinical burden.[2][3][4] In this context, the electrocardiogram (ECG) is central to the diagnostic process and treatment allocation, as early diagnosis allows for a timely reperfusion strategy. Though differentiation between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) is pivotal, over the years, several electrocardiographic patterns associated with an increased risk of cardiovascular (CV) events have been described.[2][3][5][6][4]

The de Winter electrocardiogram pattern is a finding that, in a proper setting, is highly suggestive of acute occlusion of the left anterior descending artery. This electrocardiogram finding consists of an ST-segment upsloping depression at the J point of 1 to 3 mm in leads V1 to V6, associated with tall, peaked positive T waves. The pattern is considered to be equivalent to an ST elevation as a clinical indication of myocardial infarction. Therefore, clinical recognition of this finding and the additional evaluation it should precipitate is critical to improving patient outcomes. Emergent consultation with a cardiologist should be undertaken when the de Winter electrocardiogram pattern is observed to allow for timely cardiac catheterization and primary percutaneous coronary intervention, if appropriate, to ensure appropriate reperfusion as per ST-elevation myocardial infarction (STEMI) guidelines.[2][5][7][4]

Etiology

The de Winter ECG pattern is associated with occlusion of the coronary arteries, most often the LAD. However, cases involving other coronary arteries (eg, the right coronary artery and the circumflex artery) have also been described.[8][9][10][11][12][13] Most cases reported occlusion due to atherosclerotic disease in line with other presentations of myocardial infarction,[5][12][5][8] though this pattern has also been described as due to a thromboembolic event.[13][5][12][5][8][13] The de Winter ECG pattern has also been noted without an acute epicardial occlusion after a percutaneous coronary intervention, hypothesized as associated with impaired microvascular perfusion.[12]

Epidemiology

The de Winter electrocardiogram pattern is an infrequent presentation, reported to occur in 2% to 3.4% of patients with anterior myocardial infarction.[8][10][14][15] Because the de Winter electrocardiogram pattern relates to patients presenting with ACS, the risk factors associated with this pattern are similar to those of ischemic heart disease (eg, increased age, smoking, dyslipidemia, hypertension, diabetes mellitus, and obesity).[1][2][3][14] In some studies, male patients were more likely to present with this pattern, and some authors have reported that individuals with this pattern tend to be younger than those who present with an anterior STEMI.[14][15][10][15]

Pathophysiology

Though the specific pathophysiology associated with the de Winter ECG pattern is unclear, several potential mechanisms have been proposed. One that has garnered substantial interest relates to subendocardial ischemia, with ensuing subendocardial, as compared to subepicardial, action potentials at a hyperacute stage of the event before transmural ischemia becomes predominant.[16][14][17][18] Another theory is that collateral circulation causes the de Winter ECG pattern.[18][19] This latter hypothesis, however, does not fully explain reports of this presentation in patients without adequate collateral circulation.[8][16][14] Other proposed mechanisms include anatomical variants in the Purkinje fibers and myocardial metabolism downregulation.[8][11][17] A contemporary cardiac magnetic resonance imaging study by Zorzi et al highlighted the potential interplay of several mechanisms (eg, differential action potential expression and collateral circulation) resulting in the de Winter ECG pattern.[18]

History and Physical

Given that the de Winter ECG pattern is generally associated with an ACS, patients frequently will present with a medical history positive for heart disease risk factors, including a family or personal history of heart disease, hypertension, or dyslipidemia. Clinical features are also consistent with ACS (eg, oppressive acute chest pain and shortness of breath).[2][5][16][11][19][4]

Because the de Winter ECG pattern is often associated with a hyperacute stage of myocardial infarction (MI), physical examination can be unremarkable. However, some patients may present with diaphoresis and ongoing discomfort associated with acute symptomatology in the setting of ACS.[16][11][13][18][19] Findings on physical examination may also vary, as detailed by the Killip classification system, which was developed to guide the clinical assessment of patients with myocardial infarction.[2][20][2]

• Killip class I: patients without any clinical sign of heart failure
• Killip class II: patients with crackles or rales in the lungs, elevated jugular venous pressure, and an S3 gallop
• Killip class III: patients with evident acute pulmonary edema
• Killip class IV: patients with cardiogenic shock or hypotension (ie, a systolic blood pressure <90 mm Hg) and signs of low cardiac output (eg, oliguria, cyanosis, or impaired mental status)

Evaluation

The de Winter ECG pattern, as proposed in the seminal article by De Winter et al, consists of an ST-segment upsloping depression at the J point of 1 to 3 mm in leads V1 to V6, associated with tall and peaked positive T waves.[8] Additionally, most individuals present with a 1 to 2 mm ST-segment elevation in lead aVR.[8] Other possible findings include loss of R wave progression in the precordial leads and QRS complexes of normal duration or only slightly widened.[8] (see Image. The de Winter ECG pattern)

However, strict criteria defining the de Winter ECG pattern remain elusive, as elegantly reported in a systematic review by Morris et al which showed differences in categorization among studies.[9][10] In this review, upsloping depression of the ST-segment focusing on lead V3 and associated with upright T waves were consistently reported, whereas most individuals also had poor progression of the R wave as well as ST-segment elevation in lead aVR.[9] Interestingly, although initially described as comprising a static pattern, which was also noted in other studies, there are reports describing a potential temporal evolution as the ischemic event unfolds.[9][8][21][15][19]

Cardiac biomarkers, specifically high-sensitivity cardiac troponin (hs-cTn), should be assessed, though as stressed in contemporary guidelines, this should not delay the reperfusion strategy.[2][5][4] This pattern is associated with a hyperacute presentation, and therefore, clinicians should be aware that hs-cTn may be within the normal range or only mildly elevated initially.[16][22] Given the differential diagnosis, serum potassium levels may be considered, though this should not delay the reperfusion strategy.[8][16][23]

Treatment / Management

In patients with ACS risk factors or clinical features, the presence of the de Winter ECG pattern should lead to a high degree of suspicion for LAD artery occlusion.[5][10][19] Emergent consultation with a cardiologist should be undertaken, thus allowing early referral for cardiac catheterization and primary percutaneous coronary intervention (PCI) if appropriate to ensure appropriate reperfusion as per STEMI guidelines.[2][3][8][10][19][4] Additionally, optimized medication, including aspirin, a P2Y12 inhibitor, and anticoagulation, should be implemented as the interventional cardiologist recommends.[2][3][4][24] After adequate reperfusion, patients should be admitted to a monitored coronary care or intensive cardiac care unit, with subsequent management and ancillary testing recommended by current guidelines.[2][3][5][4]

Differential Diagnosis

Though most cases of this pattern are associated with an acute occlusion of the LAD artery, similar changes in repolarization can also be present in other clinical scenarios. Among these, hyperkalemia should be considered, although this condition can typically be differentiated by a distinct clinical presentation and T waves that tend to be narrow and sharply peaked.[22][23][25] Moreover, as discussed by Xu et al, tachycardia can also be associated with the upsloping depression of the ST-segment and cTn elevation.[14]

Prognosis

The de Winter ECG pattern is associated with acute coronary artery occlusion, most notably the LAD.[8][9] As such, early recognition and treatment allocation are critical to allow adequate reperfusion and improve the substantial morbidity and mortality associated with a large anterior MI.[2][26][4]

Deterrence and Patient Education

As early diagnosis plays a prominent part in the management of individuals with an ACS and given the potential adverse outcomes associated with an acute LAD occlusion, reducing any barriers to seeking medical care is essential. Therefore, patients should be counseled on the most common symptoms associated with ACS and the importance of seeking urgent medical evaluation.[2][26][4] In this way, patient delays may be avoided, thus reducing total ischemic time.[2][4]

Enhancing Healthcare Team Outcomes

The de Winter electrocardiogram pattern highly suggests acute occlusion of the LAD artery.[8][9][10] Given this background, all members involved in the interprofessional care process of individuals presenting with acute chest pain should be able to identify this ECG finding expertly, thus streamlining the diagnostic and therapeutic process of this challenging and high-risk subset of patients. Healthcare practitioners in the many departments that may encounter these patients, including primary care, emergency room, cardiology, and internal medicine, should recognize that further evaluation is warranted when the de Winter electrocardiogram pattern is present, leading to improved recognition of potential abnormalities. Additionally, electrocardiogram technicians, cardiac procedural staff, and pharmaceutical clinicians are often needed to provide care to these patients when diagnosed with acute coronary syndromes. As a result, clinicians can use this finding to help guide treatment strategies and improve patient outcomes.[2][5][10][26][4]