-Prof .Dr.Gowrishankar’s Unit

-Dr.A.Ishwarya

45 year old male patient was brought to ICCU with

C/OCHEST PAIN * 2 HOURS

K/C/O T2DM/SHT

VITAL SIGNS • PR-54/Min• BP-90/74 mm hg• JVP RAISED

O/E CVS: S1S2+

NO MURMUR RS: B/L CREPS+ CNS:NFND P/A:SOFT

Rate of P wave 80/minRate of QRS complex 60/minNot in sinus rhythmDuration of QRS <0.12 secP wave inverted in lead II, avf/ upright in aVr Varying PR intervalPP interval constant (0.8 sec)RR interval constant (1.12 sec)ST elevation in lead II ,III ,aVf/ ST elevation in V3R-

V5R,V7-V9ST depression in lead I , aVLR>S in Lead V2 & S > R in Lead aVLST depression in V2-V4 (mirrror changes of

posterior MI)

Bradyarrhythmia-Type Incidence

Sinus Bradycardia 25%

Junctional Escape Rhythm 20%

Idioventricular escape rhythm

15%

I Degree AV Block 15%

II Degree AV Block –Type 1 12%

II Degree AV Block –Type 2 4%

Complete Heart block 15%

RBBB 7%

LBBB 5%

LAFB 8%

LPFB 0.5%

Hyper vagotonia Ischemia of AV node

Site of block Intranodal Infranodal

Site of infarction Inferoposterior Anteroseptal

Compromised arterial supply

RCA (90%), LCX (10%) Septal perforators of LAD

Pathogenesis Ischemia, excess parasympathetic activity

Ischemia, necrosis, hydropic cell swelling

Predominant type of AV nodal block

First-degree (PR > 200 msec)

Mobitz type I second-degree

Mobitz type II second-degree

Third-degree

Location Proximal conduction system (His bundle)

Distal conduction system (bundle branches)

QRS width <0.12/sec[*] >0.12/sec

Rate 45-60/min but may be as low as 30/min

Often <30/min

Stability of escape rhythm

Rate usually stable; asystole uncommon

Rate often unstable with moderate to high risk of ventricular asystole

Duration of high-grade AV block

Usually transient (2-3 days)

Usually transient but some form of AV conduction disturbance and/or intraventricular defect may persist

Associated mortality rate

Low unless associated with hypotension and/or congestive heart failure

High because of extensive infarction associated with power failure or ventricular arrhythmias