AMI DIAGNOSTICS IN CASE OF LBBB AND.pptx

Diagnosis of Left Bundle Branch Block and Right Bundle branch Block

1. AMI DIAGNOSTICS IN CASE OF LBBB,RBBB

2. ACUTE MYOCARDIAL INFARCTION Myocardial necrosis due to acute obstruction of a coronary artery patients presents with chest discomfort,dyspnea,nausea and diaphoresis diagonosis is based on ECG and by the prescence of cardiac biomarkers troponin acute myocardial ischemia is suspected patients with LBBB have high specificity for AMI. findings include pathological Qwaves(indicate MI) ,ST segment shifts ,T wave inversions

3. LBBB pateints have damage in left fascicle ,there is wastage of time for current to activate refractory period is greater in left fascicle than right fascicle QRS duration greater than 0.12 sec (Broad QRS) Absence of q waves in lateral leads Tall (dominant) R wave generated in leadi,aVL, V5,V6(M shape) Deep(dominant) S waves in precordial leads(Wshape) broad monomorphic slurred R waves in V6(sluttering appearence) RABBIT-EAR APPEARENCE

4. Non - discordant ST segment elevation A2D2H2 - prescence of anterior wall myocardial infarction/ AS Digoxin toxicity /dilated cardiomyopathy hypertension/hyperkalemia LBBB can also result in ST segment elevation therefore mimicing MI obstruction of LAD-left anterior descending artery)causes infarction of anterior wall ,depending on extent ECG changes are seen in anterior wall( V1-6 ,lead I and aVL inferior wall- due to obstructio of RCA/LCX(left circumflex artery ).ECG changes seen in leads II,II,aVF

5. intermyocyte conduction -by the use of intermyocyte pathwayrther than normal fascicle sequential activation of ventricle-cardiac output will drop, Non-synchronous contraction in ventricle,cooling of blood happens in the lung,will lead to pulmonary edema Anterior wall myocardial infarction will damage the conduction system in heart and causes LBBB abnormal depolarisation of heart -abnormal repolarisation of heart (Non-discordant ST segmant elevation Failure of progression of R waves

6. RBBB rsr’, rsR’ or rSR’ complex-forming rabbit ear appearence (M shape) in lead V1,V2(anterior leads) Tall secondary R wave in V1 ,wide slurred S wave in lead I ,V5,V6 ST segment depression and T wave inversions in V1,V2 Transmission of impulse by faster His-Purkinje system slow ventricular dpolarisation from myocyte to myocyte( long QRS compplex WILLIAM MORROW - QRS looks W in V1, M IN V6(LBBB) QRS LOOKS M in V1,W IN V6(RBBB)

7. RBBB -BIFASCICULAR BLOCK LEFT ANTERIOR FASCICULAR BLOCK most common left axis deviation (lead I -positive, aVF= NEGATIVE ) qR pattern in lead aVL LEFT POSTERIOR FASCICULAR BLOCK right axis deviation qR pattern in leads III and aVF rS pattern in leads I and avL

8. LBBB

9. Right bundlesupplied by left anterior descending coronary artery More Common thanLBBB V1 ,V6 ,Lead 1, aVL used to diagonise RBBB V1 shows an rSR prime , They will be positively deflected(normally they have negatively deflected t wave)with wide QRS V6 indicates slurred S wave V1- Swave above baseline indicating M pattern(incomplete right bundle branch block)

10. RBBB