Conduction defects ECG Lathundar Left Bundle Branch Block (LBBB) Electrocardiographic Criteria and Characteristics Left bundle branch block is characterized by a significant reorganization of the…

…To address these challenges, researchers have developed ECG criteria designed to identify ischemia in the presence of left bundle branch block. The most widely recognized…

…QRS duration. A QRS duration of 120 ms (0.12 s) or more is required to diagnose a complete left bundle branch block . In addition…

…dominated by electrical vectors from the left ventricle due to its significantly larger mass compared to the right ventricle. In right bundle branch block (RBBB)…

…left ventricle. This will also yield a wide QRS complex. Altered QRS morphology – Because the normal sequence of depolarization is altered in bundle branch blocks…

…fascicular block & left posterior fascicular block Fascicular blocks were previously referred to as hemiblocks, but the latter term has been deprecated. The left bundle branch…

…electrical impulse travels through the His bundle, which bifurcates into the left and right bundle branches. The left bundle branch further subdivides into two fascicles…

…node, His bundle, Purkinje system) Preexisting AV block, bundle branch block or fascicular block may become worse. Particularly, the degree of AV block may increase…

…right and left bundle branch block on arrival ECG is 6% and 7%, respectively. A proportion of these patients have a new bundle branch block…

…to ask it. Indications Wide complex tachycardia where ventricular tachycardia must be distinguished from supraventricular tachycardia with bundle branch block or aberrancy. Narrow complex tachycardia…

…exists if the ECG displays a widened QRS appearance that is neither a left bundle branch block (LBBB) nor a right bundle branch block (RBBB)…

…left bundle branch block (LBBB) or pacemaker rhythms. Atrial fibrillation or atrial flutter Patients on medications such as nitrates, beta blockers, or calcium channel blockers…

…must be normal. For example, in the setting of left bundle branch block (LBBB), fractional shortening is not representative of ventricular function, since the activation…

…in V6 with QRS duration <120 ms) D: Profound sinus bradycardia (<30 beats/min or sinus pauses ≥3 s) Explanation: Incomplete Right Bundle Branch Block…

…arising in the atria may have wide QRS complexes if the ventricles cannot be depolarised normally (example: sinus tachycardia together with left bundle branch block)…

…ischemia or infarction may also occur in the following conditions [15]: Myocarditis Early repolarization patterns Left bundle branch block Left ventricular hypertrophy Hyperkalemia Cerebrovascular injury

…or right ventricular involvement Pre existing abnormalities such as prior infarction, left bundle branch block, Wolff–Parkinson–White patterns or ventricular pacing STEMI and non…

…LBBB morphology (i.e left bundle branch block appearance). This is explained by the fact that, as in LBBB, the left ventricle receives the depolarizing…

…at least in some leads). Pacemaker stimulated beats display wide QRS complexes and a left bundle branch block pattern on ECG; this is explained by…

…If the QRS complex in V1–V2 resembles a left bundle branch block (i.e negative QRS) V1 : The initial portion of the QRS complex…

…bundle branch block morphology. If the aberration occurs during higher heart rates, it is more likely that the QRS complex will have a left bundle…

…on — in second degree AV block Mobitz type 2, newly discovered complete heart block without current symptoms, alternating bundle branch block in acute anterior infarction…

…unless there is concomitant bundle branch block). rSR' pattern is occasionally seen in V1–V2. This resembles, but is not, right bundle branch block (RBBB)…

…Causes of left axis deviation Left bundle branch block. Left ventricular hypertrophy. Inferior infarction. Pre excitation. Left anterior fascicular block is diagnosed if the axis…

…Causes of left axis deviation Left bundle branch block. Left ventricular hypertrophy. Inferior infarction. Pre excitation. Left anterior fascicular block is diagnosed if the axis…

…2. Sinus bradycardia, two premature ventricular contractions, incomplete right bundle branch block and ST segment depressions in V2 V6. Click to zoom. Figure 3. Sinus…

…elevations that are not caused by ischemia and a significant proportion have ST T changes caused by other pathological conditions (such as bundle branch blocks)…

…Second or third degree AV block Depending on the indication Marked anaemia Correct A resting ECG that makes ST interpretation impossible — left bundle branch block…

…originate from the atria but the QRS complexes become wide due to abnormal ventricular depolarization (e.g sinus tachycardia with simultaneous left bundle branch block)…

…from the atria but the QRS complexes become wide due to abnormal ventricular depolarization (e.g. sinus tachycardia with simultaneous left bundle branch block). 2…

…left or right bundle branch block. Commonly, the premature atrial impulse arrives before one of the bundle branches has repolarized, which leads to a bundle…

…a block in the left bundle branch (i.e left bundle branch block) means that the left ventricle will not be depolarized via the Purkinje…

…prolongation of the Q T interval and sudden death. Am Heart J 1957;54:59 68. Brugada P, Brugada J. Right bundle branch block, persis

…activation of the ventricular myocardium. The ventricles should be depolarized (activated) by impulses spreading through the left and right bundle branch, which branches out into…

…interventricular) septum The ventricular septum receives Purkinje fibers from the left bundle branch and therefore depolarization proceeds from its left side towards its right side…

…ofblockade of the right bundle of His (RBBB) , the ventricle can not depolarize normally, which affects the efficiency of contraction. Left ventricular function affects right…

…excitable pathway whereas it will be blocked in the refractory pathway. If the refractory pathway has repolarized before the impulse has left the atrioventricular node…

…a critical marker of arrhythmogenic risk, particularly in the setting of ischemic heart disease or reduced left ventricular ejection fraction (LVEF). Sustained VT: Defined as…

…m2 22 ± 6 29–33 34–39 40 22 ± 6 29–33 34–39 40 ​BSA, Body surface area; LA, left atrial; RA, right atrial.

Visual assessment of regional wall motion (left ventricle) TYPE OF MOTION DEFINITION WALL MOTION SCORE Normal Normal thickening (typically 30% thickening from end diastole to…

…stenosis Distal bifurcation involvement Coexisting multivessel disease The extent of jeopardized myocardium Left ventricular systolic function Diabetes and other comorbidities Anatomical complexity and completeness of…

Echocardiography Myocardial ischemia and infarction Definition and pathophysiology Left ventricular (LV) thrombus is an intracavitary clot attached to the LV endocardium, typically overlying an akinetic…

ECG Hypertrophy and dilatation Atrial enlargement: left atrial enlargement (P mitrale) and right atrial enlargement (P pulmonale) The atria may become dilated and/or hypertrophic…

…an intuitive basis. Consider the fact that the left ventricle contracts and ejects blood into the aorta roughly 100,000 times daily, each time overcoming…

Echocardiography Left ventricular function and its echocardiographic assessment Cardiac function depends on a large number of parameters, including atrial function, valvular function, and ventricular function…

Echocardiography Size and mass of the left ventricle Left ventricular mass is a flawed proxy for ventricular systolic function and load. The mass is, however…

…orient and display the heart using the long axis of the left ventricle and selected planes oriented at 90° angles relative to the long axis…

Echocardiography Methods for assessing systolic function (contractile function) Several echocardiographic measurements are available to assess left ventricular systolic function. These methods elucidate slightly different aspects…

… OM2, 14), the left posterior descending artery (LPDA, 15), and the left posterolateral branch (LPLB, 18). (B) Corresponding CT schematic with coronary artery origins from…

…affected, then the left ventricle is virtually always affected due to the coronary anatomy (refer to the chapter Coronary Arteries and Localization of Infarction & Ischemia)…

…2) in these leads. These ECG changes were previously referred to as strain pattern because it was believed that they indicated left ventricular exhaustion. However…

…is derived by measuring flow velocities across the mitral valve using pulsed Doppler. Estimating left ventricular filling pressure via e' . Measurement of deceleration time (DT) …

…be moved along the black lines called EDPVR and ESPVR. EDPVR (End Diastolic Pressure Volume Relationship) shows the relationship between ESV and left ventricular volume…

ECG Hypertrophy and dilatation Biventricular hypertrophy Simultaneous hypertrophy of the left and right ventricle is rather common. The ECG has low sensitivity with respect to…

…a significantly increased risk of atrial fibrillation. The increase in left atrial pressure may also propagate backward to the pulmonary circulation, causing pulmonary hypertension (PH)…

Echocardiography Structure and contractile function of myocardial fibers The left ventricular wall can be subdivided into several layers. These layers are similar to those seen…

…speckle tracking As previously discussed, the left ventricular wall can be subdivided into three layers: the inner lining ( endocardium ), a thick muscle layer ( myocardium ) and…

Echocardiography Cardiomyopathy caused by tachycardia A prolonged tachycardia can cause cardiomyopathy with left ventricular dilation. This type of cardiomyopathy, referred to as tachycardia induced cardiomyopathy…

[calc_hcmrisk] Predicting Sudden Cardiac Death in Hypertrophic Cardiomyopathy (HCM) Hypertrophic Cardiomyopathy (HCM) is a genetic cardiomyopathy characterized by left ventricular hypertrophy. It is the…