ST Segment Depression In Inferior Research Articles

Comparative electrocardiographic analysis of midventricular and typical takotsubo syndrome.

Takotsubo syndrome (TTS) encompasses distinct variants, with midventricular (MV) as the most common atypical subtype. While electrocardiogram (ECG) abnormalities are well documented in typical TTS, they are less explored in MV-TTS. A retrospective case-control study was conducted where ECGs were reviewed at three time points from symptom onset (within the first 12 h, at 48 h, and at 5-7 days) and compared between patients with typical TTS (n = 33) and those with MV-TTS (n = 27), as classified by ventriculography. 12-h ECG findings revealed that typical TTS featured ST-segment elevation through anterior leads V3-V6, with maximal deviation in V3 (0.98 ± 0.99 mm) and V4 (0.91 ± 0.91 mm), whereas MV-TTS featured ST-segment depression in inferior leads (-0.24 ± 0.57 mm in II, -0.30 ± 0.52 mm in III, and -0.32 ± 0.47 mm in aVF) and in precordial leads V4-V6. In 48-h ECG findings, the most significant change was T wave inversion, which was more widespread and deeper in typical TTS, with the most pronounced negative T wave depths, exceeding 3 mm, observed in leads V3-V5; in contrast, in MV-TTS, T wave inversion was evident in fewer leads and showed less depth, with the most pronounced negative T waves reaching 1 mm at most in leads I, aVL, and V2. While the QTc interval was prolonged in both groups at 48 h, this prolongation was more pronounced in typical TTS than in MV-TTS (523 ± 52 ms vs. 487 ± 66 ms; p = 0.029). In ECGs at 5-7 days, results essentially returned to baseline. Patients with MV-TTS exhibited a distinctive pattern of ECG abnormalities, marked by ST-segment depression in inferolateral leads, less profound and less extensive T wave inversion that mostly affected leads I, aVL and V2, and attenuated QT interval prolongation compared to typical TTS.

Culprit Arteries in Patients with Inferior Wall Myocardial Infarction (IWMI) With St Segment Depression in Lead AVR

ACS is an imbalance between the myocardial oxygen demand and consumption of oxygen by the heart. While coronary plaque rupture, which results in STEMI, is almost always the cause of this mismatch development of thrombus blocking a coronary artery. Objective: To determine the frequency of culprit arteries in patients with inferior wall myocardial infarction (IWMI) with ST Segment depression in Lead AVR. Methods: This cross sectional study was conducted at Department of Adult Cardiology, NICVD, Karachi, Pakistan from November 4, 2020 to May 3, 2021. All patients who fulfilled the inclusion criteria were enrolled and consent was taken. All patients were initially stabilized and then were prepared for coronary angiography. Interpretation of coronary angiogram was done to assess the culprit arteries i.e. LCX, RCA. Data were collected in proforma. Results. Out of 317 patients, 233 (73.5%) were male while 84 (26.5%) were female with mean age of 51.4±12.4 years. Left circumflex coronary artery was found in 184 (58%) patients. Right coronary artery was found in 133 (42%) patients. Conclusions: This study concludes that LCX artery is more likely to be culprit in patients with inferior wall myocardial infarction and ST-segment depression in lead AVR. STEMI patients with IWMI should be worked up for the presence of culprit arteries to ensure adequate treatment

Prediction of intracerebral hemorrhage in patients with out-of-hospital cardiac arrest using post-resuscitation electrocardiogram: An observational cohort study

AimWe evaluated the characteristics of patients with intracerebral hemorrhage in nontraumatic out-of-hospital cardiac arrests (OHCA) after return of spontaneous circulation (ROSC) to identify patients who required brain computed tomography as the next diagnostic workup. MethodsWe conducted a retrospective cohort study on 1303 consecutive patients with nontraumatic OHCA who were admitted to Miyazaki Prefectural Nobeoka Hospital between 2008 and 2020. Among these, 454 patients achieved sustained ROSC. We excluded 126 patients with obvious extracardiac causes. Clinical and demographic characteristics of patients and post-resuscitation 12-lead electrocardiogram were compared. Patients were categorized into the intracerebral hemorrhage (n = 32, 10%) and no intracerebral hemorrhage group (n = 296). All causes of intracerebral hemorrhage were diagnosed based on brain computed tomography images by board-certified radiologists. ResultsWe included 328 patients (mean age, 74 years; women, 36%) who achieved ROSC. Logistic regression analyses showed that female sex, younger age (<75 years), no shockable rhythm changes, tachycardia (≥100 bpm), lateral ST-segment elevation, and inferior ST-segment depression on post-resuscitation electrocardiogram were independently associated with intracerebral hemorrhage. We developed a new predictive model for intracerebral hemorrhage by considering 1 point for each of the six factors. The odds ratio for intracerebral hemorrhage increased 2.36 for each 1-point increase (P < 0.001). A score ≥ 4 had 43.7% sensitivity, 90.8% specificity, 34.1% positive predictive value, and 93.7% negative predictive value. ConclusionOur new predictive model might be useful for risk stratification of intracerebral hemorrhage in patients with OHCA who achieved ROSC.

Frequency and Influence of Exercise-Induced Artifact in Electrocardiograms During Exercise Treadmill Testing for Detection of Myocardial Ischemia.

Exercise treadmill testing (ETT) is frequently utilized for noninvasive detection of myocardial ischemia and coronary artery disease. The frequency of electrocardiogram (ECG) artifacts (ECGA) during ETT and their influence on the identification of exercise-induced ischemia are not known. We reviewed all ETTs with ST segment depression in the University of California, Davis, Medical Center treadmill database during each of the years 2012 and 2016 to identify tests with exercise-induced ST segment depression in the inferior and inferolateral leads. We identified cases with ECGA during progressive phases of the test, and we assessed the influence of comorbidities and the impact of ECGA on the diagnosis of coronary artery disease. Tests were considered false or true positive based on the result of confirmatory tests. Of 2,100 tests, we identified 123 patients with exercise-induced ST segment depression in inferior or inferolateral leads (men, 43%; mean age, 59 ± 10 years; white, 59%). Tests were symptom-limited: maximum heart rate, 153 ± 18; peak METs (metabolic equivalents of resting total oxygen consumption), 9.4 ± 2.7; ECGA occurred in 91% of tests at peak exercise with earlier occurrence among females. Tests were less likely to be true positive with peak ECGA than those without ECGA (13% vs. 50%, p = 0.05). ECGA at peak exercise are frequent and related to peak heart rate and peak metabolic equivalents of resting total oxygen consumption, suggesting a motion effect. ECGA affected the diagnostic accuracy of ETT examinations, indicating that algorithms to reduce artifact for improved diagnosis of ETT require further investigation.

Marked lateral ST-segment elevation with inferior ST-segment depression in an asymptomatic 12 year-old girl: A normal variant?

Significant ST-segment changes raise concern for myocardial ischemia, cardiomyopathy or myocardial inflammation and therefore, warrant an extensive and often invasive cardiovascular evaluation. We report a 12 year-old asymptomatic African-American girl with marked ST-segment elevation in leads I and aVL and ST-segment depression in inferior leads II, III and aVF. Extensive cardiovascular evaluation did not reveal any abnormality suggesting that these findings, which have previously not been reported, are likely benign, at least in this young girl.

Reducing Insignificant High/Low Heart Rate Alarms Using the Cross-Limit Area Based Algorithm

Significant ST-segment changes raise concern for myocardial ischemia, cardiomyopathy or myocardial inflammation and therefore, warrant an extensive and often invasive cardiovascular evaluation. We report a 12 year-old asymptomatic African-American girl with marked ST-segment elevation in leads I and aVL and ST-segment depression in inferior leads II, III and aVF. Extensive cardiovascular evaluation did not reveal any abnormality suggesting that these findings, which have previously not been reported, are likely benign, at least in this young girl.

Differences in initial electrocardiographic findings between ST-elevation myocardial infarction due to left main trunk and left anterior descending artery lesions

BackgroundEarly discrimination of ST-elevation myocardial infarction (STEMI) due to a left main trunk (LMT) lesion provided by straightforward electrocardiographic criteria is useful for prompt treatment. The purpose of this study is to investigate differences in electrocardiographic findings between STEMI due to lesions of LMT and those of left anterior descending artery (LAD).MethodsInitial electrocardiogram (ECG) recordings of 435 patients with analyzable ECGs from a cohort of 940 consecutive STEMI patients were analyzed retrospectively for presence of LMT lesions (LMT, n = 39), proximal (pLAD, n = 224) and distal LAD lesions (dLAD, n = 172). ST-segment deviations in 12 leads were assessed among 3 groups without bundle branch block (n = 17 in LMT, n = 180 in pLAD, and n = 159 in dLAD).ResultsMagnitudes of ST-segment deviations showed significant differences in leads II, III, aVR aVL, aVF, and V2–V6 across the three groups. This difference suggested two possible characteristic findings in the LMT group, allowing it to be distinguished from the pLAD or dLAD group; (A) larger magnitude of ST-segment depression in lead II than that of ST-segment elevation in lead V2 (47.1% in LMT vs. 0.6% in pLAD vs. 1.3% in dLAD, P < 0.0001), and (B) ST-segment depression in lead V5 (58.8% in LMT vs. 6.7% in pLAD vs. 2.5% in dLAD, P < 0.0001). These findings exhibited superior negative predictive value over conventional ST-segment elevation in lead aVR.ConclusionsA large reciprocal ST-segment depression in inferior leads and ST-segment depression in lead V5 are useful ECG findings allowing determination of STEMI due to an LMT lesion.

Validation of Displayed Electrocardiographic Rhythms at the Central Monitoring Station

Scenario: The monitor technician made an overhead announcement to the intensive care unit (ICU) staff “bed check room 10” after seeing what appeared to be ventricular tachycardia (VT) in lead V1 at the central monitoring station (see box below). The ECG below was automatically printed from the central monitoring station following an alarm for “VTach.” The alarm occurred in a 72-year-old man admitted to the medical/surgical ICU for sepsis.False alarm caused by artifact mimicking VT in lead V1 at twice the actual heart rate. Sinus rhythm at a rate of 88 beats per minute. Possible ST-segment depression in inferior leads II and III, but wandering baseline is present.Although lead V1 shows a wide complex tachycardia suggestive of VT, the other simultaneously recorded leads show normal sinus rhythm. Note that the pulse waveform of the oxygen saturation (Spo2) is normal, indicating that the arterial pressure waveform did not change during this false alarm and the oxygen saturation is 99%. The respiratory waveform is unchanged as well. Of note, algorithms used in bedside ECG monitors often do not use all available leads for arrhythmia detection; hence, false alarms can occur. In addition, central monitoring stations typically display only 1 or 2 selected ECG leads, thus one may observe, as in this case, what appears to be VT on the central monitoring station. Verification of arrhythmias by examining all of the available leads should be standard protocol.The nurse should assess the patient immediately to ensure that no acute changes or symptoms are apparent. In addition, the nurse should check the patient’s chest to verify that lead V1 is in the correct location (4th intercostal space, right sternal border) and ensure that nothing is causing the artifact (ie, other devices, lead wires). The ST segments are consistently flattened in leads II and III. Because the T wave is also inverted in these leads, ischemia should be ruled out. Obtain a clean standard 12-lead ECG to verify that these T-wave changes are valid, and compare that ECG with a prior 12-lead ECG to determine if these changes are new.

Utility of Two-Dimensional Speckle Tracking Echocardiography in Understanding of Inferior ST Segment Depression in the Setting of Acute Anterior Myocardial Infarction

Background: A patient suffering from an anterior ST segment elevation myocardial infarction (STEMI) will frequently demonstrate ST segment depression (STD) in the inferior leads (II, III, and aVF). The aim of this study was to determine the meaning of STD in the early stages of an acute anterior MI, and whether they represent remote ischemia or reflect an electrical mechanism by using speckle-tracking echocardiography. Methods: Fifty patients suffering from acute anterior STEMI were enrolled in this prospective study. The patients were classified into two groups each one included 25 patients. Group 1 included patients who had STD in the inferior leads and group 2 included patients who had not. All of the patients were evaluated with a standard 12-lead electrocardiography (ECG), two dimensional echocardiography, speckle-tracking echocardiography, and coronary angiography. Results: The average global longitudinal peak systolic strain (Avg_GLPS%) was - 9.8 ± 2.4% in group 1 versus -10.7 ± 2.3 in group 2 (p=0.188). The longitudinal strains of the basal inferior segments were -13.6 ± 2.8% in group 1 versus -15.8 ± 3.7% in group 2 (p=0.026), and the longitudinal strains of mid inferior segments were -13 ± 3.2 in group 1 versus -15.1 ± 2.7% in group 2 (p=0.019). Group 1 had higher frequency of multivessel disease, right coronary artery (RCA) and left circumflex coronary artery (LCX) stenosis than group 2. Conclusion: This study supports the belief that inferior STD on an ECG during an acute anterior STEMI is a sign of ischemia that often involves the right coronary artery.

What is the predictive value of ST segment depression in inferior leads in first acute anterior myocardial infarction?

BackgroundElectrical phenomenon and remote myocardial ischemia are the main factors of ST segment depression in inferior leads in acute anterior myocardial infarction (AAMI). We investigated the prognostic value of the sum of ST segment depression amplitudes in inferior leads in patients with first AAMI treated with primary percutaneous coronary intervention. (PPCI). MethodsIn this prospective analysis, we evaluated the in-hospital prognostic impact of the sum of ST segment depression in inferior leads on 206 patients with first AAMI. Patients were stratified by tertiles of the sum of admission ST segment depression in inferior leads. Clinical outcomes were compared between those tertiles. ResultsUnivariate analysis revealed higher rate of in-hospital death for patients with ST segment depression in inferior leads in tertile 3, as compared to patients in tertile 1 (OR 9.8, 95% CI 1.5–78.2, p<0.001). After adjustment for baseline variables, ST segment depression in inferior leads in tertile 3 was associated with 5.7-fold hazard of in-hospital death (OR: 5.7, 95% CI 1.2–35.1, p<0.001). Spearman rank correlation test revealed correlation between the sum of ST segment depression amplitude in inferior leads and the sum of ST segment elevation amplitude in V1–6, L1 and aVL. Multivessel disease and additional RCA stenosis were also detected more often in tertile 3. ConclusionThe sum of ST segment depression amplitude in inferior leads of admission ECG in patients with first AAMI treated with PPCI provide an independent prognostic marker of in-hospital outcomes. Our data suggest the sum of ST segment depression amplitude to be a simple, feasible and clinically applicable tool for rapid risk stratification in patients with first AAMI.

Acute Myocardial Infarction in a Patient With Elevated ST-Segment in aVR Lead and Diffuse ST Segment Depression in Other Leads: A Case Report

ST elevation in aVR in conjunction with diffuse ST depression in precordial leads may indicate occlusion of very proximal portion of the left anterior descending artery. We present a 54-year old man, with crushing retrosternal pain and ST-segment elevation only in aVR lead and diffuse ST-segment depression in inferior, lateral and precordial leads. The patient was scheduled for emergent coronary angiography, which showed that left anterior descending (LAD) artery was cut off at very proximal portion and urgent CABG was performed for the patient.

Coronary artery occlusion after arterial switch operation in an asymptomatic 15-year-old boy

A 15-year-old boy with transposition of the great arteries (TGA) and neonatal arterial switch operation (ASO) presented with complete occlusion of the left main coronary artery (LMCA). Intra-operatively, an intramural left coronary artery was identified. Therefore, since age 7 years he had a series of screening exercise stress tests. At 13 years old, he had 3 to 4 mm ST segment depression in the infero-lateral leads without symptoms. This progressed to 4.2 mm inferior ST segment depression at 15 years old with normal stress echocardiogram. Sestamibi myocardial perfusion scan and cardiac magnetic resonance imaging was inconclusive. Therefore, a coronary angiogram was obtained which showed complete occlusion of the LMCA with ample collateralization from the right coronary artery system. This was later confirmed on a computed tomogram (CT) angiogram, obtained in preparation of coronary artery bypass grafting. The case illustrates the difficulty of detecting coronary artery stenosis and occlusion in young patients with rich collateralization. Coronary CT angiogram and conventional angiography were the best imaging modalities to detect coronary anomalies in this adolescent with surgically corrected TGA. Screening CT angiography may be warranted for TGA patients, particularly for those with known coronary anomalies.

Acute cocaine myocarditis: a word of caution

An otherwise healthy 25-year-old male presented to the Emergency Department with new onset severe retrosternal chest pain. Electrocardiogram demonstrated lateral ST-segment elevations in leads I and AVL with inferior ST-segment depression ( Panel A ). Initial troponin I level was 1.8 ng/mL quickly rising to >200 ng/mL within first 8 h. Coronary angiography revealed normal coronary arteries (see Supplementary material online, Video S1 ). Echocardiogram showed regional wall motion abnormalities involving inferolateral segment with moderately reduced left ventricular ejection fraction …

Acute myocardial infarction

A 62-year-old man was woken by a prolonged and very intensive episode of retrosternal pain. His past medical history included a prostate cancer treated 2 years before with radical prostatectomy and radiation therapy. Thirty minutes after the onset of symptoms, his wife called the regulatory centre of medical emergency (Service d’Aide Medicale d’Urgence). Before the arrival of the physician-staffed ambulance, she noted that her husband became apparently confused and no more complained of chest pain. She did not witness a transient loss of consciousness. When the rescue staff arrived to patient’s home, vital signs were as follows: blood pressure 155/95 mmHg, heart rate 95 beats/min, respiration rate 18 breaths/min and oxygen saturation 96%. Physical examination ruled out focal neurological and congestive heart failure signs. A 12-lead ECG showed a marked ST-segment elevation in anterior leads associated with an inferior ST-segment depression. Sublingual nitrates were ineffective on these ST-segment alterations. Despite neurological symptoms and the absence of persistent chest pain, he was treated like a ST-segment elevation myocardial infarction. Consequently, he received 250 mg of intravenous aspirin, 3000 UI of intravenous enoxaparin and 600 mg of clopidogrel. He arrived to catheterization laboratory 45 min after the first medical contact. Coronary angiogram performed via a right transradial approach demonstrated a culprit lesion on the mid-left anterior descending artery (LAD) coronary artery segment (Fig. 1). The blood flow was thrombolysis in myocardial infarction (TIMI 1) in the distal LAD segment. The remaining coronary tree was free from noticeable plaque. Thrombus aspiration followed by a direct bare-metal stent stenting restored a TIMI 3 blood flow. The brain computed tomography (CT) scan performed immediately after percutaneous coronary intervention was normal. At admission to the ICU of cardiology, haemodynamic status was stable. It remains an anterograde and a mild retrograde amnesia. He remembered the last evening, but did not remember having chest pain or coronary angiogram. He repeated continuously the same questions. Personal knowledge was spared; he was able to provide information about his past history. Physical examination did not find other cognitive impairment, focal neurological or cardiac signs. A second 12-lead ECG revealed a resolve of ST-segment alterations and the emergence of Q waves on anterior leads. Transthoracic echocardiography evaluated left ventricular ejection fraction at 45% with an area at risk concerning apical and mid (anterior, septal and lateral) segments of the left ventricle. Biological parameters ruled out hypoglycemia and unknown diabetes or dyslipidemia. Troponin peak rose to 29mg/l (normal less than 0.1mg/l) and B-type natriuretic peptide was in the normal range. The amnesic gap resolved within 12 h from the onset of symptoms. A transient global amnesia following anterior ST-segment elevation myocardial infarction was finally diagnosed. The patient was discharged from hospital on the third day with a usual postmyocardial infarction treatment. The transient neurological symptoms were explored by a cerebral MRI performed 4 weeks later, which excluded any ischemic event in the vertebrobasilar territory (Fig. 2).

A 19-year-old girl with ostial coronary lesions

A 19-year-old girl presented with retrosternal chest pain at rest associated with nausea and vomiting. She had excertional chest pain of three days’ duration. She had no past history of hypertension, diabetes or smoking. Her vital signs were stable. She weighed 53 kg and was 156 cm tall. Her body mass index was 21.7 kg/m2. On physical examination, she had extensive xanthomatosis on the extensor surfaces (knees and elbows), her buttocks and ankles, and swelling and erythema over her first and fifth metatarsophalangeal joints (Figs. 1, 2). There was a history of sudden death in her only sibling, an 18-year-old brother several years earlier. ECG showed diffuse and down-sloping ST segment depression in inferior and precordial leads along with ST segment elevation of 3 mm in avR (Fig. 3). Anti-ischaemic therapy was initiated and the patient was admitted to the Coronary Care Unit. Echocardiography showed global left ventricular ejection fraction of 45% with hypoplastic aortic root without aortic stenosis. Laboratory studies showed elevation of cardiac troponin I and creatinine kinase-MB. Lipid profile was total cholesterol of 570 mg/dL, HDL of 30 mg/dL, LDL of 522 mg/dL. Triglycerides levels were normal. She was scheduled for immediate coronary angiography. Non selective contrast injection in aortic root showed narrowing of aortic root and ostial lesion in the left main artery (Fig. 4). Right coronary injection showed ostial lesion in the right coronary artery. The patient had episodes of chest pain despite medical therapy and was scheduled for urgent coronary artery bypass grafting (CABG). During surgery, both coronary arteries had ostial lesions and CABG was performed. The patient was prescribed lipid-lowering therapy and referred for LDL aphresis on discharge. At six months follow-up, the patient remains well. Multiple xanthomas, high serum levels of LDL, and premature atherosclerosis are indicative of familial hypercholesterolaemia.

Eggshell-Like Appearance Around the Heart Mimicking Left Ventricular Mass

A 66-year-old male patient was admitted to the cardiology department with a new-onset angina. He had a history of hypertension, pericardiocentesis 24 years ago, coronary angiography, and percutaneous coronary intervention ≈4 years ago. He was on medications, including acetyl salicylic acid, clopidogrel, metoprolol succinate, valsartan, and hydrochlorothiazide. The results of his physical examination and biochemical tests were normal. ECG showed negative T waves on the D1, aVL, V5, and V6 derivations and ST-segment depression in inferior leads (Figure 1). Chest radiograph showed cardiomegaly and calcification on the apicolateral wall of the left ventricle (LV) (Figure 2). With the diagnosis of unstable angina, coronary angiography (Toshiba Infinix CSi, Japan) was performed and revealed critical coronary stenoses. On fluoroscopy, a structure of 2 pieces with a calcified wall, close to …

STEMI revealing an exceptional variant of single right coronary artery

A 58-year-old man with hypercholesterolaemia was admitted for acute coronary syndrome with ST-segment elevation in inferior ECG derivations and ST-segment depression in antero-lateral ECG derivations ( Panel A ) . The patient underwent emergency coronary catheterization. Subtotal occlusion of the third segment of the right coronary artery (RCA) (Supplementary data online, Movie …

Coronary Artery Embolization After Successful Surgical Ablation of Atrial Fibrillation

A 63-year-old woman was urgently transferred to our institution from a regional hospital with no facilities for cardiac catheterization after she presented with sudden-onset nausea and left arm pain associated with transient inferior ST-segment elevation and lateral ST-segment depression on ECG. Seven weeks earlier, she had undergone elective 3-vessel coronary artery bypass grafting when an abnormal dipyridamole 99mTc-sestamibi scan demonstrated reversible myocardial ischemia but normal left ventricular function. Surgical cryoablation (box lesion isolation of the pulmonary veins, with targeted ablation of the left atrium and left atrial appendage) was also successfully performed to treat persistent atrial fibrillation (AF). Postoperatively, she underwent anticoagulation therapy with warfarin; enoxaparin was also administered until her international normalized ratio was ≥2.0. Continuous telemetry confirmed that normal sinus rhythm was maintained during her entire postoperative stay. She continued taking warfarin on discharge, and her international normalized ratio was monitored regularly. Her comorbidities included type 2 diabetes mellitus, …

Mechanism and diagnostic potential of reciprocal ECG changes induced by acute coronary artery occlusion in pigs

Reciprocal ST-segment depression simulating additional subendocardial ischemia is commonly observed in ST-segment elevation myocardial infarction. To study the mechanism and characterization of the whole reciprocal electrocardiogram (ECG) patterns induced by acute coronary artery occlusion at different locations in the absence of additional subendocardial ischemia in pigs. Conventional 12-lead ECG and/or local extracellular epicardial, mid-myocardial, and endocardial electrograms were recorded during the acute occlusion of right coronary (RC) and left anterior descending (LAD) coronary arteries in the in situ (n = 9) or in the isolated perfused (n = 5) pig hearts. Mid-RC occlusion induced reciprocal ST-segment depression (-0.43 ± 0.14 mV; P<.01) and S-wave deepening (-0.74 ± 0.23 mV; P<.01) in anterior ECG leads. Mid-LAD occlusion induced reciprocal S-wave deepening (-0.43 ± 0.37 mV; P = .02) but not ST-segment depression in inferior leads. Proximal LAD induced reciprocal ST-segment depression (-0.21 ± 0.20 mV; P = .03) and S-wave deepening (-0.56 ± 0.58 mV; P = .04) in inferior leads. Reciprocal QRS widening was observed only during proximal LAD occlusion. Local extracellular recordings did not show significant reciprocal QRS and ST-segment changes. In the absence of additional subendocardial ischemia, acute coronary artery occlusion induces reciprocal ST-segment and S-wave changes in the 12-lead ECG that allow better differentiation between proximal and mid-LAD occlusion. Reciprocal ECG changes depend on conventional lead system design and not on the transmission of injury currents from the ischemic border zone to distant normal myocardium.

Acute Inferior Wall Myocardial Infarction due to Occlusion of the Wrapped Left Anterior Descending Coronary Artery

Acute occlusion of the left anterior descending coronary artery (LAD) generally results in ST segment elevations in precordial leads and reciprocal ST segment depression in inferior leads. The occurrence of isolated inferior myocardial infarction due to occlusion of LAD is very rare. We describe an isolated acute inferior myocardial infarction due to occlusion of a wrapped LAD at the apex which continues as the large posterior descending coronary artery (PDA) beyond the occlusion.