Inferior myocardial infarction. High-risk subgroups

Comparison of Heart Rates in Patients Initiated on Ticagrelor Versus Other P2Y12 Inhibitors After an Inferior ST Elevation Myocardial Infarction (STEMI)

BACKGROUND

P2Y12 inhibitors have differing associations of bradyarrhythmias. Ticagrelor has been shown to increase adenosine plasma concentrations leading to increases in bradyarrhythmias. While clopidogrel and prasugrel have not been shown to have any association with bradyarrhythmias.

OBJECTIVE

The objective of this study was to determine heart rates after ticagrelor initiation compared to clopidogrel/prasugrel in inferior ST Elevation Myocardial Infarction (STEMI) patients.

METHODS

This was a retrospective, multicenter study conducted at 3 primary percutaneous coronary intervention (PCI) centers between January 1, 2017 and September 30, 2022. Adult patients were included if they were diagnosed with an inferior STEMI to the right coronary artery (RCA) and treated with PCI followed by an oral P2Y12 inhibitor. The primary outcome was heart rate at 48 hours or discharge, whichever first, after administration of ticagrelor compared to clopidogrel/prasugrel.

RESULTS

This study reviewed 331 patients, 172 in the ticagrelor group and 159 in the clopidogrel/prasugrel group. There were no statistical differences between groups regarding the primary outcome, with a median heart rate of 76 beats per minute (bpm) [67-85] in the ticagrelor group versus 73 bpm [66-84] in the clopidogrel/prasugrel group (P = 0.238). No differences were observed between groups regarding any secondary outcomes.

CONCLUSION AND RELEVANCE

There were similar heart rates between ticagrelor and clopidogrel/prasugrel. There were also similarities in the ability to tolerate beta-blocker therapy after initiation of a P2Y12 inhibitor. The results of this study suggest that in inferior STEMIs when using ticagrelor as the P2Y12 inhibitor, there are not increased clinical manifestations of bradycardia.

Hibernation of the Conduction System and Atrioventricular Block Reversibility Following Revascularization in Patients without Acute Coronary Syndrome

Although myocardial infarction (MI) is a reversible cause of atrioventricular (AV) block, the association of ischemia other than MI with AV block is unclear. The purpose of this study is to investigate this relationship. Among patients nominated for pacemaker implantation due to AV block in two centers from 2017-2020, 120 patients with significant coronary artery disease (CAD) in angiography were included in the study. Patients were divided into two equal groups based on their CAD treatment approach: drug therapy and revascularization. Coronary lesions were divided into three types based on location: left anterior descending artery (type 1), dominant coronary with AV node branch (type 2), and a combination of both (type 3). After coronary disease treatment, all patients were followed up with for 14 months, and AV block reversibility was assessed. There were 7 cases of block reversibility in the revascularization group (11.7%) and 1 case in the medical group (1.7%), which differed significantly (P = .02). A history of acute coronary syndrome, smoking, opium use, chronic kidney disease, hypertension, age, sex, and chronic obstructive pulmonary disease were not significantly associated with reversible block. Also, the type of coronary obstruction had no significant relationship with block reversibility (P = .3, .5, and .8 for type 1, type 2, and type 3, respectively). Hibernation due to ischemia can be a reversible cause of an AV blockage. Therefore, it is recommended that significant coronary artery lesions be revascularized before pacemaker implantation.

Efficacy of Coronary Sinus Pacing for Cardiogenic Shock Due to Percutaneous Coronary Intervention-induced Sick Sinus Syndrome: Two Case Reports

We herein report two cases of atrial pacing with coronary sinus (CS) pacing performed to improve hemodynamic instability in cardiogenic shock due to percutaneous coronary intervention (PCI)-induced sick sinus syndrome (SSS). Ventricular pacing alone made it difficult to stabilize hemodynamics due to SSS, which had been caused by the lack of reflow and slow flow of the sinus node artery (SNA) jailed with a stent. Adding atrial pacing with CS pacing may be useful, as in our two cases, where ventricular pacing alone was unable to stabilize hemodynamics.

New ECG algorithms with improved accuracy for prediction of culprit vessel in inferior ST-segment elevation myocardial infarction

BACKGROUND

In addition to diagnosing acute myocardial infarction (MI), the electrocardiogram (ECG) may also predict the culprit coronary artery. We aimed to assess the diagnostic accuracy of ECG algorithms predicting the occluded vessel in inferior ST-segment elevation myocardial infarction (STEMI).

METHODS

This retrospective cohort study included 300 consecutive patients with inferior STEMI undergoing acute coronary angiography. A new method based on the summation of ST-segment deviations in multiple leads from the first 12-lead-ECG was used to develop algorithms to discriminate between right coronary artery (RCA) and circumflex artery (CX) occlusion. Additionally, older algorithms were reassessed.

RESULTS

The RCA was occluded in 235 patients (78%) and the CX in 65 (22%). ST-segment deviations differed significantly between RCA and CX occlusions in leads I, III, aVR, aVL, aVF and V1. ST-segment deviations in lead I showed the highest discriminatory ability of a single lead (area under the receiver operating curve [AUC]=0.77). The summation of multiple leads further increased the discriminatory ability ("III-II+aVF+aVR+V1:" AUC=0.86; "III-II-I+aVF+V1:" AUC=0.85). The best binary algorithm "III-II-I+aVF+V1>0.1 mV" classified 86% of cases correctly and was better than the best old algorithm (83.3%). The simpler algorithm "III+aVR+V1≥0.1 mV" still predicted 85.0% correctly. All algorithms had higher sensitivities for RCA than for CX detection and performed better in right-dominant anatomy.

CONCLUSIONS

A new approach summating multiple ST-segment deviations generated ECG algorithms with higher diagnostic accuracy to predict the occluded vessel in inferior STEMI compared to previous studies. These algorithms may facilitate earlier risk stratification for patients at risk of postinfarct complications.

Atrioventricular Conduction Disorders as a Complication of Inferior ST-Elevation Myocardial Infarction in Patients with COVID-19 Infection

This case series demonstrates how COVID-19 infection might affect the heart in the context of acute myocardial infarction. Atrioventricular (AV) block might appear as one of the significant cardiac complications of acute MI in patients who tested COVID-19 PCR positive regardless of the presence of CVOID-19 infection symptoms. In our series, conduction disorders as a complication of acute inferior STEMI are more common in patients who tested positive for the COVID-19 infection. 11 patients out of 18 inferior STEMI patients who have tested positive for the COVID-19 infection have atrioventricular block disorders.

Subepicardial burn injuries in bullfrog heart induce electrocardiogram changes mimicking inferior wall myocardial infarction

Using bullfrog hearts, we previously reproduced a ST segment elevation in electrocardiogram (ECG), mimicking human ischemic heart disease. In the present study, by inducing subepicardial burn injuries on the inferior part of the frog heart ventricle, we could reproduce typical ECG changes observed in human inferior wall myocardial infarction, such as the marked elevation of the ST segments in inferior limb leads (II, III, aVF) and their reciprocal depression in the opposite limb leads (I, aVL). Due to the decrease in Na⁺/K⁺-ATPase protein expression, the resting membrane potential of injured cardiomyocytes shifted toward depolarization. Such induced electrical difference between the injured and intact cardiomyocytes was thought to be responsible for the creation of “currents of injury” and the subsequent ST segment changes.

Nondominant Right Coronary Artery Occlusion: Small Vessel, Dramatic Sequelae

Nondominant right coronary artery (NDRCA) occlusion is rare and generally affects a small volume of myocardium. Despite this, NDRCA occlusion can result in dramatic clinical sequelae. These cases demonstrate the characteristic electrocardiographic findings and consequences of NDRCA occlusion, highlighting the importance of recognition of this pathologic condition to institute appropriate management. (Level of Difficulty: Intermediate.).

Short duration Vectorcardiogram based inferior myocardial infarction detection: class and subject-oriented approach

Myocardial infarction (MI) happens when blood stops circulating to an explicit segment of the heart causing harm to the heart muscles. Vectorcardiography (VCG) is a technique of recording direction and magnitude of the signals that are produced by the heart in a 3-lead representation. In this work, we present a technique for detection of MI in the inferior portion of heart using short duration VCG signals. The raw signal was pre-processed using the median and Savitzky-Golay (SG) filter. The Stationary Wavelet Transform (SWT) was used for time-invariant decomposition of the signal followed by feature extraction. The selected features using minimum-redundancy-maximum-relevance (mRMR) based feature selection method were applied to the supervised classification methods. The efficacy of the proposed method was assessed under both class-oriented and a more real-life subject-oriented approach. An accuracy of 99.14 and 89.37% were achieved respectively. Results of the proposed technique are better than existing state-of-art methods and used VCG segment is shorter. Thus, a shorter segment and a high accuracy can be helpful in the automation of timely and reliable detection of MI. The satisfactory performance achieved in the subject-oriented approach shows reliability and applicability of the proposed technique.

Electric Acupuncture Treatment Promotes Angiogenesis in Rats with Middle Cerebral Artery Occlusion Through EphB4/EphrinB2 Mediated Src/PI3K Signal Pathway

BACKGROUND

Cerebral infarction is one of the most common causes of disability and death worldwide. It is reported that electric acupuncture was able to improve the prognosis of cerebral infarction by promoting angiogenesis. However, the corresponding signal pathways of angiogenesis promotes by electric acupuncture treatment needs to be further explored.

METHODS

MCAO rat was employed as the animal model, and clopidogrel hydrogen sulfate treatment was set as the positive control. Behaviors of rats, H&E staining, and TTC-staining was used to evaluate the recovery of infarcted brain tissue and nervous function. After that, immunocytochemical and immunofluorescence staining was used to quantify the angiogenesis and compensatory circulation, which including the analysis of microvessel density, field/ microvessel area ratio, and microvessel diameter. Western blot and RT-PCR for the detection of the related signal molecule, PI3K, Src, and EphB4/ephrinB2.

RESULTS

The neurologic impairment scores were decreased, and the brain tissue damage that showed with H&E and TTC-staining was relieved by the treatment of electric acupuncture in MCAO rat. The quantification of microvessel density and field/ microvessel area ratio was improved obviously, and the microvessel diameter was decreased which represent the angiogenesis of capillary in day 3 and 7 by the electric acupuncture treatment. We also found that the level of Src and PI3K was increased markedly followed by the up-regulation of EphB4 and EphrinB2 mRNA during the electric acupuncture treatment, and the pre-treatment of Src and/or PI3K inhibitor was able to disturb the angiogenesis of capillary.

CONCLUSIONS

We proved that electric acupuncture was able to accelerate the recovery of infarcted brain tissue and nervous function in MCAO rat by the promotion of angiogenesis, which was regulated by EphB4/EphrinB2 mediated Src/PI3K signal pathway. Our study provides a potential therapy and theoretical basis for the clinical treatment of cerebral infarction by the use of electric acupuncture.

In-Hospital Outcomes of Female Patients With Inferior Wall Myocardial Infarction

Background The aim of this study was to determine the in-hospital outcome of female patients with inferior wall myocardial infarction (MI). Methodology This study was conducted from January to December 2017 at the Department of Cardiology, National Institute of Cardiovascular Disease, Karachi. A total of 59 women admitted with inferior wall MI were enrolled in the study. In all patients, in-hospital outcomes were observed. Descriptive statistics were applied. Stratification was done using chi-square test, and p-value of ≤0.05 was considered significant. Results The mean age of study participants was 58.80 ± 9.17 years, while 247 (79.7%) participants were above 50 years of age. The mean onset of duration of sign and symptoms of inferior wall MI was 3.48 ± 1.53 hours. There were 36 (61.0%) patients who had diabetes mellitus, 46 (78.0%) had hypertension, 17 (28.8%) were obese, nine (15.3%) had a family history of MI, and three (5.1%) were smokers. There were 43 (72.9%) patients who were illiterate. In our study, eight (13.6%) females were found to have sinus bradycardia, seven (11.9%) had sinus tachycardia, three (5.1%) had atrial fibrillation, and 24 (40.7%) had complete heart block. Mortality was noted in five (8.5%) patients. Conclusions Women with an acute inferior wall MI had a higher rate of complete heart block and adverse in-hospital outcomes. Female gender itself with inferior wall MI may be at risk for in-hospital adverse outcomes.

Conduction Disorders in the Setting of Acute STEMI

ST-elevation myocardial (STEMI) is frequently associated with conduction disorders. Regional myocardial ischemia or injury may affect the cardiac conduction system at various locations, and neural reflexes or changes in the balance of the autonomous nervous system may be involved. Sinoatrial and atrioventricular blocks are more frequent in inferior than anterior STEMI, while new left anterior fascicular block and right bundle branch block indicate proximal occlusion of the left anterior descending coronary artery. New left bundle branch block is associated with multi-vessel disease. Most conduction disorders associated with STEMI are reversible with reperfusion therapy, but they may still impair prognosis because they indicate a large area at risk, extensive myocardial infarction or severe coronary artery disease. Acute STEMI recognition is possible in patients with a fascicular or right bundle branch block, but future studies need to define the cut-off values for ST depression in the leads V1-V3 in inferolateral MI and for ST elevation in the same leads in anterior STEMI. In the left bundle branch block, concordant ST elevation is a specific sign of acute coronary artery occlusion, but the ECG feature has low sensitivity.

Inferior ST-Elevation Myocardial Infarction Presenting When Urgent Primary Percutaneous Coronary Intervention Is Unavailable: Should We Adhere to Current Guidelines?

The pivotal studies that led to the recommendations for emergent reperfusion therapy for ST-elevation myocardial infarction (STEMI) were conducted for the most part over 25 years ago. At that time, contemporary standard treatments including aspirin, statin, and even anticoagulation were not commonly used. The 2013 American College of Cardiology Foundation (ACCF)/American Heart Association (AHA) guidelines and the 2017 European Society of Cardiology guidelines give a class I recommendation (with the level of evidence A) for primary percutaneous coronary intervention (pPCI) in patients with STEMI and ischemic symptoms of less than 12 h. However, if the patient presents to a hospital without pPCI capacity, and it is anticipated that pPCI cannot be performed within 120 min of first medical contact, fibrinolytic therapy is indicated (if there are no contraindications) (class I indication, level of evidence A). Our review of the pertinent literature shows that the current recommendation for inferior STEMI is based on the level of evidence lower than A. We can consider level B even C, supporting the recommendation for fibrinolytic therapy if pPCI is not available for inferior STEMI.

Does electrocardiogram help in identifying the culprit artery when angiogram shows both right and circumflex artery disease in inferior myocardial infarction?

OBJECTIVE

In a subgroup of patients with inferior myocardial infarction (MI), both the right coronary artery (RCA) and circumflex coronary artery (Cx) show potentially culprit lesions, and angiography may be insufficient to determine which artery is responsible for the clinical presentation. Although many electrocardiographic (ECG) algorithms have been proposed for identifying the infarct-related artery in patients with inferior MI, it is unclear whether the current algorithms have the discriminative power to identify the real culprit artery in these patients.

METHODS

The patients with the diagnosis of acute inferior MI and underwent coronary angiography were enrolled in the study. The prediction of the infarct-related artery was attempted from the admission ECG using published algorithms and criteria. For the angiographic definition of the infarct-related artery, multiple criteria were used.

RESULTS

Total 417 inferior MI cases were enrolled during the study period; the final patient population comprised of 318 patients. Forty-five patients (14.2%) had both RCA and Cx lesions on coronary angiography. Although several criteria and algorithms are able to identify the infarct-related artery in the general inferior MI population, they lose their strength in patients with both RCA and Cx lesions. Only the Aslanger-Bozbeyoğlu criterion emerges as a more powerful diagnostic test with a sensitivity, specificity, and c-statistic of 80%, 48%, and 0.650, respectively for the whole population (p<0.001) and 81%, 58%, and 0.709, respectively, for patients with both RCA and Cx lesions (p=0.019).

CONCLUSION

The Aslanger-Bozbeyoğlu criterion is not only helpful in differentiating the infarct territory in combined inferior and anterior ST-segment elevation as previously shown, but also valuable in identifying the infarct-related artery in patients with inferior STEMI with critical lesions in both the RCA and the Cx. (Anatol J Cardiol 2020; 23: 318-23).

[Inferior myocardial infarction: first Moroccan study of 103 cases]

L'infarctus du myocarde (IDM) représente une cause majeure de mortalité cardiovasculaire. L'IDM inférieur représente 30 à 50% de l'ensemble des infarctus avec un pronostic favorable par rapport à l'infarctus antérieur. Le but de notre travail est d'étudier les aspects épidémiologiques, cliniques, électriques, échocardiographiques et angiographiques de l'IDM inférieur, ainsi que ses complications et ses modalités thérapeutiques. Sur une période de 3 ans, nous avons admis 720 patients pour ST-Elevation Myocardial Infarction (STEMI) dont 103 de topographie inférieure soit une fréquence de 14,3%. On note une nette prédominance masculine avec une moyenne d'âge de 58 ans pour les hommes et 62 ans pour les femmes. Le tabagisme représente le principal facteur de risque cardiovasculaire retrouvé dans 57,28% des cas. L'infarctus ventricule droit (VD) est objectivé chez 11,65% des malades. La moitié de ces patients ont présenté une instabilité hémodynamique. Le Bicuspid aortic valve (BAV) 3^ème degré a été diagnostiqué chez 12,6% des patients. Sur le plan thérapeutique, sept malades ont été thrombolysés et 42 ont bénéficié d'une coronarographie. La lésion coupable de l'IDM inférieur était la coronaire droite dans 53% des cas et l'artère circonflexe dans 47%. La coronaire droite est responsable de l'infarctus VD dans 100% des cas. L'angioplastie coronaire est réalisée chez 18 patients dans la suite de la coronarographie. Onze malades ont bénéficié d'une angioplastie transluminale (ATL) de la coronaire droite et celle de la circonflexe est réalisée chez 2 malades. La mortalité précoce à 30 jours est estimée à 1,94%. Dans le groupe de patients présentant un infarctus VD, la mortalité est aux alentours de 17%.

Predictors of mortality in patients with non-anterior ST-segment elevation myocardial infarction: Analysis from the HORIZONS-AMI trial

OBJECTIVES

We sought to identify clinical, electrocardiographic (ECG), and angiographic characteristics that are predictive of 3-year mortality after primary percutaneous coronary intervention (PCI) in patients with non-anterior ST-elevation myocardial infarction (NA-STEMI) from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial.

BACKGROUND

Which patients with NA-STEMI undergoing PCI have a poor prognosis is uncertain.

METHODS

NA-STEMI was defined as ST-segment elevation in lateral (V5, V6, I, aVL), inferior (II, III, aVF), or inferolateral (I, II, III, aVF, and V5-V6) ECG leads or posterior myocardial infarction with ST-segment depression of ≥1 mm in ≥2 contiguous anterior leads. Cox regression was used to identify independent predictors of 3-year mortality. Missing data were imputed using multiple imputation.

RESULTS

In HORIZONS-AMI, 2,578/3,602 patients had no prior coronary artery bypass grafting, underwent single-vessel PCI, and had baseline ECG data assessed in an independent core laboratory. Among them, 1,495 (58.0%) had NA-STEMI. Patients with NA-STEMI had lower 3-year mortality risk than those with anterior STEMI (4.5% versus 7.1%, P = 0.004). The independent predictors of increased 3-year mortality in NA-STEMI were older age (median > 59.0 years), diabetes, reduced LVEF (≤50%), Killip class ≥2, post-procedure TIMI flow 0-2 versus 3, renal insufficiency, and ST-resolution <30% at 60 min post-PCI. Patients with 0, 1, 2, 3, and ≥4 of these risk factors had 3-year mortality rates of 1.8%, 2.3%, 3.1%, 6.1%, and 36.3%, respectively (P < 0.0001).

CONCLUSIONS

Although NA-STEMI carries a better prognosis than anterior STEMI, high-risk patient cohorts with NA-STEMI may be identified who have substantial 3-year mortality.

Contemporary practice pattern of permanent pacing for conduction disorders in inferior ST-elevation myocardial infarction

BACKGROUND

Currently, there is no clear consensus regarding the optimal waiting period before permanent pacemaker implantation in patients with conduction disorders following an inferior myocardial infarction.

HYPOTHESIS

We aimed to elucidate the contemporary practice pattern of pacing, especially the timing of pacemaker implantation, for sinoatrial node and atrioventricular (AV) conduction disorders following an inferior ST-elevation myocardial infarction (STEMI).

METHODS

Using the National Inpatient Sample database from 2010 to 2014, we identified patients with a primary diagnosis of inferior STEMI. Primary conduction disorders were classified into: (a) high-degree AV block (HDAVB) consisting of complete AV block or Mobitz-type II second-degree AV block, (b) sinoatrial node dysfunction (SND), and (c) no major conduction disorders.

RESULTS

Among 66 961 patients, 2706 patients (4.0%) had HDAVB, which mostly consisted of complete AV block (2594 patients). SND was observed in 393 patients (0.6%). Among the 2706 patients with HDAVB, 267 patients (9.9%) underwent permanent pacemaker. In patients with HDAVB, more than one-third (34.9%) of permanent pacemakers were placed within 72 hours after admission. The median interval from admission to permanent pacemaker implantation was 3 days (interquartile range; 2-5 days) for HDAVB vs 4 days (3-6 days) for SND (P < .001). HDAVB was associated with increased in-hospital mortality, whereas SND was not.

CONCLUSIONS

In patients who developed HDAVB following an inferior STEMI, only one in 10 patients underwent permanent pacemaker implantation. Despite its highly reversible nature, permanent pacemakers were implanted relatively early.

Electrocardiographic Distinction of Left Circumflexand Right Coronary Artery Occlusion in PatientsWith Inferior Acute Myocardial Infarction

Previously reported electrocardiographic (ECG) criteria to distinguish left circumflex (LCCA) and right coronary artery (RCA) occlusion in patients with acute inferior ST-segment elevation myocardial infarction (STEMI) afford a modest diagnostic accuracy. We aimed to develop a new algorithm overcoming limitations of previous studies. Clinical, ECG, and coronary angiographic data were analyzed in 230 nonselected patients with acute inferior STEMI who underwent primary percutaneous coronary intervention. A decision-tree analysis was used to develop a new ECG algorithm. The diagnostic accuracy of reported ECG criteria was reviewed. LCCA occlusion occurred in 111 cases and RCA in 119. We developed a 3-step algorithm that identified LCCA and RCA occlusion with a sensitivity of 77%, specificity of 86%, accuracy of 82%, and Youden index of 0.63. The area under the ROC curve was 0.85 and resulted 0.82 after a 10-fold cross validation. The key leads for LCCA occlusion were V3 (ST depression in V3/ST elevation in III >1.2) and V6 (ST elevation ≥0.1 mV or greater than III). The key leads for RCA occlusion were I and aVL (ST depression ≥ 0.1 mV). Fifteen of 21 reviewed studies had less than 20 cases of LCCA occlusion, only 48% performed primary percutaneous coronary intervention, and previous infarction or multivessel disease were often excluded. The diagnostic accuracy of reported ECG criteria decreased when applied to our study population. In conclusion, we report a simple and highly discriminative 3-step ECG algorithm to differentiate LCCA and RCA occlusion in an "all comers" population of patients with acute inferior STEMI. The diagnostic key ECG leads were V3 and V6 for LCCA and I and aVL for RCA occlusion.

Association between coronary dominance and acute inferior myocardial infarction: a matched, case-control study

Background

Previous studies have found a connection between left coronary artery dominance and worse prognoses in patient with acute coronary syndrome, which remains a predominant cause of morbidity and mortality globally. The aim of this study was to investigate whether coronary dominance is associated with the incidence of acute inferior myocardial infarction (MI).

Methods

Between January 2011 and November 2014, 265 patients with acute inferior MI and 530 age-matched and sex-matched controls were recruited for a case-control study in the Second Affiliated Hospital of Xi’an Jiaotong University in Xi’an, China. All participants underwent coronary angiography. The exclusion criteria included history of coronary artery bypass graft surgery, chronic or systemic diseases (including hepatic failure, kidney failure, hypothyroidism and Grave’s disease), ventricular fibrillation, and known allergy to iodinated contrast agent. Patients with left- or co-dominant anatomies were placed into the LD group and those with right-dominant anatomy were included in the RD group. The association of acute inferior MI and coronary dominant anatomy were assessed using multivariable conditional logistic regression, and to estimate the odds ratio (OR) and 95% confidence interval (95%CI).

Results

Distributions of right dominance were significantly different between the acute inferior MI group and control group (94.0% vs. 87.9%, P = 0.018). Univariable conditional logistic regression revealed that right dominance may be a risk factor for the incident acute inferior MI (OR: 2.137; 95% CI: 1.210–3.776; P = 0.009). After adjusting for baseline systolic blood pressure, heart rate, smoking status, diabetes mellitus, hypertension, hyperlipidaemia, and family history of coronary artery disease, results of multivariate conditional logistic regression showed that right dominance was associated with the incidence of acute inferior MI (OR: 2.396; 95% CI: 1.328–4.321; P = 0.004).

Conclusions

Right coronary dominance may play a disadvantageous role in the incidence of acute inferior MI. However, further studies are needed to verify our findings, especially with regard to the underlying mechanisms.

ST-segment depression in left precordial leads in electrocardiogram of patients with acute inferior myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

The early identification of patients with acute inferior ST-segment elevation myocardial infarction (STEMI) with high risk features is particularly important. Acute inferior STEMI may be associated with ST-segment depression in the left precordial leads (V4-V6). This study assessed prognostic value of ST-segment depression in these left precordial leads during the admission of patients with acute inferior STEMI treated with primary percutaneous coronary intervention.

METHODS

This retrospective study enrolled 1,374 patients with acute inferior STEMI who underwent primary percutaneous coronary angioplasty between March 2011 and June 2014. The patients were divided into two groups: one group (n = 687) with left precordial ST-segment depression and the other (n = 687) without such ST-segment changes.

RESULTS

The patients with left precordial ST-segment depression were older and had higher incidence of hypertension, diabetes mellitus, and higher levels of troponin. In-hospital mortality was higher in patients with left precordial ST-segment depression. Advanced coronary artery disease was more observed in these patients.

CONCLUSION

In patients with acute inferior STEMI treated with primary coronary intervention, left precordial ST-segment depression during admission of ECG is associated with more advanced coronary artery disease, and worse in-hospital clinical outcomes.

Acute right ventricular myocardial infarction

INTRODUCTION

Acute right ventricular myocardial infarction (RVMI) is observed in 30-50% of patients presenting with inferior wall myocardial infarction (MI) and, occasionally, with anterior wall MI. The clinical consequences vary from no hemodynamic compromise to severe hypotension and cardiogenic shock depending on the extent of RV ischemia. Areas covered: The pathophysiological mechanisms, diagnostic steps, and novel therapeutic approaches of acute RVMI are described. Expert commentary: Diagnosis of acute RVMI is based on physical examination, cardiac biomarkers, electrocardiography, and coronary angiography, whereas noninvasive imaging modalities (echocardiography, cardiac magnetic resonance imaging) play a complementary role. Early revascularization, percutaneous or pharmacological, represents key step in the management of RMVI. Maintenance of reasonable heart rate and atrioventricular synchrony is essential to sustain adequate cardiac output in these patients. When conventional treatment is not successful, mechanical circulatory support, including right ventricle assist devices, percutaneous cardiopulmonary support, and intra-aortic balloon pump, might be considered. The prognosis associated with RVMI is worse in the short term, compared to non-RVMI, but those patients who survive hospitalization have a relatively good long-term prognosis.

Electrocardiographic changes in patients with acute myocardial infarction caused by left main trunk occlusion

BACKGROUND

Left main trunk (LMT) occlusion is a rare angiographic finding. The primary purpose was to investigate the ECG pattern of patients with angiographic confirmation of LMT as culprit lesion.

METHODS

Forty-eight patients (32 men; mean age 73 years) with angiographic total (21 patients; 44%) or subtotal (27 patients; 56%) occlusion of the LMT were analyzed. Twenty patients (42%) were found to have concomitant coronary lesions. Eighteen patients (38%) required intra-aortic balloon pump support.

RESULTS

A significant left axis deviation was observed in 26 cases (54%) and an intraventricular conduction delay in 32 patients (67%). The average QRS width and QTc interval were 122 and 433 ms, respectively. ST-segment elevation in lead aVR occurred in 32 patients (67%). ST-segment elevation in leads V2-5 and in leads I and aVL [classic left anterior descending (LAD) type] was frequently observed (18 cases; 35%). In six patients (13%), a partial LAD type was observed with ST-segment elevation in leads I and aVL, but not in peripheral leads. The remaining patients showed ST-segment elevation only in peripheral leads (12 cases), in inferior leads III + aVF (six cases), whereas six patients had no ST-segment elevation. Diffuse ST-segment depression only (>6 leads) was observed in 15 cases (31%). Eighteen patients (38%) died during hospitalization.

CONCLUSION

ST-segment elevation in lead aVR or a LAD-type pattern can be associated with LMT disease. Other relevant aspects are the presence of cardiogenic shock at admission, the left axis deviation and marked prolongation of QTc interval and QRS width.

Electrocardiogram criteria of limb leads predicting right coronary artery as culprit artery in inferior wall myocardial infarction: A meta-analysis

BACKGROUND

Prior studies have proposed several electrocardiogram (ECG) criteria in limb leads for identifying the culprit coronary artery (CCA) in patients with acute inferior wall myocardial infarction (IWMI). The aim of our study was to conduct an evidence-based evaluation and test accuracy comparison of these criteria.

METHODS

We searched the PubMed, Embase, and Ovid. Eligible studies to assess the diagnostic performance of ECG criteria predicting CCA in IWMI were reviewed for inclusion. A diagnostic meta-analysis of bivariate approach was performed for pooled estimates of sensitivity and specificity, and meta-regression was implemented to investigate sources of heterogeneity.

RESULTS

Twenty-four studies with 4431 unique participants met the inclusion criteria. The pooled sensitivity and specificity for ST-segment elevation (STE) in III > II, ST-segment depression (STD) in I, STD in aVL, STD in aVL > I, STE in III > II, and STD in aVL > I were 0.91 (0.88-0.94) and 0.69 (0.53-0.81), 0.80 (0.73-0.87) and 0.69 (0.62-0.76), 0.90 (0.81-0.95) and 0.41 (0.22-0.62), 0.84 (0.75-0.91) and 0.72 (0.48-0.88), and 0.79 (0.62-0.90) and 1.00 (0.37-1.00), respectively. Heterogeneity investigation showed that whether multi-vessel diseased patients were excluded, sample size, publication year, etc., could influence the diagnostic performance.

CONCLUSION

STE in III > II performed better than other criteria for predicting RCA as CCA in IWMI, and STE in III > II and STD in aVL > I were potential and simple algorithms. ECG could be an effective tool to identify the CCA, but future studies are clearly needed to address the potential of diagnostic and prognostic value.

Atrioventricular block after acute myocardial infarction and its association with other clinical parameters in Pakistani patients: an institutional perspective

OBJECTIVES

Conduction defects complicating acute myocardial infarction are frequently associated with increased morbidity and mortality. As frequency of this complication has not been widely studied in our population, therefore in this study we aimed to evaluate the frequency of complete atrioventricular block in patients with acute ST segment elevation myocardial infarction and its association with other clinical parameters.

RESULTS

The mean age of the patients was 50.55 ± 6.72 years at the time of MI. There were 147 (82.1%) males and 32 (17.9%) females. There were 83 (46.4%) patients having hypertension, 61 (34.1%) diabetes mellitus, 75 (41.9%) smokers, 75 (41.9%) patients having positive family history, 11 (6.1%) having dyslipidemia, and 73 (40.8%) obese patients in this study. The Frequency of complete atrioventricular (AV) block in acute ST segment elevation myocardial infarction was found to be 7.3%, and no association with any other clinical factor was found which could predict this condition according to results of our study. Therefore, protocols should be designed in our routine clinical practice to deal with such a life threatening condition.

Short-term outcome of acute inferior wall myocardial infarction with emphasis on conduction blocks: a prospective observational study in Indian population

OBJECTIVE

The primary aim of the present study was to evaluate the complications, particularly conduction blocks, subsequent morbidity and mortality, and effect of thrombolytic therapy in Indian patients with inferior wall myocardial infarction (IWMI).

METHODS

This was a prospective, observational, single-center study conducted at LPS Institute of Cardiology, Kanpur, from December 2011 to May 2014. Patients who presented with typical chest pain and were subsequently diagnosed by standardized diagnostic criteria as having IWMI were enrolled. Patients were grouped on basis of conduction abnormalities, right ventricular (RV) infarction and thrombolytic treatment. Each group was analyzed for comparison of complication profile and mortality.

RESULTS

Of 573 patients with IWMI enrolled in the study (mean age: 58.90±12.3 years), 81.2% were male, 225 (39.3%) had conduction blocks, and 189 (32.9%) had RV infarction. In patients with conduction blocks, mortality occurred in 27 patients (12.0%) in contrast to 3.4% of patients without conduction block (p<0.03). Also, there were 27 cases of in-hospital mortality in patients with RV infarction compared with 9 cases in patients without RV infarction (p<0.01). Thrombolytic therapy significantly reduced mortality in patients with IWMI (p<0.001). A significant reduction was observed in cardiogenic shock (p=0.002), severe mitral regurgitation (p=0.007), and left ventricular failure (p<0.001) in patients undergoing thrombolytic therapy.

CONCLUSION

In Indian patients with IWMI, incidence of conduction blocks was higher than previously reported studies. Major complications such as atrioventricular block and RV infarction are associated with increased mortality and poor clinical outcomes. Thrombolytic therapy has a beneficial role in reduction of mortality rate and other complications.

Features of electrocardiogram in patients with stenosis of the proximal right coronary artery

BACKGROUND/AIMS

Prediction of lesions of the proximal right coronary artery (pRCA) through electrocardiogram (ECG) is very important because pRCA occlusion has many complications and a high mortality rate, which has frequently been related with right ventricular infarction. The purpose of this study was to devise a screening tool that takes into account multiple leads from a 12-lead ECG to predict the pRCA lesion.

METHODS

A hundred and fifty-eight patients who were diagnosed as acute coronary syndrome and had a pure lesion of RCA or left circumf lex artery (LCX) by ECGs and angiographic findings were enrolled retrospectively. Forty-eight patients with a pure pRCA occlusion were compared to a control group of 110 patients who were diagnosed as having either a pure mid to distal RCA lesion (57 patients) or a pure LCX lesion (53 patients).

RESULTS

ECGs of patients in the pRCA group showed more prominent ST depression in lead I (p = 0.001) and ST elevation in V1 (p = 0.002) than in the control group. The combination of ST depression (≤ 0 mm) in I and ST elevation (> 0.5 mm) in V1 was the best diagnostic tool (area under the curve, 0.84).

CONCLUSIONS

ST changes in leads V1 and I allow more accurate prediction of pRCA occlusion than other criteria, such as the difference between ST elevation of leads II and III or vector direction and amplitude. These variables could help to screen for right ventricular infarction before performing reverse ECG and predicting prognosis.

Isolated right ventricular infarction: a diagnostic challenge

A 73-year-old woman was admitted to the emergency room due to sudden-onset dyspnoea, altered mental status and haemodynamic instability. ECG showed a junctional rhythm, T-wave inversion in I, aVL and V2-V6 (present in a previous ECG), and no ST/T changes in the right precordial leads. Transthoracic echocardiography, however, revealed a severe depression of global systolic function of right ventricle with akinesia of free wall and a normal left ventricular function. Coronary angiography showed an occlusion of the proximal segment of the right coronary artery, which was treated with balloon angioplasty, and a chronic lesion of the anterior descending artery. The patient had a good recovery and was discharged on the 14th day. Myocardial perfusion scintigraphy (stress and rest) was performed a month later, showing a fixed perfusion defect in the apex and anterior wall (medium-apical), with no signs of ischaemia.

Differential Clinical Implications of High-Degree Atrioventricular Block Complicating ST-Segment Elevation Myocardial Infarction according to the Location of Infarction in the Era of Primary Percutaneous Coronary Intervention

Background and Objectives

The clinical implication of high-degree (second- and third-degree) atrioventricular block (HAVB) complicating ST-segment elevation myocardial infarction (STEMI) is ripe for investigation in this era of primary percutaneous coronary intervention (PCI). We sought to address the incidence, predictors and prognosis of HAVB according to the location of infarct in STEMI patients treated with primary PCI.

Subjects and Methods

A total of 16536 STEMI patients (anterior infarction: n=9354, inferior infarction: n=7692) treated with primary PCI were enrolled from a multicenter registry. We compared in-hospital mortality between patients with HAVB and those without HAVB with anterior or inferior infarction, separately. Multivariate analyses were performed to unearth predictors of HAVB and to identify whether HAVB is independently associated with in-hospital mortality.

Results

STEMI patients with HAVB showed higher in-hospital mortality than those without HAVB in both anterior (hazard ratio [HR]=9.821, 95% confidence interval [CI]: 4.946-19.503, p<0.001) and inferior infarction (HR=2.819, 95% CI: 2.076-3.827, p<0.001). In multivariate analyses, HAVB was associated with increased in-hospital mortality in anterior myocardial infarction (HR=19.264, 95% CI: 5.804-63.936, p<0.001). However, HAVB in inferior infarction was not an independent predictor of increased in-hospital mortality (HR=1.014, 95% CI: 0.547-1.985, p=0.901).

Conclusion

In this era of primary PCI, the prognostic impact of HAVB is different according to the location of infarction. Because of recent improvements in reperfusion strategy, the negative prognostic impact of HAVB in inferior STEMI is no longer prominent.

Periprocedural temporary pacing in primary percutaneous coronary intervention for patients with acute inferior myocardial infarction

OBJECTIVE

High-degree atrioventricular block (AVB), including complete AVB in acute inferior ST-elevation myocardial infarction (STEMI), is not uncommon. However, there is no study evaluating the clinical differences between patients who have undergone temporary pacing (TP) and patients who have not. The present study was designed to investigate whether TP has any prognostic significance in inferior STEMI complicated by complete AVB.

METHODS

From January 2009 to December 2014, 295 consecutive patients diagnosed with inferior wall STEMI in a university hospital were reviewed. All of them underwent primary percutaneous coronary intervention (PCI). Among the 295 patients, there were 72 patients with complete AVB. The clinical characteristics, procedural data, and long-term major adverse cardiocerebrovascular events were compared in patients with and without TP.

RESULTS

Baseline clinical and procedural characteristics were similar between patients with and without TP. Patients with TP were more likely to present with cardiogenic shock; thus, additional interventions were attempted via a femoral approach, as patients received further treatment with intra-aortic balloon pumps and were subjected to additional cardiopulmonary resuscitation. Most cases of complete AVB were primarily caused by right coronary artery occlusion. After a median follow-up period of 344 (range, 105.5-641) days, major adverse cardiocerebrovascular events did not differ between the groups (P=0.528).

CONCLUSION

We conclude that primary PCI without TP is acceptable in complete AVB-complicated acute inferior STEMI. To avoid delay in reperfusion, we suggest that primary PCI should be the first priority therapy rather than treating patients initially with TP.

The Value of Lead aVR ST Segment Changes in Localizing Culprit Lesion in Acute Inferior Myocardial Infarction and Its Prognostic Impact

BACKGROUND

Identifying infarct-related artery (IRA) in patients with inferior ST elevation myocardial infarction (STEMI) has prognostic and therapeutic benefits.

OBJECTIVES

To differentiate IRA and the location of culprit lesion in inferior STEMI, using ST segment changes in lead aVR.

METHODS

ST segment changes in lead aVR were recorded in 150 patients, admitted with first inferior STEMI. The association of IRA and the location of culprit lesion with ST segment changes in aVR were investigated.

RESULTS

ST elevation ≥ 0.5 mm in lead aVR was present in 17 patients (11.3%), ST depression ≥ 0.5 mm in 74 patients (49.3%) and 59 patients (39.3%) did not have significant ST segment changes. Right coronary artery (RCA) was the IRA in 117 patients (78%) and left circumflex artery (LCX) in 33 patients (22%). Prevalence of RCA involvement as the IRA was different in three study groups (94.1% in ST elevation group, 83.1% in isoelectric group and 70.3% in ST depression group, P = 0.049). Presence of ST elevation had a sensitivity and specificity of 13.68 % and 96.97%, for detecting RCA lesions, respectively. ST depression had 66.67% sensitivity and 55.56% specificity for identifying LCX lesions. Clinical complications were low in our study with no significant difference among patients of three groups.

CONCLUSIONS

Presence of ST elevation is highly suggestive of RCA lesions versus LCX lesions, whereas absence of ST elevation cannot rule out RCA lesions. Presence of ST depression has a moderate sensitivity and specificity for LCX lesions.

Intracoronary administration of anisodamine and nicorandil in individuals undergoing primary percutaneous coronary intervention for acute inferior myocardial infarction: A randomized factorial trial

In acute inferior myocardial infarction (AIMI), numerous conventional drugs that are used to improve the myocardial microcirculation can significantly reduce blood pressure (BP) and coronary perfusion pressure, aggravate bradyarrhythmia and cause a deterioration in the hemodynamic state of the whole body, which greatly limits the application of these drugs in clinical settings. The aim of the present study was to assess the effect of anisodamine and nicorandil regimens on the prevention of no-reflow (NR) and the amelioration of myocardial reperfusion in patients with AIMI undergoing primary percutaneous coronary intervention (PCI). A total of 104 consecutive patients with AIMI were included in this study and randomly assigned to one of four groups: A (control group), B (anisodamine group), C (nicorandil group) and D (anisodamine and nicorandil group). Patients underwent PCI via transradial artery access and the angiographic results were evaluated. Coronary diastolic BP (DBP) and systolic and mean BPs were measured by invasive catheterization. The primary end-point was a post-PCI Thrombolysis In Myocardial Infarction (TIMI) myocardial perfusion grade (TMPG) of 3. Composite end-points (mortality + new MI + target vessel revascularization) were evaluated during the hospital stay and 30 days after discharge. Following the procedure, the proportion of patients achieving TMPG 3 was significantly higher in group D than that in the other groups (P=0.014); furthermore, the incidence of a postprocedural TIMI score of 3 was the highest in group D. Three days after the procedure, the peak creatine kinase-MB and cardiac troponin I levels were the lowest and the left ventricular ejection fraction was the highest in group D. A thrombus score of 3/4 and low DBP were the independent risk factors for poor myocardial reperfusion (expressed as TMPG <3), while 2 mg anisodamine plus 2 mg nicorandil prior to PCI was protective for optimal myocardial reperfusion following the procedure. The combination of anisodamine and nicorandil can effectively ameliorate myocardial reperfusion and protect cardiac function in patients with AIMI undergoing primary PCI.

Association of Admission Glycaemia With High Grade Atrioventricular Block in ST-Segment Elevation Myocardial Infarction Undergoing Reperfusion Therapy: An Observational Study

Several studies have demonstrated the association between elevated admission glycaemia (AG) and the occurrence of some arrhythmias such as atrial fibrillation, ventricular tachycardia, and ventricular fibrillation after myocardial infarction. However, the impact of elevated AG on the high grade atrioventricular block (AVB) occurrence after ST-segment elevation myocardial infarction (STEMI) remains unclear. Included were 3359 consecutive patients with STEMI who received reperfusion therapy. The primary endpoint was the development of high grade AVB during hospital course. Patients were divided into non-diabetes mellitus (DM), newly diagnosed DM, and previously known DM according to the hemoglobin A1c level. The optimal AG value was determined by receiver operating characteristic curves analysis with AG predicting the high grade AVB occurrence. The best cut-off value of AG for predicting the high grade AVB occurrence was 10.05 mmol/L by ROC curve analysis. The prevalence of AG ≥ 10.05 mmol/L in non-DM, newly diagnosed DM, and previously known DM was 15.7%, 34.1%, and 68.5%, respectively. The incidence of high grade AVB was significantly higher in patients with AG ≥ 10.05  mmol/L than <10.05  mmol/L in non-DM (5.7% vs. 2.1%, P < 0.001) and in newly diagnosed DM (10.2% vs.1.4%, P < 0.001), but was comparable in previously known DM (3.6% vs. 0.0%, P = 0.062). After multivariate adjustment, AG ≥ 10.05  mmol/L was independently associated with increased risk of high grade AVB occurrence in non-DM (HR = 1.826, 95% CI 1.073-3.107, P = 0.027) and in newly diagnosed DM (HR = 5.252, 95% CI 1.890-14.597, P = 0.001). Moreover, both AG ≥ 10.05  mmol/L and high grade AVB were independent risk factors of 30-day all cause-mortality (HR = 1.362, 95% CI 1.006-1.844, P = 0.046 and HR = 2.122, 95% CI 1.154-3.903, P = 0.015, respectively). Our study suggested that elevated AG level (≥10.05  mmol/L) might be an indicator of increased risk of high grade AVB occurrence in patients with STEMI.

Significant narrowing of the circumflex artery leads to worse outcomes than right coronary artery narrowing in patients with anterior myocardial infarction treated invasively

BACKGROUND

Occlusion of the circumflex artery (Cx) often does not present signs in the ECG. It can lead to delayed angiography during ST-elevation myocardial infarction (STEMI). The aim of this analysis was to determine if Cx narrowing is related to diverse outcomes in comparison with right coronary artery (RCA) stenosis in patients with STEMI, treated with percutaneous coronary intervention (PCI) of the left descending artery (LAD).

METHODS AND RESULTS

Inclusion criteria were as follows: first STEMI treated with PCI of the LAD and additional significant (≥ 70 %) Cx or RCA narrowing-two-vessel disease. A total of 234 consecutive patients with STEMI were included. Total mortality was estimated during long-term follow-up, at mean 639 (± 224) days after STEMI. Patients with Cx narrowing constituted 46 % (N = 108) of the study population, and patients with RCA narrowing amounted to 54 % (N = 126). Patients with narrowing of the Cx had worse long-term outcomes in terms of mortality than patients with RCA narrowing (22 vs. 11 %, p < 0.05, respectively). Multiple regression analysis showed independent risk factors for death during long-term follow-up such as: age, ejection fraction and Cx narrowing.

CONCLUSION

Significant Cx narrowing leads to worse outcomes than RCA narrowing in patients with STEMI treated with PCI of the LAD.

Primary percutaneous coronary intervention ameliorates complete atrioventricular block complicating acute inferior myocardial infarction

Objective

Complete atrioventricular block (CAVB) in acute inferior ST-segment elevation myocardial infarction (STEMI) is associated with poor clinical outcomes after noninvasive treatment. This study was designed to determine the effect of primary percutaneous coronary intervention (PCI) in patients with CAVB complicating acute inferior STEMI, at a single center.

Methods

We enrolled 138 consecutive patients diagnosed with STEMI involving the inferior wall; of these, 27 patients had CAVB. All patients received primary PCI. The clinical characteristics, procedural data, and clinical outcomes were compared in patients with versus without CAVB.

Results

Baseline clinical characteristics were similar between patients with and without CAVB. Patients with CAVB were more likely to present with cardiogenic shock, and CAVB was caused primarily by right coronary artery occlusion. Door-to-balloon time was similar between those two groups. After primary PCI, CAVB was reversed in all patients. The peak creatinine phosphokinase level, left ventricular ejection fraction and in-hospital mortality rate were similar between the two groups. After a median follow up of 318 days, major adverse cardiac events did not differ between the groups (8.1% in patients without CAVB; 11.1% in patients with CAVB) (P=0.702).

Conclusion

We conclude that primary PCI can ameliorate CAVB-complicated acute inferior STEMI, with an acceptable rate of major adverse cardiac events, and suggest that primary PCI should be the preferred reperfusion therapy in patients with CAVB complicating acute inferior myocardial infarction.

Haemodynamic collapse in a patient with acute inferior myocardial infarction and concomitant traumatic acute spinal cord injury

A 71-year-old man suddenly collapsed and went into cardiopulmonary arrest. The cardiopulmonary resuscitation attempt succeeded in restoration of spontaneous circulation. The initial 12-lead electrocardiogram showed inferior acute myocardial infarction (AMI). The patient was initially diagnosed as having cardiogenic shock associated with inferior AMI. In spite of early coronary revascularisation, bradycardia and hypotension were sustained. After termination of sedation and extubation, he was found to have a quadriplegia and diagnosed with a cervical spinal cord injury (SCI). Therefore, the patient was finally diagnosed with neurogenic shock caused by acute cervical SCI due to the traumatic injury preceded by loss of consciousness complicating inferior AMI. We should recognise that SCI has unique haemodynamic features that mimic those associated with inferior AMI, but requires very different treatment.

Cardiac surgical procedures for the coronary sequelae of Kawasaki disease

OBJECTIVES

The aim of this article is to make an evaluation on the clinical features of patients with Kawasaki disease who require a cardiac surgical procedure including coronary artery bypass grafting, coronary arterial aneurysmorrhaphy or heart transplantation.

METHODS

English literature of Kawasaki disease for cardiac surgery (1990-2011) was retrieved in the Pubmed database. The clinical features of the patient setting from the representative articles were collected and analyzed.

RESULTS

Patients with Kawasaki disease were very young, with some requiring a cardiac surgical procedure at a very early age. The interval between the onset and the surgical operation was 9.5±9.4 years. The prevalence of myocardial infarction and re-infarction was high. Giant aneurysm, critical stenosis with calcification and thrombus formation of the coronary arteries often warrant coronary artery bypass, heart transplantation or coronary arterial aneurysm plication. The left internal mammary artery to the left anterior descending coronary artery was the most commonly used graft in coronary artery bypass. Graft patency rate was 82.4% at 21.4±32.3 (range 0.1-252) month follow-up. The early and late mortalities of this patient setting were 0.6 and 3.0%, respectively.

CONCLUSIONS

Patients with Kawasaki disease may develop coronary artery lesions prone to aneurysmal formation with calcification and thrombus and may require coronary artery bypass at a very early age. With the left internal mammary artery as the first choice of bypass graft, the long-term patency and patient survival was satisfactory.

Jeopardised Inferior Myocardium (JIM) Score: An Arithmetic Electrocardiographic Score to Predict the Infarct-Related Artery in Inferior Myocardial Infarction

Introduction: A few electrocardiographic criteria have been described to identify the infarct-related artery in inferior myocardial infarction. The aim of this study was to devise an arithmetic score to further improve the diagnostic accuracy. Materials and Methods: From 2004 to 2006, 78 patients who underwent primary angioplasty for inferior myocardial infarction within 6 hours from symptom onset were recruited for electrocardiographic and angiographic analysis. Results: The mean age of patients was 65 ± 12 years with male predominance (74%). Less ST depression in lead I and aVL, and more prominent ST depression in lead V1-3 were observed in left circumflex artery (LCX) than right coronary artery (RCA) occlusions. In addition, more prominent ST depression in lead I and ST elevation in V1 were found in proximal RCA than distal RCA occlusions. Based on the findings, the Jeopardised Inferior Myocardium (JIM) score was constructed and defined as [II–V3/III+V1– I]. The sensitivity and specificity of JIM score ≤0.5 to predict proximal RCA occlusions; 0.5 <JIM score ≤1.5 to predict distal RCA occlusions; and JIM score >1.5 to predict LCX occlusions were 58% and 85%, 69% and 68%, and 79% and 94%, respectively. The accuracy of prediction is slightly better than the 2 previously reported criteria. Conclusion: By taking into account more leads, the JIM score is capable of identifying the infarct-related artery with an improved diagnostic accuracy. Key words: Coronary angiography, Electrocardiography

Implications of ST-segment elevation in leads V5 and V6 in patients with reperfused inferior wall acute myocardial infarction

During inferior acute myocardial infarction, ST-segment elevation (ST↑) often occurs in leads V(5) to V(6), but its clinical implications remain unclear. We examined the admission electrocardiograms from 357 patients with a first inferior acute myocardial infarction who had Thrombolysis In Myocardial Infarction 3 flow of the right coronary artery or left circumflex artery within 6 hours after symptom onset. The patients were divided according to the presence (n = 76) or absence (n = 281) of ST↑ >2 mm in leads V(5) and V(6). Patients with ST↑ in leads V(5) and V(6) were subdivided into 2 groups according to the degree of ST↑ in leads III and V(6): ST↑ in lead III greater than in V(6) (n = 53) and ST↑ in lead III equal to or less than in V(6) (n = 23). The perfusion territory of the culprit artery was assessed using the angiographic distribution score, and a mega-artery was defined as a score of ≥0.7. ST↑ in leads V(5) and V(6) with ST↑ in lead III greater than in V(6) and ST↑ in leads V(5) and V(6) with ST↑ in lead III equal to or less than in V(6) were associated with mega-artery occlusion and impaired myocardial reperfusion, as defined by myocardial blush grade 0 to 1. Right coronary artery occlusion was most common (96%) in the former, and left circumflex artery occlusion was most common (96%) in the latter, especially proximal left circumflex occlusion (74%). Multivariate analysis showed that ST↑ in leads V(5) and V(6) with ST↑ in lead III greater than that in V(6) (odds ratio 4.81, p <0.001) and ST↑ in leads V(5) and V(6) with ST↑ in lead III equal or less than that in V(6) (odds ratio 5.96, p <0.001) were independent predictors of impaired myocardial reperfusion. In conclusion, ST↑ in leads V(5) and V(6) suggests a greater risk area and impaired myocardial reperfusion in patients with inferior acute myocardial infarction. Furthermore, comparing the degree of ST↑ in lead V(6) with that in lead III is useful for predicting the culprit artery.