Humans ; Bundle-Branch Block/diagnosis*

PURPOSE: Patients with a suspected acute myocardial infarction (AMI) in the setting of a new or presumably new left bundle branch block (LBBB) present an important diagnostic and therapeutic challenge to clinicians. This study was conducted to identify the frequency of ST-segment elevation myocardial infarction (STEMI)-equivalent in this population, determine the diagnostic value of electrocardiographic and echocardiographic features and propose a new diagnostic algorithm. METHODS: From 793 patients who underwent emergent coronary angiography between January 1, 2012 and July 31, 2015, we examined data pertaining to 21 patients with new or presumably new LBBB. These patients were classified into three groups: 1) STEMI-equivalent, defined as an acute coronary occlusion on coronary angiogram (six patients), 2) non-STEMI (NSTEMI) (six patients), and 3) diagnosis other than myocardial infarction (non-MI) (nine patients). RESULTS: Six patients who met the ST-segment concordance criteria (score≥3) were STEMI-equivalent. On the other hand, seven patients with a discordant ST-elevation of ≥5 mm (score=2) were NSTEMI or non-MI. Therefore ST-segment concordance was highly sensitive and specific for the diagnosis of STEMI-equivalent. Compared with NSTEMI patients, nine non-MI patients with a normal angiogram had a low ejection fraction (35.6±19.0 vs. 56.0±12.9, p=0.04) and increased left ventricle end-diastolic dimension (63.9±8.8 vs. 51.7±6.4, p=0.012). CONCLUSION: Only a minority of patients with LBBB and suspected AMI have a STEMI-equivalent. Low ejection fraction and increased end-diastolic dimension of left ventricle indicate normal coronary angiogram in patients without ST-segment concordance of Sgarbossa criteria. We propose a new modified diagnostic algorithm in this population.
Bundle-Branch Block ; Coronary Angiography ; Coronary Occlusion ; Diagnosis ; Echocardiography ; Electrocardiography ; Hand ; Heart Ventricles ; Humans ; Myocardial Infarction

The ST segment corresponds to the plateau phase of ventricular repolarization, i.e., phase 2 of the action potential. Heightened awareness of the characteristic patterns of ST segment changes is vital to quickly identifying life-threatening disorders. The differential diagnosis of ST segment elevation includes four major processes: ST segment elevation myocardial infarction (STEMI); early repolarization; pericarditis; and ST elevation secondary to an abnormality of the QRS complex (left bundle branch block, left ventricular hypertrophy, or preexcitation). Other processes that may be associated with ST elevation include hyperkalemia, pulmonary embolism, and Brugada syndrome. Two particular patterns of ST segment depression reflect STEMI rather than non-ST-segment elevation acute coronary syndrome: ST segment depression that is reciprocal to a subtle and sometimes overlooked ST-segment elevation, and ST segment depression that is maximal in leads V₁-V₃, suggesting true posterior infarction. The clinical setting and specific electrocardiographic criteria often allow identification of the cause.
Action Potentials ; Acute Coronary Syndrome ; Brugada Syndrome ; Bundle-Branch Block ; Depression ; Diagnosis, Differential ; Electrocardiography ; Hyperkalemia ; Hypertrophy, Left Ventricular ; Infarction ; Myocardial Infarction ; Pericarditis ; Pulmonary Embolism

INTRODUCTIONDoor-to-balloon (DTB) time is critical to ST elevation myocardial infarction (STEMI) patients' survival. Although DTB time is reduced with direct cardiovascular laboratory (CVL) activation by emergency physicians, concerns regarding false-positive activation remain. We evaluate false-positive rates before and after direct CVL activation and factors associated with false-positive activations.

MATERIALS AND METHODSThis is a retrospective single centre study of all emergency CVL activation 3 years before and after introduction of direct activation in July 2007. False-positive activation is defined as either: 1) absence of culprit vessel with coronary artery thrombus or ulceration, or 2) presence of chronic total occlusion of culprit vessel, with no cardiac biomarker elevations and no regional wall abnormalities. All false-positive cases were verified by reviewing their coronary angiograms and patient records.

RESULTSA total of 1809 subjects were recruited; 84 (4.64%) identified as false-positives. Incidence of false-positive before and after direct activation was 4.1% and 5.1% respectively, which was not significant (P = 0.315). In multivariate logistic regression analysis, factors associated with false-positive were: female (odds ratio (OR): 2.104 [1.247-3.548], P = 0.005), absence of chest pain (OR: 5.369 [3.024-9.531], P <0.0001) and presence of only left bundle branch block (LBBB) as indication for activation (OR: 65.691 [19.870-217.179], P <0.0001).

CONCLUSIONImprovement in DTB time with direct CVL activation by emergency physicians is not associated with increased false-positive activations. Factors associated with false-positive, especially lack of chest pain or LBBB, can be taken into account to optimise STEMI management.

Bundle-Branch Block ; epidemiology ; Cardiac Catheterization ; Chest Pain ; epidemiology ; Coronary Angiography ; Disease Management ; Emergency Medicine ; Humans ; Logistic Models ; Multivariate Analysis ; Percutaneous Coronary Intervention ; Physicians ; Retrospective Studies ; ST Elevation Myocardial Infarction ; diagnosis ; epidemiology ; therapy ; Sex Factors ; Singapore ; epidemiology ; Time-to-Treatment

OBJECTIVES: Risk factors for heart failure (HF) have not yet been studied in myocardial infarction (MI) patients in Iran. This study was conducted to determine these risk factors. METHODS: In this nationwide, hospital-based, case-control study, the participants were all new MI patients hospitalized from April 2012 to March 2013 in Iran. The data on 1,691 new cases with HF (enrolled by census sampling) were compared with the data of 6,764 patients without HF as controls. We randomly selected four controls per one case, matched on the date at MI and HF diagnosis, according to incidence density sampling. Using conditional logistic regression models, odds ratios (ORs) with a 95% confidence interval (CI) were calculated to identify potential risk factors. RESULTS: The one-year in-hospital mortality rate was 18.2% in the cases and higher than in the controls (12.1%) (p<0.05). Significant risk factors for HF were: right bundle branch block (RBBB) (OR, 2.86; 95% CI, 1.95 to 4.19), stroke (OR, 2.00; 95% CI, 1.39 to 2.89), and coronary artery bypass grafting (CABG) (OR, 2.03; 95% CI, 1.34 to 3.09). Diabetes, hypertension, percutaneous coronary intervention (PCI), atrial fibrillation, ventricular tachycardia, and age were determined to be the factors significantly associated with HF incidence (p<0.05). The most important factor in women was diabetes (OR, 1.41; 95% CI, 1.05 to 1.88). Age, hypertension, PCI, CABG, and RBBB were the most important factors in men. CONCLUSIONS: Our findings may help to better identify and monitor the predictive risk factors for HF in MI patients. The pattern of risk factors was different in men and women.
Atrial Fibrillation ; Bundle-Branch Block ; Case-Control Studies* ; Censuses ; Cohort Studies* ; Coronary Artery Bypass ; Diagnosis ; Epidemiology ; Female ; Heart Failure* ; Heart* ; Hospital Mortality ; Humans ; Hypertension ; Incidence ; Iran* ; Logistic Models ; Male ; Mortality ; Myocardial Infarction* ; Odds Ratio ; Percutaneous Coronary Intervention ; Risk Factors* ; Stroke ; Tachycardia, Ventricular

A patient with non-ischaemic cardiomyopathy, and pre-existing atypical atrial flutter and left bundle branch block, developed broad complex tachycardia. In this unique and uncommon case of double tachycardia, we discuss the diagnostic approach of ventricular tachycardia in patients with broad complex tachycardia, and the use of different contemporary algorithms to help diagnose ventricular tachycardia and differentiate it from supraventricular tachycardia with aberrant conduction.
Algorithms ; Atrial Flutter ; complications ; diagnosis ; Bundle-Branch Block ; physiopathology ; Cardiomyopathies ; complications ; diagnosis ; Diagnosis, Differential ; Echocardiography ; Electrocardiography ; Humans ; Male ; Middle Aged ; Tachycardia, Supraventricular ; diagnosis ; physiopathology ; Tachycardia, Ventricular ; diagnosis ; physiopathology

Rate dependent left bundle branch block (RDLBBB) is an uncommon case. RDLBBB is defined as an intraventricular conduction defect that may return, if only temporarily, to sinus rhythm at lower heart rates. It appears when the heart rate exceeds a certain critical value. Although RDLBBB is usually benign, its diagnosis and treatment have clinical importance for association of RDLBBB and myocardial ischemia and infarction. Therefore, in the case of detection of intraoperative RDLBBB, a clear differentiation should be done as soon as possible. Also it is important to start appropriate treatment and to do clinical follow-up examination. We report a case of intraoperative RDLBBB during general anesthesia for laparoscopic cholecystectomy in 82 years old female patient who has a history of hypertension.
Anesthesia, General ; Bundle-Branch Block* ; Cholecystectomy, Laparoscopic ; Diagnosis ; Electrocardiography ; Female ; Follow-Up Studies ; Heart Rate ; Humans ; Hypertension ; Infarction ; Myocardial Ischemia

PURPOSE: Coronary artery disease is the most common cause of out-of-hospital cardiac arrest (OHCA). However, there are no definite indications of coronary angiography (CAG) followed by percutaneous coronary intervention (PCI) in patients with OHCA for diagnosis and treatment. The aim of this study was to determine correlation between ECG findings and results of CAG of patients with return of spontaneous circulation after OHCA. METHODS: We collected data from January 2010 until April 2014. CAG was performed in patients with ROSC after OHCA in whom ST-elevation or left bundle branch block (LBBB) was detected on ECG. If ECG showed another rhythm and no obvious non-cardiac cause of cardiac arrest, CAG was performed as an agreement between the emergency physician and cardiologist following by Samsung Medical Center OHCA protocol. RESULTS: CAG was performed in 75 patients among 131 patients who were successfully resuscitated from OHCA. We divided patients into two groups, ST-elevation or LBBB group and other group. Twenty nine patients in the ST-elevation or LBBB group had coronary lesion and nine patients in the other group had coronary lesion on CAG (p<0.01); 15 patients and five patients, respectively, had undergone PCI (p=0.02). CONCLUSION: ECG findings of ST-elevation or LBBB were highly associated with coronary lesions in successfully resuscitated patients from OHCA. However, these ECG findings were not an absolute indication for performing CAG because coronary artery lesions were also observed in patients in the other group.
Bundle-Branch Block ; Coronary Angiography* ; Coronary Artery Disease ; Coronary Vessels ; Diagnosis ; Electrocardiography* ; Emergencies ; Heart Arrest ; Humans ; Out-of-Hospital Cardiac Arrest* ; Percutaneous Coronary Intervention

Transient left bundle branch block (LBBB) is uncommon during anesthesia. It is mainly related to the changes in blood pressure or heart rate. Its occurrence can be confused with acute myocardial ischemia or ventricular tachycardia, therefore differential diagnosis is important. We report a case of transient LBBB which developed with hypoxia during monitored anesthesia care. LBBB is reversed to sinus rhythm after recovery from hypoxia.
Anesthesia* ; Anoxia* ; Blood Pressure ; Bundle-Branch Block* ; Conscious Sedation ; Diagnosis, Differential ; Heart Rate ; Myocardial Ischemia ; Tachycardia, Ventricular

Using 49 capacitive-coupled electrodes, mattress-type harness was developed to obtain posterior body surface potential map (P-BSPM) in dressed individuals. The aim of this study was to investigate how valuable information P-BSPM could provide, especially in discrimination of old myocardial infarction (OMI). P-BSPM of 59 individuals were analyzed; 23 normal control, 11 right bundle branch block (RBBB), 3 left bundle branch block (LBBB) and 19 OMI patients. Principal component analysis and linear hyper-plane approach were used to evaluate diagnostic performance. The axes of P-BSPM vector potential corresponded well with 12-lead electrocardiogram. During QRS, the end point of P-BSPM vector potential demonstrated characteristic clockwise rotation in RBBB, and counterclockwise rotation in LBBB patients. In OMI, initial negativity on P-BSPM during QRS was more frequently located at lower half, and also stronger in patients with inferior myocardial infarction (MI). The area under the receiver-operating characteristic curve of P-BSPM during QRS in diagnosing overall OMI, anterior MI, and inferior MI was 0.83 (95% confidence interval, 0.70-0.97), 0.71 (0.47-0.94), and 0.98 (0.94-1.0), respectively (P = 0.022 for anterior vs inferior MI groups). In conclusion, the novel P-BSPM provides detailed information for cardiac electrical dynamics and is applicable to diagnosing OMI, especially inferior myocardial infarction.
Adult ; Aged ; Area Under Curve ; Body Surface Potential Mapping/instrumentation/*methods ; Bundle-Branch Block/diagnosis ; Electrocardiography ; Electrodes ; Humans ; Male ; Middle Aged ; Myocardial Infarction/diagnosis ; Principal Component Analysis ; ROC Curve