ECG: Coronary Sinus Rhythm

ECG of the weekECG of the week

By Dr. C. R. RajakumarBy Dr. C. R. Rajakumar

M5 unit M5 unit

Prof. P. Vijayaraghavan’s unitProf. P. Vijayaraghavan’s unit

Patient presented with c/oPatient presented with c/o– Chest pain for the past 3 hrsChest pain for the past 3 hrs

He was a known hypertensive on drugs for He was a known hypertensive on drugs for the past 5yrs.the past 5yrs.

ECG was takenECG was taken

ECG findingsECG findings

Heart rate 100 per minute.Heart rate 100 per minute. Inverted P waves in leads II, III, aVF.Inverted P waves in leads II, III, aVF. PR interval 140ms (3 ½ small squares)PR interval 140ms (3 ½ small squares) QRS Duration normalQRS Duration normal Axis 30ºAxis 30º ST elevation in II, III, aVF (III>II) with T wave ST elevation in II, III, aVF (III>II) with T wave

inversioninversion ST depression in V2-V4 with tall R and upright T ST depression in V2-V4 with tall R and upright T

wavewave

Diagnosis Diagnosis

Coronary sinus rhythm with Infero posterior Coronary sinus rhythm with Infero posterior wall MI wall MI

Atrial RhythmsAtrial Rhythms

Atrial rhythm resembles sinus rhythm, but Atrial rhythm resembles sinus rhythm, but origins from a different atrial focus. origins from a different atrial focus.

It can be recognised by the abnormal It can be recognised by the abnormal configuration of the p-waveconfiguration of the p-wave

Characteristics of atrial Characteristics of atrial rhythmrhythm

Atrial Rhythms

Atrial frequency 50 – 100 bpm

Ventricular frequency 1:1

Regularity Regular

Origin Atrium

P wave Present but differs form sinus rhythm

Effect of adenosine Slows down

FREQUENCY OF ECTOPIC FREQUENCY OF ECTOPIC SITESITE

Frequency of atrial ectopic sitesFrequency of atrial ectopic sites

Algorithm to identify site of Algorithm to identify site of atrial rhythmatrial rhythm

Coronary sinus rhythm;Coronary sinus rhythm;

inverted p waves in lead 2 ,3 aVF and inverted p waves in lead 2 ,3 aVF and PR PR intervalinterval normal normal

Which chamber?Which chamber?

Right atrialRight atrial A negativeA negative or biphasic or biphasic

(positive, then negative) P-(positive, then negative) P-wave in lead Vwave in lead V11 was was

associated with a 100% associated with a 100% specificity for a tachycardiaspecificity for a tachycardia

arising from the RA.arising from the RA.

Left atrialLeft atrial A positive or biphasic A positive or biphasic

(negative, then(negative, then positive) P-positive) P-wave in lead Vwave in lead V11 was was

associated with a 100% associated with a 100% sensitivity for a tachycardia sensitivity for a tachycardia originating in the LA.originating in the LA.

Superior or inferior location of Superior or inferior location of ectopic impulse?ectopic impulse?

In general, the polarityIn general, the polarity of leads II, III, aVF of leads II, III, aVF is deeply negative for an inferiorly located is deeply negative for an inferiorly located ectopic impulse.ectopic impulse.

Low amplitude, positive, or biphasic for a Low amplitude, positive, or biphasic for a superiorlysuperiorly located ectopic impulse.located ectopic impulse.