AN INTERESTING ECG

Prof. Dr. Mageshkumar’s Unit

A 75 year old female patient, a known diabetic and hypertensive presented with sudden onset of chest pain…

No other significant historyAn ECG done 3 months in Master health checkup before was supposed to be normal

• O/E patient was conscious oriented PR-120/min, regular BP- 180/110 CVS- S1S2(+) RS-BAE(+), B/L NVBS(+)

• Rate- 120/min• Rhythm regular• Left axis deviation• P wave- normal• PR interval- 0.16• QRS-Duration>0.12sec RR’ pattern in I, aVL, V5, V6 QS in V1, V2• ST segment- reciprocal changes• T wave- Reciprocal changes

• Impression: LBBB Acute MI with proximal LAD occlusion Kilip class I

Patient treated with INJ.HEPARIN

REPEAT ECG AFTER 24 HRS

• Rate- 84/min• Normal axis• P wave- normal• PR interval- 0.12sec• QRS- Duration- 0.08sec Increased QRS magnitude• T wave- inversion in II, III, aVF, V2-V4

• Impression: LVH Anterior and inferior wall ischemia

• CAUSES OF LBBB

Aortic stenosis Dilated cardiomyopathy

Acute myocardial infarction Extensive coronary artery disease

Primary disease of the cardiac electrical conduction system hypertension

LEFT BUNDLE BRANCH BLOCK

– Left bundle branch block (LBBB) is present in approximately 7 percent of acute infarctions

– LBBB confers increased risk for mortality in the setting of suspected AMI; however, the increased

risk is significantly associated with older age and co-morbidity risk factors.

• Two specific patient settings might be encountered:

• 1. When the patient has LBBB on admission and recent previous ECGs are normal, the patient is presumed to have new-onset LBBB,

which in many occasions is accepted as the

equivalent of electrocardiographic findings supportive of AMI

• 2. When the patient has LBBB on arrival and is known to have LBBB on previous ECGs

SGARBOSSA CRITERIA

Used in case of a LBBB and suspicion of AMI are: • ST elevation > 1mm in leads with a positive QRS

complex(V5-V6) (score 5) • ST depression > 1 mm in V1-V3 (score 3) • ST elevation > 5 mm in leads with a negative QRS

complex(V1-V3) (score 2).

At a score-sum of 3, these criteria have a specificity of 90% for detecting a myocardial infarction.

5 points for concordant 1 mm ST elevation. (any lead) 3 points for concordant 1 mm ST depression in v1 to v3 2 points for discordant 5 mm ST elevation. (any lead )

– Cabrera sign Prominent (>0.05 sec) notching

in the ascending limb of the S wave in leads V3 –V5

– Chapman sign : Prominent notching (>/= 0.05

sec ) of the ascending limb of the R wave in lead V5 or V6

– These signs have a specificity that approaches 90 percent.

• ST-T changes — The sequence of repolarization is altered in LBBB, with the ST segment and T wave vectors being directed opposite to the QRS complex. These changes may mask the ST segment depression and T wave inversion induced by ischemia.

• The presence of deep T wave inversions in leads with a predominantly negative QRS complex (eg, V1-V3) is highly suggestive of evolving ischemia or MI.

• ST elevations in leads with a predominant R wave (as opposed to QS or rS waves) are also strongly suggestive of acute ischemia.

• Pseudonormalization of previously inverted T waves is suggestive but not diagnostic of ischemia.

Several studies have evaluated the value of different ECG findings of acute MI in LBBB.

• The most useful ECG criteria were:

• Serial ECG changes — 67 %sensitivity • ST segment elevation — 54 sensitivity • Abnormal Q waves — 31 percent sensitivity • Cabrera's sign — 27 percent sensitivity, 47 percent for anteroseptal MI • Initial positivity in V1 with a Q wave in V6 — 20 percent sensitivity but 100 percent specificity for anteroseptal MI

THANK YOU!!