One ECG with 2 Rare Findings: Wellens Syndrome With Prolonged QT Interval in Acute Myocardial Infarction Due to LAD Occlusion

Introduction

Wellens syndrome is considered a sign of threatening left anterior descending (LAD) coronary artery occlusion and anterior wall myocardial infarction with increased risk of complications [1]. Acquired prolongation of the QT interval might be caused by repolarization disorders in myocardial ischemia and lead to life-threatening rhythm disorders, such as the R-on-T phenomenon, inducing ventricular fibrillation or torsade de pointes. Both findings might be seen in patients with myocardial infarction, but it is extremely unique to find them at the same time. We found very few similar cases described in the literature [2].

We describe a rare case of 2 electrocardiogram (ECG) findings occurring suddenly during hospitalization in a patient admitted to the invasive cardiology department due to a non-ST elevation myocardial infarction. Two days after admission, the presence of extremely long QT intervals and Wellens syndrome was observed in the standard 12-lead ECG.

Case Report

A 75-year-old female patient with chronic lymphocytic leukemia and hypertension presented to the emergency department with intermittent chest pain of 2 days’ duration. The chest pain was described as burning, located behind the sternum, radiating to the jaw, and recurring during the slightest exertion. In the electrocardiogram on admission a normal sinus rhythm with negative T waves in I, aVL, and V6; and corrected QT (QTc) interval of 431 ms were observed. High-sensitivity troponin T levels (max 451 ng/L; N<14) and creatine phosphokinase-myocardial band (CK-MB) levels (max 43 U/L, N<24) were noted. Coronary angiography revealed the critical stenosis of the distal left main (LM) and proximal LAD coronary artery with Thrombolysis In Myocardial Infarction (TIMI) scale flow 3 (Video 1).

The coronary angioplasty was postponed in accordance with the decision of the Heart Team. Transthoracic echocardiography revealed a mildly reduced ejection fraction of 40% with no valvular disorders. Chest pain subsided but the deep inverted T waves in the V2–V4 leads and the QTc prolongation to the maximum of 828 ms were observed on the ECG 2 days after coronary angiography. Wellens syndrome, an equivalent of ST elevation myocardial infarction (STEMI) was recognized. The patient was immediately referred to the local Heart Team, which made the decision to conduct an urgent high-risk percutaneous coronary intervention (PCI). No risk factors for acquired long QT syndrome were found, including medications that prolong the QT. The patient was not using any neuroleptics, antidepressants, antiarrhythmics, or antileukemic drugs; she denied infection treated with antibiotics in the last couple of months. She denied any history of faints or sudden cardiac deaths in the family. She had well-balanced electrolytes (potassium level 4.5 mmol/L, sodium level 142 mmol/L, magnesium level 1.1 mmol/L, ionized calcium level 1.05 mmol/L). Her white blood count was 48.75×103/μL and was similar to the previous results seen in this patient during the chronic lymphocytic leukemia observation. Due to high bleeding risk, clopidogrel was administered. The right radial artery approach was obtained, and a 6-French guiding catheter was introduced in the LM ostium. A Viperwire Advance (CSI, St. Paul, MN, USA) facilitated orbital atherectomy (OA) with the Diamondback 360 coronary system (CSI, St. Paul, MN, USA). OA was launched backward and forward with the speed of 80 000 to 120 000 rpm in the LM and proximal LAD. Sequentially, pre-dilatation with non-compliant 3.0 and 3.5 balloons was performed. The next step was implantation of a Resolute 3.0/18 mm stent to the LM and LAD followed by post-dilatation with 3.5 non-compliant balloon. A proximal optimization technique with a 4.0 non-compliant balloon was used to optimize the stent apposition. An optimal angiographic result was confirmed with intravascular ultrasound. The result of the PCI is presented in Video 2.

During 14 days of hospital stay, a gradual reduction of the QT interval was observed. Any medications that could provoke QT prolongation were excluded – no antiarrhythmics, antihistamines, antidepressants, neuroleptics, fluoroquinolones, or macrolides were started in this patient. Electrolytes were checked regularly and supplemented during the hospitalization to maintain the upper range of potassium, calcium, and magnesium. Due to bradycardia of 45 bpm, the use of a beta-blocker was limited to the minimal dose of 1.25 mg of bisoprolol. During ECG telemetry and Holter monitoring, several episodes of short coupled premature ventricular contractions (PVCs) were observed (Figures 1, 2). The patient also underwent cardiac rehabilitation during the whole hospital stay. At discharge, QTc was 537 ms, and the patient remained asymptomatic. At the 1-month follow-up visit, the patient presented with no symptoms; her QTc was 520 ms. Examples of the ECG are shown in Figure 2. The QTc evolution during hospitalization is shown in Figure 3. The decision about the implantable cardioverter-defibrillator implantation in this patient was waived as the QT prolongation was considered acquired and reversible, due to myocardial infarction.

Discussion

Wellens syndrome is considered an equivalent of STEMI and is highly specific for critical stenosis of the proximal LAD coronary artery [3]. Wellens syndrome type A is characterized by biphasic T waves, with initial positivity and subsequent negativity. Deep inverted T waves are the typical finding for Wellens type B syndrome. Those changes are most prominent in precordial leads. Wellens syndrome was described in the 1980s [4]. It is estimated that nearly 20% of patients with Wellens syndrome may have a total occlusion of the LAD. The 2023 European Society of Cardiology (ESC) guidelines for the management of acute coronary syndromes mention Wellens syndrome as an important ECG pattern indicating the risk of LAD occlusion associated with increased mortality [5]. Typically, signs of Wellens syndrome occur on ECG after chest pain subsides. Fast recognition of Wellens syndrome and timely revascularization of the LAD decreases the myocardial injury and diminishes the frequency of complications in such patients.

Long QT syndrome is a life-threatening arrhythmia characterized by a prolongation of QT interval in the ECG. QT interval should be corrected for the heart rate (QT corrected – QTc). Typically, the Bazett formula is used to calculate the QTc in patients with heart rhythm between 50 bpm and 100 bpm. Due to the bradycardia in our patient, we calculated QTc with the Fridericia formula, which is not affected by heart rhythm below 50 bpm.

Congenital long QT syndrome is usually diagnosed at a young age and presents with prolongation of the QT interval in a basic ECG. According to the “2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death”, the mean age of patients presenting with long QT syndrome is 14 years [6]. Our patient was 79 years old at the time of the diagnosis and had a normal QTc of 431 ms on admission. She denied any history of fainting. We decided not to perform genetic testing for long QT syndrome as we believe QT prolongation in this patient was induced by severe ischemia. What is more, we advised family members to perform the ECG screening; in 2 of them who agreed to do the test, their QTc values were within normal limits.

Acquired long QT syndrome is mainly caused by specific medications, eg anticancer medications, hypokalemia, hypocalcemia, or hypomagnesemia. In patients with hematological issues, acquired long QT syndrome is mostly caused by oncological drug-related adverse effects [7]. However, we did not find any registered case of acquired long QT syndrome in chronic lymphocytic leukemia, the disorder that affected our patient. Our patient was not receiving any targeted antileukemic treatment directly before and during the onset of myocardial infarction.

What is more, QT prolongation may also be induced by myocardial ischemia and occur during acute coronary syndrome. In patients with STEMI, QT prolongation is associated with a higher risk of mortality and adverse events [8]. Prolonged monitoring in an ambulatory clinic and control ECG or Holter monitoring should be performed in patients with persistent QT prolongation at hospital discharge. QT prolongation is usually especially marked in elderly patients, female patients, and patients with LAD occlusion, as in the presented case. In this case, though, typical ST elevation in ECG was not observed; instead, the STEMI equivalent, Wellens syndrome, was present. Extreme QT prolongation in this patient might have been caused by the myocardial ischemia accompanied by severely elevated white blood count due to chronic lymphocytic leukemia, affecting the blood density and slowing down reperfusion. Further observations of patients with chronic lymphocytic leukemia and myocardial infarction should be performed to scrutinize this hypothesis.

Conclusions

This is a very rare case of these 2 ECG pathologies coexisting at the same time. Wellens syndrome may rarely be accompanied by acquired long QT syndrome. Repeated or continuous ECG recording may help in early diagnosis of Wellens syndrome, but may also help with diagnosis of QT prolongation and arrival at a more rapid decision to provide urgent PCI. Wellens syndrome might not be seen in initial ECG. Careful analysis of the prescribed medications should be performed in any case of acquired long QT syndrome.